Hydrostatic clutch system and method for making power under acceleration

Abstract

A hydrostatic clutch system for dually charging the accumulators while speeding up and slowing down. The hydrostatic clutch system includes a hydraulic pump having a pump housing with openings therein; a manifold/end cover; and a fluid circuit assembly in operable communication with the hydraulic pump. The hydrostatic clutch system may be used with at least one transmission or gear set in operable communication with the hydrostatic clutch. The hydrostatic clutch system may be used to create a variable speed from a fixed input speed. The hydrostatic clutch system may also be used as a hybrid system by changing the pump into a motor for launch and for powering the vehicle with the engine disconnected using accumulated hydraulic pressure. The hydrostatic clutch system captures the resistance of the weight of the vehicle in order to make power while the vehicle is accelerating.

Claims

1. A hydrostatic clutch system comprising: a hydraulic pump having a pump housing with openings therein, and a manifold/end cover, wherein the hydraulic pump is an axial piston pump comprising a plurality of pistons and having a cylinder block; a hydraulic fluid circuit wherein the hydraulic fluid circuit is interconnected to high and low pressure inlet ports and an outlet port in the manifold/end cover, wherein the manifold/end cover is coupled to the hydraulic pump, wherein the fluid circuit also includes at least one fluid control valve in operable communication with the outlet port for creating backpressure in the pump; a valve to selectively control flow through the inlet ports in the end cover; at least one gear set or transmission, an input shaft in communication with the hydraulic pump, and input shaft lockup members including lockup plates with each said lockup plate having flanges attached to and spaced along a perimeter of the respective lockup plate, wherein one or more of the lockup plates are movably disposed face to face with the flanges of one of the lockup plates engagable with the flanges of an adjacent said lockup plate to lockup and prevent the rotation of the input shaft.

2. The hydrostatic clutch system as described in claim 1, wherein when the low pressure inlet port is closed; high pressure is routed to the high pressure inlet port so that the function of the pump is changed to that of a motor.

3. The hydrostatic clutch system as described in claim 2, wherein to effect reverse, high pressure is routed into the outlet port and exits out the low pressure inlet port, while the pump is functioning as the motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

(2) FIG. 1 is a cross-sectional schematic view of one embodiment of a new system for making power under acceleration configured as a hydrostatic clutch.

(3) FIG. 2 is a perspective view of the hydrostatic clutch system, including the hydraulic pump, manifold/end cover, input shaft of the present invention together with the engine/power source lockup device.

(4) FIG. 3 is perspective view of the manifold/end cover housing, including the various intake and outlet ports of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(5) With reference now to the drawings, and in particular to FIGS. 1 through 3 thereof, a new hydrostatic clutch system embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.

(6) As best illustrated in FIGS. 1 through 3, the hydrostatic clutch system 10 may generally comprise a hydraulic pump 11 having a pump housing 12 with openings 13, 14 therein, and a manifold/end cover 16, and may also comprise a fluid circuit assembly 15 in operable and conventional communication with the hydraulic pump 11. The hydraulic pump 11 is an axial piston pump comprising a plurality of pistons and having a cylinder block. The hydrostatic clutch system 10 may be used with an accumulator (not shown) for storing hydraulic fluid pressure. The manifold/end cover 16 may be conventionally coupled to the hydraulic pump 11 and may include a side wall 36 with ports 17, 18, & 21 disposed therein and include a bore 35 disposed therethrough. The fluid circuit assembly 15 may also include at least one fluid control valve 19 in operable and conventional communication with one of the ports 17 for controlling and releasing hydraulic fluid pressure, and may also include additional manifolds and valves (not shown) to control the inlet ports, 18 and 21. As further illustrated in FIG. 2, the hydrostatic clutch 10 includes an input shaft 23, with one end in communication with the power source and the lockup device. The other end of the input shaft 23 may be in communication with the cylinder block 31 of the hydraulic pump 11. The hydrostatic clutch 10 also includes an output shaft 27.

(7) The hydrostatic clutch 10 may be used in conjunction with any gear set or transmission 20 to power a vehicle. The case 12 of the hydraulic pump 11 may be attached to a case of the any gear set or transmission 20 using any method of fastening, while the output shaft 27 may be conventionally coupled with the shafts and/or gears of the any gear set or transmission 20 so as to allow interaction between the hydrostatic clutch 10 and the any gear set or transmission 20.

