The essential thing for driving an excavator is the daily maintenance and fault maintenance. Good digging can sort out some knowledge questions and answers about the excavator maintenance.
1. After checking that the damping hole has no wall plug, why can't the pressure of the safety valve be adjusted?
Most of this situation is due to the tight closing of the poppet valve and the valve seat, so that the oil pressure in the C cavity cannot be established.
2. What should be paid attention to when grinding the end face of the gear?
After the gear pump gear is worn, it needs to be ground with a high-precision grinder, and it is necessary to find a responsible master to operate. For example, the grinding machine workbench must be absolutely clean and no dust is allowed on the platform. Because the worktable is slightly unclean, the ground plane will be offset from the vertical line of the bearing hole.
3. How to know the perpendicularity of the ground plane of the gear and the bearing hole has changed?
4. What should be paid attention to when assembling the gear pump?
The wear of the pump housing will be a little more in the oil inlet cavity. If the pump housing is symmetrical, it can be turned 180. reuse. For the passive gear, the two ends cannot be replaced, and a mark must be made when removing. Because the gear will wear on one side. The active tooth is integrated with the rotating shaft and cannot be turned over; turning the passive tooth over can change the contact point of the meshing line of the two gears. After the pump is assembled, you need to add a little lubricating oil before rotating it by hand. The feel should be smooth.
5. Should the bearings on the end face be replaced at the same time during assembly?
Must be replaced at the same time. Because of the wear of the pump end surface, the bearing clearance is too large, which causes the gear to swing during rotation.
6. One track can only move forward but not backward. What is the reason?
Is caused by the overload and overflow spool in the travel motor being stuck. To protect the safety of the system, two overload relief valves are installed in the system. If one of the overload relief valve spools is stuck in the overflow position, the system pressure will be lost.
7. Why is it very heavy to pull the excavator's walking control handle (almost cannot be moved)?
Walking distribution valve is different from other distribution valves. The walking distribution valve of most machines is not hydraulically controlled, but directly pulled by hand through a mechanical pull rod. As the machine is old or the distribution spool has been worn, the cooperation clearance between the walking spool and the hole becomes larger, and high-pressure oil will leak from the oil passage through the spool clearance to the end with the spring. Therefore, when the high pressure is formed in the cover, the control valve is very heavy when the distribution valve is to be shifted to the spring side (it is lighter in the other direction).
