What is a Vane Pump – Working, Types, and Applications

A vane pump is a positive displacement pump that delivers a constant flow rate under different pressure conditions. It is a self-priming pump. It is known as a “vane pump” because it pressurizes the fluid due to the impact of the vanes. Charles C. Barnes of Sackville, New Brunswick, invented the first vane pump and patented it On June 16, 1874.

This pump has a different number of vanes installed on a rotor that moves in the cavity. Sometimes, these vanes can be of variable length and tensioned to uphold contact with the wall as the pump derives. The pump also has a pressure relief valve that stops pressure build-up inside the pump that could break the pump.

The latest vane pumps have a surface contact between stator and rotor instead of line contact.

These pumps are most widely used in air conditioning systems, power steering and automobiles.

This positive displacement pump uses to transform high-pressure gas into a low-pressure gas. Vane pumps are not suitable for highly viscous fluids. The vane pump can handle fluids with medium viscosity and is best suitable for handling liquids with low viscosity, such as alcohols, solvents, ammonia, and LPG.

Read also: Different Types of Pumps

Working of Vane Pump

A vane pump works in the following way:

• First of all, the power is delivered to the shaft through an electric motor or engine.

• The shaft is connected with the rotor, which rotates according to the rotation of the shaft.

• This rotor has multiple vanes which rotate as the rotor rotates.

• As the rotor rotates, a vacuum generates inside the pump; due to that, it sucks external water into the pump.

• As the water enters the rotor area, the rotor blades move the water outward due to the centrifugal force.

• When the water hits the vanes, these vanes convert the K.E of the water into speed and send it toward the diffuser or volute casing area.

• The volute casing has a reducing area; due to that, it converts the speed of the water into pressure and increases the pressure according to the requirements.

• After pressurizing the water, the water discharges and delivers to the desired area.

For a better understanding, watch the following video:

Components of Vane Pump

The vane pump has the following major components:

• Casing

• Inlet Port

• Cam Ring

• Outlet Port

• Vanes

• Rotor

• Shaft

1) Casing

This is an outer part of the rotary vane pump. It provides safety to all the internal components of the pump. It prevents the internal parts, such rotor, shaft, sliding vanes etc., from any damage due to the external source.  

2) Inlet Port

This port uses to suck the fluid into the pump. It works as a one-way valve.

3) Outlet Port

After pressurizing the fluid, the pump discharges the fluid through the outlet port. It also works as a one-way valve.

4) Shaft

A shaft of the pump is connected with an electric motor. This motor delivers power to the shaft and rotates the shaft. This shaft further connects with the rotor. 

5) Rotor

It is the most important part of the pump, which play a big role in fluid suction and pressurization. It connects with the shaft. The rotor rotates according to the rotation of the shaft. It has multiple vanes.

When the rotor rotates, it creates a vacuum inside the pump due to that pump sucks fluid.

6) Vanes

The vanes of the vane pump are mounted on the rotor. The main objective of the vanes is to convert the kinetic energy of the fluid into its speed. These vanes have a rectangular shape. Sliding Vanes are present in the slots of the rotor. The sliding vanes move inside the slots of the

7) Cam Ring

This Ring is installed on the inner wall of the pump housing. 

Read also: Working of Centrifugal Pump

Types Of Vane Pumps

The vane pump has the following major types:

• Balanced Vane Pump

• Unbalanced Vane Pump

• Variable Displacement Vane Pump

1) Unbalanced Vane Pump

1. This pump is a most common type of vane pump.

2. The pressure difference between suction and discharge valves causes a lateral thrust on the pump shaft. This lateral thrust on the shaft shortens the bearing life. This type of vane pump is known as an unbalanced vane pump because of the pressure difference between the inlet and outlet valves.

3. While the balanced vane pump doesn’t have lateral thrust on the rotor shaft.

4. Unbalanced vane pump has a cylindrical rotor that is installed on the offset of a circular housing. This means that the centre of the cylindrical rotor does not coincide with the centre of the housing. There is a certain distance between the centre of the rotor and the centre of the housing.

