Working principle and performance characteristics of axial piston pump

Axial piston pump is generally composed of cylinder block, oil distribution plate, plunger and swash plate and other main parts. There are multiple plungers in the cylinder body, the plunger is arranged axially, that is, the center line of the plunger is parallel to the axis of the transmission shaft, so it is called the axial plunger pump. But it is different from the reciprocating plunger pump, because it is not only the plunger in the pump cylinder to do reciprocating motion, and the plunger and the pump cylinder and swash plate relative rotating motion. The plunger is in contact with the swash plate by a spherical end. There are high and low pressure moon shaped grooves on the oil distribution plate. They are separated from each other by a partition wall to ensure a certain tightness. They are respectively communicated with the oil inlet and oil outlet of the pump. There is an oblique Angle between the axis of the swash plate and the axis of the cylinder block.

 

The working principle of axial piston pump, when the motor drives the rotation of the transmission shaft, the pump cylinder and the plunger rotate together, the plunger head always keeps in contact with the swashplate, because the swashplate and the cylinder into an Angle, so the cylinder rotates, the plunger in the pump cylinder to do reciprocating motion. Take a plunger as an example, it turns from 0° to 180°, that is, to the position of the plunger above, the volume of the plunger cylinder gradually increases, so the liquid is absorbed by the oil suction port A of the oil distribution tray; When the plunger turns from 180° to 360°, the volume of the plunger cylinder decreases gradually, so the liquid in the cylinder is discharged through the outlet of the oil distribution tray. As long as the drive shaft continues to rotate, the pump will continue to work.

 

By changing the Angle of the tilting element, the stroke length of the plunger in the pump cylinder can be changed, and the flow of the pump can be changed. The fixed tilt Angle is called the quantitative pump, and the tilt Angle can be changed is called the variable pump.

 

Axial piston pump according to the different inclined components, there are two types of inclined plate and inclined shaft.

 

Swash plate type is the inclined Angle of the swash plate relative to the rotating cylinder, which causes the plunger to move back and forth in the pump cylinder. The axis of the drive shaft is consistent with the axis of the cylinder block. This structure is simple, high speed, but the working conditions require high, the end of the plunger and the swash plate of the contact part is often a weak link. The swashplate axis of the inclined shaft type is consistent with the axis of the drive shaft. It is due to the plunger cylinder block relative to the drive shaft tilt an Angle so that the plunger reciprocating motion. Flow regulation depends on the Angle of the swing piston cylinder body to achieve, so some is also called pendulum cylinder type. Compared with the swash plate, it works reliably and has a large flow rate, but the structure is complex.

 

Axial piston pump is generally used in machine tools, metallurgy, forging, mining and lifting machinery in the hydraulic transmission system, especially widely used in high-power hydraulic transmission system. In order to improve efficiency, in the application of gear pump or vane pump is usually used as an auxiliary oil pump, used to give oil, make up for leakage and maintain a certain pressure in the oil road.