Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
SYSTEM, METHOD, AND KIT FOR DYNAMICALLY AFFECTING A FORCE APPLIED THROUGH A RAIL VEHICLE AXLE
Document Type and Number:
WIPO Patent Application WO/2009/049178
Kind Code:
A1
Abstract:
A system is provided for dynamically affecting a force applied through at least one axle in a rail vehicle configured to travel along a rail track. The rail vehicle includes a plurality of wheels, where the wheels are received by a plurality of axles. The plurality of wheels are configured to move along a respective rail of the rail track in a travel direction. The system includes a device configured to dynamically affect the force applied through the at least one axle. As the rail vehicle travels along the rail track, at least one characteristic of the force is selected to affect the traction performance of the rail vehicle.

Inventors:
KUMAR AJITH KUTTANNAIR (US)
WORDEN BRET DWAYNE (US)
Application Number:
US2008/079540
Publication Date:
April 16, 2009
Filing Date:
October 10, 2008
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
GEN ELECTRIC (US)
KUMAR AJITH KUTTANNAIR (US)
WORDEN BRET DWAYNE (US)
International Classes:
B61C15/04; B60L3/10; B61C15/08; B61F3/04
Domestic Patent References:
WO1997013653A11997-04-17
Foreign References:
DE1035681B1958-08-07
FR1289653A1962-04-06
EP0779194A11997-06-18
US20050251299A12005-11-10
GB1116012A1968-06-06
Attorney, Agent or Firm:
KRAMER, John, A. et al. (General Electric Company, Global Patent OperationPO Box 861, 2 Corporate Drive,Suite 64, Shelton CT, 06484, US)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A system for applying a force in a railway vehicle configured to travel along a rail track, the system comprising: at least one axle having at least one wheel, the wheel being arranged to be in contact with the rail track; and a device coupled to the axle for adjusting a characteristic of the force as applied through the wheel so as to affect a traction performance of the railway vehicle.

2. The system of claim 1, wherein said force is a normal force applied through said at least one axle in a normal direction to said rail track, and said at least one characteristic of said normal force includes at least one of a magnitude of said normal force and a direction of said normal force.

3. The system of claim 2, wherein: said at least one characteristic of said normal force is selected to adjust an aggregate adhesion between said plurality of rail vehicle wheels and said rail track, and further wherein said plurality of axles includes at least one first axle coupled to at least one wheel in a slipping condition on said rail track, and at least one second axle coupled to at least one wheel in a non-slipping condition on said rail track; and the device is configured to dynamically affect at least one of said magnitude and said direction of said normal force applied through said at least one first axle to control a creep condition of said at least one wheel.

4. The system of claim 2, wherein said plurality of axles comprises: at least one performance limited axle, said device being configured to dynamically affect at least one of said magnitude and said direction of said normal force applied through said at least one performance limited axle to reduce a level of tractive effort passed through said performance limited axle.

5. The system of claim 2, wherein said plurality of axles comprises : at least one friction brake axle, during the application of a rail vehicle brake including one of an emergency air brake, an independent brake and a train brake, said device is configured to dynamically affect at least one of said magnitude and said direction of said normal force applied through said at least one friction brake axle.

6. The system of claim 2, wherein said plurality of wheels comprise: at least one flatspot wheel having a flat spot along a circumference of said wheel, said device being configured to dynamically affect at least one of said magnitude and said direction of said normal force applied through at least one axle having received said flatspot wheel to impart an upward lift force on said at least one flatspot wheel to limit damage to one of said flatspot wheel, said rail track, and said rail vehicle.

7. The system of claim 2, wherein said plurality of wheels comprise: at least one locked wheel received by a respective locked axle, said device being configured to dynamically affect at least one of said magnitude and said direction of said normal force applied through said respective locked axle to impart an upward lift force on said at least one locked wheel to reduce a likelihood of rail vehicle derailment.

8. The system of claim 2, wherein said traction performance characteristic of said rail vehicle is based upon an operating characteristic of said rail vehicle.

9. The system of claim 2, wherein said plurality of axles comprises: at least one non-powered axle and at least one powered axle, upon a weight of said rail vehicle having decreased by a weight of consumed rail vehicle fuel, said device is configured to dynamically affect said respective normal force passing through said at least one powered axle and said at least one non-powered axle to increase a weight of said at least one powered axle to a weight of said at least one powered axle prior to said consumption of rail vehicle fuel and to decrease a weight

of said at least one non-powered axle to a weight lower than a weight of said at least one non-powered axle prior to said consumption of rail vehicle fuel.

10. The system of claim 2, wherein said device is configured to dynamically affect said force applied through said at least one axle to reduce an amount of ballast on said rail vehicle.

11. The system of claim 2, wherein said dynamic affecting of said normal force through said at least one rail vehicle axle is utilized to provide a weight balance of said rail vehicle across opposing ends, said weight balance configured to reduce a need to provide ballast on said rail vehicle.

12. The system of claim 2, wherein said plurality of axles comprises: at least one powered axle and at least one non-powered axle, said dynamic affecting of said normal force through said at least one axle involves a weight shift to said at least one powered axle for a limited time period to achieve at least one traction performance requirement of said rail vehicle.

13. A system for dynamically affecting a traction performance of a rail vehicle having a plurality of axles for receiving a respective plurality of wheels, said plurality of wheels being configured to move along a rail track in a travel direction, said system comprising: a pair of trucks configured to receive said plurality of axles; wherein the pair of trucks is configured to be rotated to a common alignment from an opposite alignment with respect to said travel direction, wherein said common alignment of the trucks is configured to affect said traction performance of said rail vehicle as said rail vehicle travels along said rail track.

14. The system of claim 13 , wherein : each truck includes at least one powered axle and at least one non-powered axle, said common alignment of said trucks is configured to increase a weight

imparted by said at least one powered axle on said rail track and decrease a weight imparted by said at least one non-powered axle on said rail track; said plurality of axles includes at least one powered axle, said powered axle includes a respective traction motor and a gear, said weight imparted by said at least one powered axle is based upon a relative side of said powered axle in which said gear is positioned relative to said travel direction; and the system further comprises a device configured to dynamically affect a normal force applied through said plurality of axles in a normal direction to said rail track surface in contact with said wheels, at least one characteristic of said normal force being selected to affect traction performance of said rail vehicle as said rail vehicle travels along said rail track.

15. The system of claim 1, wherein said force is a lateral force applied through said at least one axle in a lateral direction to said rail track surface in contact with said wheels, at least one characteristic of said lateral force being selected to enhance a curve performance characteristic of said rail vehicle as said rail vehicle travels over a curve in said rail track.

16. A system for coupling at least two axles of a plurality of axles on a rail vehicle, said rail vehicle having a plurality of wheels arranged to contact and travel along a rail track, said plurality of wheels being received by a plurality of axles, said system comprising: a coupling device configured to couple said at least two axles to dynamically affect a force applied through at least one of said at least two axles, at least one characteristic of said force being selected to affect traction performance of said rail vehicle as said rail vehicle travels along said rail track.

17. The system of claim 16, wherein: the dynamic effect of the force applied through said at least one axle is configured to affect a level of tractive effort passed through said at least two axles; the force is a normal force applied through said at least one axle in a normal direction to said rail track surface in contact with said wheels; and

the at least one characteristic of said normal force includes at least one of a magnitude of the normal force and a direction of the normal force.

18. The system of claim 17, wherein: the at least two axles comprise a pair of powered axles and one non-powered axle, wherein each powered axle includes a respective traction motor; and said coupling device is a mechanical coupling device coupled to the respective traction motor of at least one of the powered axles, wherein the mechanical coupling device is one of a rigid member, at least one flexible member, and at least one compliant member.

19. The system of claim 18, wherein: said pair of powered axles comprise said respective traction motor within a motor frame and a respective gear, said pair of powered axles being rotated by said respective gear, said respective gear being driven by said respective traction motor; during said rotation of said pair of powered axles by said respective gear, a normal force is imparted on said pair of powered axles and one of a stationary component of said traction motor, and a rotating component of said traction motor through a bearing; and upon said normal force being imparted on said pair of powered axles and said stationary component of said traction motor, said mechanical coupling is coupled to said non-powered axle through a journal bearing housing, said mechanical coupling device configured to impart a secondary normal force on said non-powered axle through said journal bearing housing to increase said level of said normal force and therefore said tractive effort passed through said pair of powered axles and one non- powered axle.

20. The system of claim 19, wherein: said rail vehicle includes a pair of trucks; a respective pair of powered axles and a non-powered axle are received by a respective truck;

a fixed collective normal force is applied through said pair of powered axles and said non-powered axle; and a variable powered axle normal force is applied through said pair of powered axles and a variable non-powered axle normal force is applied through said non- powered axle, wherein the sum of said variable powered axle normal force and said variable non-powered axle normal force is said fixed collective force.

21. The system of claim 17, wherein: the coupling device comprises a plurality of hydraulic actuators respectively coupled to said plurality of axles, wherein a compressed fluid within a first hydraulic actuator coupled to a first axle is selectively supplied to a second hydraulic actuator coupled to a second axle of said plurality of axles, said compressed fluid within said second hydraulic actuator being configured to impart a secondary force on said second axle; and the second axle is one of a powered axle and a non-powered axle, said at least one characteristic of the force includes at least one of a magnitude of the force and a direction of the force, at least one of the magnitude and the direction of the secondary force is selected to increase a level of tractive effort passed through said at least one second axle.

22. A system for dynamically affecting a force applied through at least one axle of a rail vehicle configured to travel along a rail track, said rail vehicle having a plurality of axles and a plurality of wheels being received by said plurality of axles, said system comprising: a device configured to selectively impart said force through said at least one axle to control a respective weight of said at least one axle on said rail track for affecting a traction performance of said rail vehicle traveling along said rail track.

