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Title:
ELECTRIC AXLE TRANSMISSION WITH A BALL VARIATOR CONTINUOUSLY VARIABLE PLANETARY TRANSMISSION WITH AND WITHOUT TORQUE VECTORING FOR ELECTRIC AND HYBRID ELECTRIC VEHICLES
Document Type and Number:
WIPO Patent Application WO/2018/045146
Kind Code:
A1
Abstract:
An electric axle powertrains having a continuously variable electric drivetrain comprising a motor/generator and a ball-type continuously variable planetary having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls; a drive wheel axle operably coupled to the continuously variable electric drivetrain; and a first wheel and a second wheel coupled to the drive wheel axle. In some embodiments, the continuously variable electric drivetrains include one or more gear sets to provide power paths that reduce torque through the ball-type continuously variable planetary. In some embodiments, the continuously variable electric drivetrains include gearing configurations to reduce speed through the ball-type continuously variable planetary. In some embodiments, the electric axles are provided with gearing configurations that enable torque vectoring.

Inventors:
KUMAR, Krishna (7420 Nightingale Drive, Holland, OH, 43528, US)
MCINDOE, Gordon, M. (15304 Randolph Street, Volente, TX, 78641, US)
MILLER, Travis, J. (2930 Grand Oaks Loop #202, Cedar Park, TX, 78613, US)
WALTZ, William, F. (3514 Northwood Avenue, Toledo, OH, 43613, US)
WESOLOWSKI, Steven, J. (8089 Silverstone Drive, Waterville, OH, 43566, US)
Application Number:
US2017/049567
Publication Date:
March 08, 2018
Filing Date:
August 31, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
DANA LIMITED (3939 Technology Drive, PO Box 1000Maumee, OH, 43537, US)
International Classes:
B60K1/00; B60K17/02; B60K17/04; F16H15/28; F16H15/40; F16H15/52
Domestic Patent References:
WO2014039447A12014-03-13
WO2014179719A12014-11-06
WO2014039901A12014-03-13
Foreign References:
DE102013016441A12015-04-02
US20150252881A12015-09-10
US20140274536A12014-09-18
US20150204429A12015-07-23
US20080121487A12008-05-29
US8469856B22013-06-25
US8870711B22014-10-28
Attorney, Agent or Firm:
EVANS, Stephen, P. et al. (Marshall & Melhorn LLC, Four SeaGate- 8th FloorToledo, OH, 43604, US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. An electric axle powertrain comprising:

a continuously variable electric drivetrain comprising a motor/generator, a ball-type continuously variable planetary having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls;

a first clutch operably coupled to the motor/generator and the first traction ring assembly;

a drive wheel axle operably coupled to the continuously variable electric drivetrain; and

a first wheel and a second wheel coupled to the drive wheel axle.

2. The electric axle powertrain of Claim 1 , wherein the first clutch is configured to selectively engage a first gear set having a first gear ratio and a second gear set having a second gear ratio.

3. The electric axle powertrain of Claim 1 , further comprising a differential coupled to the continuously variable electric drivetrain and the drive wheel axle.

4. The electric axle powertrain of Claim 2, wherein the continuously variable electric drivetrain further comprises a third gear set operably coupled to the second traction ring assembly, wherein the third gear set is configured to transmit power in or out of the continuously variable electric drivetrain.

5. The electric axle powertrain of Claim 1 further comprising a first gear set operably coupled to the second traction ring assembly and a second gear set operably coupled to the first gear set, wherein the second gear set is configured to transmit power in or out of the continuously variable electric drivetrain.

6. The electric axle powertrain of Claim 1 further comprising a first planetary gear set operabiy coupled to the second traction ring assembly, the first planetary gear set having a first ring gear, a first planet carrier and a first sun gear, wherein the first sun gear is operabiy coupled to the second traction ring, wherein the first ring gear is a grounded member, and wherein the first planet carrier is configured to transmit power in or out of the continuously variable electric drivetrain.

7. The electric axle powertrain of Claim 1 , further comprising:

a first planetary gear set operabiy coupled to the motor/generator, the first planetary gear set having a first ring gear, a first planet carrier and a first sun gear, wherein the first ring gear is operabiy coupled to the first traction ring assembly; and

a second clutch operabiy coupled to the first ring gear and the second traction ring,

wherein the first clutch is operabiy coupled to the first ring gear, wherein the motor/generator is operabiy coupled to the first sun gear, and

wherein the first planet carrier is a grounded member.

8. The electric axle powertrain of Claim 1 , further comprising:

a first planetary gear set operabiy coupled to the motor/generator, the first planetary gear set having a first ring gear, a first planet carrier and a first sun gear,

wherein the first ring gear is operabiy coupled to the first traction ring assembly,

wherein the first clutch is operabiy coupled to the first ring gear, wherein the first sun gear is operabiy coupled to the second traction ring assembly, and

wherein the motor/generator is operabiy coupled to the first planet carrier.

9. The electric axle powertrain of Claim 8, further comprising a second clutch operably coupled to the second traction ring.

10. The electric axle powertrain of Claim 8, further comprising:

a second planetary gear set having a second sun gear operably coupled to the first ring gear, a second planet carrier operably couple to the first wheel, and a second ring gear operably coupled to a first brake; and

a third planetary gear set having a third sun gear operably coupled to the second traction ring assembly, a third planet carrier operably coupled to the second wheel, and a third ring gear operably coupled to a second brake.

1 . The electric axle powertrain of Claim 10, further comprising a second clutch operably coupled to the second traction ring and the second sun gear.

12. An electric axle powertrain comprising:

a continuously variable electric drivetrain comprising a motor/generator and a ball-type continuously variable planetary having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls;

a drive wheel axle operably coupled to the continuously variable electric drivetrain;

a first wheel and a second wheel coupled to the drive wheel axle; and a first planetary gear set operably coupled to the motor/generator, the first planetary gear set having a first ring gear, a first planet carrier and a first sun gear,

wherein the first planet carrier is operably coupled to the first traction ring assembly.

13. The electric axle powertrain of Claim 12, further comprising a first clutch and a second clutch, wherein the first ring gear is operably coupled to the first clutch and the second clutch, the first planet carrier operably coupled to the second clutch, and the first sun gear operably coupled to the motor/ generator.

