IP Library Granted Patent US 8,418,797
Granted Patent B2
US 8,418,797 · App. 12/937,815 · Granted Apr 16, 2013

Work vehicle

Inventors: Keiji Matsumoto (Osaka, JP); Jun Terashima (Osaka, JP)
Assignee: Yanmar Co., Ltd.
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Quick Facts
Patent No.
US 8,418,797
App. No.
12/937,815
Granted
Apr 16, 2013
Kind
B2
Abstract

The purpose of the present invention is to provide a work vehicle that does not slip. The work vehicle has an engine ( 10 ) generating a rotational power, a hydraulic stepless transmission (HST) ( 20 ) having a hydraulic pump ( 22 ) and a hydraulic motor ( 24 ) and changing the speed of rotation generated by the engine ( 10 ) and transmitting it to drive wheels ( 40 ), an actuator ( 73 ) for adjusting the transmission ratio of the HST ( 20 ) by changing the tilt angle of a movable swash plate ( 22 a ) of the hydraulic pump ( 22 ), a shift lever (speed setting means) ( 50 ) for setting the speed of a motor output shaft ( 25 ) changed by the HST ( 20 ), and a control device ( 60 ) for controlling operation of the actuator ( 73 ) so that the speed of the motor output shaft ( 25 ) changed by the HST ( 20 ) changes at a predetermined rate of change (β) until it reaches the speed (preset speed) set by the shift lever ( 50 ).

Claims (6)

1. A work vehicle comprising:

an engine generating a rotational power;

a hydraulic stepless transmission having a hydraulic pump and a hydraulic motor, speed-changing the rotational power generated by the engine and transmitting the power to a drive wheels;

a speed setting means for changing a tilt angle of a movable swash plate of the hydraulic pump so as to adjust a speed change ratio of the hydraulic stepless transmission;

a damper having an adjustable damping force for restricting movement of the speed setting means at a rate determined based on a friction coefficient between the drive wheel and a ground surface; and

a damping force setting means for adjusting the damping force of the damper so as to set the rate.

Assignments (2)
CHANGE OF NAME Recorded Aug 26, 2020
From: YANMAR CO., LTD.
To: YANMAR POWER TECHNOLOGY CO., LTD.
Reel/Frame 054162/0112 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 13, 2010
From: MATSUMOTO, KEIJI; TERASHIMA, JUN
To: YANMAR CO., LTD.
Reel/Frame 025476/0273 →
Priority Claims (1)
JP 2008-105038 · Apr 14, 2008 · national
Continuity (1)
Related Publication 20110048829A1 · Mar 3, 2011