| 摘要 |
PURPOSE:To improve the small turning performance by providing with a pump control mechanism controls which the swash-plate angle of a hydraulic pump so that the peripheral speed of a front wheel increases (reduces) as the steering angle for a front wheel increases (reduces), and utilizing the advantages of 4- wheel driving. CONSTITUTION:The driving system for front wheels 2 is constituted of a hydraulic transmission 15 in the hydraulic combinatin of a hydraulic pump 19 and a hydraulic motor 21. An angle detection mechanism 39 for detecting the steering angle for front wheels 2 is provided, and a pump control mechanism 40 is provided which controls the swash-plate angle of the hydraulic pump 19 so that the peripheral speed of the front wheel increases (reduces) as the steering angle for the front wheel 2 increases (reduces). When small turning is executed, the turning angle of the front wheel 2 increases, and the angle detection mechanism 39 detects said turning angle, and the control mechanism 40 moves to increase the discharge amount of the hydraulic pump 21, and then the peripheral speed of the front wheel 2 is steplessly changed in proportion to said turning angle, and the small turning performance can be improved. |