14. The electric axle powertrain of Claim 12, further comprising:

a second planetary gear set having a second ring gear, a second planet carrier, and a second sun gear;

a first clutch is operably coupled to the second planet carrier and the first planet carrier; and

a second clutch is operably coupled to the second traction ring assembly and the first planet carrier,

wherein the second sun gear is operably coupled to the second traction ring assembly, and

wherein the second ring gear is operably coupled to the first traction ring assembly.

15. An electric axle powertrain comprising:

a continuously variable electric drivetrain comprising a motor/generator and a ball-type continuously variable planetary having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls;

a drive wheel axle operably coupled to the continuously variable electric drivetrain;

a first wheel and a second wheel coupled to the drive wheel axle; and a first planetary gear set operably coupled to the motor/generator, the first planetary gear set having a first ring gear, a first planet carrier and a first sun gear,

wherein the first ring gear is operably coupled to the first traction ring assembly.

16. The electric axle powertrain of Claim 15, further comprising:

a first clutch is operably coupled to the first planet carrier; and

a second clutch is operably coupled to the first ring gear and the first planet carrier,

wherein the first sun gear is operably coupled to the motor/generator.

17. The electric axle powertrain of Claim 15, further comprising:

a first clutch operably coupled to the motor/generator and the first planet carrier;

a second clutch operably coupled to the first sun gear and the

motor/generator;

a first brake operably coupled to the first planet carrier; and

a third clutch operably coupled to the first sun gear and the second traction ring assembly.

18. The electric axle powertrain of Claim 15, further comprising:

a first clutch operably coupled to the motor/generator and the first planet carrier;

a second clutch operably coupled to the first sun gear and the

motor/generator;

a third clutch operably coupled to the first sun gear and the second traction ring assembly;

a fourth clutch operably coupled to the first ring gear and the first traction ring assembly;

a fifth clutch operably coupled to the first planet carrier and the first traction ring assembly; and

a first brake operably coupled to the first ring gear.

19. The electric axle powertrain of Claim 15, further comprising:

a second planetary gear set having a second ring gear, a second planet carrier, and a second sun gear;

a first clutch is operably coupled to the first ring gear and the second planet carrier; and

a second clutch is operably coupled to the second traction ring assembly and the first ring gear,

wherein the second sun gear is operably coupled to the second traction ring assembly, and

wherein the motor/generator is operably coupled to the first sun gear.

Description:
ELECTRIC AXLE TRANSMISSION WITH A BALL VARIATOR

CONTINUOUSLY VARIABLE PLANETARY TRANSMISSION WITH AND WITHOUT TORQUE VECTORING FOR ELECTRIC AND HYBRID ELECTRIC VEHICLES

RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application No. 62/381 ,675 filed on August 31 , 2016, U.S. Provisional Application No. 62/381 ,682 filed on August 31 , 2016, U.S. Provisional Application No.

62/381 ,693 filed on August 31 , 2016, U.S. Provisional Application No.

62/428,127 filed on November 30, 2016, U.S. Provisional Application No.

62/434,015 filed on December 14, 2016, and U.S. Provisional Application No. 62/452,714 filed on January 31 , 2017, which are incorporated herein by reference in their entirety.

BACKGROUND

Hybrid vehicles are enjoying increased popularity and acceptance due in large part to the cost of fuel and greenhouse carbon emission government regulations for internal combustion engine vehicles. Such hybrid vehicles include both an internal combustion engine as well as an electric motor to propel the vehicle.

In current electric axle designs for both consuming as well as storing electrical energy, the rotary shaft from a combination electric motor/generator is coupled by a gear train, planetary gear set, to the wheel. As such, the rotary shaft for the electric motor/generator unit rotates in unison with the wheel based on the speed ratio of the gear train.

These fixed ratio designs have many disadvantages, for example, the electric motor/generator unit achieves its most efficient operation, both in the sense of generating electricity and also providing additional power to the wheel or the main shaft of the internal combustion engine, only within a relatively narrow range of revolutions per minute of the motor/generator unit. As such, the overall electric or hybrid electric vehicle operates at less than optimal efficiency over a drive cycle. Therefore, there is a need for powertrain configurations that improve the efficiency of electric and hybrid electric vehicles.

SUMMARY

Provided herein is an electric axle powertrain including: a continuously variable electric drivetrain including a motor/generator and a ball-type continuously variable planetary having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls; a first clutch operably coupled to the motor/generator and the first traction ring assembly; a drive wheel axle operably coupled to the continuously variable electric drivetrain; and a first wheel and a second wheel coupled to the drive wheel axle.

Provided herein is an electric axle powertrain including: a continuously variable electric drivetrain including a motor/generator and a ball-type continuously variable planetary having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls; a drive wheel axle operably coupled to the continuously variable electric drivetrain; a first wheel and a second wheel coupled to the drive wheel axle; and a first planetary gear set operably coupled to the motor/generator, the first planetary gear set having a first ring gear, a first planet carrier and a first sun gear, wherein the first planet carrier is operably coupled to the first traction ring assembly.

Provided herein is an electric axle powertrain including: a continuously variable electric drivetrain including a motor/generator and a ball-type continuously variable planetary having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls; a drive wheel axle operably coupled to the continuously variable electric drivetrain; a first wheel and a second wheel coupled to the drive wheel axle; and a first planetary gear set operably coupled to the motor/generator, the first planetary gear set having a first ring gear, a first planet carrier and a first sun gear, wherein the first ring gear is operably coupled to the first traction ring assembly. INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

Novel features of the preferred embodiments are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present embodiments will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the preferred embodiments are utilized, and the accompanying drawings of which:

Figure 1 is a side sectional view of a ball-type variator.

Figure 2 is a plan view of a carrier member that is used in the variator of

Figure 1.

Figure 3 is an illustrative view of different tilt positions of the ball-type variator of Figure 1.

Figure 4 is a schematic diagram of an electric axle powertrain having a continuously variable electric drivetrain drivingly engaged to a differential, axle, and wheels of a vehicle.

Figure 5 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a clutch, and multiple gear sets.

