Important position of gear pump in hydraulic system

Gear pump plays an important role in the hydraulic system, which is the power source to ensure the normal work of the hydraulic system.

Compared with other structures of the pump, the gear pump is simple in structure, light in weight, low in price, simple in manufacture, convenient in maintenance, large in speed variation range, and the system is not sensitive to oil pollution, so it is widely used in mechanical systems.

Modern mechanical engineering also put forward a lot of new requirements on the gear pump, such as high pressure, large displacement, low pulsation, low noise, so the performance analysis and improvement of the gear pump has become a very important topic.

In this paper, the flow characteristics and radial meshing forces of the gear pump are analyzed theoretically and calculated numerically, which provides the necessary theoretical basis for the design of the gear pump.

The tooth profile equation and meshing line equation are obtained according to the involute formation principle.

The meshing degree and meshing slip of gear are analyzed.

The flow rate between the gear pump tooth area and the flow rate of the gear meshing area are calculated respectively. Finally, the flow rate of the gear pump is obtained.

In the case of time and speed determination, get gear pump velocity.

The structure of external gear pump has a great influence on its internal flow field. Fluent finite volume method was used to solve the calculation model, and the change characteristics of internal flow field of external gear pump were compared under different center distances and rotating speeds.

The results show that :(1) the pressure at the oil suction port of the gear pump is lower than that at the oil pressure port, and the fluid pressure changes periodically, and the trapped oil is formed between the gear meshing tooth pairs;

(2) The smaller (larger) the center distance, the greater (smaller) the average velocity at the exit, the greater (smaller) the pressure difference between the inlet and outlet, and the higher (lower) the pressure in the trapped oil zone. (3) There is a linear proportional relationship between the velocity at the exit and the rotational speed.

A slightly larger center distance can reduce the pressure of trapped oil area.

Through theoretical analysis, it can be known that the pressure around the gear is circumferential, and the hydraulic radial force received by the gear is asymmetric, which is verified by numerical simulation.

Because of the meshing of two gears, the meshing forces of the gears interact with each other. The meshing forces and torques of the gears are obtained by calculation.

By means of finite element method and ANSYS software, the contact stress of gear is numerically analyzed, and the stress distribution of gear is obtained, which provides reference for the design of gear.

The above is about the "gear pump in the important position of the hydraulic system" introduction