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Title:
ELECTROMECHANICAL VARIABLE TRANSMISSION
Document Type and Number:
WIPO Patent Application WO/2011/163135
Kind Code:
A2
Abstract:
A vehicle drive includes a first gear set and a second gear set both having a sun gear, a ring gear and planetary gears which couple the sun gear to the ring gear. The planetary gears of both sets are rotatably supported by respective planetary gear carriers which are coupled to each other. The vehicle drive also includes an engine, a first clutch which selectively engages the engine to the ring gear of the first gear set, a first motor/generator coupled to the sun gear of the first gear set and a second motor/generator coupled to the sun gear of the second gear set and electrically coupled to the first motor/generator, a second clutch which selectively engages the engine to the second motor/generator, and a third clutch and a third gear set which operate to selectively engage the ring gear of the second gear set to the planetary gear carriers.

Inventors:
MORROW, Jon (1224 Kampo Court, Neenah, WI, 54956, US)
STEINBERGER, Dave (5180 Channel View Dr, Oshkosh, WI, 54902, US)
BRAUN, Eric (7075 Fahley Road, Oshkosh, WI, 54904, US)
KOTLOSKI, Andrew (297 N. Westhaven Dr, #Z201Oshkosh, WI, 54904, US)
NASR, Nader (3620 Park Lane Drive, Neenah, WI, 54956, US)
Application Number:
US2011/041089
Publication Date:
December 29, 2011
Filing Date:
June 20, 2011
Export Citation:
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Assignee:
OSHKOSH CORPORATION (2307 Oregon Street, Oshkosh, WI, 54901, US)
MORROW, Jon (1224 Kampo Court, Neenah, WI, 54956, US)
STEINBERGER, Dave (5180 Channel View Dr, Oshkosh, WI, 54902, US)
BRAUN, Eric (7075 Fahley Road, Oshkosh, WI, 54904, US)
KOTLOSKI, Andrew (297 N. Westhaven Dr, #Z201Oshkosh, WI, 54904, US)
NASR, Nader (3620 Park Lane Drive, Neenah, WI, 54956, US)
International Classes:
B60K6/445; B60K6/365; B60K6/52; F16H3/72; F16H37/08; F16H37/10
Attorney, Agent or Firm:
GUNDERSEN, Jeffrey, S. et al. (Foley & Lardner LLP, 777 E. Wisconsin AvenueMilwaukee, WI, 53202, US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A vehicle drive comprising:

a first gear set including a sun gear, a ring gear and planetary gears which couple the sun gear to the ring gear;

a second gear set including a sun gear, a ring gear and planetary gears which couple the sun gear to the ring gear, wherein the planetary gears of both sets are rotatably supported by respective planetary gear carriers which are coupled to each other;

an engine;

a first clutch which selectively engages the engine to the ring gear of the first gear set;

a first motor/generator coupled to the sun gear of the first gear set;

a second motor/generator coupled to the sun gear of the second gear set and electrically coupled to the first motor/generator;

a second clutch which selectively engages the engine to the second motor/generator; and

a third clutch and a third gear set which operate to selectively engage the ring gear of the second gear set to the planetary gear carriers.

2. The drive of claim 1, further comprising a fourth gear set including at least two gears which couple the first clutch to the ring gear of the first gear set.

3. The drive of claim 1, further comprising a fifth gear set including at least two gears which couple the second clutch to the second motor/generator.

4. The device of claim 1, wherein the third gear set includes a first pair of gears which couple the ring gear of the second gear set to the third clutch, and a second pair of gears which couple the third clutch to the planetary gear carriers.

5. The drive of claim 1, further comprising a brake mechanism for preventing rotation of the first motor/generator.

6. The drive of claim 1, further comprising a planetary gear set having at least a ring gear, wherein the planetary gear carriers are coupled to the ring gear of the planetary gear set.

7. A vehicle transmission, comprising:

a first planetary gear set having planetary gears;

a second planetary gear set having planetary gears directly coupled to the planetary gears of the first planetary gear set;

an engine rotationally coupled to the first planetary gear set; a first electromagnetic device rotationally coupled to the first planetary gear set; and

a second electromagnetic device rotationally coupled to the second planetary gear set and selectively rotationally engaged with the engine.

8. The transmission of claim 7, wherein the first electromagnetic device and the second electromagnetic device are electrically connected to one another to permit the transfer of electrical power between the electromagnetic devices.

