METERLESS HYDRAULIC SYSTEM HAVING LOAD-HOLDING BYPASS

摘要

A hydraulic system (46) is disclosed. The hydraulic system may have a pump (50), a hydraulic actuator (22), and first and second passages (56, 58) fluidly connecting the pump to the hydraulic actuator in a closed-loop. The hydraulic system may also have a control valve (132), and a load-holding valve (86, 88) configured to selectively lock movement of the hydraulic actuator. The load-holding valve may include a valve block (102) at least partially defining a pump passage (90), an actuator passage (92), a control passage (96), a restricted passage (94) connecting the actuator passage and the control passage, and a bypass passage (109) connecting the actuator passage and the control passage. The load-holding valve may also include a valve element (100) movable between a first position at which flow between the pump and the hydraulic actuator is blocked, and a second position at which fluid is allowed to flow between the pump and the hydraulic actuator, the valve element being spring-biased toward the first position.