Causes and solutions of radial force in gear pump

For machine lubrication, oil supply or other liquid systems, it is necessary to use gear pump. Gear pump is a kind of rotary hydraulic pump. There are two or more gears meshed in the gearbox, and the fluid is drawn in from one side and discharged to the other side under the action of rotation. Today, let's look at the causes and solutions of radial force.

 

Reason:

 

① The pressure distribution acting on the outer circle of the gear is different. The pressure distribution from the oil pressure chamber to the oil suction chamber is gradually reduced by stages, and there is a radial force produced by the existence of pressure difference;

 

② There is a radial clearance between the tooth top and the surface of the pump body; the resultant force of the uneven oil force acts on the pump shaft, making the shaft bear the radial force generated by the unidirectional pressure.

 

The higher the working pressure of the oil gear pump, the greater the radial force. The resultant force F1 of the radial force on the driving gear: smaller. The resultant force F2 of the radial force on the driven gear is larger, F2 ＞ F1. Because the meshing point of the gear is constantly changing, the magnitude and direction of the force change periodically. Hazard: vibration, noise, early bearing damage, affecting service life.

 

terms of settlement:

 

1. Reduce the pressure port size. The area of the pressure oil cavity acting on the gear is reduced to the range of 1-2 gears.

2. Open the hydraulic balance tank. Two hydraulic balance grooves are opened on the end cover or bearing in the transition area from the oil suction port to the oil pressure port, so that the oil pressure port and the oil suction port are respectively connected with the balance groove close to the oil suction port and the oil pressure port, so that the radial force will be balanced to a certain extent.

3. Expand the high pressure area. Expand the oil pressure chamber to the side close to the oil suction chamber, only keep the gap between the last one or two top teeth and the shell small, and enlarge the gap between the other parts of the top teeth. The pressure in a large top clearance area is equal to the outlet pressure, and the radial force in the symmetrical area is finally balanced, which reduces the radial force acting on the bearing.

The above:Gear pump grinding process