9. The transmission of claim 7, wherein the second planetary gear set also includes a ring gear coupled to the planetary gears of the first planetary gear set.

10. The transmission of claim 9, wherein the first planetary gear set is coupled to at least one of a front axle and a rear axle of a vehicle.

11. The transmission of claim 10, wherein the second planetary gear set is selectively rotationally engaged with at least one of the front axle and the rear axle of the vehicle.

12. The transmission of claim 11 , wherein when the second planetary gear set is selectively rotationally engaged with at least one of the front axle and the rear axle of the vehicle, the second electromagnetic device is disengaged from the engine.

13. A vehicle having a drive train, comprising:

a dual-mode transmission comprising a first gear set and a second gear set; an engine coupled to the first gear set;

a first electromagnetic device coupled to the first gear set;

a second electromagnetic device coupled to the second gear set; and at least one drive axle coupled to the transmission;

wherein during a first mode of operation of the vehicle the second electromagnetic device is selectively coupled to the drive axle via the second gear set and during a second mode of operation of the vehicle the second electromagnetic device is selectively coupled to the engine.

14. The drive train of claim 13, wherein the first electromagnetic device and the second electromagnetic device are electrically connected to one another so that one of the first and second electromagnetic devices may provide electrical power to the other of the first and second electromagnetic devices.

15. The vehicle of claim 13, wherein the first mode of operation is a low speed mode of operation and the second mode of operation is a high speed mode of operation.

16. The vehicle of claim 13, wherein the transmission further comprises a third gear set that is coupled to the at least one drive axle of the vehicle.

17. The vehicle of claim 16, wherein the at least one drive axle is at least one of a front axle and rear axle.

18. A transmission for a vehicle, comprising:

a first gear set having a first gear configured to be coupled to an engine, a second gear configured to be coupled to a first electromechanical device, and a third gear configured to be rotationally engaged to a drive axle of the vehicle;

a second gear set having a first gear configured to be coupled to a second electromechanical device, a second gear configured to be coupled to the third gear of the first gear set, and a third gear configured to be selectively rotationally engaged with the drive axle of the vehicle.

19. The transmission of claim 18, further comprising a third gear set having a first gear rotationally engaged with the third gear of the first gear set and selectively rotationally engaged with the third gear of the second gear set.

20. The transmission of claim 19, wherein the first gear of the third gear set is selectively rotationally engaged with the third gear of the second gear set by a clutch.

Description:
ELECTROMECHANICAL VARIABLE TRANSMISSION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Application No. 12/820,928, filed June 22, 2010, which is incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR

DEVELOPMENT

[0002] The government of the United States has certain rights in this invention pursuant to Contract No. N0014-09-C-0601 awarded by the Office of Naval Research.

BACKGROUND

[0003] The present disclosure relates generally to the field of transmissions for vehicles. More specifically, the present disclosure relates to the field of electromechanical infinitely variable transmissions for vehicles.

SUMMARY

[0004] One exemplary embodiment relates to a vehicle drive including a first gear set including a sun gear, a ring gear and planetary gears which couple the sun gear to the ring gear. The vehicle drive also includes a second gear set including a sun gear, a ring gear and planetary gears which couple the sun gear to the ring gear. The planetary gears of both sets are rotatably supported by respective planetary gear carriers which are coupled to each other. The vehicle drive further includes an engine and a first clutch which selectively engages the engine to the ring gear of the first gear set. The vehicle drive still further includes a first motor/generator coupled to the sun gear of the first gear set and a second motor/generator coupled to the sun gear of the second gear set and electrically coupled to the first motor/generator. The vehicle drive still further includes a second clutch which selectively engages the engine to the second motor/generator and a third clutch and a third gear set which operate to selectively engage the ring gear of the second gear set to the planetary gear carriers. [0005] Another exemplary embodiment relates to a vehicle transmission including a first planetary gear set having planetary gears and a second planetary gear set having planetary gears directly coupled to the planetary gears of the first planetary gear set. The vehicle transmission also includes an engine rotationally coupled to the first planetary gear set. The vehicle transmission further includes a first electromagnetic device rotationally coupled to the first planetary gear set and a second electromagnetic device rotationally coupled to the second planetary gear set and selectively rotationally engaged with the engine.

