Residential transmission

Patent metadata

Field	Value
Publication number	US-9791029-B2
Application number	US-201414245527-A
Country	US
Kind code	B2
Filing date	Apr 4, 2014
Priority date	Apr 4, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Provided is a hydrostatic transmission including a pump/motor module having a reservoir housing and a hydraulic pump and motor disposed in the reservoir housing, and a speed reduction module having a speed reduction housing coupled to the reservoir housing and a speed reduction assembly disposed in the speed reduction housing. The speed reduction assembly includes an input member driven by the output shaft of the hydraulic motor, an output member rotationally connected to the input member by one or more belts/chains, and an axle shaft driven by rotation of the output member. By providing the speed reduction assembly in a separate housing from the hydraulic fluid in the reservoir housing, the speed reduction assembly is isolated from the hydraulic fluid thereby preventing particulates from the speed reduction assembly from entering the hydraulic fluid in the reservoir housing.

First claim

What is claimed is:

1. A hydrostatic transmission including:
a pump/motor module including:
a reservoir housing forming interiorly thereof a reservoir chamber for containing hydraulic fluid;
a hydraulic pump disposed in the reservoir housing, the hydraulic pump including an input shaft projecting from the reservoir housing through an input shaft opening in the reservoir housing and having an input wheel attached to the input shaft; and
a hydraulic motor disposed in the reservoir housing and fluidly coupled to the hydraulic pump, the hydraulic motor including an output shaft extending through an output shaft opening in the reservoir housing, the output shaft having a rotational axis perpendicular to a rotational axis of the input shaft of the hydraulic pump; and

a speed reduction module including:
a speed reduction housing configured to be coupled to the reservoir housing; and
a speed reduction assembly disposed in the speed reduction housing, the speed reduction assembly including an input member driven by the output shaft of the hydraulic motor, an output member rotationally connected to the input member by one or more belts/chains, and only a single axle shaft extending through an axle shaft opening in the speed reduction housing and being driven by rotation of the output member, the single axle shaft having thereon a single wheel hub to which a wheel of a vehicle can be mounted, whereby there is just one pump/motor module and one speed reduction module for driving a respective wheel of the vehicle; and

wherein the output shaft opening in the reservoir housing through which the output shaft passes is sealed to prevent hydraulic fluid in the reservoir housing from flowing out of the reservoir housing and into the speed reduction housing; and
wherein the speed reduction housing includes a casing and a cover for closing an opening in the casing through which access can be had to the one or more belts/chains, and the cover is removable from the casing without having to remove the speed reduction housing of the speed reduction module from the reservoir housing of the pump/motor module.

2. The hydrostatic transmission according to claim 1 , wherein a rotational axis of the output shaft of the hydraulic motor is parallel to a rotational axis of the axle shaft.

3. The hydrostatic transmission according to claim 1 , wherein the pump/motor module includes a shaft seal surrounding the output shaft of the hydraulic motor for preventing fluid in the reservoir chamber from flowing into the speed reduction housing.

4. The hydrostatic transmission according to claim 1 , wherein the pump/motor module and the speed reduction module form a u-shaped configuration when coupled together.

5. The hydrostatic transmission according to claim 1 , wherein the input member surrounds the output shaft of the motor, and wherein rotation of the output shaft effects rotation of the input member.

6. The hydrostatic transmission according to claim 1 , wherein the output member surrounds the axle shaft, and wherein rotation of the output member effects rotation of the axle shaft.

7. The hydrostatic transmission according to claim 1 , wherein the input member includes a first pulley/sprocket and the output member includes a second pulley/sprocket.

8. The hydrostatic transmission according to claim 7 , wherein the speed reduction assembly further includes an intermediate shaft and third and fourth pulley/sprockets surrounding the intermediate shaft.

9. The hydrostatic transmission according to claim 8 , wherein the speed reduction assembly includes a first belt/chain connecting the first pulley/sprocket and the third pulley/sprocket, and a second belt/chain connecting the fourth pulley/sprocket and the second pulley/sprocket, thereby providing a two stage reduction assembly.

10. The hydrostatic transmission according to claim 9 , wherein the speed reduction assembly further includes a brake assembly connected to the third and fourth pulley/sprockets for braking the axle shaft.

11. The hydrostatic transmission according to claim 9 , wherein the fourth pulley/sprocket is coupled to the third pulley/sprocket for rotation therewith.

12. The hydrostatic transmission according to claim 1 , wherein the speed reduction housing is an L-shaped housing having one leg housing the input and output members and the one or more belts/chains, and another leg housing the axle shaft.

13. A mower including:
a frame;
a mower deck supported by the frame; and
a pair of hydrostatic transmissions according to claim 1 mounted to the frame and to which respective wheels of the mower are individually mounted.

14. The hydrostatic transmission according to claim 1 , wherein the speed reduction module further includes a brake acting on the first intermediate member for braking the axle shaft, and the brake is located between the cover and the first intermediate member.

15. The hydrostatic transmission according to claim 1 , wherein the speed reduction housing is coupled to the reservoir housing at a first side of the reservoir housing, and the hydraulic pump has a pump control shaft that extends through a pump control shaft opening in the reservoir housing at a side of the reservoir housing opposite the first side of the reservoir housing.

16. A hydrostatic transmission including:
a pump/motor module including:
a reservoir housing forming interiorly thereof a reservoir chamber for containing hydraulic fluid;
a hydraulic pump disposed in the reservoir housing, the hydraulic pump including an input shaft projecting from the reservoir housing through an input shaft opening in the reservoir housing and having an input wheel attached to the input shaft; and
a hydraulic motor disposed in the reservoir housing and fluidly coupled to the hydraulic pump, the hydraulic motor including an output shaft extending through an output shaft opening in the reservoir housing, the output shaft having a rotational axis perpendicular to a rotational axis of the input shaft of the hydraulic pump; and

a speed reduction module including:
a speed reduction housing configured to be coupled to the reservoir housing; and
a speed reduction assembly disposed in the housing, the speed reduction assembly including an input member driven by the output shaft of the hydraulic motor, a first intermediate member rotationally connected to the input member by a first belt/chain, a second intermediate member connected to the first intermediate member for rotation therewith, an output member rotationally connected to the second intermediate member by a second belt/chain, and only a single axle shaft extending through an axle shaft opening in the speed reduction housing and being driven by rotation of the output member, the single axle shaft having thereon a single wheel hub to which a wheel of a vehicle can be mounted, whereby there is just one pump/motor module and one speed reduction module for driving a respective wheel of the vehicle; and

wherein the output shaft opening in the reservoir housing through which the output shaft passes is sealed to prevent hydraulic fluid in the reservoir housing from flowing out of the reservoir housing and into the speed reduction housing; and
wherein the speed reduction housing includes a casing and a cover for closing an opening in the casing through which access can be had to the first belt/chain and second belt/chain, and the cover is removable from the casing without having to remove the speed reduction housing of the speed reduction module from the reservoir housing of the pump/motor module.

17. The hydrostatic transmission

Assignees

• Parker Hannifin Corp

Inventors

• Crosby Michael Tholan
• Emmette Jason Lee
• Heathcoat Jr David Mark
• Richardson Jason Scot

Classifications

• F16H7/02

  with belts; with V-belts · CPC title

• F16H47/02

  the fluid gearing being of the volumetric type · CPC title

• F16H39/06 Primary

  pump and motor being of the same type · CPC title

• A01D69/03 Primary

  fluid · CPC title

• B60K17/105

  Units comprising at least a part of the gearing and a torque-transmitting axle, e.g. transaxles (B60K17/14 takes precedence) · CPC title