Sliding valve vacuum pump suction principle and rotary vane pump similar, but the two different structures. Sliding valve vacuum pump is the use of slide valve body to change the suction chamber volume, it is called the spool pump. Although the slide valve pump is an old pump, compared with rotary vane pumps, it has such outstanding advantages as high working pressure (104 Pa), large pumping capacity, continuous operation in harsh environments, durability and the like In the vacuum smelting, vacuum drying, vacuum impregnation, vacuum distillation and other industries have been widely used. At present, the oil-sealed vacuum pumps widely used in the vacuum industry are mostly medium and small rotary vane pumps and medium and large-sized slide valve pumps. Rotary vane pump In dirty working conditions, the vane pump stuck in the rotor slot. Although the slide valve pump to overcome this shortcoming to some extent, but the spool center of mass relative to the center of rotation distance is not a fixed value, although some structural measures taken to balance, but not yet fully balanced, so the vibration is difficult Completely eliminated. In particular, the greater the capacity of the pump, the vibration is greater. At the same time, the above two pumps, especially the spool pump, have a larger external dimension compared with their displacement.