GEAR BOX FOR HYDRAULIC ENERGY RECOVERY

• US 20100018194A1
• Filed: 10/05/2009
• Published: 01/28/2010
• Est. Priority Date: 04/22/2005
• Status: Active Grant

• Current Assignee: Hao Zhang, James H. Blalock, Joseph A. Kovach, Stacy H. Turner, Steven C. Rink
• Original Assignee: Hao Zhang, James H. Blalock, Joseph A. Kovach, Stacy H. Turner, Steven C. Rink
• Inventors: Zhang, Hao, Blalock, James H., Rink, Steven C., Turner, Stacy H., Kovach, Joseph A.
• Granted Patent: US 8,490,739 B2
• Time in Patent Office: Days
• US Class Current: 60/327
• CPC Class Codes: F16H 2047/025 the fluid gearing comprising a plurality of pumps or motors
• CPC Class Codes: F16H 47/02 the fluid gearing being of the volumetric type

Abstract

A hydraulic energy recovery and a mechanical drive system in one unit that also provides integral mounting of hydraulic pump/motors for primary drive, secondary drive, and pumps for cooling, lubrication, and low pressure systems along with a mounting position for a power take-off device.

Claims

1. A power transfer apparatus for a vehicle comprising a housing having an axis, a power input shaft at one axial end of the housing that is connectable to a prime mover of the vehicle for receiving power from the prime mover, an output drive shaft at an opposite axial end of the housing that is connectable to one or more wheels of the vehicle for transfer of power to the one or more wheels, a primary hydraulic pump mounted to a first axial end of the housing, a hydraulic motor mounted to an opposite second axial end of the housing, and a transmission assembly contained within the housing, the transmission assembly including a pump coupling for coupling the primary hydraulic pump to the power input shaft, and a motor coupling for coupling the hydraulic motor to the output drive shaft.

2. An apparatus as set forth in claim 1, wherein the primary hydraulic pump and the hydraulic motor have respective rotational drive shafts extending parallel to the power input and output drive shafts.

3. An apparatus as set forth in claim 1, wherein a plurality of hydraulic motors are mounted to the second axial end of the housing.

4. An apparatus as set forth in claim 1, further comprising an energy storage device in which energy can be stored, and primary hydraulic pump power circuitry for transferring hydraulic power from the primary hydraulic pump to the energy storage device.

5. An apparatus as set forth in claim 4, further comprising hydraulic motor power circuitry for transferring energy from the energy storage device to the hydraulic motor.

6. An apparatus as set forth in claim 5, wherein the hydraulic motor is reversely operable as a hydraulic pump when driven by the output drive shaft, and the hydraulic motor power circuitry is operable to transfer hydraulic power from the hydraulic motor to the energy storage device when the hydraulic motor is operated as a hydraulic pump.

7. An apparatus as set forth in claim 6, where the energy storage device includes at least one hydropneumatic accumulator, and the primary hydraulic pump power circuitry and hydraulic motor power circuitry includes hydraulic circuits respectively connecting the primary hydraulic pump and hydraulic motor to the at least one hydropneumatic accumulator.

10. An apparatus as set forth in claim 1, wherein the transmission assembly includes a mechanical transmission connected between the hydraulic motor and the output drive shaft, the mechanical transmission having first and second gear ratios and a clutch for shifting between the first and second gear ratios.

11. An apparatus as set forth in claim 1, wherein the transmission assembly includes a clutch for selectively drivingly connecting the primary hydraulic pump to the power input shaft.

12. An apparatus as set forth in claim 1, wherein the transmission assembly includes a clutch for selectively drivingly connecting the output drive shaft to the power input shaft.

26. An apparatus as set forth in claim 1, wherein the primary hydraulic pump and motor are externally mounted to the housing.

8. (canceled)

9. (canceled)

13. A power transfer apparatus for a vehicle comprising a housing;

a power input shaft that is connectable to a prime mover of the vehicle for receiving power from the prime mover;

an output drive shaft that is connectable to one or more wheels of the vehicle for transfer of power to the one or more wheels;

a primary hydraulic pump mounted to the housing;

a hydraulic motor mounted to the housing; and

a transmission assembly contained within the housing, the transmission assembly including a pump coupling for coupling the primary hydraulic pump to the power input shaft, and a motor coupling for coupling the hydraulic motor to the output drive shaft; and

wherein the housing has a pump mounting surface against which the primary hydraulic pump is removably sealingly mounted externally of the housing, and the housing has a motor mounting surface to which the hydraulic motor is removably sealing mounted externally of the housing.

