Hydrostatic transaxle

• US 20070012503A1
• Filed: 07/14/2006
• Published: 01/18/2007
• Est. Priority Date: 07/15/2005
• Status: Active Grant

• Current Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Original Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Inventors: Iida, Masaru
• Granted Patent: US 7,487,635 B2
• Time in Patent Office: Days
• US Class Current: 180/305
• CPC Class Codes: B60K 17/105 Units comprising at least a part of the gearing and a torque-transmitting axle, e.g. transaxles B60K17/14 takes precedence
• CPC Class Codes: F16H 39/14 with cylinders carried in rotary cylinder blocks or cylinder-bearing members
• CPC Class Codes: F16H 47/02 the fluid gearing being of the volumetric type
• CPC Class Codes: Y10T 74/19665 Bevel gear type

Abstract

In a housing of a hydrostatic transaxle, an HST including mutually fluidly connected hydraulic pump and motor, an axle, and a deceleration gear train interposed between the hydraulic motor and the axle are disposed. The deceleration gear train includes an L-shaped counter shaft. The L-shaped counter shaft consists of mutually perpendicular first and second shaft portions. The first shaft portion is disposed in parallel to a motor shaft of the hydraulic motor. The second shaft portion is disposed in parallel to the axle. A first gear fitted on the motor shaft meshes with a second gear fitted on the first shaft portion. A third gear fitted on the second shaft portion meshes with a fourth gear fitted on the axle.

Claims

1. A hydrostatic transaxle comprising:

a hydrostatic transmission including mutually fluidly connected hydraulic pump and motor;

an axle;

a deceleration gear train drivingly connecting the hydraulic motor to the axle;

a housing incorporating the hydrostatic transmission, the axle and the deceleration gear train;

a motor shaft of the hydraulic motor extended perpendicular to the axle;

an L-shaped counter shaft belonging to the deceleration gear train, wherein a first shaft portion and a second shaft portion disposed perpendicular to each other are joined to each other so as to constitute the L-shaped counter shaft, wherein the first shaft portion is disposed in parallel to the motor shaft, and wherein the second shaft portion is disposed in parallel to the axle;

a first gear fitted on the motor shaft;

a second gear fitted on the first shaft portion so as to mesh with the first gear;

a third gear fitted on the second shaft portion; and

a fourth gear fitted on the axle so as to mesh with the third gear.

2. The hydrostatic transaxle according to claim 1, further comprising:

a fifth bevel gear fitted on the first shaft portion of the L-shaped counter shaft; and

a sixth bevel gear fitted on the second shaft portion of the L-shaped counter shaft so as to mesh with the fifth bevel gear.

3. The hydrostatic transaxle according to claim 1, further comprising:

a block fixed in the housing so as to support one end of the first shaft portion and one end of the second shaft portion joined to each other, wherein the other end of the first shaft and the other end of the second shaft are supported by the housing.

4. The hydrostatic transaxle according to claim 1, wherein the hydraulic pump includes a pump shaft disposed in parallel to the motor shaft, and wherein the hydraulic pump and the hydraulic motor are juxtaposed in the axial direction of the axle.

5. The hydrostatic transaxle according to claim 4, wherein the hydraulic pump includes a displacement controlling operation shaft disposed between the pump shaft and the axle in the direction perpendicular to the axle.

6. The hydrostatic transaxle according to claim 5, wherein the displacement controlling operation shaft is disposed in parallel to the pump shaft and the motor shaft.

7. The hydrostatic transaxle according to claim 5, further comprising:

a first divisional part and a second divisional part joined to each other so as to constitute the housing; and

a center section disposed in the housing and formed therein with a fluid passage, wherein the hydraulic pump and the hydraulic motor are mounted onto the center section so as to be fluidly connected to each other through the fluid passage, and wherein the displacement controlling operation shaft is supported at opposites ends thereof by the first and second divisional parts, or by the center section and one of the first and second divisional parts, respectively.

8. The hydrostatic transaxle according to claim 4, wherein the hydraulic pump includes a displacement controlling operation shaft which can be selectively disposed between the pump shaft and the axle in the direction perpendicular to the axle, or opposite to the axle with respect to the pump shaft in the direction perpendicular to the axle.

9. The hydrostatic transaxle according to claim 8, wherein the displacement controlling operation shaft is disposed in parallel to the pump shaft and the motor shaft.

10. The hydrostatic transaxle according to claim 8, further comprising:

a first divisional part and a second divisional part joined to each other so as to constitute the housing; and

a center section disposed in the housing and formed therein with a fluid passage, wherein the hydraulic pump and the hydraulic motor are mounted onto the center section so as to be fluidly connected to each other through the fluid passage, and wherein the displacement controlling operation shaft is supported at opposites ends thereof by the first and second divisional parts, or by the center section and one of the first and second divisional parts, respectively.

11. The hydrostatic transaxle according to claim 1, further comprising:

a first divisional part and a second divisional part joined to each other so as to constitute the housing; and

a brake disposed in the housing so as to brake the axle, the brake including

a brake shaft disposed in parallel to the motor shaft, wherein the brake shaft are divided into first and second brake shaft portions, wherein the first brake shaft portion is supported by the first divisional part of the housing, and the second brake shaft portion is supported by the second divisional part of the housing, and wherein one of the first and second brake shaft portions is rotatably centered on the axis thereof,

a swingable member interposed between the first and second brake shaft portions so as to be rotatably integral with the rotatable first or second brake shaft portion, and

a brake shoe supported by the swingable member so as to be interposed together with the swingable member between the first and second brake shaft portions, wherein the second gear is disposed between the swingable member and the brake shoe, and wherein, when the swing arm is rotated, the swing arm acts as a cam so as to push the brake shoe in the axial direction of the brake shaft, thereby pressing and braking the second gear.