Figure 6 is a lever diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, two clutches, and a planetary gear set.

Figure 7 is a lever diagram of another continuously variable electric drivetrain having a ball-type continuously variable planetary, two clutches, and a planetary gear set.

Figure 8 is a schematic diagram of a continuously variable electric drivetrain having a clutch, two gear sets, a ball-type continuously variable planetary, and a motor/generator. Figure 9 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a planetary gear set, a clutch, and a motor/generator.

Figure 10 is a schematic diagram of a continuously variable electric drivetrain (CVED) having a ball-type continuously variable planetary, a planetary gear set, a motor/generator, a brake, and three clutches.

Figure 11 is a table depicting operating modes of the CVED of Figure

10.

Figure 12 is a schematic diagram of a continuously variable electric drivetrain (CVED) having a ball-type continuously variable planetary, a planetary gear set, a motor/generator, a brake, and five clutches.

Figure 13 is a table depicting operating modes of the CVED of Figure

12.

Figure 14 is a schematic diagram of a continuously variable electric drivetrain (CVED) having a ball-type continuously variable planetary, a planetary gear set, a motor/generator, a clutch, and a directional one-way clutch.

Figure 15 is a schematic diagram of another continuously variable electric drivetrain (CVED) having a ball-type continuously variable planetary, a planetary gear set, a motor/generator, a clutch, and a directional one-way clutch.

Figure 16 is a schematic diagram of yet another continuously variable electric drivetrain (CVED) having a ball-type continuously variable planetary, a planetary gear set, a motor/generator, a clutch, and a directional one-way clutch.

Figure 17 is a schematic diagram of yet another continuously variable electric drivetrain (CVED) having a ball-type continuously variable planetary, a planetary gear set, a motor/generator, a clutch, and a directional one-way clutch.

Figure 8 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a planetary gear set, a clutch, and a motor/generator. Figure 19 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a planetary gear set, two clutches, and a motor/generator.

Figure 20 is a schematic diagram of a powertrain having the

continuously variable electric drivetrain of Figure 19, two planetary gear sets, and two brakes.

Figure 21 is a schematic diagram of a powertrain having the

continuously variable electric drivetrain of Figure 20, two planetary gear sets, and two brakes.

Figure 22 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a motor/generator, and a two selectable gear sets.

Figure 23 is a schematic diagram of another continuously variable electric drivetrain having a ball-type continuously variable planetary, a motor/generator, and a two selectable gear sets.

Figure 24 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a motor/generator, and a selectable gear set for forward and neutral.

Figure 25 is a schematic diagram of another continuously variable electric drivetrain having a ball-type continuously variable planetary, a motor/generator, and a selectable gear set for forward and neutral.

Figure 26 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a motor/generator, two planetary gear sets, and selectable forward and neutral.

Figure 27 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, a motor/generator, a planetary gear set and selectable forward and neutral.

Figure 28 is a schematic diagram of a continuously variable electric drivetrain having a ball-type continuously variable planetary, two

motor/generators, and a fixed ratio gear set. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS This powertrain relates to electric powertrain configurations and architectures that will be used in hybrid vehicles. The powertrain and/or drivetrain configurations use a ball planetary style continuously variable transmission, such as the VariGlide ® , in order to couple power sources used in a hybrid vehicle, for example, combustion engines (internal or external), motors, generators, batteries, and gearing. The powertrains disclosed herein are applicable to HEV, EV and Fuel Cell Hybrid systems.

A typical ball planetary variator CVT design, such as that described in United States Patent Publication No. 2008/0121487 and in United States

Patent No. 8,469,856, both incorporated herein by reference in their entirety, represents a rolling traction drive system, transmitting forces between the input and output rolling surfaces through shearing of a thin fluid film. The technology is called Continuously Variable Planetary (CVP) due to its analogous operation to a planetary gear system. The system includes an input disc (ring) driven by the power source, an output disc (ring) driving the CVP output, a set of balls fitted between these two discs and a central sun, as illustrated in Figure 1. The balls are able to rotate around their own respective axle by the rotation of two carrier disks at each end of the set of balls axles. The system is also referred to as the Ball-Type Variator.

The preferred embodiments will now be described with reference to the accompanying figures, wherein like numerals refer to like elements throughout. The terminology used in the descriptions below is not to be interpreted in any limited or restrictive manner simply because it is used in conjunction with detailed descriptions of certain specific embodiments. Furthermore,

embodiments disclosed herein include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the embodiments described.

Provided herein are configurations of CVTs based on a ball type variators, also known as CVP, for continuously variable planetary. Basic concepts of a ball type Continuously Variable Transmissions are described in United States Patent No. 8,469,856 and 8,870,711 incorporated herein by reference in their entirety. Such a CVT, adapted herein as described throughout this specification, includes a number of balls (planets, spheres) 1 , depending on the application, two ring (disc) assemblies with a conical surface contact with the balls, as input 2 and output 3, and an idler (sun) assembly 4 as shown on FIG. 1. Sometimes, the input ring 2 is referred to in illustrations and referred to in text by the label "r1". The output ring is referred to in illustrations and referred to in text by the label "r2". The idler (sun) assembly is referred to in illustrations and referred to in text by the label "s". The balls are mounted on tiltable axles 5, themselves held in a carrier (stator, cage) assembly having a first carrier member 6 operably coupled to a second carrier member 7. Sometimes, the carrier assembly is denoted in illustrations and referred to in text by the label "c". These labels are collectively referred to as nodes ("r1", "r2", "s", "c"). The first carrier member 6 rotates with respect to the second carrier member 7, and vice versa. In some embodiments, the first carrier member 6 is substantially fixed from rotation while the second carrier member 7 is configured to rotate with respect to the first carrier member, and vice versa. In one embodiment, the first carrier member 6 is provided with a number of radial guide slots 8. The second carrier member 7 is provided with a number of radially offset guide slots 9, as illustrated in FIG. 2. The radial guide slots 8 and the radially offset guide slots 9 are adapted to guide the tiltable axles 5. The axles 5 are adjusted to achieve a desired ratio of input speed to output speed during operation of the CVT. In some embodiments, adjustment of the axles 5 involves control of the position of the first and second carrier members to impart a tilting of the axles 5 and thereby adjusts the speed ratio of the variator. Other types of ball CVTs also exist, like the one produced by Milner, but are slightly different.

