Top Effective Repair Methods for Common Piston Pump Failures

1,Not zero oil displacement at neutral position

Variable Axial Piston Pump swashplate tilt angle of zero is called the neutral position, the pump output flow should be zero. However, sometimes the neutral position deviates from the adjustment mechanism of the midpoint of the phenomenon, in the midpoint when there is still flow output. The reason for this is that the position of the controller is deviated, loose or damaged, which needs to be re-zeroed, tightened or replaced. Pump angle maintenance force is not enough, tilt angle trunnion wear will also produce this phenomenon.

2,output flow fluctuations

Output flow fluctuations are related to many factors. Variable pumps can be considered to be poor control of the variable mechanism, such as foreign objects into the variable mechanism, the control piston on the scribing step marks, abrasions, scars, etc., resulting in unstable operation of the control piston. Instability of the control piston can be caused by insufficient amplifier power or damaged parts, or by the poor effectiveness of the damper of the control piston containing the spring. Flow instability is often accompanied by pressure fluctuations. This type of failure is generally to disassemble the hydraulic pump, replace damaged parts, increase damping, improve spring stiffness and control pressure.

Piston Pump failure Repair method

3, abnormal output pressure

Pump output pressure is determined by the load, and input torque is approximately proportional. Output pressure abnormality has two kinds of faults.

3.1 Low output pressure

When the pump in the self-priming state, if the inlet pipeline leakage or the system of hydraulic cyLinders, check valves, reversing valves and other large leaks, will make the pressure up. It is necessary to find out where the air leakage, fastening, replacement of seals, you can raise the pressure. Relief valve failure or adjust the pressure is low, the system pressure does not go up, should re-adjust the pressure or overhaul the relief valve. If the cylinder of the hydraulic pump and the flow distribution plate deviation caused by a large number of leaks, in serious cases, the cylinder may be cracked, it should be re-grinding surface or replacement of the hydraulic pump.

3.2 High output pressure

If the circuit load continues to rise, the pump pressure also continues to rise, it is normal. If the load must be, the pump pressure over the load required pressure value, the pump should be checked outside the hydraulic components, such as directional valves, pressure valves, transmission devices and return piping. If Z large pressure is too high, the relief valve should be adjusted.