Axial piston pump
The plunger pump uses a plunger and a cylinder block as main working members. When the plunger reciprocates in the plunger hole of the cylinder block, a volume change occurs in the closed working volume formed by the plunger and the cylinder bore, and the suction and discharge processes are completed. According to the different arrangement of the plunger in the cylinder, the plunger pump is divided into two types: radial type and axial type. Radial piston pumps have been gradually replaced by axial piston pumps in many applications due to their complex structure and large volume. In the last section of this chapter, a brief description of the valved radial piston pump with certain characteristics is given.
The plunger centerline of the axial piston pump is parallel (or substantially parallel) to the axis of the cylinder block. These pumps have good sealing performance, high working pressure (rated working pressure is generally 32~40Mpa), and can maintain relatively high volumetric efficiency (generally around 95%) and total efficiency (generally 90%) under high pressure. The above) is easy to realize the advantages of variable and light weight per unit of power. Its shortcoming is that the structure is more complicated, and some parts have higher requirements on materials and processing technology. Therefore, among all kinds of positive displacement pumps, the price of the plunger pump is the highest. The plunger pump is sensitive to oil contamination and has strict requirements on use and maintenance. The maximum allowable speed of the pump is limited by factors such as cavitation, grinding parts and bearing life, generally not exceeding 4000r/min, and small displacement specifications up to 8000~10000r/min. As a medium and high pressure oil source, axial piston pumps are widely used in various industrial sectors.
A7V series inclined shaft variable displacement piston pump