The working principle of such a CVP of FIG. 1 is shown on FIG. 3. The CVP itself works with a traction fluid. The lubricant between the ball and the conical rings acts as a solid at high pressure, transferring the power from the input ring, through the balls, to the output ring. By tilting the balls' axes, the ratio is changed between input and output. When the axis is horizontal the ratio is one, illustrated in FIG. 3, when the axis is tilted the distance between the axis and the contact point change, modifying the overall ratio. All the balls' axes are tilted at the same time with a mechanism included in the carrier and/or idler. Embodiments of the disclosed here are related to the control of a variator and/or a CVT using generally spherical planets each having a tiltable axis of rotation that is adjusted to achieve a desired ratio of input speed to output speed during operation. In some embodiments, adjustment of said axis of rotation involves angular misalignment of the planet axis in a first plane in order to achieve an angular adjustment of the planet axis in a second plane that is substantially perpendicular to the first plane, thereby adjusting the speed ratio of the variator. The angular misalignment in the first plane is referred to here as "skew", "skew angle", and/or "skew condition". In one embodiment, a control system coordinates the use of a skew angle to generate forces between certain contacting components in the variator that will tilt the planet axis of rotation. The tilting of the planet axis of rotation adjusts the speed ratio of the variator.

As used here, the terms "operationally connected," "operationally coupled", "operationally linked", "operably connected", "operably coupled", "operably linked," and like terms, refer to a relationship (mechanical, linkage, coupling, etc.) between elements whereby operation of one element results in a corresponding, following, or simultaneous operation or actuation of a second element. It is noted that in using said terms to describe inventive

embodiments, specific structures or mechanisms that Jink or couple the elements are typically described. However, unless otherwise specifically stated, when one of said terms is used, the term indicates that the actual linkage or coupling is capable of taking a variety of forms, which in certain instances will be readily apparent to a person of ordinary skill in the relevant technology.

It should be noted that reference herein to "traction" does not exclude applications where the dominant or exclusive mode of power transfer is through "friction." Without attempting to establish a categorical difference between traction and friction drives here, generally these will be understood as different regimes of power transfer. Traction drives usually involve the transfer of power between two elements by shear forces in a thin fluid layer trapped between the elements. The fluids used in these applications usually exhibit traction coefficients greater than conventional mineral oils. The traction coefficient (μ) represents the maximum available traction force which would be available at the interfaces of the contacting components and is the ratio of the maximum available drive torque per contact force. Typically, friction drives generally relate to transferring power between two elements by frictional forces between the elements. For the purposes of this disclosure, it should be understood that the CVTs described here are capable of operating in both tractive and frictional applications. For example, in the embodiment where a CVT is used for a bicycle application, the CVT operates at times as a friction drive and at other times as a traction drive, depending on the torque and speed conditions present during operation.

Embodiments disclosed herein are directed to hybrid vehicle

architectures and/or configurations that incorporate a CVP in place of or in addition to a regular fixed ratio planetary leading to a continuously variable electric axle or hybrid electrical vehicle drivetrain. It should be appreciated that the embodiments disclosed herein are adapted to provide hybrid modes of operation that include, but are not limited to series, parallel, series-parallel, or EV (electric vehicle) modes. The core element of the power flow is a CVP, such as a VariGlide ® , which functions as a continuously variable transmission having four nodes (r1 , r2, c, and s). The CVP enables the electric machines (motor/generators, among others) to run at an optimized overall efficiency. It should be noted that hydro-mechanical components such as hydromotors, pumps, accumulators, among others, are capable of being used in place of the electric machines indicated in the figures and accompanying textual

description. Furthermore, it should be noted that embodiments of E-axle architectures disclosed herein could incorporate a supervisory controller that chooses the CVP ratio of highest efficiency and/or power from motor/generator to wheel. Embodiments disclosed herein enable hybrid powertrains that are capable of operating at the best potential overall efficiency point in any mode and also provide torque variability, thereby leading to the optimal combination of powertrain performance and efficiency. It should be understood that electric or hybrid electric vehicles incorporating embodiments of the hybrid

architectures disclosed herein are capable of including a number of other powertrain components, such as, but not limited to, high-voltage battery pack with a battery management system or ultracapacitor, on-board charger, DC-DC converters, a variety of sensors, actuators, and controllers, among others.

For purposes of description, schematics referred to as lever diagrams are used herein. A lever diagram, also known as a lever analogy diagram, is a translational-system representation of rotating parts for a planetary gear system. In certain embodiments, a lever diagram is provided as a visual aid in describing the functions of the transmission. In a lever diagram, a compound planetary gear set is often represented by a single vertical line ("lever"). The input, output, and reaction torques are represented by horizontal forces on the lever. The lever motion, relative to the reaction point, represents direction of rotational velocities. For example, a typical planetary gear set having a ring gear, a planet carrier, and a sun gear is represented by a vertical line having nodes "R" representing the ring gear, node "S" representing the sun gear, and node "C" representing the planet carrier. It should be appreciated that any mechanical coupling is depicted on a lever diagram as a node or a solid dot.

For example, a node represents two components in a drivetrain that are rigidly connected.

Referring to FIG. 4, in some embodiments, an electric axle powertrain 10 includes a continuously variable electric drivetrain 12 operably coupled to a differential 13. In some embodiments, the differential 13 is a common differential gear set implemented to transmit rotational power. The differential 13 is operably coupled to a wheel drive axle 14 configured to drive a set of vehicle wheels 5 (labeled as 5Α" and "15B" in FIG. 4).

Moving now to FIG. 5, in some embodiments, a continuously variable electric drivetrain (CVED) 20 is optionally used with the electric axle

powertrains depicted in FIG. 4. The CVED 20 includes a motor/generator 21 and a ball-type continuously variable planetary 22 having a first traction ring assembly 23 and a second traction ring assembly 24. In some embodiments, the CVED 20 includes a clutch 25 configured to selectively engage a first gear set 26 or a second gear set 27. The first gear set 26 and the second gear set 27 are operably coupled to the motor/generator 21. The clutch 25 is coupled to the first traction ring assembly 23. The CVED 20 is provided with a third gear set 28 operably coupled to the second traction ring assembly 24. The third gear set 28 is configured to transmit power in or out of the CVED 20.

