Study on Constant Pressure Characteristics of Pump Group for Hydraulic Hoist of Plane Lifting Gate

The hydraulic hoist for plane lifting gates is a specialized lifting machinery for steel gates in water conservancy and hydropower projects, with its core being a parallel constant-pressure variable-displacement piston pump group. A constant-pressure variable pump is a type of hydraulic pump that maintains a constant output pressure by regulating its flow. When three constant-pressure variables-displacement piston pumps are connected in parallel to form a pump group, the pressure setting of the constant-pressure valves in each pump may be inconsistent. Although the error is minimal, it can still affect the dynamic response of the parallel pump group. This study takes the parallel constant pressure variable pump group of a hydraulic hoist for plane lifting gates in a large flood control wall channel gate project as the research object. It conducts a theoretical analysis of the working principle of constant-pressure variable pumps, establishes an AMESim software simulation model for the parallel constant-pressure variable pump group of the gate hydraulic hoist, and analyzes the influence of different spring pre-tightening forces of the constant-pressure valve on the dynamic response of the parallel pump group. Through dynamic response analysis, it was found that when there is an error in the constant pressure valve settings of the three pumps, a spring pre-tightening force set too small causes the constant pressure valve response speed to increase, while a spring pre-tightening force set too large results in no response after a load step.