[0006] Another exemplary embodiment relates to a vehicle having a drive train including a dual-mode transmission having a first gear set and a second gear set. The vehicle also includes an engine coupled to the first gear set. The vehicle further includes a first electromagnetic device coupled to the first gear set and a second electromagnetic device coupled to the second gear set. The vehicle still further includes at least one drive axle coupled to the transmission. During a first mode of operation of the vehicle the second electromagnetic device is selectively coupled to the drive axle via the second gear set and during a second mode of operation of the vehicle the second electromagnetic device is selectively coupled to the engine

[0007] Another exemplary embodiment relates to a transmission for a vehicle including a first gear set having a first gear configured to be coupled to an engine, a second gear configured to be coupled to a first electromechanical device, and a third gear configured to be rotationally engaged to a drive axle of the vehicle. The transmission also includes a second gear set having a first gear configured to be coupled to a second electromechanical device, a second gear configured to be coupled to the third gear of the first gear set, and a third gear configured to be selectively rotationally engaged with the drive axle of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a schematic view of drive train for a vehicle according to an exemplary embodiment.

[0009] FIG. 2 is a detailed schematic view of the drive train shown in FIG. 1 according to an exemplary embodiment.

[0010] FIG. 3 is a schematic diagram of a control system for the drive train shown in FIG. 1 according to an exemplary embodiment. DETAILED DESCRIPTION

[0011] Referring to FIG. 1, a schematic view of a drive train for a vehicle VI is shown according to an exemplary embodiment. The vehicle VI may be a work or commercial vehicle, a military vehicle, or any other type of vehicle.

[0012] According to an exemplary embodiment, the drive train includes an engine El coupled to a transmission Tl . The vehicle VI also includes a first electromagnetic device EMI coupled to the transmission Tl and a second electromagnetic device EM2 coupled to the transmission Tl . The vehicle VI also includes at least one drive axle (such as, e.g., rear axle RA1 and/or front axle FA1) coupled to the transmission Tl .

[0013] According to an exemplary embodiment, the engine El is configured to provide rotational mechanical energy to the transmission Tl . The engine El may be any source of rotational mechanical energy which is derived from a stored energy source such as a liquid or gaseous fuel. Examples are an internal combustion engine (such as a gas, natural gas, or diesel powered engine), turbine, fuel cell, electric motor or any other type of motor capable of providing rotational mechanical energy to the transmission Tl . According to one exemplary embodiment, the engine El is a twelve liter diesel engine capable of providing approximately 400 to 600 horsepower, 400-1500 ft-lbs of torque, and has a rotational speed of approximately 0 to 2100 rpm. According to one exemplary embodiment, the engine El is operated at a relatively constant speed (such as, e.g., 1600 rpm) to maximize fuel efficiency.

[0014] According to an exemplary embodiment, the electromagnetic devices EMI, EM2 are electric motor/generator devices that are capable of providing rotational electrical energy (as an electric motor) and/or capable of producing electrical power (as a generator). According to one exemplary embodiment, the electromagnetic devices EMI, EM2 provide electric power to one another, depending on the specific mode of operation of the vehicle VI . For example, the first electromagnetic device EMI may be operated as a generator to provide electric power to the second electromagnetic device EM2. Alternatively, the second electromagnetic device EM2 may be operated as a generator to provide electric power to the first electromagnetic device EMI.

[0015] According to one exemplary embodiment, the first electromagnetic device EMI and the second electromagnetic device EM2 may be the same (or similar) to one another. However, according to other exemplary embodiments, the first electromagnetic device EMI and the second electromagnetic device EM2 may be sized differently as required by a particular application. According to one exemplary embodiment, the electromagnetic devices EMI, EM2 are each capable of providing up to approximately 300 horsepower and 1300 ft-lbs of torque and are capable of rotational speeds from approximately -6,000 to 6,000 rpm (i.e., both forward and reverse from 0 to 6,000 rpm).

[0016] According to an exemplary embodiment, the transmission Tl is coupled to at least one drive axle of the vehicle VI (such as, e.g., rear axle RAl and/or front axle FA1 as shown in FIG. 1). According to one exemplary embodiment, both the rear axle RAl and the front axle FA1 are driven by the transmission Tl . According to other exemplary

embodiments, only one of the axles may be driven by the transmission Tl . According to yet another exemplary embodiment, additional axles (e.g., such as additional rear axles not shown) may be driven by the transmission Tl. According to an exemplary embodiment, each of the axles are coupled to the transmission via a differential gear set (such as, e.g., rear differential RD1 and/or front differential FD1 shown in FIG. 1). Each axle is configured to drive (i.e., provide rotational energy to) one or more wheels/tires to propel (e.g., move, push, drive etc.) the vehicle VI .

