Axial piston pumps are generally composed of main components such as the cylinder body, oil distribution plate, plunger, and swash plate. There are multiple plungers in the cylinder body, which are arranged axially, meaning that the centerline of the plunger is parallel to the axis of the transmission shaft, hence it is called an axial piston pump. But it is different from a reciprocating piston pump because its plunger not only moves back and forth within the pump cylinder, but also rotates relative to the swash plate between the plunger and the pump cylinder. The plunger contacts the swashplate with a spherical end. There are high and low pressure lunar grooves on the oil distribution plate, which are separated from each other by partitions to ensure a certain degree of sealing. They are respectively connected to the inlet and outlet of the pump. There is a tilt angle between the axis of the swashplate and the axis of the cylinder block.

The working principle of an axial piston pump is that when the electric motor drives the transmission shaft to rotate, the pump cylinder and plunger rotate together, and the plunger head always maintains contact with the swashplate. As the swashplate is at an angle to the cylinder body, the plunger moves back and forth in the pump cylinder when the cylinder body rotates. Taking a plunger as an example, it rotates from 0 ° to 180 °, that is, to the position of the upper plunger, and the volume of the plunger cylinder gradually increases. Therefore, the liquid is sucked into the oil cylinder through the oil suction port a of the oil distribution plate; When the plunger is turned from 180 ° to 360 °, the volume of the plunger cylinder gradually decreases, so the liquid in the cylinder is discharged through the outlet of the oil distribution plate. As long as the transmission shaft continues to rotate, the pump will continue to work.

By changing the angle of the tilt element, the stroke length of the plunger in the pump cylinder can be changed, thereby changing the flow rate of the pump. A fixed tilt angle is called a quantitative pump, while a variable tilt angle that can be changed is called a variable displacement pump.

There are two types of axial piston pumps: swash plate and swash shaft, depending on the tilt components.

The swashplate type has a tilt angle relative to the rotating cylinder body, causing the plunger to move back and forth in the pump cylinder. The axis of the transmission shaft and the axis of the cylinder body are consistent. This type of structure is relatively simple, with high rotational speed, but high working conditions are required. The contact between the end of the plunger and the swashplate is often a weak link. The axis of the inclined shaft type inclined plate is consistent with the axis of the transmission shaft. It is caused by the inclination of the plunger cylinder body relative to the transmission shaft, causing the plunger to move back and forth. Flow regulation relies on the angle of the swinging plunger cylinder body to achieve, so some are also called swinging cylinder type. Compared with the swashplate type, it has reliable operation, large flow rate, but complex structure.

Axial piston pumps are generally used in hydraulic transmission systems of machine tools, metallurgy, forging, mining, and lifting machinery, and are particularly widely used in high-power hydraulic transmission systems. In order to improve efficiency, gear pumps or sliding vane pumps are often used as auxiliary oil pumps in applications to supply oil, compensate for leaks, and maintain a certain amount of pressure in the oil circuit.