23. The system of claim 22, wherein said force is a normal force applied through said at least one axle in a normal direction to said rail track, and wherein said device is at least one hydraulic actuator coupled to a respective rail vehicle axle.

24. The system of claim 23, further comprising: a variable displacement pump coupled to said hydraulic actuator, said variable displacement pump configured to supply a pressurized hydraulic fluid at a selectively controlled pressure to said hydraulic actuator, said hydraulic actuator configured to selectively impart said force through said respective axle based upon said selectively controlled pressure, wherein said hydraulic actuator is directly coupled to said respective rail vehicle axle.

25. The system of claim 23 , further comprising : a compliant member disposed between said hydraulic actuator and said respective axle such that said hydraulic actuator is coupled to said respective axle in a compliant manner; a pair of displacement limits coupled to said hydraulic actuator to limit said force selectively imparted on said respective axle; and at least one control valve coupled to said variable displacement pump and said hydraulic actuator, said at least one control valve being selectively activated to control a position of said hydraulic actuator.

26. The system of claim 23, further comprising: a positive displacement pump coupled to said hydraulic actuator, said positive displacement pump configured to selectively control a position of said hydraulic actuator based upon supplying a pressurized hydraulic fluid at a variable pressure to said hydraulic actuator, said hydraulic actuator configured to selectively impart said force through said respective axle based upon said selectively controlled position of said hydraulic actuator.

27. The system of claim 23, wherein: the at least one hydraulic actuator is configured to selectively impart said force through said respective at least one axle based upon energy captured from a vibration of a vibrated axle of said plurality of axles along said rail track; and

the system further comprises a pressurized hydraulic fluid pump coupled to said vibrated axle and said hydraulic actuator, said captured vibrational energy is utilized to pressurize said hydraulic fluid within said pump.

28. A system for dynamically determining a force applied through a plurality of axles in a rail vehicle configured to travel along a rail track in a travel direction, said rail vehicle having a plurality of wheels, said plurality of wheels being received by said plurality of axles, said system comprising: a controller configured to determine a respective dynamic weight shift of said plurality of wheels on said rail track based upon a dynamic factor of said rail vehicle as said rail vehicle travels along said rail track.

29. The system of claim 28, wherein said force is a normal force applied through said at least one axle in a normal direction to said rail track, said controller is configured to receive at least one characteristic of said rail vehicle to determine a static weight of said plurality of axles on said rail track when said rail vehicle is stationary, said controller is further configured to determine a respective dynamic weight of said plurality of wheels on said rail track based upon said static weight of said plurality of wheels and said dynamic factor of said rail vehicle as said rail vehicle travels along said rail track.

30. The system of claim 29, further comprising: at least one sensor coupled to said controller, said at least one sensor configured to measure said dynamic factor of said rail vehicle.

31. The system of claim 3,0 wherein said dynamic factor is one of a speed of said rail vehicle, a tractive effort of a respective rail vehicle axle attributed to a torque applied to a traction motor of said respective rail vehicle axle, a level of fuel within a fuel tank of said rail vehicle, a brake cylinder pressure applied to said axle during a braking mode, or a drawbar force exerted on a drawbar coupling said rail vehicle to an adjacent rail vehicle.

32. The system of claim 30, further comprising: a device coupled to at least one respective axle of said plurality of axles, said device being coupled to said controller to selectively impart said normal force through said respective axle, wherein said at least one sensor is respectively coupled to said respective axle, said at least one sensor is configured to measure one of said normal force and an incremental force applied by said device imparted through said respective axle, and said at least one sensor is configured to communicate one of said normal force and incremental force to said controller.

33. The system of claim 29, further comprising: a grade sensor coupled to said rail vehicle and said controller, said grade sensor configured to determine at least one grade factor of said rail vehicle when said rail vehicle is stationary, said controller is configured to receive said at least one grade factor to determine said static weight of said plurality of wheels on said rail.

34. A system for dynamically determining a force applied through a plurality of axles in a rail vehicle configured to travel along a rail track in a travel direction, said rail vehicle having a plurality of wheels, said plurality of wheels being received by said plurality of axles, said system comprising: a controller, said controller configured to receive at least one of a rail track condition, a rail vehicle operating condition, an operator input, and a geographical input of a location along said rail track; wherein said controller is configured to determine a respective dynamic weight command of said plurality of axles on said rail track to dynamically shift a respective weight of said plurality of axles on said rail track based upon said at least one a rail track condition, a rail vehicle operating condition, an operator input, and a geographical input of a location along said rail track.

35. A kit for reconfiguring a rail vehicle from a first tractive effort configuration to a second tractive effort configuration, said rail vehicle being configured to travel along a rail track, said rail vehicle having a plurality of axles with a plurality of wheels, the wheels being arranged to be in contact with the rail track,

said first tractive effort configuration of said rail vehicle including a fixed respective weight of said plurality of axles on said rail track prior to said rail vehicle traveling along said rail track, said kit comprising: a device configured to be respectively coupled to at least one of said plurality of axles in said second tractive effort configuration; wherein upon operatively coupling said device to said respective axle, said device selectively imparts a force through said at least one axle to dynamically vary said respective weight of said at least one axle on said rail track to affect a traction performance of said rail vehicle in said second tractive effort configuration traveling along said rail track.

Description:

SYSTEM, METHOD, AND KIT FOR DYNAMICALLY AFFECTING A FORCE APPLIED THROUGH A RAIL VEHICLE AXLE

BACKGROUND OF THE INVENTION

[001] The subject matter herein relates to rail vehicles, and, more particularly, to axle systems for locomotives and other rail vehicles.

[002] A diesel-electric locomotive typically includes a diesel internal combustion engine coupled to drive a rotor of at least one traction alternator to produce alternating current (AC) electrical power. The traction alternator may be electrically coupled to power one or more electric traction motors mechanically coupled to apply torque to one or more axles of the locomotive. The traction motors may include AC motors operable with AC power, or direct current motors operable with direct current (DC) power. For DC motor operation, a rectifier may be provided to convert the AC power produced by the traction alternator to DC power for powering the DC motors.

[003] AC-motor-equipped locomotives typically exhibit better performance and have higher reliability and lower maintenance than DC motor equipped locomotives. In addition, more responsive individual motor control may be provided in AC-motor-equipped locomotives, for example, via use of inverter-based motor control. However, DC-motor-equipped locomotives are relatively less expensive than comparable AC-motor-equipped locomotives. Thus, for certain hauling applications, such as when hauling relatively light freight and/or relatively short trains, it may be more cost efficient to use a DC-motor-equipped locomotive instead of an AC-motor- equipped locomotive.

[004] For relatively heavy hauling applications, diesel-electric locomotives are typically configured to have two trucks including three axles per truck, where the

three axles include one or more powered axles and one or more non-powered axles. Each powered axle of the truck is typically coupled, via a gear set, to a respective motor mounted in the truck near the axle. Each axle is mounted to the truck via a suspension assembly that typically includes one or more springs for transferring a respective portion of a locomotive weight (including a locomotive body weight and a locomotive truck weight) to the axle while allowing some degree of movement of the axle relative to the truck.

[005] A locomotive body weight is typically configured to be about equally distributed between the two trucks. The locomotive weight is usually further configured to be symmetrically distributed among the axles of the trucks. For example, a conventional locomotive weighing 420,000 pounds is typically configured to equally distribute weight to the six axles of the locomotive, so that each axle supports a force of 420,000/6 pounds per axle, or 70,000 pounds (about 31, 751 kg) per axle.

[006] Locomotives are typically manufactured to distribute weight symmetrically to the trucks and then to the axles of the trucks so that relatively equal portions of the weight of the locomotive are distributed to the axles. Typically, the weight of the locomotive and the adhesion capability of the locomotive determine a tractive effort capability rating of the locomotive. Accordingly, the weight applied to each of the powered axles times the amount of friction or adhesion that can be developed to the powered axle determines a tractive effort capability of the corresponding powered axle. Consequently, the heavier a locomotive, the more tractive effort that it can generate. Additional weight, or ballast, may be added to a locomotive to bring it up to a desired overall weight for achieving a desired tractive effort capability. For example, due to manufacturing tolerances that may result in varying overall weights among locomotives built to a same specification, locomotives

are commonly configured to be slightly lighter than required to meet a desired tractive effort capability, and then ballast is added to reach a desired overall weight capable of meeting the desired tractive effort rating. In conventional locomotive systems, the weight distribution among the powered axles and non-powered axles is statically adjusted prior to shipment, and is not capable of being dynamically adjusted once the locomotive trip has begun.

BRIEF DESCRIPTION OF THE INVENTION

[007] Embodiments of the present invention are for use in a rail vehicle configured to travel along a railroad in a direction of travel. In a typical case, the railroad has two or more rail tracks for supporting and guiding the rail vehicle. The rail vehicle includes a plurality of wheels, which are received by a plurality of axles, e.g., there are two or more axles each carrying two or more wheels. The wheels are configured to move along the railroad track rails.

[008] One embodiment of the present invention provides a system for dynamically affecting a force applied through at least one axle in a rail vehicle. The system includes a device configured to dynamically affect the force applied through the at least one axle. As the rail vehicle travels along the rail track, at least one characteristic of the force is selected to affect the traction performance of the rail vehicle.

[009] Another embodiment of the present invention provides a system for dynamically affecting a traction performance of a rail vehicle. The rail vehicle includes a plurality of axles for receiving a respective plurality of wheels. Each of the plurality of wheels is configured to move along a respective rail of a rail track in a travel direction. The system includes a pair of trucks configured to receive the plurality of axles, where the pair of trucks is configured to rotate to a common

alignment from an opposite alignment with respect to the travel direction. The common alignment of the trucks is configured to affect the traction performance of the rail vehicle as the rail vehicle travels along the rail track.