[0017] Referring now to FIG. 2, a detailed schematic view of the drive train for the vehicle VI is shown according to exemplary embodiment. As shown in FIG. 2, the transmission Tl includes two planetary gear sets. According to an exemplary embodiment, the transmission Tl includes a first planetary gear set PI and a second planetary gear set P2. A third planetary gear set P3 is provided as a torque divider (e.g., 30% torque to the front and 70% torque to the rear) if both the front and rear vehicle axles are powered.

[0018] According to one exemplary embodiment, the first planetary gear set PI is configured as a power split device or power splitting planetary gear set, the second planetary gear set P2 is configured as a gear reduction device, and the third planetary gear set P3 is configured as a torque proportioning device. As shown in FIG. 2, the first planetary gear set PI is coupled to the engine El, the first electromechanical device EMI, the second electromechanical device EM2 (via the second planetary gear set P2), and to gear G5. The second planetary gear set P2 is also coupled to the gear G5 (via gears G13, G14, G15, clutch C2 and shaft S6). [0019] As shown in FIG. 2, the engine El is coupled to a clutch C3 that is configured to selectively rotationally engage/disengage the engine El with the transmission Tl . The clutch C3 may be any type of clutch capable of rotationally fixing the engine El to the transmission Tl . When the clutch C3 is engaged, the engine El is coupled to a shaft SI . A gear G6 is coupled (e.g., rotationally fixed) to shaft SI and engages a gear G7 that is coupled (e.g., rotationally fixed) to a shaft S2. The gear G7 in turn is coupled to the first planetary gear set PI via the shaft S2.

[0020] As shown in FIG. 2, the first planetary gear set PI comprises an annulus or ring gear Gl which is coupled to the shaft S2. As shown, the clutch C3, the gears G6 and G7, and the shaft S2 cooperate to permit engine El to drive the ring gear Gl . The ring gear Gl is engaged with at least one planetary gear G2 (e.g., one, two, three, four or more planetary gears G2 that are coupled to one another (e.g., rotatably supported) by a planetary gear carrier PGC1). The planetary gear(s) G2 are engaged with a sun gear G3 of the first planetary gear set PI to couple the ring gear Gl to the sun gear G3.

[0021] The sun gear G3 is directly coupled to the first electromagnetic device EMI by a shaft S3. The first electromagnetic device EMI may be coupled to an optional brake Bl by a clutch C4. The clutch C4 may be any type of clutch capable of rotationally fixing the first electromagnetic device EMI to the brake Bl . The effect of braking the first

electromechanical device EMI is to fix or hold sun gear G3 without the need to apply electrical energy to the first electromechanical device EMI to cause the first

electromechanical device EMI to generate enough holding torque to hold the gear G3 from rotating.

[0022] According to an exemplary embodiment, the planetary gear carrier PGC 1 is coupled to a carrier gear G4. The carrier gear G4 is engaged with a gear G5. In the preferred embodiment of vehicle VI, the gear G5 is part of the third planetary gear set P3 used to divide the power from the transmission Tl to the front and rear axles. In this embodiment, the gear G5 is coupled to the planetary gears of the third planetary gear set P3. If only a single axle is driven by the transmission Tl, or a different transfer device is used to drive more than one axle, the third planetary gear set P3 may not be necessary.

[0023] The carrier gear G4 is also coupled to the second planetary gear set P2 by a shaft S5 (as will be described in more detail below). [0024] Still referring to FIG. 2, the transmission Tl also includes a clutch CI that selectively rotationally engages/disengages the engine El to the second electromagnetic device EM2. The clutch CI may be any type of clutch capable of rotationally fixing the engine El to the second electromagnetic device EM2, such as a wet clutch.

[0025] As shown in FIG. 2, the clutch CI is coupled to the engine El by the shaft SI . When the clutch CI is engaged, the shaft SI is coupled to a gear G9. The gear G9 in turn is engaged with a gear G8 that is coupled to the second electromagnetic device EM2. Thus, when the clutch CI is engaged, the engine is coupled to the second electromagnetic device EM2 to allow the second electromagnetic device EM2 to be driven as a generator (e.g., to provide electrical power to the first electromagnetic device EMI).

