Piston Pump

Introduction

This is a 3D model of a Piston Pump.

Piston pumps belong to the positive displacement pump family. As with all positive displacement pumps, they can pump air and are self-priming.

This 3D model shows all major components associated with a typical piston pump, these include:

  • Swash Plate
  • Cylinder Block
  • Port Plate
  • Pistons
  • Suction Port
  • Discharge Port

3D Model Annotations

Piston Pump

A piston pump is a reciprocating positive displacement pump. This type of pump is often used for high pressure applications e.g. hydraulic systems. Due to its robust design, it is capable of pumping high viscosity fluids and fluids which contain solids.

Piston

Fluid is drawn into each cylinder space by pistons. When a piston is closest to the inlet port, it begins to move in a linear direction back towards the swash plate. As it retracts, fluid is drawn into the cylinder space. The charged cylinder then rotates towards the discharge port, whilst the piston simultaneously begins moving away from the swash plate. Movement of the piston in the cylinder causes the fluid to be discharged from the cylinder and through the discharge port. Piston pumps may consist of one or multiple pistons depending upon the pump design.

Swash Plate

The amount of fluid pumped is dictated by the swash plate angle/pitch. Changing the pitch of the swash plate, changes the stroke of each piston, which changes the amount of fluid drawn into each cylinder, and consequently the amount of fluid pumped. Moving the swash plate to a neutral pitch will result in no fluid being pumped (because the length of each piston stroke is effectively zero). It is possible to reverse the direction of the fluid being pumped by changing the angle of the swash plate.

Cylinder Block

The cylinder block consists of a round cylinder with smaller bored cylinders penetrating through its entire length. Each of the smaller bored cylinders provides the necessary space for the pistons to move linearly back and forth (reciprocating motion). As the pistons move, they charge and discharge the cylinder space. The cylinder volume charged and discharged per stroke depends upon the length of each piston’s stroke.

Port Plate

Fluid is drawn into the cylinders, and discharged from the cylinders, via the port plate (sometimes called the ‘valve plate’).

Inlet/Outlet

Fluid enters or exits the pump through this port. The swash plate dictates in which direction the fluid will flow through the pump i.e. if the port is an inlet or outlet port.

Drive Shaft

The power to rotate the pump is provided via the drive shaft. Piston pumps are usually electrically or mechanically driven, although it is also possible to hydraulically operate the pump.

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