Excavator hydraulic pump repair and improvement methods

When the excavator hydraulic pump serious wear and tear on the excavator has a fatal impact, excavators such problems must be promptly resolved. Excavator hydraulic pump repair from the following three points to find the cause of the malfunction:

(1) check the boom cylinder leakage situation

The easiest excavator hydraulic pump maintenance method is to boom up to see if there is a clear free fall. If the whereabouts of obvious removal of fuel tank inspection, seals have been worn should be replaced.

(2) check the control valve

First clean the safety valve, check whether the spool wear, such as wear and tear should be replaced. If the safety valve is still installed after the change, then check the control valve spool wear, the use of the gap limit is generally 0.06MM, serious wear and tear should be replaced.

(3) measure the pressure of the hydraulic pump

If the pressure is low, then make adjustments, the pressure is still not adjustable, the serious damage to the hydraulic pump.

First, the general result can not be raised with the main reason for the boom:

1, excavator hydraulic pump serious wear and tear

The pump leaks seriously at low speed. When the pump runs at high speed, the pump pressure slightly increases, but due to the pump wear and leakage, the volumetric efficiency drops significantly and it is difficult to reach the rated pressure. Hydraulic pump work for a long time has exacerbated the wear and tear, oil temperature, resulting in wear and tear of hydraulic components and seals aging, damage, loss of sealing ability, hydraulic oil deterioration, and finally lead to failure.

2, hydraulic components selection is not reasonable

Boom cylinder specifications for 70/40 non-standard series, the seals are also non-standard parts, high manufacturing costs and seal replacement inconvenience. Boom cylinder bore is small, the system is bound to set high pressure.

3, hydraulic system design is not reasonable

Control valve and full hydraulic steering gear for a single pump in series, safety valve set pressure points 16MPA, and the hydraulic pump rated working pressure is 16MPA. Hydraulic pump often at full load or prolonged overload (high pressure) work, and the system has a hydraulic impact, long-term oil does not change, the hydraulic oil contaminated, exacerbating the hydraulic pump wear and tear, resulting in hydraulic pump shell burst (was found Such failure).

Second, improve and effect

(1) improve the hydraulic system design

After many demonstrations, excavator hydraulic pump repair the last priority valve and load sensing the entire hydraulic steering gear form. The new system can give priority to the distribution of traffic in accordance with the steering requirements, regardless of the size of the load, the steering wheel speed can ensure adequate oil supply, the remaining part can be fully supplied to the working device circuit, thus eliminating the power supply due to excessive steering oil supply Loss, improve the system efficiency, reducing the working pressure of the hydraulic pump. Reduce the hydraulic excavator serious wear and tear.

(2) Optimize the design of boom cylinder and hydraulic pump

Reduce system stress. Through optimization calculation, the boom cylinder adopts standard series 80/4. Hydraulic displacement from 10ML / R increased to 14ML / R, the system set pressure of 14MPA, to meet the boom cylinder lifting force and speed requirements.

(3) to strengthen the daily inspection and maintenance

During the use of the excavator should also pay attention to the proper use and maintenance, regular addition or replacement of hydraulic oil, hydraulic oil to maintain cleanliness, and strengthen routine inspection and maintenance. Avoid serious excavator hydraulic pump wear, so as to reduce excavator hydraulic pump maintenance times.