[0010] Another embodiment of the present invention provides a method for applying a force of a railway vehicle configured to travel along a rail track. The method includes providing a plurality of axles each having one or more wheels, where each wheel is arranged to be in contact with the rail track. The method further includes coupling a device to the axle to adjust a characteristic of the force as applied through the wheel so to affect a traction performance of the railway vehicle.

[0011] As should be appreciated, the aforementioned embodiments provide a locomotive system that may be used to dynamically affect a force applied through a locomotive powered axle and/or a locomotive non-powered axle of a locomotive truck, so to dynamically adjust a weight distribution among the powered axle(s) and non-powered axle(s).

[0012] Another embodiment of the present invention provides a system for coupling two or more axles of a plurality of axles on a rail vehicle, for dynamically affecting a force applied through the axles of the rail vehicle. The rail vehicle includes a plurality of wheels configured to move along a rail, where the plurality of wheels is received by the plurality of axles. The system includes a coupling device that is configured to couple the two or more axles to dynamically affect a force applied through the two or more axles, e.g., so to dynamically adjust a weight distribution among powered axle(s) and non-powered axle(s). One or more characteristics of the force are selected to affect a traction performance of the rail vehicle as the rail vehicle travels along the rail track.

[0013] Another embodiment of the present invention provides a method for coupling two or more axles of a plurality of axles on a rail vehicle. The rail vehicle includes a plurality of wheels configured to move along a rail, where the plurality of wheels is received by the plurality of axles. The method includes configuring a coupling device to couple the two or more axles to dynamically affect a force applied through the two or more axles. Additionally, the method includes selecting one or more characteristics of the force to affect a traction performance of the rail vehicle as the rail vehicle travels along the rail track.

[0014] In another embodiment, the system for dynamically affecting a force applied through at least one axle of a rail vehicle includes a device configured to selectively impart the force through the at least one axle to control a respective weight of the at least one axle on the rail track. This affects a traction performance of the rail vehicle traveling along the rail track.

[0015] Another embodiment of the present invention provides a method for dynamically affecting a force applied through at least one axle of a rail vehicle configured to travel along a rail track. The rail vehicle includes a plurality of axles and a plurality of wheels received by the plurality of axles. The method includes configuring a device to selectively impart the force through the at least one axle to control a respective weight of the at least one axle on the rail track, for affecting a traction performance of the rail vehicle traveling along the rail track.

[0016] Another embodiment of the present invention provides a system for dynamically determining a force applied through a plurality of axles in a rail vehicle configured to travel along a rail track in a travel direction. The rail vehicle includes a plurality of wheels received by the plurality of axles. The system includes a controller configured to determine a respective dynamic weight shift of the plurality

of wheels on the rail track based upon a dynamic factor of the rail vehicle as the rail vehicle travels along the rail track.

[0017] Another embodiment of the present invention relates to a system for dynamically determining a force applied through a plurality of axles in a rail vehicle configured to travel along a rail track in a travel direction. The system includes a controller configured to receive a rail track condition, a rail vehicle operating condition, an operator input, and/or a geographical input of a location along the rail track. The controller is configured to determine a respective dynamic weight command of the plurality of axles on the rail track to dynamically shift a respective weight of the plurality of axles on the rail track based upon the rail track condition, a rail vehicle operating condition, an operator input, and/or a geographical input of a location along the rail track.

[0018] Another embodiment of the present invention provides a method for dynamically determining a force applied through a plurality of axles in a rail vehicle configured to travel along a rail track in a travel direction. The rail vehicle includes a plurality of wheels received by the plurality of axles. The method includes configuring a controller to receive at least one characteristic of the rail vehicle. Additionally, the method includes determining a static weight of the plurality of axles on the rail track when the rail vehicle is stationary. The method further includes configuring the controller to determine a respective dynamic weight of the plurality of wheels on the rail track based upon the static weight of the plurality of wheels and a dynamic factor of the rail vehicle as the rail vehicle travels along the rail track.

[0019] Another embodiment of the present invention relates to computer readable media containing program instructions for dynamically determining a force applied through a plurality of axles in a rail vehicle configured to travel along a rail

track in a travel direction. The rail vehicle includes a plurality of wheels received by the plurality of axles. The computer readable media includes a computer program code for determining a static weight of the plurality of axles on the rail track when the rail vehicle is stationary. The computer readable media further includes a computer program code for determining a respective dynamic weight of the plurality of wheels on the rail track based upon the static weight of the plurality of axles and a dynamic factor of the rail vehicle as the rail vehicle travels along the rail track.

[0020] Another embodiment of the present invention relates to a kit for reconfiguring a rail vehicle from a first tractive effort configuration to a second tractive effort configuration. The rail vehicle travels along a rail track, and includes a plurality of axles with a plurality of wheels in contact with the rail track. The first tractive effort configuration of the rail vehicle includes a fixed respective weight of the plurality of axles on the rail track prior to the rail vehicle traveling along the rail track. The kit includes a device to be respectively coupled to at least one axle in the second tractive effort configuration. Upon operatively coupling the device to the respective axle, the device selectively imparts a force through the at least one axle to dynamically vary the respective weight of the at least one axle on the rail track to affect a traction performance of the rail vehicle in the second tractive effort configuration traveling along the rail track.

[0021] Another embodiment of the present invention provides a method for reconfiguring a rail vehicle from a first tractive effort configuration to a second tractive effort configuration. The rail vehicle travels along a rail track, and includes a plurality of axles with a plurality of wheels in contact with the rail track. The first tractive effort configuration of the rail vehicle includes a fixed respective weight of the plurality of axles on the rail track prior to the rail vehicle traveling along the rail track. The method includes respectively coupling a device to at least one of the

plurality of axles in the second tractive effort configuration. Upon operatively coupling the device to the respective axle, the device selectively imparts a force through the at least one axle to dynamically vary the respective weight of the at least one axle on the rail track to affect a traction performance of the rail vehicle in the second tractive effort configuration traveling along the rail track.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] A more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. These drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope.

[0023] FIG. 1 is a side view of an exemplary embodiment of a locomotive with a pair of trucks in a reverse alignment;

[0024] FIG. 2 is a side view of an exemplary embodiment of a system for dynamically affecting a normal force applied through a locomotive axle of a locomotive with a pair of trucks in a common alignment;

[0025] FIG. 3 is flowchart illustrating an exemplary embodiment of a method for dynamically affecting a normal force applied through a locomotive axle of the locomotive illustrated in FIG. 2;

[0026] FIG. 4 is a partial side view of an exemplary embodiment of a locomotive truck including a powered axle and a non-powered axle received by the truck;

[0027] FIG. 5 is a partial side view of an exemplary embodiment of a system for coupling at least two locomotive axles on a locomotive;

[0028] FIG. 6 is a side view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0029] FIG. 7 is a partial side view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle illustrated in FIG. 6;

[0030] FIG. 8 is a schematic view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0031] FIG. 9 is a schematic view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0032] FIG. 10 is a schematic view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0033] FIG. 11 is a schematic view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0034] FIG. 12 is a schematic view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0035] FIG. 13 is a schematic view of an exemplary embodiment of a system for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0036] FIG. 14 is a schematic view of an exemplary embodiment of a system for determining a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track;

[0037] FIG. 15 is a schematic view of an exemplary embodiment of a system for determining a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track;

[0038] FIG. 16 is a schematic view of an exemplary embodiment of a system for determining a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track;

[0039] FIG. 17 is a flowchart illustrating an exemplary embodiment of a method for coupling at least two locomotive axles on the locomotive illustrated in FIG. 5;

[0040] FIG. 18 is a flowchart illustrating an exemplary embodiment of a method for dynamically affecting a force applied through a locomotive axle of a locomotive configured to travel along a rail track;

[0041] FIG. 19 is a flowchart illustrating an exemplary embodiment of a method for determining a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track; and

[0042] FIG. 20 is a flowchart illustrating an exemplary embodiment of a method for installing a kit for reconfiguring a rail vehicle from a first tractive effort configuration to a second tractive effort configuration.

DETAILED DESCRIPTION OF THE INVENTION

[0043] Reference will now be made in detail to the embodiments consistent with the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used throughout the drawings and refer to the same or like parts.

[0044] FIG. 1 illustrates an exemplary embodiment of a system 10 for dynamically affecting a normal force 12 applied through one or more of a plurality of locomotive axles 30, 32, 34, 36, 38, 40. Although FIG. 1 illustrates a locomotive 18, the embodiment of the system 10 of the present invention, and all embodiments of the present invention discussed below, may be utilized with any rail vehicle, including a locomotive, for example. The locomotive 18 illustrated in FIG. 1 is configured to travel along a rail track (see track 320'" in FIG. 9), and includes a plurality of locomotive wheels 20 which are each received by a respective axle 30, 32, 34, 36, 38, 40. The plurality of wheels 20 received by each axle 30, 32, 34, 36, 38, 40 are configured to move along a respective rail of the rail track in a travel direction 24.