(8) The input shaft 23 may also include input shaft lockup members 39, 42 conventionally disposed about the end of the shaft 23 with at least one of the input shaft lockup members 39 conventionally coupled to the pump end cover 16 to lockup the shaft 23 with the hydraulic fluid pressure being used to propel the vehicle. The input shaft lockup members 39, 42 may be lockup plates 39, 42 with holes disposed therethrough and with each lockup plate 39, 42 having flanges 41, 44 conventionally attached to and spaced along a perimeter 40, 43 of the respective lockup plate 39, 42. One or more of the lockup plates 39, 42 may be movably disposed face to face with the flanges 41 of one of the lockup plates 39 conventionally engagable with the flanges 44 of an adjacent lockup plate 42 to lockup and prevent the rotation of the shaft 23 so that the stored hydraulic fluid pressure is used to propel the vehicle. In place of the lockup device, any mechanism may be used to disconnect the power source from the hydrostatic clutch system, such as a clutch. In an alternative embodiment, the power source may be turned off.

(9) In use, while the vehicle is under acceleration, the said any gear set or transmission 20 may be actuated by the output shaft 27 of the hydrostatic clutch 10. Backpressure in the pump 11 is created by using the weight of the vehicle as resistance to apply a load to the hydrostatic pump 11, effectively braking the pump 11. Fluid flow from the hydrostatic clutch 10 is restricted at the outlet port 17 by the valve 19, and the hydraulic backpressure/power created in the pump 11 is sent to an accumulator (not shown), and is then further sent to an assist motor (not shown) which can be located anywhere in the drivetrain. The assist motor thus assists the power source in powering the vehicle by using the fluid pressure from the accumulators, and/or the hydrostatic pump system. The hydraulic fluid pressure may be variably regulated and released by the at least one control valve 19 and by the rotation resistance of the hydrostatic clutch system 10 as a result of the weight of the vehicle. The speed of the hydraulic pump 11 and the vehicle with a fixed input from the engine of the vehicle may be controlled using the hydraulic fluid pressure from the accumulator to effect variable speed while the fluid pressure is being created. The pump 11 controls the speed of the vehicle through the transmission or gear set 20, as the slower the pump goes, the faster the vehicle goes.

(10) During variable speed mode, and at lower speeds, the hydraulic fluid is routed through the low pressure inlet port 18 of the manifold/end cover 16, and exits the manifold/end cover 16 through the high pressure outlet port 17, making power and charging the accumulators while the vehicle is accelerating.

(11) At such time that the accumulators reach, full capacity, and the assist motor cannot accept all of it, the excess is sent to a holding tank.

(12) During hybrid mode, the input shaft lockup members 39 & 42 are engaged, locking up the shaft 23 and therefore disengaging the engine power; while the hydraulic fluid pressure from the accumulator may be sent to the motor and thus used to variably propel the vehicle without using power from the engine of the vehicle.

(13) The size of the accumulators used determines the distance traveled by the vehicle with the engine disconnected.

(14) The manifold/end cover 16 used with the hydrostatic clutch system may have at least two inlet ports, including that of the depicted 18 & 21. In normal use, the inlet port 18 is open, and low pressure from the fluid circuit assembly 15, enters there; while the inlet port 21 is closed. At that time, the outlet port 17 is being regulated by the valve 19.

(15) For additional launch power when the vehicle is stopped, the lockup plates 39 & 42 may be engaged, therefore input from the power source is disconnected from the hydrostatic clutch 10. The low pressure inlet 18 in the manifold/end cover 16 may be closed, and high pressure fluid from the accumulators may be routed into the manifold/end cover 16 through port 21 and then out port 17; and thus the pump 11 functions as a motor. This motor is then used to launch the vehicle with high pressure fluid from the accumulators. When the vehicle has reached a set speed, the high pressure inlet port 21 is closed, and the inlet port 18 is opened, therefore the pump again functions as a pump.

(16) From a stop, with the engine turned off, both assist motors may be used to launch the vehicle, reducing fuel usage and lowering emissions.

(17) Use of the present invention results in reduced fuel usage, as well as lowered emissions. The size of the system depends on the size of the vehicle. For example, a mid-sized pickup with the engine turning 2000 RPM's sends approximately 150 horsepower to the wheels at 70 mph. When the pressure from the accumulators and from the hydraulic pump is sent to the assist motor, the assist motor puts an approximate 125 horsepower to the wheels. Since only an additional 25 horsepower is needed to power the vehicle at 70 mph, at that time the RPM's of the engine may be reduced down to an approximate 900 RPM's; therefore, resulting in a 75-80% reduction in fuel usage, along with the accompanying major reductions in emissions. Through the use of the power from both assist motors, no power is needed from the engine for launch.

(18) While the vehicle is under de-celeration, or slowing down, backpressure in the pump 11 is created by the weight of the vehicle acting as a brake, with the pressure being, stored in the accumulator. When full capacity of the accumulators is reached, a pressure regulator opens, and the excess fluid pressure goes to a holding tank.

(19) As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.

(20) With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

(21) Therefore, the foregoing is considered as illustrative only of the principles of the hydrostatic clutch system. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.