Hydrostatic transmission

Patent metadata

Field	Value
Publication number	US-9488261-B2
Application number	US-201314031962-A
Country	US
Kind code	B2
Filing date	Sep 19, 2013
Priority date	Oct 4, 2012
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

In a hydrostatic transmission (HST), a lubricating fluid passage is formed in an input shaft and has a pair of radially opposite lubricating fluid spill ports open at an outer peripheral surface of the input shaft. Both of the radially opposite lubricating fluid spill ports face a lubricated object of the HST. The lubricating fluid passage includes an axial fluid passage and a pair of radial fluid passages that are extended radially from the axial fluid passage to the outer peripheral surface of the input shaft so as to be radially opposite each other. Open ends of the respective radial fluid passages at the outer peripheral surface of the input shaft serve as the respective radially opposite lubricating fluid spill ports.

First claim

What is claimed is:

1. A hydrostatic transmission comprising:
an input shaft, wherein axial and radial directions of any component or portion in the hydrostatic transmission are defined to coincide to axial and radial directions of the input shaft;
a plunger block fixed on the input shaft;
pump plungers disposed in the plunger block;
a pump swash plate disposed on one axial side of the plunger block so as to contact heads of the pump plungers projecting from the plunger block;
a hydraulic motor driven by hydraulic fluid pressurized by the pump plungers rotating together with the plunger block and the input shaft;
a lubricated object; and
a lubricating fluid passage formed in the input shaft and having a pair of radially opposite lubricating fluid spill ports open at an outer peripheral surface of the input shaft,
wherein both of the radially opposite lubricating fluid spill ports face the lubricated object,
wherein the lubricating fluid passage includes an axial fluid passage extended axially and a pair of radial fluid passages extended radially from the axial fluid passage to the outer peripheral surface of the input shaft so as to be radially opposite each other,
wherein open ends of the respective radial fluid passages at the outer peripheral surface of the input shaft serve as the respective radially opposite lubricating fluid spill ports, and
wherein the radially opposite lubricating fluid spill ports are disposed at different axial positions.

2. The hydrostatic transmission according to claim 1 , wherein the lubricated object has opposite axial end potions and an inside section between the axial end portions, wherein one of the lubricating fluid spill ports disposed at one of the different axial positions faces the inside section of the lubricated object adjacent to one of the axial end portions of the lubricated object, and the other of the lubricating fluid spill ports disposed at the other of the different axial positions faces an axial middle portion of the inside section of the lubricated object.

3. The hydrostatic transmission according to claim 1 , further comprising:
motor plungers disposed in the plunger block so as to be fluidly connected to the pump plungers; and
a motor swash plate disposed on another axial side of the plunger block opposite the pump swash plate and contacting heads of the motor plungers projecting from the plunger block so as to constitute the hydraulic motor,
wherein the lubricated object is a bearing disposed on the outer peripheral surface of the input shaft so as to support the motor swash plate.

4. A hydrostatic transmission comprising:
an input shaft, wherein axial and radial directions of any component or portion in the hydrostatic transmission are defined to coincide to axial and radial directions of the input shaft;
a plunger block fixed on the input shaft;
pump plungers and motor plungers disposed in the plunger block;
a pump swash plate disposed on one axial side of the plunger block so as to contact heads of the pump plungers projecting from the plunger block;
a motor swash plate disposed on another axial side of the plunger block opposite the pump swash plate so as to contact heads of the motor plungers projecting from the plunger block;
a roller bearing interposed between an outer peripheral surface of the input shaft and an inner peripheral surface of the motor swash plate, wherein the roller bearing includes rollers and a roller retaining ring that holds the rollers in the inside thereof, wherein the rollers contact the outer peripheral surface of the input shaft, wherein the roller retaining ring contacts the inner peripheral surface of the motor swash plate at an outer peripheral surface thereof, and wherein the roller bearing has an inside gap space in the inside of the roller retaining ring along the outer peripheral surface of the input shaft to accommodate the rollers;
a lubricating fluid passage formed in the input shaft and having a lubricating fluid spill port open at the outer peripheral surface of the input shaft, wherein the lubricating fluid spill port faces the inside gap space of the roller bearing,
wherein the lubricating fluid passage includes an axial fluid passage extended axially and a pair of radial fluid passages extended radially from the axial fluid passage to the outer peripheral surface of the input shaft so as to be radially opposite each other, and wherein each of open ends of the radial fluid passages at the outer peripheral surface of the input shaft serves as the lubricating fluid spill port, and
wherein the radially opposite lubricating fluid spill ports are disposed at different axial positions.

5. The hydrostatic transmission according to claim 4 , wherein one of the lubricating fluid spill ports disposed at one of the different axial positions faces an axial end portion of the inside gap space of the roller bearing between an axial end of the roller retaining ring and an axial end of each of the rollers, and the other of the lubricating fluid spill ports disposed at the other of the different axial positions faces an axial middle portion of each of the rollers in the inside gap space.

6. The hydrostatic transmission according to claim 4 , wherein each of the rollers of the roller bearing has its own axis that is extended in the axial direction of the input shaft.

Assignees

• Kanzaki Kokyukoki Mfg Co Ltd

Inventors

• Mochizuki Yasuhisa
• Tsuji Tomoyuki
• Oota Tooru

Classifications

• F16H39/14 Primary

  with cylinders carried in rotary cylinder blocks or cylinder-bearing members · CPC title

• F16H57/0471

  Bearing · CPC title