Excavator to rest, hydraulic maintenance skills to learn together!
1, grinding gear face should pay attention to what?
Gear pump gear wear and tear, with high precision grinding machine for grinding, looking for a strong sense of responsibility of the teacher.
Grinding machine for example, the workbench to absolutely clean, do not allow the platform with the dust.
Because the workbench slightly unclean, will make the ground plane and the bearing hole of vertical migration.
2, when assembling gear pump should pay attention to?
Pump casing wear in the oil chamber will be a little more, if the pump is symmetrical, you can turn 180.
To use again.
For passive gear, two head can't change, when you remove the marking.
Because the gear side wear will happen.
Active with the axis of rotation is one of the teeth, cannot reverse it.
Passive tooth will flip, can make the change of two gear meshing line contact.
Pump assembly, want to add a little oil until to slightly rotate with the hand, feel is smooth.
3, the assembly end bearing on whether should change at the same time?
Be sure to change at the same time.
Because the end of the pump wear and tear, is mainly the bearing gap is too big, make the gear swing in rotation.
4, through inspection damping hole no blockage, the relief valve pressure why not tuned up?
This kind of circumstance is because most of the cone valve and valve seat closed lax, making C cavity pressure build up.
5, how do you know the gear surface and bearing holes verticality has changed?
Can only be found during assembly of the gear pump, because the end face of the gap is very small, usually in 0.
5 mm or so.
If the end verticality changed with the bearing holes, the pump gear shaft will not move after assembly.
If the lock screw loose a little, but still didn't turn on smoothly and to overhaul the gear pump, end face and scratch mark.
This is the end plane and is not caused by vertical bearing hole.
6, side track can only forward can't back?
Is walking in the motor overload caused by overflow valve core is jammed.
Walking motor to protect the safety of the system, set up two overload overflow valve in the system, if one of the overload overflow valve jammed in the overflow valve core, the system pressure loss.
7, side tracked walked slowly, but if at the same time do a rotary action, crawler can wake up, why?
The failure in many excavator.
This is due to the insufficient supply walking motor piston pump flow.
When the excavator to do another action at the same time, is also coupled with a plunger pump flow.
In komatsu 200-2 pump flow
2 type excavator control valve will get confluence, komatsu - 200
Type 3 to PC200 -
6 type excavator, the straight confluence valve.
Plunger pump flow is insufficient, is not necessarily the pump has been damaged, majority is caused by the flow control valve not adjust good reason.
8, throw walking excavator control handle, feel very heavy,
Why is that?
Walking different distributing valve and other distribution valve.
Most of the walking machine distributing valve is not hydraulic control, but rather through mechanical lever, driven directly by hand.
As the old machines, or distribution of slide valve has wear and tear, makes walking fitting clearance of slide valve and the hole bigger, high pressure oil from the oil duct through the slide valve clearance leakage to one end of the spring, spring has spring cover cover tightly, make the enclosure formed high pressure, cause the distributing valve to have a spring side shift, joystick is very heavy,
In the other direction is lighter)
9, at the same time operating two crawler walking stick from the excavator started, engine speed will drop in an instant, even flameout, is and why?
The failure is more common.
This is primarily a plunger pump variable mechanism has a problem.
Machine in the idle state, plunger pump still has a lot of traffic.
Just repaired 10, walk oil motor, small throttle crawler walk faster, down but not walk, what is the remedial method?
Walking oil motor just repaired, small throttle crawler walk faster, down but not walk, is why and what's the remedy?
This is because the maintenance when grinding valve plate and grinding quantity too much, make the plane of the valve plate and cylinder pressure force is not enough.
Small throttle when oil pressure is small, plane and plane between is not easy to produce leaks;
When the gas pressure increase, plane between the overflow, cause down when the crawler can't move.
Remedial method can add the gasket in the spring if it is a butterfly spring, can add one piece butterfly spring.