Actuator unit for controlling hydraulic pump

Patent metadata

Field	Value
Publication number	US-10641389-B2
Application number	US-201715650358-A
Country	US
Kind code	B2
Filing date	Jul 14, 2017
Priority date	Aug 7, 2014
Publication date	May 5, 2020
Grant date	May 5, 2020

Abstract

An HST control mechanism includes a rotary member, a servo unit, a telescopic member, and a biasing device. The rotary member for controlling a displacement of a hydrostatic transmission (HST) is pivoted outside of a casing incorporating the HST. The servo unit includes a telescopically movable actuator and a valve controlling the telescopic movement of the actuator. The actuator is interlockingly connected to the rotary member. The servo unit is pivotally supported on the casing via a first pivot. The servo unit rotates centered on the first pivot as the rotary member rotates according to the telescopic movement of the actuator hydraulically controlled by the valve. The telescopic member is pivotally supported on the casing via a second pivot. The telescopic member is provided with the biasing device that biases the telescopic member and the rotary member toward a position corresponding to a neutral state of the HST.

First claim

What is claimed is:

1. An actuator unit for controlling a hydraulic pump, the actuator unit comprising:
an actuator for controlling a rotational position of a displacement control member of the hydraulic pump, wherein the actuator is a piston in a hydraulic cylinder;
a connection member connected to the actuator, the connection member being formed with a boss extended from the connection member and a recess disposed coaxially in the boss,
wherein a tip portion of a trunnion shaft serving as a pivotal shaft of the displacement control member is fitted into the recess; and
a fastener passed through the boss to engage with the tip portion of the trunnion shaft in the recess so as to fasten the trunnion shaft to the connection member, wherein the fastener is oriented axially with the boss,
wherein the actuator and connection member are configured to be removed from the trunnion shaft after removal of the fastener without any disassembly of the actuator or connection member.

2. The actuator unit according to claim 1 ,
wherein the recess and the tip portion of the trunnion shaft are tapered.

3. The actuator unit according to claim 1 ,
wherein the hydraulic pump controlling actuator unit is a servo unit including the hydraulic cylinder incorporating the piston serving as the actuator.

4. An actuator unit for controlling a hydraulic pump, the actuator unit comprising:
an actuator for controlling a rotational position of a displacement control member of the hydraulic pump, wherein the actuator is a piston in a hydraulic cylinder;
a connection member connected to the actuator, the connection member being formed with a boss extended from the connection member and a recess disposed coaxially in the boss,
wherein a tip portion of a trunnion shaft serving as a pivotal shaft of the displacement control member is fitted into the recess;
a fluid passage in communication with the trunnion shaft, wherein a part of fluid supplied to the hydraulic cylinder is supplied through the fluid passage as lubricating fluid to the trunnion shaft fastened to the connection member; and
a fastener passed through the boss to engage with the tip portion of the trunnion shaft in the recess so as to fasten the trunnion shaft to the connection member,
wherein the hydraulic pump controlling actuator unit is a servo unit including the hydraulic cylinder incorporating the piston serving as the actuator.

5. The actuator unit according to claim 1 , wherein the fastener is oriented coaxially with the boss.

Assignees

• Kanzaki Kokyukoki Mfg Co Ltd

Inventors

• Matsuura Jun
• Iwaki Koji
• Tsuji Tomoyuki
• Kamada Minoru
• Kanenobu Hideki
• Sasahara Kengo

Classifications

• F16H61/4069 Primary

  Valves related to the control of neutral, e.g. shut off valves · CPC title

• F16H39/04

  with liquid motor and pump combined in one unit · CPC title

• F04B23/04

  Combinations of two or more pumps · CPC title

• F16H61/431

  Pump capacity control by electro-hydraulic control means, e.g. using solenoid valves · CPC title

• F16H47/02

  the fluid gearing being of the volumetric type · CPC title