5. The rotor has a radial groove that is grooved in the drive shaft. The rotor moves in the cam ring. Each radial groove has a vane that can move freely in and out of the groove by centrifugal force. The vanes are designed in such a way that they make contact with the cam ring surface as the rotor rotates.

6. There is no leakage between the housing and the vane tip.

2) Balanced Vane Pump

• The balanced rotary vane pump has an elliptical casing. The elliptical casing and rotor have the same centre. There is no offset.

• These vane pumps are versatile in design and most widely used in mobile and industrial applications.

• The pressure difference doesn’t create between the inlets and outlets because this pump has two inlets and an outlet.

• The two inlet ports are on opposite sides of each other. Similarly, the outlet ports are also on opposite sides.

• This assembly of the inlet and outlet ports balance equal and opposite thrust forces so that the rotor shaft doesn’t face any lateral thrust forces.

• This balance pump offers better performance and long service life.

• This type of pump has a perfect service life in many applications. In industrial applications, the balance vane pumps have more than 24,000 hours of service life.

• The cavity size between two vanes decreases from inlet side to outlet.

• The pump sucks fluid from the inlet port while discharges from the outlet port.

• The pressure acting on the rotor in the exit area is high; the forces in the two outlet areas are equal but opposite. Therefore, there is no net load on the bearings of the shaft.

3) Variable Displacement Vane Pump

• The variable displacement vane pump allows to change the size of the pocket.

• Because of the different sizes of the pump pocket, the delivery rate also varies.

• In the case of this pump, the vanes don’t come into direct contact with the pump housing.

• This rotary vane pump has a ring between the vane and casing. This ring is called the reaction ring.

• One end of this ring connects to the spring, and the other end connects to the adjusting screw.

• The size of the pump pocket changes through the adjusting screws.

• As the adjusting screw starts rotating, the reaction ring also moves up and down.

• As the reaction ring moves up and down, the offset between the rotor centre and the reaction ring centre is changed.

• Due to the variation in the offset, the size of the pocket also changes, which in turn changes the delivery flow rate from the pump.

Read Also: Working of Reciprocating Pump

The advantages and disadvantages of the vane pump are given below:

Advantages of Vane Pump

1. The pumps have self-priming capability.

2. These have a robust design.

3. They deliver a constant supply of fluid at a given speed.

4. A rotary vane pump delivers a continuous delivery with negligible pulsation.

5. They don’t need to check valves

6. These pumps have lightweight.

7. These have a robust and compact design.

8. They have high volumetric efficiency and overall efficiency.

9. This positive displacement pump can control fluids having gases and vapours.

10. They have low vibration and noise levels.

11. These have easy maintenance.

12. They provide a pulsating free flow.

13. These are best for a wide range of applications.

Disadvantages of Vane Pump

1. It requires a relief valve to prevent the pump from sudden stoppage of the delivery.

2. These types of pumps aren’t appropriate for abrasive fluids.

3. A rotary vane pump requires a good seal.

4. These pumps need a top-quality filtration system because foreign particles can cause pump failure.

5. These have a complex design of housing and many other components.

6. These pumps are not best for high viscosity or high-pressure applications.

Applications of Vane Pumps

• Vane pumps are used in beverage processing machines

• These pumps use in oil and gas applications.

• Vane pumps are also used for mid-range pressures applications such as dispenser machines (espresso, coffee, and soft drinks).

• These use in Aerosol and Propellants

• These pumps are most widely utilized for high-pressure applications such as power steering, air conditioners and superchargers.

• These pumps use for the filling of the LPG cylinders.

• They use for aviation services such as fuel transfer and deicing

• They use for bulk transferring of NH3 and LPG

Difference between Centrifugal Pump and Vane Pump

The difference between the centrifugal pump and vane pump is given below: