Transmission assembly

Patent metadata

Field	Value
Publication number	US-10557461-B1
Application number	US-201715784880-A
Country	US
Kind code	B1
Filing date	Oct 16, 2017
Priority date	Dec 23, 2010
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A drive device includes a housing forming a sump. A pump and motor are mounted on a center section having a porting system and a pair of ports with check plugs disposed therein. A bypass arm is engaged to one end of a bypass shaft external to the housing and rotates the bypass shaft to selectively cause engagement fingers to move each check plug to an open position. A housing projection is contacted by the bypass arm to selectively limit rotation thereof. The axes of rotation of a swash plate trunnion shaft, a pump input shaft and a motor output shaft may all be disposed in a single plane. The input shaft is supported by a housing bearing and an opening in the center section and is restrained from axial movement by the bearing and a thrust surface on the center section.

First claim

What is claimed is:

1. A hydraulic drive device, comprising:
a housing forming an internal sump;
a center section mounted in the internal sump and having a pump running surface, a motor running surface, a hydraulic porting system disposed therein to hydraulically connect the pump running surface to the motor running surface, and a pair of ports formed therein that hydraulically connect the hydraulic porting system to the internal sump;
a hydraulic pump rotatably disposed on the pump running surface;
a hydraulic motor rotatably disposed on the motor running surface;
a pair of check plugs disposed in the pair of ports and connected to hydraulic porting formed in the center section, each check plug having a closed position and an open position, the pair of check plugs permitting fluid flow from the hydraulic porting to the internal sump when in the open position; and
a rotary bypass mechanism comprising:
a shaft disposed in the housing and having a longitudinal axis;
a pair of engagement fingers, each engagement finger located along the longitudinal axis of the shaft adjacent to one of the pair of check plugs, and
a bypass arm engaged to one end of the shaft and disposed external to the housing, the bypass arm capable of rotating the shaft along the longitudinal axis between a first position in which each engagement finger is not in contact with a respective one of the pair of check plugs and a second position in which each engagement finger contacts the respective one of the pair of check plugs to cause each of the pair of check plugs to move to the open position,

wherein the housing comprises a projection formed thereon adjacent the bypass arm, wherein a first surface of the bypass arm contacts the projection when the bypass arm is in the first position to limit rotation of the bypass arm relative to the housing in a first direction and a second surface of the bypass arm contacts the projection when the bypass arm is in the second position to limit rotation of the bypass arm relative to the housing in a second different direction.

2. The hydraulic drive device of claim 1 , wherein the bypass arm further comprises a deformable portion between the first and second surfaces, said deformable portion configured to contact a portion of the projection formed on the housing when the bypass arm is moved from the first position to the second position and from the second position to the first position to cause the deformable portion to deform.

3. The hydraulic drive device of claim 2 , wherein the bypass arm further comprises first and second recesses formed therein, wherein the portion of the projection formed on the housing is disposed within the first recess when the bypass arm is in the first position and the portion of the projection formed on the housing is disposed within the second recess when the bypass arm is in the second position.

4. The hydraulic drive device of claim 3 , wherein the first recess is located between the first surface and the deformable portion and the second recess is located between the second surface and the deformable portion.

5. A hydraulic drive device, comprising:
a housing forming an internal sump;
a hydraulic pump and a hydraulic motor both disposed in the housing;
a swash plate disposed in the housing and engaged to the hydraulic pump for varying an output thereof;
a trunnion shaft having a first axis of rotation, a first end engaged to the swash plate, and a second end disposed outside the housing;
a control arm disposed on the second end of the trunnion shaft for rotating the trunnion shaft about the first axis of rotation;
an input shaft having a second axis of rotation, extending into the housing, and driving the hydraulic pump; and
an output shaft having a third axis of rotation, extending from the housing, and driven by the hydraulic motor,
wherein the first axis of rotation, the second axis of rotation, and the third axis of rotation are all disposed in a single plane.

6. The hydraulic drive device of claim 5 , wherein the first axis of rotation and the third axis of rotation are parallel.

7. The hydraulic drive device of claim 5 , wherein the first axis of rotation is perpendicular to at least one of the second axis of rotation and the third axis of rotation.

8. The hydraulic drive device of claim 5 , further comprising a rotary bypass mechanism comprising a shaft disposed in the housing, the shaft having a fourth axis of rotation.

9. The hydraulic drive device of claim 8 , wherein the fourth axis of rotation is perpendicular to the single plane.

10. A hydraulic drive device, comprising:
a housing defining first and second openings therethrough;
a first bearing disposed in the first opening;
a second bearing disposed in the second opening;
a center section mounted in the housing, the center section having a pump running surface, a motor running surface, and a thrust surface formed thereon and the center section defining a first journal opening and a second journal opening;
a hydraulic pump rotatably disposed on the pump running surface;
a hydraulic motor rotatably disposed on the motor running surface;
a trunnion shaft having a first axis of rotation, a first end disposed in the housing and a second end disposed outside the housing;
an input shaft supported by the first bearing and the first journal opening, the input shaft having a second axis of rotation and being drivingly engaged to the hydraulic pump, the input shaft restrained from substantial movement in an axial direction parallel to the second axis of rotation by the first bearing and the thrust surface;
an output shaft supported by the second bearing and the second journal opening, the output shaft having a third axis of rotation and being drivingly engaged to the hydraulic motor; and
a rotary bypass mechanism comprising a shaft disposed in the housing, the shaft having a fourth axis of rotation.

11. The hydraulic drive device of claim 10 , wherein the input shaft has an annular shoulder formed thereon, an outer diameter of the annular shoulder is greater than an inner diameter of an annular surface of the first bearing, and a portion of the annular surface of the first bearing contacts a portion of the annular shoulder.

12. The hydraulic drive device of claim 10 , wherein the third axis of rotation is perpendicular to the second axis of rotation.

13. The hydraulic drive device of claim 10 , wherein the output shaft is restrained from substantial movement in an axial direction parallel to the third axis of rotation by the second bearing and a retaining ring.

14. The hydraulic drive device of claim 13 , wherein the output shaft has an annular shoulder formed thereon, an outer diameter of the annular shoulder is greater than an inner diameter of an annular surface of the second bearing, and a portion of the annular surface of the second bearing contacts a portion of the annular shoulder.

15. The hydraulic drive device of claim 14 , wherein a distance between the retaining ring and the second journal opening is greater than a distance between the annular shoulder and the second journal opening.

16. The hydraulic drive device of claim 10 , wherein:
the input shaft has a first annular shoulder formed thereon, an outer diameter of the first annular shoulder is greater than an inner diameter of a first annular surface of the first bearing, and a portion of the first annular surface of the first bearing contacts a portion of the first annular shoulder; and
the output shaft has a second annular shoulder formed thereon, an outer diameter of the second annular shoulder is greater tha

Assignees

• Hydro Gear Lp

Inventors

• Probst Jesse L
• Phanco Eric S
• Niemerg Joseph P
• Deters Shane A

Classifications

• F15B21/045

  Compensating for variations in viscosity or temperature · CPC title

• F04B1/2078 Primary

  Swash plates · CPC title

• F15B11/08

  with only one servomotor · CPC title

• F16D31/02

  using pumps with pistons or plungers working in cylinders · CPC title

• F01B3/02

  with wobble-plate · CPC title