In high-pressure, long-duration foundation construction, SANY rotary drilling rigs’ main pumps often face issues like pressure loss, slow response, or reduced flow. When repairing or maintaining these systems, attention must be paid to the following critical hydraulic pump components:

1. Swash Plate

Responsible for variable displacement control. Wear or misalignment reduces the system's ability to respond precisely to load changes.

2. Pistons

Subject to high-frequency reciprocating motion, pistons wear easily. Use wear-resistant OEM-grade pistons to maintain volumetric efficiency.

3. Valve Plate

Worn sealing surfaces lead to internal leakage and pressure loss. Surface flatness and wear marks should be inspected regularly.

4. Cylinder Block

The precision fit between pistons and the cylinder block is vital. If worn, the cylinder block should be replaced entirely.

5. Return Spring/Shoe Plate

If the pistons are not resetting properly, check the return spring tension or the shoe plate's contact surface.

6. Drive Shaft Bearing

Bearings can loosen under prolonged heavy-duty loads, causing vibration and excessive noise. Replace if radial play is detected.

7. Seals & O-rings

All seals must be made of high-pressure and high-temperature resistant materials. Inferior seals often lead to hydraulic leaks.