[0045] As illustrated in the exemplary embodiment of FIG. 1, the locomotive

18 includes a pair of rotatable trucks 26, 28 which are configured to receive a respective plurality of axles (30, 32, 34)(36, 38, 40). The pair of trucks 26, 28 are

configured to be rotated from an opposite alignment 43 (FIG. 1) to a common alignment 42 (FIG. 2) with respect to the travel direction 24, such that the common alignment 42 of the trucks 26, 28 is configured to enhance the traction performance of the locomotive 18 as the locomotive travels along the rail track. Each truck 26, 28 includes a pair of spaced powered axles (30, 34)(36, 40) and a non-powered axle (32)(38) positioned between the pair of spaced powered axles. The powered axles (30, 34)(36, 40) are respectively coupled to a traction motor 44 and a gear 46. The combination of the respective powered axle (30, 34)(36, 40) and respective traction motor 44 may be referred to as the "combo," and a stationary (e.g., non-rotating) component of the "combo" is coupled to the respective truck 26, 28 using a reaction member 133, as illustrated in FIGS. 1, 2, 4, and 5. In an exemplary embodiment of the present invention, the reaction member 133 may take an "L-shaped" form. The reaction member 133 couples the stationary component of the "combo" to the respective truck 26, 28 frame to exert a vertical force. The vertical force displaces the "combo" relative to the truck 26, 28 frame in the vertical direction. The direction of the vertical force is upward or downward, depending on the direction 24 of the tractive effort. In the exemplary embodiment of the opposite alignment 43 illustrated in FIG. 1, the respective gear 46 of a pair of powered axles 30, 34 for one of the trucks 26 are positioned on an opposite side of the powered axles 30, 34, relative to the direction of travel 24, thereby causing an upward force on the powered axles 30, 34 and reducing the tractive effort of the locomotive 18. In stark contrast, the exemplary embodiment of the common alignment 42 illustrated in FIG. 2 illustrates the respective gear 46 of all powered axles 30, 34, 36, 40 for all trucks 26, 28 positioned on the same relative side 48 of the powered axles 30, 34, 36, 40 as the direction of travel 24, thereby causing a downward force 12 on the powered axles 30, 34, 36, 40, and increasing the tractive effort of the locomotive 18.

[0046] Upon rotating the trucks 26, 28 to the common alignment 42, the weight imparted by the powered axles (30, 34)(36, 40) on the rail track increases, while the weight imparted by the non-powered axles (32)(38) on the rail track decreases, as compared to the respective values in the opposite alignment 43 arrangement. Although FIGS. 1-2 illustrate a pair of spaced apart powered axles and a non-powered axle positioned therebetween within each truck, the trucks 26, 28 may include any number of powered axles and at least one non-powered axle, within any positional arrangement. The trucks 26, 28 may be rotated by removing the locomotive 18 from the rail track and rotating the trucks 26, 28 about a traction pin (not shown), for example, before repositioning the locomotive 18 on the rail track with the trucks 26, 28 in the new relative alignment.

[0047] Although the system 10 increases the traction performance of the locomotive 18 by rotating the trucks 26, 28 to a common alignment 42, the system 10 may further include an optional device 27, 29 (FIG. 2) coupled to the respective axles (30, 32, 34)(36, 38, 40) of the trucks 26, 28, to provide additional traction performance. Although FIG. 2 illustrates a single device 27, 29 respectively coupled to each truck 26, 28, a single device may be individually coupled to each axle, as discussed in the embodiments below. The optional device 27, 29 is discussed generally herein, and more specific examples of the device 27, 29 are discussed in detail in other later embodiments of the present invention. However, the system 10 may increase the traction performance of the locomotive 18 with the trucks 26, 28, and without the optional device 27, 29.

[0048] As illustrated in the exemplary embodiment of FIG. 2, a respective device 27, 29 may be coupled to the trucks 26, 28 of the locomotive 18, where each device is configured to dynamically affect the normal force 12 applied through one or more of the axles (30, 32, 34)(36, 38, 40) in a normal direction to the rail track surface

in contact with the wheels 20. In dynamically affecting the normal force 12, one or more characteristics of the normal force 12 is selected to affect the traction performance of the locomotive 18 as the locomotive 18 travels along the rail track. For example, such characteristics of the normal force 12 may include the magnitude and/or direction of the normal force 12.

[0049] In an exemplary embodiment of the system 10, the respective device

27, 29 is configured to increase the aggregate adhesion between the plurality of locomotive wheels 20 and the rail track, by selecting a characteristic of the normal force and dynamically affecting that characteristic. For example, a first axle 30 of the axles (30, 32, 34)(36, 38, 40) is coupled to a respective pair of wheels 20 in a slipping condition on the rail track. Additionally, a second axle 34 is coupled to a respective pair of wheels 20 in a non-slipping condition on the rail track. The respective device 27 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the first axle 30 to control a creep condition of the respective pair of wheels 20, and reduce the slipping condition of the pair of wheels 20, for example. Additionally, the respective device 27 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the second axle 32 to control a creep condition of the respective pair of wheels 20 and maintain the non-slipping condition of the pair of wheels 20, for example.

[0050] In a further exemplary embodiment, the plurality of axles (30, 32,

34)(36, 38, 40) may include a performance limited axle, and the respective device 27 may be configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the performance limited axle to reduce a level of tractive effort passed through the performance limited axle. Examples of such a performance limited axle include: an axle having incurred a limitation in tractive effort attributed to a failure of a mechanical and/or electrical component of the locomotive 18, a

thermally affected axle based on a temperature of the traction motor, a mechanical drive train and electric drive of the thermally affected axle exceeding a predetermined threshold, and a reduced capability axle providing limited traction effort efficiency.

[0051] In an additional exemplary embodiment of the system 10, the plurality of axles (30, 32, 34)(36, 38, 40) include a friction brake axle, where during the application of a locomotive brake such as an emergency air brake, an independent brake or a train brake, the respective device 27, 29 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the friction brake axle. The dynamic effect of the normal force 12 is based on an open loop or closed loop format, where the closed loop format involves a sensor coupled to the device 27, 29 to detect a creep factor of the friction brake axle. The device 27, 29 is configured to dynamically affect the normal force 12 based upon the creep factor received from the sensor. However, the open loop format involves the respective device 27, 29 dynamically affecting the magnitude and/or direction of the normal force 12, until a particular parameter is achieved, such as a minimum increase in the tractive performance of the locomotive, for example.

[0052] In an additional exemplary embodiment of the system 10, the plurality of wheels 20 may include a flatspot wheel with a flat spot along a circumference of the wheel 20. The respective device 27, 29 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through an axle 30 which has received the flatspot wheel 20 to impart an upward lift force on the flatspot wheel 20 to limit damage to the flatspot wheel, the rail track, and/or the locomotive 18. If the respective device 27, 29 does not dynamically affect the magnitude and/or direction of the normal force 12 through the axle 30 and impart the upward lift force on the flatspot wheel 20, the flat spot along the flatspot wheel 20 would increase, and possibly lead to damage of the locomotive 18. In an additional exemplary

embodiment of the system 10, the plurality of wheels 20 may include a locked wheel 20, received by a respective locked axle 30. In the exemplary embodiment, the respective device 27, 29 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the respective locked axle 30 to impart an upward lift force on the locked wheel 20 to reduce a likelihood of locomotive derailment.

[0053] As discussed above, the system 10 is provided to affect a traction performance characteristic of the locomotive 18, and such traction performance characteristics may be based upon an operating characteristic of the locomotive 18. For example, the dynamic effect of the normal force 12 applied through the plurality of axles (30, 32, 34)(36, 38, 40) is configured to affect the traction performance of the locomotive 18 when the locomotive 18 is traveling over the rail track at a low speed lower than a speed threshold. Additionally, the traction performance affected by the system 10 may include a creep factor of the plurality of wheels 20 and a tractive effort of the plurality of wheels 20, for example. In another example, the dynamic effect of the normal force 12 applied the plurality of axles (30, 32, 34)(36, 38, 40) is configured to affect a wheel wear of the plurality of wheels 20, a ride quality of the locomotive 18, or a creep factor of the plurality of wheels 20 when the locomotive 18 is traveling over the rail track at a high speed greater than a speed threshold. The speed threshold may be any arbitrary speed, such as 12 miles per hour, for example. In yet another example, the dynamic effect of the normal force 12 applied through the plurality of axles (30, 32, 34)(36, 38, 40) is configured to dynamically control a respective weight of a pair of wheels 20 across an axle 30 which receives the pair of wheels 20, and/or to dynamically control a respective weight distribution between two axles 30, 32, to affect a curve performance characteristic of the locomotive 18 when the locomotive 18 travels over a curve in the rail track. Although the exemplary embodiment refers to dynamically controlling the weight of the pair of wheels 20

across the axle 30, the system may dynamically control the weight of a pair of wheels across multiple axles. Additionally, although the exemplary embodiment refers to dynamically controlling a weight distribution between two axles 30, 32, the system may be employed to dynamically control weight distribution between more than two axles.

[0054] In an additional exemplary embodiment of the system 10, the respective device 27, 29 may dynamically affect a lateral force perpendicular to the normal force 12, where the lateral force is applied through a locomotive axle 30 in the locomotive 18 to enhance a curve performance characteristic of the locomotive 18 when the locomotive travels along a curve in the rail track.

[0055] In an additional exemplary embodiment of the system 10, upon a weight of the locomotive 18 having decreased by a weight of consumed locomotive fuel, the respective device 27, 29 is configured to dynamically affect the respective normal force 12 passing through the powered axle 30 and the non-powered axle 32 to increase a weight of the powered axle 30 to the weight of the powered axle 30 prior to the consumption of the locomotive fuel, and further to decrease a weight of the non- powered axle 32 to a weight lower than a weight of the non-powered axle 32 prior to the consumption of the locomotive fuel. In one exemplary embodiment, the weight of consumed locomotive fuel is determined by an algorithm performed by a locomotive controller, or a direct fuel level measurement within the fuel tank. When dynamically affecting the normal force 12 to increase the weight of the powered axle 30, the increase in the weight of the powered axle 30 is configured not to exceed a respective weight threshold for the powered axle 30.

[0056] In an additional exemplary embodiment of the system 10, the device

27, 29 is configured to dynamically affect the force 12 applied through the plurality of

axles (30, 32, 34)(36, 38, 40) to reduce an amount of ballast on the locomotive 18. The dynamic effect of the normal force 12 through the plurality of axles (30, 32, 34)(36, 38, 40) is utilized to provide a weight balance of the locomotive 18 across opposing ends, where the weight balance is configured to reduce a need to provide ballast on the locomotive.