[0026] The electromagnetic device EM2 is also coupled to the second planetary gear set P2 by a shaft S4. The shaft S4 is connected to a sun gear G12 of the second planetary gear set P2. The sun gear G12 is engaged with at least one planetary gear Gl 1 (e.g., one, two, three, four or more planetary gears Gl 1 that are coupled to one another (e.g., rotatably supported) by a planetary gear carrier PGC2). The planetary gear(s) Gl 1 in turn are engaged with an annulus or ring gear G10 to couple the sun gear G12 to the ring gear G10.

[0027] According to an exemplary embodiment, the planet gear carrier PGC2 of the second planetary gear P2 is coupled to the carrier gear G4 (and the planet gear carrier PGC1) of the first planetary gear set PI by a shaft S5. Thus, the planet gear carrier PGC1 and the planet gear carrier PGC2 are coupled to one another so that the second

electromagnetic device EM2 is coupled to the first planetary gear set PI via the second planetary gear set P2.

[0028] The second electromagnetic device EM2 is also coupled to the third planetary gear set P3 via the second planetary gear set P2. According to an exemplary embodiment, the ring gear G10 of the second planetary gear P2 is coupled to an output gear G13 that is engaged with an idler gear G14. The idler gear G14 in turn is engaged with a gear G15 that is selectively engaged/disengaged to the third planetary gear set P3 by a clutch C2 (via a shaft S6). The clutch C2 may be any type of clutch capable of rotationally fixing the gear G15 to the shaft S6, such as a wet clutch.

[0029] According to an exemplary embodiment, the third planetary gear set P3 is a torque proportioning device for the front and rear axles of the vehicle VI . Torque is delivered from the third planetary gear set P3 to the front axle FAl and/or the rear axle RAl via shafts S7 and S8. As discussed above, in other exemplary embodiments, the third planetary gear set P3 is not necessary when either the front axle FAl or rear axle RAl of the vehicle VI is not driven by the transmission Tl .

[0030] According to an exemplary embodiment, the transmission Tl is operated in a low speed mode (e.g., a vehicle speed of approximately 0-10 mph) by having the clutch C2 engaged and the clutch C 1 disengaged. According to another exemplary embodiment, the transmission Tl is operated in a high speed mode (e.g., a vehicle speed of approximately 10-65 mph) by having the clutch CI engaged and the clutch C2 disengaged. According to other various embodiments, the vehicle speeds in the low and high speed modes may vary higher or lower.

[0031] According to an exemplary embodiment, an operator (e.g., driver) of vehicle VI may manually switch the transmission Tl from low speed mode to high speed mode or vice- versa. According to another exemplary embodiment, the transmission Tl is automatically switched from low speed mode to high speed mode (and vice-versa) by a control system (see, e.g., FIG. 3). The control system may include various operator inputs (such as, e.g., desired vehicle speed, torque, traction, terrain, etc.) and also various system inputs (such as, e.g., current vehicle speed, engine speed, power, and torque, electromagnetic device speed, power, and torque, etc.). As shown in FIG. 3, according to one exemplary embodiment, the control system is configured to monitor and/or control the engine, the mode of the transmission, the first electromagnetic device EMI, the second electromagnetic device EM2, the clutch CI, the clutch C2, and/or the clutch C3.

[0032] According to an exemplary embodiment, gears within the transmission Tl are sized according to the specific application and desired performance characteristics of the vehicle VI . According to one exemplary embodiment, the gears within the transmission Tl have tooth counts as shown in Table 1. However, according to other exemplary

embodiments, the tooth counts of the gears may vary more or less than that shown.

According to other exemplary embodiments, the engine El, the electromagnetic devices EMI and EM2, the clutches C1-C4, and the shafts S1-S8 may all vary according to the specific application and desired performance characteristics of the vehicle VI . Table 1.

[0033] It should be noted that references to "front," "rear," "top," and "base" in this description are merely used to identify various elements as are oriented in the FIGS., with "front" and "rear" being relative to the environment in which the device is provided.

[0034] For the purpose of this disclosure, the term "coupled" means the joining of two members directly or indirectly to one another. Such joining may be stationary or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature.

[0035] It is important to note that the construction and arrangement of the

electromechanical variable transmission as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (for example, variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting

arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative

embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present embodiments.