Rotor pump

The rotor pump is a form of positive displacement pump. It is composed of a rotating rotor and a stationary pump body. It has no suction or discharge valves. The working volume is changed by the relative movement between the rotor and the pump body, and the liquid is discharged by the squeezing action of the rotating rotor. At the same time, space is left on the other side to form a low pressure, so that the liquid is continuously sucked in.

According to its structure and principle, the rotor pump can be divided into gear pumps, screw pumps, rotary piston pumps (cam pumps, Roots pumps), flexible impeller pumps, vane pumps, hose pumps, etc. The rotor pump is a rotating positive displacement pump with a positive displacement property, and its flow rate does not change with the back pressure.

The occasions where the rotor pump is preferred are: viscous liquids, occasions where metering is required, occasions where self-priming is required, occasions containing gas, small flow occasions, pumps that require no shearing of the medium, high pressure occasions where the pump needs to be reversed, etc.

The common characteristics of various rotor pumps are as follows.

① There is no suction valve and discharge valve, and their main working parts are the pump housing and rotor (such as gears, screws, cams, etc.).

② Compared with reciprocating pumps, the rotor makes a rotary motion, has no impact, has a higher speed, a compact structure, and a smaller volume.

③ The discharge pressure is generally higher, but lower than that of a reciprocating pump, and the flow rate is smaller than that of a reciprocating pump. The efficiency is lower. It is generally only suitable for conveying a small amount of liquid and is mostly used as an auxiliary device.

④ Most rotor pumps are lubricated by the liquid they convey, so they are generally suitable for conveying liquids with lubricity and no solid particles.

⑤ The rotor pump also discharges liquid intermittently, so the fluctuation of the flow rate is larger than that of a centrifugal pump and smaller than that of a reciprocating pump, but it can be regarded as approximately uniform.

⑥ When there is a liquid film on the surface of the rotor (transporting lubricating liquid), the pump will have self-priming ability.