[0057] In an additional exemplary embodiment of the system 10, the plurality of axles (30, 32, 34)(36, 38, 40) include powered axles (30, 34)(36, 40) and a non- powered axle (32)(38), and the dynamic effect of the normal force 12 through the axles (30, 32, 34)(36, 38, 40) involves a weight shift to the powered axles (30, 34)(36, 40) for a limited time period to achieve one or more traction performance requirements of the locomotive 18. A maximum weight shift to the powered axles (30, 34)(36, 40) from the non-powered axle (32, 38) is performed within a minimum time period to minimize a structural impact on a locomotive 18 and rail track infrastructure. In an exemplary embodiment, such a maximum weight shift is 20,000 lbs, for example. In an additional exemplary embodiment, the plurality of wheels 20 have a respective plurality of diameters, where the respective device 27, 29 is configured to dynamically affect the normal force 12 passed through the axles (30, 32, 34)(36, 38, 40) to normalize a wheel wear characteristic of the plurality of wheels 20 attributed to a disparity in the respective plurality of diameters.

[0058] FIG. 3 illustrates an exemplary embodiment of a method 100 for dynamically affecting a normal force 12 applied through one or more locomotive axles (30, 32, 34)(36, 38, 40) in a locomotive 18 configured to travel along a rail track. The method 100 begins (block 101) by configuring (block 102) a device 27, 29 to dynamically affect the normal force 12 applied through one or more axles of the plurality of axles (30, 32, 34)(36, 38, 40). Additionally, the method 100 includes selecting (block 104) one or more characteristics of the force 12 to affect a traction

performance of the locomotive 18 as the locomotive travels along the rail track, before ending at block 106. Another embodiment relates to a method for applying a force of a railway vehicle configured to travel along a rail track. The method comprises providing at least one axle having at least one wheel, the wheel being arranged to be in contact with the rail track. The method further comprises coupling a device to the axle for adjusting a characteristic of the force as applied through the wheel so as to affect a traction performance of the railway vehicle.

[0059] FIG. 4 illustrates a conventional truck 126 of a locomotive 116, in which a powered axle 112 and a non-powered axle 114 are not directly coupled to one another. FIG. 5 illustrates an exemplary embodiment of a system 110 for coupling the powered axle 112 to the non-powered axle 114 on a locomotive 116. The locomotive 116 includes a plurality of locomotive wheels 118 and a rail track (not shown), where the plurality of locomotive wheels 118 are received by a respective axle 112, 114.

[0060] The system 110 includes a coupling device 124, which is configured to couple the powered axles 112, 115 to the non-powered axle 114 to dynamically affect forces 128, 129 applied through one of the powered axles 112, 115 and non-powered axle 114. One or more characteristics of the forces 128, 129 applied through the powered axles 112, 115 and non-powered axle 114 are selected to affect the traction performance of the locomotive 116 as the locomotive travels along the rail track. In an exemplary embodiment, the one or more characteristics of the forces 128, 129 are selected to optimize the traction performance of the locomotive 116 as the locomotive travels along the rail track.

[0061] In the exemplary embodiment of the system 110 illustrated in FIG. 5, by dynamically affecting the forces 128, 129 applied through one or more of the powered axles 112, 115 and non-powered axle 114, a level of tractive effort passed

through the axles 112, 115, 114 is affected. In an exemplary embodiment, a characteristic of the forces 128, 129 is the magnitude and/or direction of the forces, for example.

[0062] As illustrated in the exemplary embodiment of FIG. 5, the coupling device 124 is a mechanical coupling device configured to mechanically couple the powered axles 112, 115 and the non-powered axle 114. Although FIG. 5 illustrates the coupling device 124 coupling a pair of powered axles 112, 115 to a non-powered axle 114, the coupling device may be utilized to coupled one powered axle or more than two powered axles to one or more non-powered axles, for example. The mechanical coupling device 124 is coupled to a respective traction motor 130 of the powered axle 112. As illustrated in FIG. 5, the coupling device 124 is utilized to couple a pair of powered axles 112, 115 to the non-powered axle 114, and the mechanical coupling device 124 may be a rigid member or a flexible member, and one or more compliant members 113 couple the mechanical coupling device 124 to the non-powered axle 114.

[0063] In the illustrated exemplary embodiment of FIG. 5, the pair of powered axles 112, 115 include a respective traction motor 130 within a motor frame 131 and a respective gear 132. Additionally, the pair of powered axles 112, 115 is rotated by the respective gear 132, which is driven by the respective traction motor 130. In the exemplary embodiment of the system 110, during the rotation of the pair of powered axles 112, 115 by the respective gear 132, a force 129 is imparted on the pair of powered axles 112, 115, a stationary component of the traction motor, and a rotating component of the traction motor through a bearing. Once the force 129 is imparted on the pair of powered axles 112, 115 and the stationary component of the traction motor, the mechanical coupling device 124 is coupled to the non-powered axle 114 through a journal bearing housing 136. The mechanical coupling device 124 is

configured to impart a secondary force 128 on the non-powered axle 114 through the journal bearing housing 136 to increase the level of tractive effort passed through the pair of powered axles 112, 115 and the non-powered axle 114.

[0064] As discussed above and as illustrated in the exemplary embodiment of

FIG. 2, the locomotive 116 includes a pair of trucks 26, 28, and a respective pair of powered axles 112, 115 and a non-powered axle 114 received by a respective truck. A fixed collective force is applied through the respective pair of powered axles 112, 115 and the non-powered axle 114 for each respective truck. A variable powered force is applied through the respective pair of powered axles 112, 115 and a variable non-powered force is applied through the non-powered axle 114, where the sum of the variable powered and non-powered forces is the fixed collective force. For example, the fixed collective force through a pair of powered axles and a non-powered axle of a truck may be 210,000 lbs, but the variable powered force applied through the pair of powered axles may vary between 120,000 lbs and 160,000 lbs, while the variable non- powered force applied through the non-powered axle may respectively vary between 90,000 lbs and 50,000 lbs, for example. As discussed above, and in further detail below, the coupling device 124 is provided to maximize the variable powered force through the pair of powered axles 112, 115, while minimizing the variable non- powered force through the non-powered axle 114. As discussed above, although the illustrated truck in FIG. 5 includes a respective pair of powered axles 112, 115 and a non-powered axle 114, the truck may include one or more than two powered axles and may include more than one non-powered axle, for example. The mechanical coupling device 124 is configured to affect the magnitude and/or direction of the variable powered force and the variable non-powered force applied through the respective pair of powered axles 112, 115 and the non-powered axle 114.

[0065] As further illustrated in the exemplary embodiment of FIG. 5, the mechanical coupling device 124 includes a slot 140 coupled to the stationary component of the traction motor 130. The slot 140 is configured to receive a respective member 137 coupled to a respective motor frame 131 of the pair of powered axles 112, 115. The slot 140 and respective member 137 are configured to provide a one-way coupling such that the mechanical coupling device 124 imparts the secondary force 128 on the non-powered axle 114 when the force 129 is imparted on the pair of powered axles 112, 115, and the mechanical coupling device 124 is decoupled from the non-powered axle 114 when the force 129 is imparted on the pair of powered axles 112, 115 in an upward direction away from the rail track to increase a level of tractive effort passed through the pair of powered axles 112, 115. The particular slot 140 and respective member 137 are dimensioned and positioned such that the one-way coupling is provided based upon the direction of the force 129 imparted on the pair of the powered axles 112, 115, and thus whether the force 129 increases or decreases the tractive effort passed through the pair of powered axles 112, 115.

[0066] As discussed in further detail in the embodiments below, instead of a rigid member, the coupling device 124 may take the form of a plurality of hydraulic actuators respectively coupled to the plurality of axles 112, 114, 115, where a compressed fluid within a first hydraulic actuator coupled to a first axle 112 is selectively supplied to a second hydraulic actuator coupled to a second axle 114 of the plurality of axles. In the exemplary embodiment, the compressed fluid within the second hydraulic actuator is configured to impart the secondary force 128 on the second axle 114. One of more characteristics of the secondary force 128 may be affected, including the magnitude and/or direction of the force 128, to increase a level of tractive effort passed through the second axle 114.

[0067] FIG. 17 illustrates an exemplary embodiment of a method 200 for coupling two or more axles 112, 114 of a plurality of axles 112, 114, 115 on a locomotive 116. The method 200 begins at block 201 by configuring (block 202) a coupling device 124 to couple the two or more axles 112, 114, 115 to dynamically affect a force 128, 129 applied through the two or more axles 112, 114, 115. The method 200 further includes selecting (block 204) one or more characteristics of the force 128, 129 to affect traction performance of the locomotive 116 as the locomotive 116 travels along the rail track, before ending at block 206.

[0068] FIG. 11 illustrates an exemplary embodiment of a system 310 for dynamically affecting a force applied through a locomotive axle 314 of a locomotive 318 configured to travel along a rail track. The locomotive 318 includes a plurality of locomotive axles and a plurality of locomotive wheels received by the respective plurality of axles. The system 310 includes a device configured to selectively impart a force through a locomotive axle 314 to control a respective weight of the locomotive axle 314 on the rail track for affecting a traction performance of the locomotive 318 traveling along the rail track. Although FIG. 11 illustrates a system 310 to selectively impart a force through one locomotive axle 314, the system may be configured to selectively impart a force through more than one locomotive axle.