14. An apparatus as set forth in claim 13, wherein two said hydraulic motors are mounted at respective mounting surfaces of the housing at opposite sides of a center plane through the housing coplanar with the output drive shaft.

15. An apparatus as set forth in claim 13, forming part of the vehicle, wherein the prime mover is drivingly connected to the power input shaft, and the output drive shaft is drivingly connected to at least one wheel of the vehicle.

16. A vehicle as set forth in claim 15, wherein the prime mover is an internal combustion engine.

17. A vehicle as set forth in claim 15, wherein the vehicle includes an energy storage device in which energy can be stored, primary hydraulic pump power circuitry for transferring hydraulic power from the primary hydraulic pump to the energy storage device, and hydraulic motor power circuitry for transferring energy from the energy storage device to the hydraulic motor.

18. A vehicle as set forth in claim 17, wherein the hydraulic motor is reversely operable as a hydraulic pump when driven by the output drive shaft, and the hydraulic motor power circuitry is operable to transfer hydraulic power from the hydraulic motor to the energy storage device when the hydraulic motor is operated as a hydraulic pump.

19. A vehicle as set forth in claim 18, wherein the transmission assembly includes a first clutch for selectively drivingly connecting the output drive shaft to the power input shaft, and a second clutch for selectively drivingly connecting the hydraulic motor to the output drive shaft, and further comprising a controller for controlling the first and second clutches for selective connection of the power input shaft to the output shaft for enabling the prime mover to drive the vehicle'"'"'s wheel or wheels and for energy recovery during braking when the hydraulic motor acts as pump for supplying energy to the energy storage device.

20. A vehicle as set forth in claim 19, wherein when the controller is operative to control the first clutch and the speed of the engine for enabling the engine to be operated at an optimal speed for recharging the energy storage device or to be shut off when the energy storage device is sufficiently charged.

24. A vehicle as set forth in claim 19, wherein the energy storage device includes at least one hydropneumatic accumulator.

21. A power transfer apparatus for a vehicle comprising a power input shaft that is connectable to a prime mover of the vehicle for receiving power from the prime mover, an output drive shaft that is connectable to one or more wheels of the vehicle for transfer of power to the one or more wheels, a primary hydraulic pump, a variable displacement hydraulic motor, a transmission assembly including a pump coupling for coupling the primary hydraulic pump to the power input shaft and a motor coupling for coupling the hydraulic motor to the output drive shaft, and hydraulic power circuitry for directly or indirectly supplying hydraulic power from the hydraulic pump to the hydraulic motor, and wherein the transmission assembly includes a mechanical transmission connected between the hydraulic motor and the output drive shaft, the mechanical transmission has first and second gear ratios and a clutch for shifting between the first and second gear ratios, and the displacement of the hydraulic motor is controlled by a controller to synchronize the speed and/or torque output of the hydraulic motor to the rotational speed of the output drive shaft for shifting between the first and second gear ratios while the output drive shaft is rotating.

22. A method of shifting a multi-speed power drive unit from a first gear ratio to a second gear ratio comprising the steps of removing torque load from the gear set of the power drive unit;

separating the gears forming the first gear ratio; and

controlling a tilt angle of a swash plate of a hydraulic motor to vary a displacement of the hydraulic motor and thus the speed of a gear of the second gear ratio to synchronize the speed of the gears of the second gear ratio; and

engaging the gears of the second gear ratio when synchronized.

27. The method of claim 22, further including the step of utilizing a three-position clutch to shift between the first and second gear ratios and a neutral position.

28. The method of claim 22, further including supplying from an energy storage device all of the fluid used by the hydraulic motor to vary the speed of the gear of the second gear ratio.

23. (canceled)

25. An apparatus forming a portion of a vehicle drive system, the apparatus comprising:

a hydraulic motor;

a gear assembly, the gear assembly, in a first mode, enabling the hydraulic motor to drive wheels of the vehicle and, in a second mode, providing a direct mechanical connection to the wheels of the vehicle with an engine of the vehicle for enabling the engine to drive the wheels; and

a controller for shifting the gear assembly between the first and second modes as a function of the speed of the vehicle.