In the hydraulic pump maintenance problems, the volume speed regulation loop caused by the fault is usually: 1, hydraulic pump overspeed fault; 2. 2, hydraulic pump output flow is not enough; 3, hydraulic pump can not immediately stop; 4. Aging and deterioration of hydraulic oil in the oil tank. The following is the volume speed regulation loop problems, resulting in hydraulic pump overspeed movement and insufficient output flow fault analysis and troubleshooting methods.

1. Hydraulic pump overspeed rotation troubleshootingFailure phenomenon: as shown in figure 1, under the influence of load change, external interference, reversing impact and other factors, hydraulic pump often produces the phenomenon of excessive rotation (when no balance valve is installed).Exclusion method: in order to prevent the hydraulic pump overspeed rotation, add a balance valve (liquid control sequence valve), when there is external disturbance, the balance valve control pressure drop, so that the hydraulic pump back oil reduction, plays the role of export throttle brake deceleration, can avoid the hydraulic pump overspeed rotation.2, hydraulic pump output flow is not enough troubleshootingFault phenomenon: after a long time of use of the equipment, hydraulic pump internal parts wear or seal failure, resulting in insufficient output flow, this is due to the hydraulic pump leakage increase.Exclusion: replace seals, replace or repair worn parts.