[0069] In the illustrated exemplary embodiment of FIG. 11 , the system 310 includes the device to selectively impart a force through the locomotive axle 314, such as a hydraulic actuator 326 coupled to the respective locomotive axle 314. Although FIG. 11 illustrates one hydraulic actuator 326 coupled to a locomotive axle 314, a hydraulic actuator may be coupled to more than one respective locomotive axle, to selectively impart a force through the respective locomotive axle. A variable displacement pump 328 is coupled to the hydraulic actuator 326, and the variable displacement pump 328 is configured to supply a pressurized hydraulic fluid 330 at a

selectively controlled pressure to the hydraulic actuator 326. The hydraulic actuator 326 is configured to selectively impart the force through the respective locomotive axle 314 based upon the selectively controlled pressure. In the illustrated exemplary embodiment of FIG. 11, the hydraulic actuator 326 is directly coupled to the respective locomotive axle 314. Although FIG. 11 illustrates one variable displacement pump 328, more than one variable displacement pump may be utilized. A plurality of control valves 332, 334, 336, 338 are respectively coupled to the variable displacement pump 328 and the hydraulic actuator 326, and the control valves 332, 334, 336, 338 are selectively activated to control the force imparted through the respective locomotive axle 314.

[0070] FIG. 12 illustrates an additional exemplary embodiment of a system

310' for dynamically affecting a force applied through a locomotive axle 314' of a locomotive 318' configured to travel along a rail track. As illustrated in the exemplary embodiment of FIG. 12, the system 310' includes a compliant member 340', such as a spring, for example, disposed between the hydraulic actuator 326' and the respective locomotive axle 314' such that the hydraulic actuator 326' is coupled to the respective locomotive axle 314' in a compliant manner. The system 310' further includes a pair of displacement limits (not shown) coupled to the hydraulic actuator 326' to limit the force selectively imparted on the respective locomotive axle 314'. As further illustrated in the exemplary embodiment of FIG. 12, the system 310' includes a plurality of control valves 332', 334', 336', 338' coupled to the variable displacement pump 328' and the hydraulic actuator 326', where the plurality of control valves 332', 334', 336', 338' are selectively activated to control a position 342' of the hydraulic actuator. Those elements not specifically discussed herein are similar to those equivalent-numbered elements described in the previous embodiments, with prime notation, and require no further discussion herein.

[0071] FIG. 13 illustrates an additional exemplary embodiment of a system

310" for dynamically affecting a force applied through a locomotive axle 314" of a locomotive 318" configured to travel along a rail track. The system 310" includes a positive displacement pump 344" coupled to the hydraulic actuator 326", where the positive displacement pump 344" is configured to selectively control a position 342" of the hydraulic actuator 326" based upon supplying a pressurized hydraulic fluid 330" at a variable pressure to the hydraulic actuator 326". The hydraulic actuator 326" is configured to selectively impart the force through the respective locomotive axle 314" based upon the selectively controlled position 342" of the hydraulic actuator 326". As with the embodiment of FIG. 12, a compliant member 340", such as a spring, for example, is disposed between the hydraulic actuator and the respective axle such that the hydraulic actuator is coupled to the respective axle in a compliant manner. Additionally, a plurality of control valves 332", 334", 336", 338" are coupled to the positive displacement pump 344" and the hydraulic actuator 326", where the control valves 332", 334", 336", 338" are selectively activated to control the position 342" of the hydraulic actuator. A pair of displacement limits (not shown) is coupled to the hydraulic actuator 326" to limit the force selectively imparted on the respective locomotive axle 314". Those elements not specifically discussed herein are similar to those equivalent-numbered elements described in the previous embodiments, with double prime notation, and require no further discussion herein.

[0072] FIGS. 9-10 illustrate a number of exemplary embodiments of a system

310'" for dynamically affecting a force applied through a locomotive axle 314'" of a locomotive 318'" configured to travel along a rail track. As illustrated in the exemplary embodiment of FIG. 9, the system 310'" includes a hydraulic actuator 326'" configured to selectively impart the force through the respective locomotive axle 314'" based upon energy captured from a vibration of a vibrated axle 316'" of the plurality of axles along the rail track. The system 310'" includes a pressurized

hydraulic fluid pump 322'" coupled to the vibrated axle 316'" and the hydraulic actuator 326'", where the captured vibrational energy is utilized to pressurize the hydraulic fluid within the hydraulic fluid pump 322'".

[0073] The hydraulic actuator 326'" is configured to selectively impart the force through the respective locomotive axle 314'" based upon the pressurized hydraulic fluid delivered from the pump 322'" to the hydraulic actuator 326'". The system 310'" further includes a pair of displacement limits (not shown) coupled to the hydraulic actuator 326'" to limit the force selectively imparted on the respective locomotive axle 314'". A compliant member 340'", such as a spring, for example, is disposed between the hydraulic actuator 326'" and the respective locomotive axle 314'" such that the hydraulic actuator 326'" is coupled to the respective locomotive axle 314'" in a compliant manner. Once the hydraulic actuator 326'" selectively imparts the force through the respective locomotive axle 314'", the compliant member 340'" is configured to exert a reactive force on the respective locomotive axle 314'". Although FIGS. 9-10 illustrate one vibrated axle 316'" from which vibrational energy is obtained, and one locomotive axle 314'" to which the hydraulic actuator 326'" selectively imparts the force, the system 310'" may include more than one vibration axle from which vibrational energy is obtained and/or more than one locomotive axle to which a respective hydraulic actuator selectively imparts a force. The locomotive axles 314'", 316'" may include one or more powered axles, or one or more non- powered axles.

[0074] In the exemplary embodiment illustrated in FIG. 10, the pressurized hydraulic fluid pump 322'" has an input which delivers pressurized hydraulic fluid to a bottom chamber of the hydraulic actuator 326" which is coupled to a non-powered axle 314'", thereby imparting an upward force on the non-powered axle 314'" in a normal direction to the rail track. In the exemplary embodiment illustrated in FIG. 9,

the pressurized hydraulic fluid pump 322" has an input which delivers pressurized hydraulic fluid to a top chamber of the hydraulic actuator 326" which is coupled to a powered axle 314", thereby imparting a downward force on the powered axle 314" in a normal direction to the rail track. As further illustrated in the exemplary embodiments of FIGS. 9-10, a control valve 346'" is coupled to the hydraulic actuator 326'" to selectively control a pressure difference across the hydraulic actuator 326'". The control valve 346'" may be activated to rapidly remove a weight shift imparted on a respective locomotive axle 314'" based upon the selective imparting of the force on the respective locomotive axle 314'". In addition to the control valve 346'", the exemplary embodiments of FIGS. 9-10 include a high restriction valve 348'" coupled to the hydraulic actuator 326'" to selectively decrease a pressure difference across the hydraulic actuator 326'". The high restriction valve 348'" is selectively activated to slowly remove a weight shift imparted on a respective locomotive axle 314'" based upon the selective imparting of the force on the respective locomotive axle 314'". Those elements not specifically discussed herein are similar to those equivalent- numbered elements described in the previous embodiments, with triple prime notation, and require no further discussion herein.

[0075] Although FIGS. 9-13 illustrate a hydraulic actuator 326, 326', 326",

326'" being utilized as a device to selectively impart a force through a locomotive axle (e.g., 314'") to control a respective weight of the locomotive axle (e.g., 314'") on the rail track (e.g., 320'"), a pneumatic actuator 350"", as illustrated in FIGS. 6-8, may be similarly utilized in place of the hydraulic actuator and similarly coupled to the locomotive axle 314"". In an exemplary embodiment of a system 310"" illustrated in FIG. 8, a controlled pressure regulator 352"" is coupled to the pneumatic actuator 350"", where the controlled pressure regulator 352"" is configured to selectively control a position 354"" of the pneumatic actuator 350"" based upon supplying pressurized air at a near constant pressure to the pneumatic actuator 350"".

The pneumatic actuator 350"" is configured to selectively impart the force through the respective locomotive axle 314"" based upon the selectively controlled position 354"" of the pneumatic actuator. The system 310"" further includes a pair of control valves 356"", 358"" coupled to the controlled pressure regulator 352"" and the pneumatic actuator 350"", where the control valves 356"", 358"" are selectively activated to control a force imparted by the pneumatic actuator 350"". Although FIG. 7 illustrates a pair of control valves, less than two or more than two control valves may be utilized. A pair of displacement limits 360"", 362"" is coupled to a locomotive truck frame 364"", where the respective locomotive axle 314"" is received by the locomotive truck frame 364"", and the pair of displacement limits 360"", 362"" are configured to limit the position 354"" of the respective locomotive axle 314"" based upon the controlled force imparted by the pneumatic actuator 350"". Additionally, a pair of relief valves 366"", 368"" are coupled to the pneumatic actuator 350"", and are configured to rapidly remove a weight shift imparted on a respective locomotive axle 314"" based upon the selectively controlled forced imparted by the pneumatic actuator 350"". Those elements not specifically discussed herein are similar to those equivalent-numbered elements described in the previous embodiments, with quadruple prime notation, and require no further discussion herein.

[0076] In addition to the embodiments discussed above, the device configured to selectively impart a force through a locomotive axle to control a respective weight of the locomotive axle on the rail track may be a mechanical actuator, an electromechanical actuator, a motor driven actuator, a manual driven actuator, and/or a mechanical linkage actuator, coupled to a respective locomotive axle.

[0077] FIG. 18 illustrates an exemplary embodiment of a method 400 for dynamically affecting a force applied through a locomotive axle 314 of a locomotive 318 configured to travel along a rail track. The method 400 begins (block 401) by

configuring (block 402) a device to selectively impart the force through the locomotive axle 314 to control a respective weight of the locomotive axle 314 on the rail track for affecting a traction performance of the locomotive 318 traveling along the rail track, before ending at block 404.

[0078] The above-discussed embodiments describe exemplary embodiments of systems including a device for dynamically affecting a force applied through a locomotive axle. The following embodiment of the present invention discusses a control system for determining the extent of force to apply through one or more locomotive axles, so to enhance the tractive performance of the locomotive. FIGS. 14-16 illustrate a system 500 for dynamically determining a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track in a travel direction. The system 500 includes a controller 502 configured to receive one or more locomotive characteristics 504 of the locomotive (FIG. 14) to determine a static weight 503 of the plurality of axles on the rail track when the locomotive is stationary. The system 500 further includes a sensor 506 coupled to the controller 502 (FIG. 14), where the sensor 506 is configured to measure a dynamic factor of a force applied through a respective axle at a fixed time when the locomotive is in motion along the rail track. The sensor 506 is configured to communicate the dynamic factor of the axle to the controller 502. The controller 502 is configured to determine a respective dynamic weight 508 of the plurality of wheels on the rail track at the fixed time based upon the static weight 503 of the plurality of wheels and the dynamic factor of the force applied through the respective axle at the fixed time. In an exemplary embodiment of the system 500, the dynamic factor is based upon a tractive effort passed through the plurality of locomotive axles during one of a braking mode or a motoring mode of the locomotive. For example, the dynamic factor may be based upon a brake cylinder pressure 510 applied to the axle during a braking mode, or a torque 512 applied to a traction motor of the axle during a

motoring mode, for example. Additionally, the dynamic factor may be based upon a drawbar force 514 exerted on a drawbar coupling the locomotive to an adjacent locomotive or an adjacent train car, for example.

[0079] As discussed in the previous embodiments, a device may be coupled to a respective locomotive axle and the controller to selectively impart a force through the respective axle, to affect a tractive characteristic of the locomotive. The device may be any one of a hydraulic actuator, a pneumatic actuator, an electro magnetic actuator, a mechanical actuator, a motor driven actuator and a manually operated actuator, for example. In an exemplary embodiment of the system 500, the sensor 506 may be respectively coupled to the respective locomotive axle, to measure the force imparted by the device through the respective axle, and communicate the measured force to the controller 502. As further discussed in the previous embodiments of the present invention, such devices are configured to selectively impart a force through the respective axle in a direction away from the rail or toward the rail. The force may be based upon one or more dynamic characteristics of the hydraulic actuator or the pneumatic actuator, for example. In an exemplary embodiment of the system 500, the sensor 506 is coupled to the hydraulic actuator or the pneumatic actuator to measure the one or more dynamic characteristics of the hydraulic actuator or pneumatic actuator, where the dynamic characteristic may be the position or an applied pressure of the hydraulic actuator or the pneumatic actuator, for example.

[0080] Additionally, in the exemplary embodiment of FIG. 14, the system 500 includes a respective weight sensor 516 coupled to the plurality of axles and the controller 502, where the respective weight sensor 516 is configured to measure a respective static weight of the plurality of wheels on the rail track when the locomotive is stationary. Upon measuring the static weight of the plurality of wheels

on the rail track, the respective weight sensor 516 is configured to communicate the respective static weight to the controller 502. The respective weight sensor 516 may be provided as a backup or alternative calculation of the static weight 503 calculation based upon the locomotive characteristics 504, as discussed above. An example of the locomotive characteristics 504 which are utilized to determine the static weight 503 of the locomotive are an established static weight of each wheel on the rail, an established static weight of the locomotive, a static weight of fuel within a locomotive fuel tank, a static weight of sand within a locomotive sand applicator, and a respective diameter of the plurality of wheels.

[0081] As further illustrated in the exemplary embodiment of FIG. 14, the system 500 includes a grade sensor 520 coupled to the locomotive and the controller 502, where the grade sensor 520 is configured to determine one or more grade factors of the locomotive when the locomotive is stationary. The controller 502 is configured to receive the one or more grade factors to determine the static weight 503 of the plurality of wheels on the rail track.

[0082] In addition to determining the static weight 503 of the plurality of wheels on the rail track, the controller 502 is configured to determine a respective target weight 522 of the plurality of wheels on the rail. As illustrated in the exemplary embodiment of FIG. 14, in which the controller 502 involves an axle weight management algorithm which receives as input the dynamic weight 508 of the plurality of wheels on the rail, and a respective weight threshold 509 for the respective plurality of axles, and generates the respective target weight 522 of the plurality of wheels on the rail. Accordingly, the respective target weight 522 of the plurality of wheels on the rail is based upon the respective dynamic weight 508 of the plurality of wheels on the rail, and the respective weight threshold 509 for the respective plurality of axles. The respective dynamic weight 508 of the plurality of

the plurality of wheels on the rail track is subsequently modified to the respective target weight 522 of the respective plurality of wheels. The respective target weight 522 for the plurality of wheels on the rail is configured to affect a level of tractive effort passed through the plurality of wheels along the rail. As illustrated in the exemplary embodiments of FIGS. 15-16, upon determining the respective target weight 522 for the plurality of wheels on the rail, the controller 502 is configured to compare the respective target weight 522 of the plurality of wheels on the rail with the respective dynamic weight 508 of the plurality of wheels on the rail. As illustrated in the exemplary embodiment of FIG. 16, the controller 502 may compare these quantities in a closed loop or an open loop arrangement. Regardless of which method of comparison is used, upon comparing the respective target weight 522 and the respective dynamic weight 508, the controller 502 is configured to determine a respective command 524 to a hydraulic actuator or pneumatic actuator respectively coupled to the respective plurality of axles. Although such devices as a hydraulic actuator and pneumatic actuator are discussed in this exemplary embodiment of the controller 502 for imparting a force through the plurality of locomotive axles, other devices may be utilized which similarly are capable of selectively imparting a force through a respective locomotive axle.

[0083] Upon determining the respective commands 524, the controller 502 is configured to communicate the respective commands 524 to the respective hydraulic actuator or pneumatic actuator respectively coupled to the plurality of axles and configured to impart a force through the respective axle in a direction either away from the rail or toward the rail, in response to the respective commands 524. Once the hydraulic actuator or pneumatic actuator impart the force through the respective locomotive axle, the dynamic weight of the plurality of wheels on the rail is modified to the respective target weight of the plurality of wheels on the rail, and one or more tractive characteristics of the locomotive is enhanced.

[0084] In an additional exemplary embodiment of the system 500, a controller

502 is configured to determine a respective dynamic weight command 524 of the plurality of axles on the rail track to dynamically shift a respective weight of the plurality of axles on the rail track based upon a rail track condition, a locomotive operating condition, an operator input, and/or a geographical input of a location along the rail track. In an exemplary embodiment of the system 500, the locomotive operating condition may be a locomotive speed traveling along the rail track, and such a locomotive speed below a speed threshold may prompt the dynamic weight command 524 of the plurality of axles on the rail tracks to shift a respective weight among the plurality of axles. In an additional exemplary embodiment, a notch level of a throttle may be the locomotive operating condition, and upon a locomotive operator increasing the notch level above a notch threshold (e.g., 8), this may prompt the dynamic weight command 524 of the plurality of axles on the rail tracks to shift a respective weight among the plurality of axles. In an additional exemplary embodiment, a level of tractive effort may be utilized as the locomotive operating condition and may prompt the dynamic weight command 524 of the plurality of axles, for example. In an additional exemplary embodiment, a creep factor of the plurality of wheels, such as a slipping wheel condition or a non-slipping wheel condition, for example, may be utilized to prompt the dynamic weight command 524 of the plurality of axles, for example. In an additional exemplary embodiment, a level of fuel within a fuel tank of the locomotive may be utilized as the locomotive operating condition to prompt the dynamic weight command 524 of the plurality of axles, for example.

[0085] FIG. 19 illustrates an exemplary embodiment of a method 600 for dynamically determining a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track in a travel direction. The method 600 begins (block 601) by configuring (block 602) a controller 502 to receive one or

more characteristics 504 of the locomotive. The method 600 further includes determining (block 604) a static weight 503 of the plurality of axles on the rail track when the locomotive is stationary. The method 600 further includes configuring (block 606) the controller 502 to determine a respective dynamic weight 508 of the plurality of wheels on the rail track based upon the static weight 503 of the plurality of wheels and the dynamic factor of the locomotive as the locomotive travels along the rail track, before ending at block 614.

[0086] Based on the foregoing specification, the above-discussed embodiments of the invention may be implemented using computer programming or engineering techniques including computer software, firmware, hardware or any combination or subset thereof, wherein the technical effect is to dynamically determine a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track in a travel direction. Any such resulting program, having computer-readable code means, may be embodied or provided within one or more computer-readable media, thereby making a computer program product, i.e., an article of manufacture, according to the discussed embodiments of the invention. The computer readable media may be, for instance, a fixed (hard) drive, diskette, optical disk, magnetic tape, semiconductor memory such as read-only memory (ROM), etc., or any transmitting/receiving medium such as the Internet or other communication network or link. The article of manufacture containing the computer code may be made and/or used by executing the code directly from one medium, by copying the code from one medium to another medium, or by transmitting the code over a network.

[0087] One skilled in the art of computer science will easily be able to combine the software created as described with appropriate general purpose or special purpose computer hardware, such as a microprocessor, to create a computer system or

computer sub-system of the method embodiment of the invention. An apparatus for making, using or selling embodiments of the invention may be one or more processing systems including, but not limited to, a central processing unit (CPU), memory, storage devices, communication links and devices, servers, I/O devices, or any sub-components of one or more processing systems, including software, firmware, hardware or any combination or subset thereof, which embody those discussed embodiments the invention.

[0088] Thus, one embodiment of the present invention relates to computer readable media containing program instructions for dynamically determining a force applied through a plurality of axles in a rail vehicle configured to travel along a rail track in a travel direction. The computer readable media comprises a computer program code for determining a static weight of the plurality of axles on the rail track when the rail vehicle is stationary. The computer readable media also comprises a computer program code for determining a respective dynamic weight of the plurality of wheels on the rail track based upon the static weight of the plurality of axles and a dynamic factor of the rail vehicle as the rail vehicle travels along the rail track.

