Excavator main pump

Excavator main pump is a key component of the excavator's hydraulic system, which provides high-pressure hydraulic oil for the excavator's hydraulic travel motor, hydraulic slewing motor, hydraulic cylinder and other actuators, drives the action of these components, and realizes various working actions such as walking, rotating, excavating, and lifting of the excavator. Let's take a look at it!

First, Types & Characteristics
  1. Type: The main pump of the excavator usually adopts a piston pump, specifically a swash plate variable axial piston pump.
  2. Features: high working pressure, generally 20 - 40MPa, the rated pressure of the main pump of the excavator can reach 34MPa, and the maximum pressure of the moment is 39MPa; Compact structure, high efficiency, convenient flow adjustment, can accurately control the flow of hydraulic oil according to work requirements, to meet the excavator excavator excavation, lifting and other large load operation requirements.

Second, how it works
  The engine drives the drive shaft of the main pump to rotate through the coupling, and the drive shaft drives the cylinder block to rotate together through the spline, and a plurality of plungers (generally odd number, 9 are more common) arranged along the drive shaft in the cylinder bore rotate with the cylinder block. The sliding shoe at the end of the plunger is always in contact with the swash plate under the action of the pressure plate, and the plunger produces reciprocating motion in the cylinder bore due to the inclination angle of the swash plate. When the volume formed by the plunger and the plunger hole becomes larger, under the action of suction and atmospheric pressure, the hydraulic oil enters the cylinder bore, and when the volume becomes smaller, the hydraulic oil is squeezed out into the hydraulic system through the distribution plate, so as to achieve oil suction and oil discharge.

Third, ways to extend the service life of the main pump of the excavator:

Correct operation
  1. Avoid overload: operate in strict accordance with the rated working capacity of the excavator, avoid the excavation force exceeding the bearing range of the main pump, and prevent the main pump from working under high pressure and heavy load for a long time.
  2. Smooth operation: When operating the excavator's actions, such as starting, braking, reversing, etc., it should be as stable as possible, and avoid emergency stops, starts, and violent action switching, so as to reduce the impact on the main pump.

Regular maintenance
  1. Oil maintenance: regularly check the oil quality, oil level and oil temperature of the hydraulic oil to ensure that the oil is clean, sufficient and the temperature is normal. Replace the hydraulic oil and filter elements according to the specified cycles to prevent oil contamination and deterioration from causing wear and tear on the main pump.
  2. Equipment inspection: regularly check the connection parts and seals of the main pump to ensure that the connection is firm and there is no leakage. Detect and deal with abnormal noise, vibration and other problems of the main pump in time to avoid further deterioration of the fault.

Optimize the work environment
  1. Keep it clean: Keep the excavator main pump working site clean and reduce the chance of dust, impurities and other impurities entering the hydraulic system. When repairing and maintaining the main pump, it is also necessary to ensure that the working environment is clean to prevent foreign objects from entering the main pump.
  2. Control oil temperature: To avoid long-term continuous operation of the excavator in a high-temperature environment, the hydraulic oil temperature can be controlled within the normal range by improving the heat dissipation conditions and regularly cleaning the radiator, so as to prevent the oil viscosity from being reduced due to excessive oil temperature and affecting the lubrication and sealing performance of the main pump.

Professional repairs
  1. Professional maintenance: When the main pump fails, it should be overhauled by professional maintenance personnel and replaced with genuine accessories to ensure the quality of maintenance and avoid affecting the service life of the main pump due to improper maintenance.
  2. Preventive maintenance: according to the use of the excavator and the operation status of the main pump, formulate a preventive maintenance plan, regularly inspect and replace the wearing parts of the main pump, and eliminate potential faults in advance.

Main hydraulic pump diagram

Excavator hydraulic pump types