Referring now to FIG. 6, in some embodiments, a continuously variable electric drivetrain (CVED) 30 is optionally used with the electric axle

powertrains depicted in FIG. 4. The CVED 30 includes a motor/generator 31 and a ball-type continuously variable planetary 32 having a first traction ring assembly 33 and a second traction ring assembly 34. The CVED 30 is provided with a planetary gear set 35 having a ring gear 36, a planet carrier 37, and a sun gear 38. The sun gear 38 is operably coupled to the

motor/generator 31. In some embodiments, the CVED 30 is provided with a first clutch 39 operably coupled to the ring gear 36. The first clutch 39 is configured to selectively engage the ring gear 36 to ground. The CVED 30 is provided with a second clutch 40 operably coupled to the ring gear 36 and the planet carrier 37. The second clutch 40 is configured to selectively couple the ring gear 36 to the planet carrier 37. The planet carrier 37 is operably coupled to the first traction ring assembly 33. The second traction ring assembly 34 is configured to transmit power in or out of the CVED 30.

Turning now to FIG. 7, in some embodiments, a continuously variable electric drivetrain (CVED) 41 is optionally used with the electric axle

powertrains depicted in FIG. 4. The CVED 41 includes a motor/generator 42 and a ball-type continuously variable planetary 43 having a first traction ring assembly 44 and a second traction ring assembly 45. The CVED 41 is provided with a planetary gear set 46 having a ring gear 47, a planet carrier 48, and a sun gear 49. The sun gear 49 is operably coupled to the motor/ generator 42. In some embodiments, the CVED 41 is provided with a first clutch 56 operably coupled to the planet carrier 48. The first clutch 56 is configured to selectively engage the planet carrier 48 to ground. The CVED 41 is provided with a second clutch 51 operably coupled to the ring gear 47 and the planet carrier 48. The second clutch 51 is configured to selectively couple the ring gear 47 to the planet carrier 48. The ring gear 47 is operably coupled to the first traction ring assembly 44. The second traction ring assembly 45 is configured to transmit power in or out of the CVED 41. Referring now to FIG. 8, in some embodiments, a continuously variable electric drivetrain (CVED) 52 is optionally used in the embodiments of electric axles disclosed herein. The CVED 52 includes a motor/generator 53 and a ball-type continuously variable planetary 54 having a first traction ring assembly 55 and a second traction ring assembly 56. In some embodiments, the motor/generator 53 is operably coupled to a clutch 57. The clutch 57 is operably coupled to the first traction ring assembly 55. The CVED 52 includes a first gear set 58 operably coupled to the second traction ring assembly 56 and a second gear set 59 operably coupled to the first gear set 58. It should be appreciated that any number of fixed ratio gear sets are optionally configured to transmit power in and out of the second traction ring assembly 56.

Turning now to FIG. 9, in some embodiments, a continuously variable electric drivetrain (CVED) 60 is optionally used in the embodiments of electric axles disclosed herein. The CVED 60 includes a motor/generator 6 and a ball-type continuously variable planetary 62 having a first traction ring assembly 63 and a second traction ring assembly 64. In some embodiments, the CVED 60 includes a clutch 65 operably coupled to the motor/generator 61 . The clutch 65 is coupled to the first traction ring assembly 63. The CVED 60 includes a planetary gear set 66 operably coupled to the second traction ring assembly 64. The planetary gear set 66 is provided with a ring gear 67, a planet carrier 48, and a sun gear 69. In some embodiments, the ring gear 67 is a grounded member, the sun gear 69 is coupled to the second traction ring assembly 64, and the planet carrier 68 is configured to transmit power in or out of the CVED 60.

Referring now to FIG. 10, in some embodiments, a continuously variable electric drivetrain (CVED) 70 is optionally used in the embodiments of electric axles disclosed herein. The CVED 70 includes a motor/generator 71 and a ball-type continuously variable planetary 72 having a first traction ring assembly 73 and a second traction ring assembly 74. The CVED 70 includes a planetary gear set 75 operably coupled to the first traction ring assembly 73. The planetary gear set 75 is provided with a ring gear 76, a planet carrier 77, and a sun gear 78. In some embodiments, the ring gear 76 is coupled to the first traction ring assembly 73. In some embodiments, the planet carrier 77 is operably coupled to the motor/generator 71 through a first clutch 79. In some embodiments, the planet sun gear 78 is operably coupled to a second clutch 80. In some embodiments, the planet carrier 77 is operably coupled to ground through a brake 81. In some embodiments, the second traction ring assembly 74 is coupled to the sun gear 78 at a combining node 83. In some

embodiments, a third clutch 82 is coupled to the sun gear 78 and the combining node 83. In some embodiments, rotational power is transmitted in and out of the CVED 70 through the combining node 83.

Turning now to FIG. 11 , during operation of the CVED 70, a power split mode of operation corresponds to a disengaged condition of the brake 81 and the second clutch 80 while the first clutch 79 and the third clutch 82 are in an engaged condition. The CVED 70 is optionally operated in a condition where all power from the motor/generator 71 is passed through the ball-type continuously variable planetary 72, referred to in the table of FIG. 26 as "100% thru CVP". The operating condition 100% thru CVP corresponds to an engaged condition of the brake 81 and the second clutch 80, and a disengaged condition of the first clutch 79 and the third clutch 82. The CVED 70 is optionally operated in a condition where all power from the motor/generator 71 is transmitted to the combining node 83 without passing through the ball-type continuously variable planetary 72, referred to in the table of FIG. 26 as "Direct (No tq thru CVP)". The Direct (No tq thru CVP) mode of operation corresponds to a disengaged condition of the brake 81 and the first clutch 79 while the second clutch 80 and the third clutch 82 are in an engaged condition.

