Analysis on the cause of severe wear of hydraulic pump
Analysis on the cause of severe wear of hydraulic pump
When the hydraulic pump of excavator is seriously worn, it will have a fatal effect on excavator. Therefore, such problems of excavator must be solved timely.In the maintenance of hydraulic pump of excavator, fault reasons are found from the following three points:
(1) Check the internal leakage of the boom cylinder
The simplest maintenance method for hydraulic pumps in excavators is to raise the boom and see if there is a significant free fall.If the drop is obvious, remove the cylinder for inspection, and replace the sealing ring if it is worn.
(2) Check the control valve
First clean the safety valve, check whether the spool wear, such as wear should be replaced.If there is no change after the installation of the relief valve, check the wear condition of the control valve spool again. The clearance limit is generally 0.06mm. If the wear is serious, it should be replaced.
(3) Measurement of hydraulic pump pressure
If the pressure is low, then adjust, add the pressure is still not up, it shows that the hydraulic pump serious wear.
In general, the main reasons for the failure to lift the movable arm are as follows:
1. Hydraulic pump of excavator is seriously worn
Severe leakage in the pump at low speed;High speed operation, the pump pressure slightly increased, but because of the wear and leakage of the pump, the volume efficiency significantly decreased, it is difficult to reach the rated pressure.The hydraulic pump works for a long time aggravates the wear and tear, and the oil temperature rises, which causes the wear of hydraulic components and the aging and damage of seals, the loss of sealing ability, the deterioration of hydraulic oil, and finally leads to the failure.
2. Unreasonable selection of hydraulic components
Boom cylinder specifications for 70/40 non-standard series, sealing parts are also non-standard parts, high manufacturing costs and the replacement of sealing parts inconvenient.The small diameter of the movable arm cylinder is bound to make the system adjust the high pressure.
3. Unreasonable design of hydraulic syste
The operation valve and the full hydraulic steering gear are single pump in series, the relief valve is set at 16MPA, and the hydraulic pump is also rated at 16MPA.Hydraulic pump is often under full load or overload (high pressure) for a long time, and the system has hydraulic impact, long-term oil does not change, hydraulic oil is contaminated, aggravating hydraulic pump wear, so that the hydraulic pump shell burst (found such faults later).
