Vacuum Pump


This is a 3D model of a Vacuum Pump.

3D Model Annotations

Two Stage Vacuum Pump

This 3D model represents a two-stage liquid ring vacuum pump used for removing gases or vapour from a system.

Gas and Liquid Suction Port

Gas and liquid are drawn into the first-stage chamber through this port.

Gas Suction

Gas or vapour is drawn into the pump through this connection.

Liquid Suction

Liquid is drawn into the pump through this connection.

Pump Discharge

Liquid with entrained gas is discharged from the pump through this connection.

First Stage Chamber

The first stage chamber compresses the liquid and gas as they flow through the pump. The liquid moves to the outer periphery of the chamber due to centrifugal force, whilst the gas remains closes to the shaft.

Second Stage Chamber

The second stage chamber operates in the same manner as the first stage chamber; it further increases the pressure of the gas and liquid by reducing the flow area between the pump vanes.


Fluid and gas flow into the space between the vanes and then outwards radially. Due to centrifugal force, the liquid will occupy the space furthest from the shaft, whilst gas and/or vapour will occupy the space closest to the shaft. The space between the vanes decreases as the fluid passes through the pump (first to second stage), this results in an increase in fluid pressure.

Mechanical Seal

A mechanical seal is used to seal the space between the pump shaft and casing. The seal prevents fluids leaking out of the intended flow area.


Bearings carry the axial and radial loads generated by the pump when it is stationary and in service. The type of bearing used depends upon many factors, although ball bearings are considered a suitable bearing for many service applications. This pump uses double and single row anti-friction ball bearings.


The shaft transfers the rotary motion created by the electric motor to the vanes. The shaft is held in alignment by bearings.

Electric Motor

An electric motor is used to rotate the vanes. Three phase variable frequency drive motors are typical for this type of application.

Vane Ring

The vane ring lends structural support to the pump vanes; this reduces the likelihood of the vanes cracking and failing.

Drive Shaft

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

Transfer Pipe

Liquid and gas travels from the first to second stage chamber via the transfer pipe.

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