| 摘要 |
<p>A travelling equipment for hydraulic four-wheel drive vehicles which provides a stable traction and travelling speed even in travelling on a bumpy road surface, offers a long service life for hydraulic equipment, and is economical. The equipment, having a variable displacement hydraulic pump and front and rear wheel side hydraulic motors, comprises a closed center type front wheel side directional switching valve (3F) provided for the front wheel side hydraulic motor (2F), a closed center type rear wheel side directional switching valve (3R) provided for the rear wheel side hydraulic motor (2R), pump flow rate control means for controlling a pump discharge oil quantity so as to maintain differential pressures across the respective directional switching valves (3F, 3R) constant, and a communication valve (5) provided between an oil passage (4F) extending from the front wheel side directional switching valve to the front wheel side hydraulic motor and an oil passage (4R) extending from the rear wheel side directional switching valve to the rear wheel side hydraulic motor to provide communication or shut-off between these oil passages. <IMAGE></p> |
