PVD-OOB-15P PVD-00B-15P Nachi Hydraulic Pump Repair Seal Kit

The piston pump is mainly composed of two parts: the power end and the hydraulic end, and is also composed of a pulley, a check valve, a safety valve, a voltage stabilizer, and a lubrication system. It is a kind of reciprocating pump, which belongs to the volume pump. Its plunger is driven by the eccentric rotation of the pump shaft and reciprocates. Its suction and discharge valves are all one-way valves. When the plunger is pulled out, the pressure in the working chamber decreases and the outlet valve closes. When it is lower than the inlet pressure, the inlet valve opens and the liquid enters; when the plunger is pushed inward, the working chamber pressure rises and the inlet valve closes. The outlet valve opens and the liquid drains. There are several reasons that may cause the failure of the plunger pump for your reference:

1. Insufficient output flow or no oil at all

Large suction resistance or suction air; poor shaft force; damaged return spring or return plate; dirt between the valve plate and cylinder block; damaged plunger or plunger hole; wrong position of the variable mechanism; too high oil temperature; assembly not good.

2. The pressure is not raised or not at all

Insufficient flow may be caused; the variable mechanism is not adjusted well; other reasons.

3. The pump is noisy and the pressure fluctuates greatly

Inhalation of air; inflexible movement of the variable piston; too small angle of the triangular groove; low rigidity of the variable mechanism; loose fitting between the sliding shoe and the ball head; large leakage of the variable mechanism.

4. The pump heats up and the oil temperature rises too high

Plunger and plunger hole, valve plate and cylinder joint surface are worn, and leakage is large; the motion pair in the pump is severely worn and rough, and the mechanical efficiency is low; the pump eccentricity is small or the working pressure is low; Transmission is stiff.

5. The leaking oil pipe has serious oil leakage (internal and external leakage)

Cylinder block and valve plate, plunger and plunger hole, etc. wear; variable piston wear, resulting in leakage; joint seal damage; oil seal leakage.

6 The pump cannot turn

The plunger is stuck; the slipper falls off; the ball head is broken; the return disc is broken; the cylinder block and the valve plate are sintered;

7 Variable mechanism failure

The arc surface of the variable head bearing bush is seriously worn; the control oil channel is blocked; the variable piston is stuck; the control spool spring is damaged; the variable mechanism leaks.

8. The contact surface of the valve plate and the cylinder body is worn or burned out

The oil is dirty; there is no oil in the pump when starting; the hardness of the valve plate is not enough; the material of the cylinder block is poor; the valve plate is deformed at high temperature and high pressure; the coaxiality between the support hole in the pump casing and the transmission shaft is poor; the matching clearance between the cylinder block and the bearing is too large Large; the gap between the splines of the transmission shaft is too small; the distribution surface of the cylinder block is not perpendicular to the rotation center; the transmission shaft is bent; the high and low pressure transition area of ​​the distribution plate is seriously trapped in oil.

9. The contact surface of the sliding shoe and the swash plate is worn or burned out

Oil pollution; the damping hole of the plunger or shoe is blocked; the hardness or machining accuracy of the swash plate is not enough; the thickness of the shoulder of the shoe is inconsistent; the static pressure bearing accuracy of the surface of the shoe is not enough; the plane of the plunger ball is too small.

YNF Machinery provides not only the hydraulic pump seal kits but also the hydraulic parts.