Excavator Hydraulic Pump Diagram: For Better Conceptual and Functional Understanding

You cannot ignore the importance of an excavator hydraulic pump. Without this, you would be unable to operate your excavator. It is used to reduce vibration and wear of the system and prolongs the excavator’s life.

The excavator hydraulic pump system controls every aspect of an excavation machine, including digging, arm movement, boom movement, and bucket movement. The design of a hydraulic pump depends on the pressure, flow rate, and other demands placed upon it.

The Excavator Hydraulic Pump is used for hydraulically powered machines and equipment. Applications include construction and mining machines, fuel tanks and storage systems, loaders, drilling machinery, cranes, and excavators.

What is an Excavator Hydraulic Pump?

Excavator hydraulic pump is the heart of your excavator’s hydraulic system. It delivers power to the hydraulic motors and supplies oil at high pressure.

The oil then moves through hoses, valves, and filters to the various hydraulic cylinders. This oil powers various articulating joints (boom, arm, bucket, or other attachments) where it is sent out through passages.

This oil is then stored in sumps before being recycled through the system to ensure that there is always enough pressure at all times.

Excavator Hydraulic Pump Diagram

Excavator Hydraulic Pump Diagram is used to present the internal and external components of the Excavator Hydraulic Pump, and it depicts the working principle of the Excavator Hydraulic Pump.

The diagram gives an overview of the significant parts of the excavator hydraulic pump, which helps in understanding the functions and operation.

The diagram also shows how different pump components are connected: valve plate, cylinder block, ball guide, drive shaft, servo block, support, pilot valve, flow regulator, etc.

Sr. No. Pump Components Sr. No. Pump Components
1 Valve Plate 8 Support
2 Cylinder Block 9 Drive Shaft Front
3 Ball Guide 10 Drive Shaft Rear
4 Retainer Plate 11 Servo Block
5 Piston Shoe 12 Charge Pump 2/4 holes
6 Thrust Plate 13 Pilot Valve
7 Swash Plate 14 Flow Regulator


Types of Hydraulic Pumps Used in Excavator

The main pump types widely used in your excavator include variable displacement pumps.

A variable displacement pump is a hydraulic pump that uses the displacement principle to change the flow rate.

The pump can be adjusted according to changing conditions, and working efficiency and maintenance costs will be reduced while lowering fluid consumption. Variable displacement pumps have high efficiency and long service life.

Further exploring variable displacement pumps will represent you with:

  • Piston Pumps
  • Axial Piston Pump
  • Radial Piston Pump
  • Vane Pumps

1)   Piston Pumps

The piston pump is a hydraulic power unit with a variable displacement and pressure. It works utilizing suction action or compression, which delivers fluid through an orifice such as a nozzle or valve to affect a helpful result.

It is used in excavators and other industrial equipment to lubricate, recirculate, and transfer high-pressure fluid to operate some devices.

The piston pump is widely used in automobiles, construction equipment, agricultural machinery, water conservancy equipment, etc.

Piston pumps can be operated with or without a pressure-regulating device.

They are self-priming and do not require any suction lift or suction head, making them uniquely suitable for many applications.

Although they have been used as standard hydraulic components in excavators since the beginning, they still have some advantages that have become more important over time.

The piston pumps are very beneficial for your machine as they provide high performance, reliable operations, and extended engine life. It has features like less internal leakage, low noise, and vibrations.

These pumps work efficiently when they receive optimum fluid supplies.

·        Axial Piston Pump

Axial piston pumps are an excellent choice for applications where high performance and long-lasting durability matter.

These types of pump systems typically have nine or more rotating pistons. They move up or down along their central shaft. The swashplate aids in operation, with each upward motion forcing more fluid through tubes into higher levels. This will then fill up the reservoir before being forced back down to facilitate excavator operation.

When the piston moves to the dead center, the intake port gets closed, and thus, the fluid is moved out utilizing the pressure port.

This process then continues. The axial piston pump uses a swash plate to change the angle of the bent axis, and as this reduces stroke, the flow rate decreases.

The life of this type of pump is comparatively longer because of zero contacting pump parts, so there is no wear and tear and ultimately no replacement issues.

·        Radial Piston Pump

Among hydraulic pumps, a radial piston pump is the one that is mounted on the parent shaft symmetrically and moves in or out radially.

This creates the main difference between axial and radial piston pumps, among which the former moves axially.

In the radial piston pumps, the arrangement that a pump follows comprises a cylinder block mounted on a shaft that rotates.

The fluid moves in and out of the cylinder. All pistons on the barrel rotate with the shaft, take fluid in, and move it out with an inlet and outlet port arrangement.

In variable displacement pump types of radial piston pumps, the inclination of the swash plate is altered to increase or decrease the stroke of the pistons.

The advantages of this pump are that it has high efficiency, can operate at pressures up to 14000 psi, and has low vibration, noise, and flow rates.

A disadvantage would be its size compared to axial water pumps, which fit into smaller spaces or applications where space may not permit an additional component. They take up a little more space in comparison to axial piston pumps.

2)   Vane Pump

A vane pump achieves an excavator’s working pressure. The primary function of this hydraulic pump is to increase the desired pressure. One of its main advantages over other hydraulic pumps is that you can adjust its working pressure according to your needs.

Vane pumps are several vanes of variable lengths that spin at high speed to help generate high speeds of piston movement. The faster these vanes spin, the higher the pressure and flow rate.

A Vane pump is a hydraulic pump that uses the centrifugal force of spinning to move fluid through a pump shaft, and it consists of vanes rotating in an open-centered housing.

The large-diameter center housing creates high pressure, while the vanes create centrifugal force at the end of the shaft that allows fluid to flow through the outlet port. This hydraulic pump is used in many tractors, excavators, and other heavy machinery.

The vane pump also comprises a pressure relief valve that releases excess pressure when not needed, thus ensuring the long life of your vane pump.

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