Axial Piston Pump: Overview, Parts, Working, Advantages, And Application

The piston pump is a positive displacement pump that is usually used in high-pressure applications. It consists of a piston-cylinder arrangement. 

The piston is connected to the crank using connecting rod. When the crank rotates 180 degrees, the piston moves from right to left, and thus suction is created inside the cylinder. So the inlet port open and allows the liquid to enter inside the cylinder. 

Now when the crank will again move 180-degree angle, the piston will try to move from left to right. It will compress the liquid to high pressure. Hence the outlet valve opens and allows the liquid to move out.

There are various types of piston pumps, and the axial piston pump is one of them. The axial piston pump is also a positive displacement pump with several pistons within the cylinder block. All the pistons are connected to the swash plate. They reciprocate on the axis of the cylinder. Hence it is called an axial piston pump. 

You can adjust the pump outflow rate as required by changing the angle of the swash plate. It has various applications that include the automotive industry, oil and gas industry, and many more.

The article discusses more about the axial piston pump. So, you can keep reading this article to learn more about axial piston pumps’ components, working, advantages, and applications.

Parts Of Axial Piston Pump

The axial piston pump is also a swash plate axial piston pump. Here the piston will suck the fluid in half revolution and push fluid out during the other half of the revolution.

There are various components of the axial piston pump. We are listing them below.

1. Electric Motor

The cylinder and piston rotate with the help of an electric motor.

2. Coupling

The coupling connects two shafts. It connects the motor shaft with the pump shaft.

3. Swash Plate

The swash plate is the main component of the axial piston pump, which is connected to the pump shaft or drive shaft. It is set at a particular angle.

When the shaft rotates, the swash plate will cause the cylinder block and piston to rotate. The swash plate’s angle can vary depending on the fluid output flow.

4. Shoe Plate

The shoe plate is mounted on the swash plate and is connected to the connecting rod.

5. Rotating Cylinder Block

The cylinder block comprises pistons arranged in a circular pattern in the pump shaft. The piston moves inside and outside the bore on the rotation of the cylinder block.

6. Piston

The piston moves in a reciprocating motion inside the cylinder block, allowing the fluid to enter and exit from the axial piston pump. There are springs connected to the piston.

7. Valve Plate

The valve plate comprises of inlet valve and an outlet valve. The inlet valve and outlet valve are unidirectional valves.

8. Port Plate

The port plate comprises of inlet and outlet port. The inlet port allows the fluid to enter inside the axial piston pump, whereas the outlet port allows the fluid to exit from the axial piston pump.

8. Slipper

The slipper is attached to the swash plate so the pistons can rotate smoothly.

Working Of Axial Piston Pump

The axial piston pump helps to convert the rotary motion into axial reciprocating motion to provide fluid at high pressure.

The axial piston pump is always contented to a power source. For example, it is connected to an electric motor. 

The motor shaft is connected to the pump shaft through a coupling. When you switch on the motor, the motor shaft rotates, which rotates the pump shaft or drive shaft. It helps to rotate the cylinder block.

The swash plate is set at a shallow angle. When the cylinder block rotates 180 degrees, the piston will start moving inward, i.e., from right to left. 

The volume of the cylinder increases, and hence the pressure begins to decrease, and thus a vacuum will be created in the cylinder. The low pressure created inside the cylinder is sufficient to draw the fluid inside the cylinder.

Now when the cylinder block rotates the other half, i.e., another 180 degrees, the connecting rod will push the piston, i.ethe piston will move from left to right. It will compress the drawn liquid inside the cylinder. Its pressure rises above the atmospheric pressure. 

Hence the outlet valve opens, and the high-pressure liquid is released outside.

If you use two bores in the cylinder block, there will be suction in a 180-degree shaft rotation, and in another 180-degree rotation, there will be a discharge of the fluid flow. We cannot achieve continuous high-pressurized liquid using two bores inside the cylinder lock. It explains the importance of multiple bores or pistons inside the cylinder block.

There are usually 8 or 12 bores inside the cylinder block, continuously performing suction and discharge in proper order. For instance, if eight bores are inside the cylinder block, four will do the suction process, and the other four bores will discharge the high-pressurized liquid. 

Hence in this way, the discharge flow of pressurized fluid will be smooth and continuous.

The flow rate of the liquid discharged from the axial piston pump depends on various factors like the bore, diameter of the piston, swash plate angle, and number of pistons inside the cylinder block.

Function Of Swash Plate

• You can change the discharge (outlet flow of liquid) by changing the angle of the swash plate.
• The angle of the swash plate changes the stroke length of the piston.
• No discharge occurs when the swash plate is 90 degrees to the pump axis.
• The discharge increases when the swash plate angle increases from perpendicular to the pump axis.  

Advantages Of Axial Piston Pump

• You can control the fluid’s discharge flow rate by controlling the swash plate’s angle.
• They are smooth and quiet while operating. It helps to reduce noise and vibrations in hydraulic systems.
• Compact size
• They work at high rotational speed and provide a high liquid flow rate at the outlet.
• The axial piston pumps have high efficiency, leading to less energy consumption and operating costs.
• The components of the axial piston pump are durable when appropriately maintained.

Disadvantages Of Axial Piston Pump

• The axial piston pump has various moving parts that can wear and tear with time.
• It is expensive compared to other pumps.
• Limited suction capability
• It consists of various moving components that will require lubrication from time to time.

How Can I Say That My Axial Piston Pump Has Gone Bad?

If your axial piston pump goes bad, it may show some of the following conditions.

• Most of the axial piston pumps create noise during operation. But the device can have issues if your axial piston pump is creating loud, erratic noise.
• If you find a lot of contaminants in the discharge fluid, there can be some issues with the axial piston pump.
• You can expect heat or vibration when the axial piston pump works. But if you experience excess heat or vibration, there can be some problems with the axial piston pump.

Applications Of Axial Piston Pump

The applications of axial piston pump are listed below.

• Construction equipemnts
• Automotive industry
• Oil and gas industry
• Paper manufacturing industry
• Chemical processing industry
• Robotics
• Aerospace

Conclusion

The axial piston pump is a type of piston pump that has numerous pistons inside the cylinder block. 

These pistons are involved in continuous suction and discharge of the fluid. The best thing about this pump is that you can control the discharge flow rate by changing the angle of the swash plate. 

We have discussed the axial piston pump, its parts, and working principle with advantages and disadvantages and hope the information is helpful.

Thank you for reading this article.