Referring now to FIG. 12, in some embodiments, a continuously variable electric drivetrain (CVED) 90 is optionally used in the embodiments of electric axles disclosed herein. The CVED 90 includes a motor/generator 91 and a ball-type continuously variable planetary 92 having a first traction ring assembly 93 and a second traction ring assembly 94. The CVED 90 includes a planetary gear set 95 operably coupled to the first traction ring assembly 93. The planetary gear set 95 is provided with a ring gear 96, a planet carrier 97, and a sun gear 98. The CVED 90 includes a brake 99, a first clutch 100, a second clutch 101 , a third clutch 102, a fourth clutch 103, and a fifth clutch 104. In some embodiments, the ring gear 96 is operably coupled to the first traction ring assembly 93 through the fourth clutch 103. The planet carrier 97 is operably coupled to the motor/generator 91 through the first clutch 100. In some embodiments, the planet carrier 97 is operably coupled to the first traction ring assembly 93 through the fifth clutch 104. In some embodiments, the sun gear 98 is operably coupled to the motor/generator 91 through the second clutch 101. In some embodiments, the second traction ring 94 is coupled to the sun gear 98 at a combining node 105. In some embodiments, the third clutch 102 is coupled to the sun gear 98 and the combining node 105. In some embodiments, rotational power is transmitted in and out of the CVED 90 through the combining node 105.

Turning now to FIG. 13, during operation of the CVED 90, a power split mode of operation corresponds to a disengaged condition of the brake 99, the second clutch 101 , and the fifth clutch 104 while the first clutch 100, the third clutch 102, and the fourth clutch 103 are in an engaged condition. The CVED 90 is optionally operated in a condition where all power from the

motor/generator 91 is transmitted to the combining node 105 without passing through the ball-type continuously variable planetary 192, referred to in the table of FIG. 28 as "Direct (No tq thru CVP)". There are two options to provide operation in the Direct (No tq thru CVP) mode. In some embodiments, the Direct (No tq thru CVP) mode of operation corresponds to a disengaged condition of the brake 99, the first clutch 100, the fourth clutch 103, and the fifth clutch 104 while the second clutch 101 and the third clutch 102 are in an engaged condition. In some embodiments, the Direct (No tq thru CVP) mode of operation corresponds to an engaged condition of the brake 99, the first clutch 100, and the third clutch 102 while the second clutch 101 , the fourth clutch 103, and the fifth clutch 104 are in a disengaged condition. The CVED 90 is optionally operated in a "speed reduction planetary input to CVP" mode corresponding to an engaged condition of the brake 99, the second clutch 101 , and the fifth clutch 04 while the first clutch 100, the third clutch 102, and the fourth clutch 103 are in a disengaged condition.

Referring now to FIG. 14, in some embodiments, a continuously variable electric drivetrain (CVED) 110 is optionally used in the embodiments of electric axles disclosed herein. The CVED 0 includes a motor/generator 11 and a ball-type continuously variable planetary 1 2 having a first traction ring assembly 113 and a second traction ring assembly 14. The CVED 110 includes a planetary gear set 115 operably coupled to the first traction ring assembly 113. The planetary gear set 1 15 is provided with a ring gear 1 16, a planet carrier 117, and a sun gear 118. In some embodiments, the planet carrier 1 17 is coupled to the first traction ring assembly 1 13 through a directional one-way clutch 119. The sun gear 118 is coupled to the

motor/generator 111. The ring gear 116 is a grounded member. In some embodiments, the second traction ring 1 14 is coupled to the planet carrier 1 7 at a combining node 121 through a clutch 120. In some embodiments, rotational power is transmitted in and out of the CVED 110 through the combining node 121.

Referring now to FIG. 15, in some embodiments, a continuously variable electric drivetrain (CVED) 125 is optionally used in the embodiments of electric axles disclosed herein. The CVED 125 includes a motor/generator 126 and a ball-type continuously variable planetary 127 having a first traction ring assembly 128 and a second traction ring assembly 129. The CVED 125 includes a planetary gear set 130 operably coupled to the first traction ring assembly 28. The planetary gear set 130 is provided with a ring gear 131 , a planet carrier 132, and a sun gear 133. In some embodiments, the ring gear 131 is coupled to the first traction ring assembly 128 through a directional oneway clutch 134. The sun gear 133 is coupled to the motor/generator 126. The planet carrier 132 is a grounded member. In some embodiments, the second traction ring 129 is coupled to the ring gear 131 at a combining node 136 through a clutch 135. In some embodiments, rotational power is transmitted in and out of the CVED 10 through the combining node 136.

Referring now to FIG. 16, in some embodiments, a continuously variable electric drivetrain (CVED) 140 is optionally used in the embodiments of electric axles disclosed herein. The CVED 140 includes a motor/generator 41 and a ball-type continuously variable planetary 142 having a first traction ring assembly 143 and a second traction ring assembly 144. The CVED 140 includes a first planetary gear set 145 having a first ring gear 146, a first planet carrier 147, and a first sun gear 148. The CVED 140 includes a second planetary gear set 149 having a second ring gear 150, a second planet carrier 51 , and a second sun gear 152. In some embodiments, the motor/generator 141 is coupled to the first sun gear 148. The first ring gear 146 is a grounded member. The first planet carrier 147 is operably coupled to the second planet carrier 151 through a direction one-way clutch 153. The second sun gear 152 is coupled to the second traction ring assembly 144 at a first combining node 155. The first planet carrier 147 is operably coupled to the second traction ring assembly 144 through a clutch 154 at a second combining node 156. In some embodiments, rotational power is transmitted in and out of the CVED 140 through the second combining node 156.

Referring now to FIG. 17, in some embodiments, a continuously variable electric drivetrain (CVED) 160 is optionally used in the embodiments of electric axles disclosed herein. The CVED 160 includes a motor/generator 161 and a ball-type continuously variable planetary 162 having a first traction ring assembly 163 and a second traction ring assembly 164. The CVED 160 includes a first planetary gear set 165 having a first ring gear 166, a first planet carrier 167, and a first sun gear 168. The CVED 160 includes a second planetary gear set 169 having a second ring gear 170, a second planet carrier 171 , and a second sun gear 172. In some embodiments, the motor/generator 161 is coupled to the first sun gear 168. The first planet carrier 167 is a grounded member. The first ring gear 66 is operably coupled to the second planet carrier 171 through a direction one-way clutch 173. The second sun gear 172 is coupled to the second traction ring assembly 164 at a first combining node 175. The first ring gear 166 is operably coupled to the second traction ring assembly 164 through a clutch 174 at a second combining node 176. In some embodiments, rotational power is transmitted in and out of the CVED 160 through the second combining node 176.

Referring now to FIG. 18, in some embodiments, a continuously variable electric drivetrain (CVED) 180 is optionally used in the embodiments of electric axles disclosed herein. The CVED 180 includes a motor/generator 181 and a ball-type continuously variable planetary 182 having a first traction ring assembly 183 and a second traction ring assembly 184. The CVED 180 includes a planetary gear set 185 operably coupled to the first traction ring assembly 183. The planetary gear set 185 is provided with a ring gear 186, a planet carrier 187, and a sun gear 188. In some embodiments, the ring gear 186 is coupled to the first traction ring assembly 183. The planet carrier 187 is coupled to the motor/generator 181. In some embodiments, the second traction ring 184 is coupled to the sun gear 188 at a combining node 190. In some embodiments, a clutch 189 is adapted to selectively coupled the first traction ring assembly 183 to the ring gear 186. In some embodiments, rotational power is transmitted in and out of the CVED 180 through the ring gear 186 and the combining node 190. In some embodiments, rotational power is transmitted in and out of the ring gear 186 and the combining node 190 each to a planetary gear set such as shown in FIG. 16. It should be appreciated that in some embodiments, a typical ravigneaux gear set is optionally used in placed of planetary gear sets described herein.

Referring now to FIG. 19, in some embodiments, a continuously variable electric drivetrain (CVED) 191 is optionally used in the embodiments of electric axles disclosed herein. The CVED 191 includes a motor/generator 192 and a ball-type continuously variable planetary 193 having a first traction ring assembly 194 and a second traction ring assembly 195. The CVED 191 includes a planetary gear set 196 operably coupled to the first traction ring assembly 194. The planetary gear set 196 is provided with a ring gear 197, a planet carrier 198, and a sun gear 199. In some embodiments, the ring gear 197 is operably coupled to the first traction ring assembly 194. The planet carrier 198 is coupled to the motor/generator 192. In some embodiments, the second traction ring 195 is operably coupled to the sun gear 199 at a

combining node 20 . In some embodiments, a first clutch 200 is adapted to selectively couple the first traction ring assembly 194 to the ring gear 197. In some embodiments, a second clutch 202 is adapted to selectively couple the second traction ring assembly 195 to the combining node 201 . In some embodiments, rotational power is transmitted in and out of the CVED 191 through the ring gear 197 and the combining node 201. In some embodiments, rotational power is transmitted in and out of the ring gear 197 and the

combining node 201 each to a planetary gear set optionally provided on the electric axle powertrain 10 to transmit power to the wheel drive axle 14. it should be appreciated that in some embodiments, a typical ravigneaux gear set is optionally used in placed of planetary gear sets described herein.

Turning now to FIGS. 20 and 21 , in some embodiments, a powertrain 203 is configured to include the CVED 180 in the powertrain. In some embodiments, a powertrain 215 is configured to include the CVED 191 in the powertrain. It should be appreciated that the powertrains disclosed herein are configurable for torque vectoring where the speed ratio between the left and right wheels can be controlled using the variator with the CVEDs disclosed herein.

Referring now to FIG. 22, in some embodiments, a continuously variable electric drivetrain (CVED) 300 is optionally used in the embodiments of electric axles disclosed herein. In some embodiments, the CVED 300 is enclosed in a housing 301 through which a shift lever 302 is disposed. The shift lever 302 is optionally coupled to a manual or automated actuator for selecting, for example, forward, reverse, or neutral. The CVED 300 includes a ball-type continuously variable planetary (CVP) 303 having a first traction ring assembly 304 and a second traction ring assembly 305. The CVED 300 includes a motor/generator 306 operably coupled to the first traction ring assembly 304. In some embodiments, the second traction ring assembly 1 105 is coupled to a forward gear set 307 and a reverse gear set 308. The shift lever 302 selectably engages either the forward gear set 307 or the reverse gear set 308. In some embodiments, the reverse gear set 308 is provided with a reverse idler gear 309. In some embodiments, a final drive gear set 310 operably couples the forward gear set 307 and the reverse gear set 308 to a differential 31 1 . The differential 31 1 is coupled to the wheels 15A, 15B.

Referring now to FIG. 23, in some embodiments, a continuously variable electric drivetrain (CVED) 320 is optionally used in the embodiments of electric axles disclosed herein. In some embodiments, the CVED 320 is enclosed in a housing 321 through which a shift lever 322 is disposed. The shift lever 322 is optionally coupled to a manual or automated actuator for selecting, for example, forward, reverse, or neutral. The CVED 320 includes a ball-type continuously variable planetary (CVP) 323 having a first traction ring assembly 324 and a second traction ring assembly 325. The CVED 320 includes a motor/generator 326 operably coupled to the first traction ring assembly 324 with a transfer gear set 327. In some embodiments, the second traction ring assembly 325 is coupled to a forward gear set 328 and a reverse gear set 329. The shift lever 322 selectably engages either the forward gear set 328 or the reverse gear set 329. In some embodiments, the reverse gear set 329 is provided with a reverse idler gear 330. In some embodiments, the forward gear set 328 and the reverse gear set 329 is operably coupled to a differential 331 . The differential 331 is coupled to the wheels 15A, 15B.

Referring now to FIG. 24, in some embodiments, a continuously variable electric drivetrain (CVED) 340 is optionally used in the embodiments of electric axles disclosed herein. In some embodiments, the CVED 340 is enclosed in a housing 341 through which a shift lever 342 is disposed. The shift lever 342 is optionally coupled to a manual or automated actuator for selecting, for example, forward or neutral. The CVED 340 includes a ball-type continuously variable planetary (CVP) 343 having a first traction ring assembly 344 and a second traction ring assembly 345. The CVED 340 includes a motor/generator 346 operably coupled to the first traction ring assembly 344 with a transfer gear set 347. In some embodiments, the second traction ring assembly 345 is coupled to a forward gear set 348. The shift lever 342 selectably engages either the forward gear set 348 or disengages to provide a neutral operating condition. In some embodiments, the forward gear set 348 is operably coupled to a final drive gear 349. The final drive gear 349 is coupled to a differential 350. The differential 350 is coupled to the wheels 15A, 5B.

Referring now to FIG. 25, in some embodiments, a continuously variable electric drivetrain (CVED) 360 is optionally used in the embodiments of electric axles disclosed herein. In some embodiments, the CVED 360 is enclosed in a housing 361 through which a shift lever 362 is disposed. The shift lever 362 is optionally coupled to a manual or automated actuator for selecting, for example, forward or neutral. The CVED 360 includes a ball-type continuously variable planetary (CVP) 363 having a first traction ring assembly 364 and a second traction ring assembly 365. The CVED 360 includes a motor/generator 366 operably coupled to the first traction ring assembly 364 with a transfer gear

OCl ou / . i l l o i i i o i iL/uUii ι ιυι no, u cuui iu u duuui ι < coupled to a forward gear set 368. The shift lever 362 selectably engages either the forward gear set 368 or disengages to provide a neutral operating condition. The shift lever 362 is aligned coaxially with the motor/generator 366. In some embodiments, the forward gear set 368 is operably coupled to a final drive gear 369. The final drive gear 369 is coupled to a differential 370. The differential 370 is coupled to the wheels 15A, 15B.

Referring now to FIG. 26, in some embodiments, a continuously variable electric drivetrain (CVED) 380 is optionally used in the embodiments of electric axles disclosed herein. In some embodiments, the CVED 380 is enclosed in a housing 381. The CVED 380 includes a ball-type continuously variable planetary (CVP) 382 having a first traction ring assembly 383 and a second traction ring assembly 384. The CVED 380 includes a motor/generator 385 operably coupled to the second traction ring assembly 384 with a first planetary gear set 386. The first planetary gear set 386 includes a first ring gear 387, a first planet carrier 388, and a first sun gear 389. In some embodiments, the motor/generator 385 is coupled to the first sun gear 389. The second traction ring assembly 384 is coupled to the first planet carrier 388. The first ring gear 387 is coupled to the housing 381. The CVED 380 includes a second planetary gear set 390 having a second ring gear 391 , a second planet carrier 392, and a second sun gear 393. In some embodiments, the second sun gear 393 is operably coupled to the first traction ring assembly 383. The second ring gear 391 is operably coupled to a brake 394. The brake 394 selectably couples the second ring gear 391 to the housing 381 to provide forward or neutral operation. In some embodiments, the second planet carrier 392 is operably coupled to a final drive gear 395. The final drive gear 395 is coupled to a differential 396. The differential 396 is coupled to the wheels 15A, 15B.

Referring now to FIG. 27, in some embodiments, a continuously variable electric drivetrain (CVED) 400 is optionally used in the embodiments of electric axles disclosed herein. In some embodiments, the CVED 400 is enclosed in a housing 401 . The CVED 400 includes a ball-type continuously variable planetary (CVP) 402 having a first traction ring assembly 403 and a second traction ring assembly 404. The CVED 400 includes a motor/generator 405 r> ¾KI* ' o trqnofpr n fl'" 406. In some embodiments, the second traction ring assembly 404 is operably coupled to a first planetary gear set 407. The first planetary gear set 407 includes a first ring gear 408, a first planet carrier 409, and a first sun gear 4 0. In some embodiments, the second traction ring assembly 404 is coupled to the first sun gear 410. The first ring gear 408 is coupled to a brake 41 1. The brake 41 1 selectably couples the first ring gear 408 to the housing 401. In some embodiments, the first planet carrier 409 is operably coupled to a final drive gear 412. The final drive gear 412 is coupled to a differential 413. The differential 413 is coupled to the wheels 15A, 15B.

Turning now to FIG. 28, in some embodiments, a continuously variable electric drivetrain (CVED) 420 is optionally used in the embodiments of electric axles disclosed herein. In some embodiments, the CVED 420 includes a first motor/generator 421 operably coupled to a ball-type continuously variable planetary (CVP) 422. The CVED 420 includes a second motor/generator 423 operably coupled to first fixed ratio gear set 424. The CVP 422 and the fixed ratio gear set 424 are operably coupled at a combining node 425. The combining node 425 is optionally configured as a combining planetary gear set configured to transfer a combined power from the CVP 422 and the fixed ratio gear set 424. The combining node 425 is optionally coupled to an additional fixed ratio gear set 426 for power transfer out of the CVED 400.

It should be understood that additional clutches/brakes, step ratios are optionally provided to the hybrid powertrains disclosed herein to obtain varying powerpath characteristics. It should be noted that, in some embodiments, two or more planetary gears and a variator are optionally configured to provide a desired speed ratio range and operating mode to the electric machines. It should be noted that the connections of the electric machines to the

powerpaths disclosed herein are provided for illustrative example and it is within a designer's means to couple the electric machines to other components of the powertrains disclosed herein.

It should be noted that the battery is capable of being not just a high voltage pack such as lithium ion or lead-acid batteries, but also ultracapacitors or other pneumatic/hydraulic systems such as accumulators, or other forms of energy storage systems. The motor/generators described herein are capable of representing hydromotors actuated by variable displacement pumps, electric machines, or any other form of rotary power such as pneumatic motors driven by pneumatic pumps. The electric axle powertrain architectures depicted in the figures and described in text is capable of being extended to create a hydro- mechanical CVT architectures as well for hydraulic hybrid systems.

It should be noted that the description above has provided dimensions for certain components or subassemblies. The mentioned dimensions, or ranges of dimensions, are provided in order to comply as best as possible with certain legal requirements, such as best mode. However, the scope of the preferred embodiments described herein are to be determined solely by the language of the claims, and consequently, none of the mentioned dimensions is to be considered limiting on the inventive embodiments, except in so far as any one claim makes a specified dimension, or range of thereof, a feature of the claim.

While preferred embodiments have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the preferred embodiments. It should be understood that various alternatives to the embodiments described herein are capable of being employed in practice. It is intended that the following claims define the scope of the preferred

embodiments and that methods and structures within the scope of these claims and their equivalents be covered thereby.