[0089] Another embodiment of the present invention provides a kit for reconfiguring a rail vehicle, such as a locomotive 18, for example, from a first tractive effort configuration to a second tractive effort configuration. As previously illustrated in FIG. 1, the locomotive 18 is configured to travel along a rail track, and includes a plurality of axles 30, 32, 34, 36, 38, 40 having a plurality of wheels 20, where the wheels 20 are in contact with the rail track. The first tractive effort configuration of the locomotive 18 includes a fixed respective weight of the plurality of axles 30, 32, 34, 36, 38, 40 on the rail track prior to the locomotive 18 traveling along the rail track. As further illustrated in the exemplary embodiment of FIG. 1, the locomotive 18 includes a pair of trucks 26, 28, including a respective plurality of axles (30, 32,

34)(36, 38, 40). As illustrated in FIG. 1, the kit includes a device 27 configured to be respectively coupled to a pair of plurality of powered axles (30, 34)(36, 40), of the respective trucks 26, 28 in the second tractive effort configuration, as previously discussed in regard to FIG. 1. Although FIG. 1 illustrates the individual devices 27, 29 coupled to three respective axles (30, 32, 34)(36, 38, 40) within the trucks 26, 28, the device 27 of the kit may be individually coupled to each powered axle (30, 34)(36, 40) of the pair of trucks 26, 28. Upon operatively coupling the device 27 to the respective axle 30, 34, 36, 40, the device 27 selectively imparts a force through the axles 30, 34, 36, 40 to dynamically vary the respective weight of the axles 30, 34, 36, 40 on the rail track to affect a traction performance of the locomotive 18 in the second tractive effort configuration traveling along the rail track. The device 27 may be operated using the controller 502 previously discussed in a previous embodiment of the present invention.

[0090] Additionally, the kit may include a mechanism configured to decouple an axle 32, 38 of a respective truck 26, 28 from the traction system of the locomotive 18. Such a mechanism may include any common tools appreciated by one of skill in the art that are utilized to remove one or more cables in the process of decoupling an axle 32, 38 from a traction system of the locomotive 18, for example.

[0091] In an exemplary embodiment, the locomotive 18 in the first tractive effort configuration is an AC-powered locomotive with each axle (30, 32, 34)(36, 38, 40) of the pair of trucks 26, 38 being coupled to a traction system of the AC-powered locomotive. In the exemplary embodiment, the locomotive 18 in the second tractive effort configuration exhibits a variable traction performance based on the mechanism having decoupled at least one (32)(38) non-powered axle of the pair of trucks 26, 28 from the traction system of the locomotive 18. Additionally, the variable traction performance is based on the dynamic variation of the respective weight of the

powered axles (30, 34)(36, 4) of the pair of trucks 26, 38 being coupled to the traction system.

[0092] The variable traction performance of the locomotive 18 in the second tractive effort configuration may be variably adjusted to an equivalent traction performance of a DC-powered locomotive with each axle of the pair of trucks being coupled to a traction system of the DC-powered locomotive. The pair of trucks 26, 28 of the locomotive 18 in the second tractive effort configuration include at least one (30, 34)(36, 40) powered axles coupled to the traction system and at least one non- powered axle (32)(38) decoupled from the traction system. The pair of trucks of the DC-powered locomotive include all axles being coupled to a traction system of the DC-powered locomotive. In the exemplary embodiment, the pair of trucks 26, 28 of the locomotive 18 in the second tractive effort configuration respectively includes two powered axles (30, 34)(36, 40) and one non-powered axle (32)(38). The pair of trucks of the DC-powered locomotive respectively include three powered axles. In the exemplary embodiment, the variable traction performance of the four powered axles (30, 34)(36, 40) of the locomotive 18 in the second tractive effort configuration is variably adjusted to exhibit an equivalent traction performance of the six powered axles of the DC-powered locomotive based upon dynamic variation of the respective weight of the four powered axles (30, 34)(36, 40). In the specific exemplary embodiment discussed above, the respective weight of each powered axle (30, 34)(36, 40) of the locomotive 18 in the second tractive effort configuration is dynamically varied to produce one and a half times the tractive effort of each powered axle of the DC-powered locomotive, for example.

[0093] FIG. 20 illustrates an exemplary embodiment of a method 700 for reconfiguring a locomotive 18 from a first tractive effort configuration to a second tractive effort configuration. The method begins (block 701) by respectively coupling

(block 702) a device 27 to a plurality of axles (30, 34)(36, 40) of the respective locomotive trucks 26, 28 in the second tractive effort configuration. Upon operatively coupling the device 27 to the respective axle (30, 34)(36, 40), the device 27 selectively imparts a force through the axle (30, 34)(36, 40) to dynamically vary the respective weight of the axle (30, 34)(36, 40) on the rail track to affect a traction performance of the locomotive 18 in the second tractive effort configuration traveling along the rail track, before ending at block 704.

[0094] The kit for reconfiguring the rail vehicle may provide various advantages upon installation, such as enhancing a traction performance of the locomotive in a second tractive effort configuration traveling along the rail track.

[0095] One embodiment relates to a kit for reconfiguring a rail vehicle from a first tractive effort configuration to a second tractive effort configuration. (The rail vehicle is configured to travel along a rail track, and has a plurality of axles with a plurality of wheels, the wheels being arranged to be in contact with the rail track.) The first tractive effort configuration of the rail vehicle includes a fixed respective weight of the plurality of axles on the rail track prior to the rail vehicle traveling along the rail track. In this embodiment, the kit includes a device configured to be respectively coupled to at least one of the plurality of axles in the second tractive effort configuration. Thus, upon operatively coupling the device to the respective axle, the device selectively imparts a force through the at least one axle to dynamically vary the respective weight of the at least one axle on the rail track to affect a traction performance of the rail vehicle in the second tractive effort configuration traveling along the rail track. The kit may also include a mechanism configured to decouple at least one of the plurality of axles from a traction system of the rail vehicle.

[0096] In another embodiment, the rail vehicle is a locomotive comprising a pair of trucks, with each truck having at least one axle of the plurality of axles. The first tractive effort configuration may include an AC-powered locomotive with each axle of the pair of trucks being coupled to a traction system of the AC-powered locomotive.

[0097] In another embodiment, the second tractive effort configuration includes the locomotive exhibiting a variable traction performance based upon the mechanism having decoupled at least one axle of the pair of trucks from the traction system of the locomotive and the dynamic variation of the respective weight of the axles of the pair of trucks being coupled to the traction system. The variable traction performance may be variably adjusted to a nominal equivalent traction performance of a DC-powered locomotive with each axle of the pair of trucks being coupled to a traction system of the DC-powered locomotive. The pair of trucks of the locomotive in the second tractive effort configuration may comprise at least one powered axle coupled to the traction system and at least one powered axle decoupled from the traction system. The pair of trucks of the DC-powered locomotive includes the plurality of powered axles coupled to a traction system of the DC-powered locomotive. Additionally, the pair of trucks of the locomotive in the second tractive effort configuration may respectively comprise two powered axles and one non- powered axle, and the pair of trucks of the DC-powered locomotive may respectively include three powered axles.

[0098] In another embodiment of the kit, the variable traction performance of the four powered axles of the locomotive in the second tractive effort configuration is variably adjusted to exhibit a nominal equivalent traction performance of the six powered axles of the DC-powered locomotive based upon dynamic variation of the respective weight of the at least one axle. The respective weight of each powered axle

of the locomotive in the second tractive effort configuration is dynamically varied to produce nominally one and a half times the tractive effort of each powered axle of the DC-powered locomotive.

[0099] In one embodiment, the device included in the kit is one or more hydraulic actuators to be respectively coupled to the at least one axle. The kit may also include a variable displacement pump that is configured to be respectively coupled to the hydraulic actuator upon coupling the hydraulic actuator to the respective axle. The variable displacement pump is configured to supply a pressurized hydraulic fluid at a selectively controlled pressure to the hydraulic actuator. Thus, upon coupling the hydraulic actuator to the respective axle, the hydraulic actuator is configured to selectively impart the force through the respective axle based upon the selectively controlled pressure. The kit may also include at least one control valve, which is to be respectively coupled to the variable displacement pump and the hydraulic actuator upon coupling the variable displacement pump to the hydraulic actuator. The control valve is configured to be selectively activated to control the force imparted through the respective axle.

[00100] In another embodiment, the kit includes a compliant member configured to be positioned such that the hydraulic actuator is to be coupled to the respective axle through the compliant member in a compliant manner. The kit may also include a pair of displacement limits configured to be coupled to the hydraulic actuator to limit the force selectively imparted on the respective axle.

[00101] In another embodiment, the kit includes a positive displacement pump, which is configured to be coupled to the hydraulic actuator upon coupling the hydraulic actuator to the respective axle. The positive displacement pump is configured to selectively control a position of the hydraulic actuator based upon

supplying a pressurized hydraulic fluid at a variable pressure to the hydraulic actuator. The hydraulic actuator is configured to selectively impart the force through the respective axle based upon the selectively controlled position of the hydraulic actuator.

[00102] In another embodiment, the device included in the kit is at least one pneumatic actuator to be respectively coupled to the at least one axle. The kit may also include a controlled pressure regulator, which is to be coupled to the pneumatic actuator upon coupling the at least one pneumatic actuator to the respective at least one axle. The controlled pressure regulator is configured to selectively control the force imparted by the pneumatic actuator based upon supplying pressurized air at a constant pressure to the pneumatic actuator, with the pneumatic actuator being configured to selectively impart the force through the respective axle. The kit may also include at least one control valve to be coupled to the controlled pressure regulator and the pneumatic actuator. In operation, the at least one control valve is selectively activated to control the position of the pneumatic actuator.

[00103] While the invention has been described herein with reference to various exemplary embodiments, it will be understood by those skilled in the art that various changes, omissions and/or additions may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.