Modular hydrostatic transmission

Patent metadata

Field	Value
Publication number	US-10167937-B2
Application number	US-201414765686-A
Country	US
Kind code	B2
Filing date	Feb 14, 2014
Priority date	Feb 15, 2013
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A center section/motor sub-assembly for use in a hydrostatic transmission includes a center section having a pump running face for interfacing with a pump, and a motor running face for interfacing with a motor. The center section and the motor are configured for the hydraulic separating forces of the motor to be reacted only into the center section. The center section has two internal passages between pump kidney ports and motor kidney port, and the motor kidney ports are raised in elevation relative to the pump kidney ports. The internal passages run parallel to each other as they rise in elevation. A hydrostatic transmission includes the sub-assembly enclosed by a housing, in combination with a pump and output shaft assembly. For installation, the output shaft assembly is configured as a separate component from the sub-assembly of the center section and the motor.

First claim

What is claimed is:

1. A center section/motor sub-assembly for use in a hydrostatic transmission, the sub-assembly comprising:
a center section having a pump running face for interfacing with a pump, and a motor running face for interfacing with a motor; and
a motor including a motor housing and an internal rotor set, wherein the motor housing is secured to the center section adjacent to the motor running face in a manner that permits rotation of the rotor set; and
a bearing supported by the motor housing;
wherein:
the center section forms an end cover for the motor housing to which the motor housing is secured, the end cover including the motor running face adjacent to the internal rotor set, and the motor running face having motor kidney ports that open into the motor housing;
the center section forms a porting manifold for communicating hydraulic fluid to the motor;
the porting manifold comprising at least two internal passages between pump kidney ports on the pump running face and motor kidney ports on the motor running face, and the motor kidney ports are raised in elevation relative to the pump kidney ports; and
the internal passages run parallel to each other as they rise in elevation between the pump kidney ports and the motor; and
wherein the center section forming the end cover and the porting manifold is a unitary member.

2. The center section/motor sub-assembly of claim 1 , wherein the pump running face is oriented 90° relative to the motor running face.

3. The center section/motor sub-assembly of claim 1 , wherein the internal rotor set has a gerotor configuration comprising an inner rotor and an outer rotor.

4. The center section/motor sub-assembly of claim 1 , further comprising a press-in filter that is pressed into cylindrical bores in valve cavities in the center section adjacent to the pump running face.

5. The center section/motor sub-assembly of claim 1 , wherein the end cover is oriented vertically such that the motor running face is oriented vertically and oriented 90° relative to the pump running face; and
wherein the end cover includes horizontally extending fastening receivers that receive corresponding fastening elements that secure the motor housing horizontally to the end cover such that the motor running face is adjacent to the internal rotor set.

6. A hydrostatic transmission comprising:
a center section having a pump running face for interfacing with a pump, and a motor running face for interfacing with a motor;
a pump that interfaces with the center section against the pump running face;
a motor including a motor housing and an internal rotor set, wherein the motor housing is secured to the center section adjacent to the motor running face in a manner that permits rotation of the rotor set;
a bearing supported by the motor housing; and
a top housing that encloses the center section, pump, and motor;
wherein:
the center section forms an end cover for the motor housing to which the motor housing is secured, the end cover including the motor running face adjacent to the internal rotor set, and the motor running face having motor kidney ports that open into the motor housing;
the center section forms a porting manifold for communicating hydraulic fluid to the motor;
the porting manifold comprising at least two internal passages between pump kidney ports on the pump running face and motor kidney ports on the motor running face, and the motor kidney ports are raised in elevation relative to the pump kidney ports; and
the internal passages run parallel to each other as they rise in elevation between the pump kidney ports and the motor; and
wherein the center section forming the end cover and the porting manifold is a unitary member.

7. The hydrostatic transmission of claim 6 , further comprising an output shaft assembly that extends through a bore in the top housing.

8. The hydrostatic transmission of claim 7 , wherein the output shaft assembly comprises:
an output shaft having a first end that is positioned adjacent to the rotor element of the motor, and a second end opposite the first end that extends outward from the top housing;
another bearing that is supported by the motor housing;
a low profile retaining ring, wherein prior to installation of the output shaft assembly, the low profile ring retains a key for transmitting torque from the motor to the output shaft when installed; and
a shaft seal that provides a seal between the output shaft and the bore of the housing.

9. The hydrostatic transmission of claim 8 , wherein for installation the output shaft assembly is configured as a separate component from a sub-assembly comprising the center section and the motor.

10. The hydrostatic transmission of claim 8 , wherein during installation the low profile retaining ring aligns the key for installation into the motor, and the low profile retaining ring slides off the key and becomes fit around the output shaft.

11. The hydrostatic transmission of claim 6 , further comprising a fluid reservoir within the top housing, wherein the top housing has an integral expansion volume into which the fluid in the reservoir can expand.

12. The hydrostatic transmission of claim 6 , wherein the center section further comprises valve cavities for receiving hydraulic fluid, and each valve cavity has a check valve for controlling the flow of hydraulic fluid.

13. The hydrostatic transmission of claim 12 , further comprising a press-in filter that is pressed into cylindrical bores in the valve cavities.

14. The hydrostatic transmission of claim 6 , further comprising:
a control arm that varies displacement of the pump; and
a return-to-neutral mechanism coupled to the control arm.

15. The hydrostatic transmission of claim 6 , wherein a back plate is secured to the top housing, and the back plate has a magnet adjacent to valve cavities of the center section for removing ferrous materials from the hydraulic fluid.

16. The hydrostatic transmission of claim 6 , wherein the pump running face is oriented 90° relative to the motor running face.

17. The hydrostatic transmission of claim 6 , wherein the internal rotor set has a gerotor configuration comprising an inner rotor and an outer rotor.

18. The hydrostatic transmission of claim 6 , further comprising an output shaft,
wherein the end cover further includes a bore hole that supports an end of the output shaft, and
the center section further comprising a bleed hole opposite the bore hole, the bleed hole extending through the center section and connecting with the bore hole.

19. A dual hydrostatic transmission system comprising:
a first hydrostatic transmission according to claim 6 attached to a first gearbox unit;
a second hydrostatic transmission according to claim 6 attached to a second gearbox unit; and
a belt that runs between the first hydrostatic transmission and the second hydrostatic transmission.

20. The dual hydrostatic transmission system of claim 19 , wherein
the first hydrostatic transmission is a right side hydrostatic transmission; and
the second hydrostatic transmission is a left side hydrostatic transmission;
wherein the center section of the right side hydrostatic transmission is rotated 180° about horizontal and vertical axes relative to the center section of the left side hydrostatic transmission.

21. The dual hydrostatic transmission system of claim 20 , wherein the right side hydrostatic transmission and the left side hydrostatic transmission have configurations that are s

Assignees

• Parker Hannifin Corp

Inventors

• Crosby Michael Tholan
• Simon Matthew Herman
• Heathcoat David Mark
• Richardson Jason Scot
• Rector John Matthew
• Collett Raymond E
• Malone Somer Renee

Classifications

• B60Y2200/223

  Ridable lawn mowers · CPC title

• F15B11/028

  for controlling the actuating force (F15B11/024 takes precedence) · CPC title

• F16H39/12 Primary

  with stationary cylinders · CPC title

• F16H47/04 Primary

  the mechanical gearing being of the type with members having orbital motion · CPC title

• B60Y2304/01

  Minimizing space with more compact designs or arrangements · CPC title