Rotary Claw

Rotary Claw vacuum pumps generate contact-free vacuum efficiently and economically. This is possible because of the principle of internal compression in the rotary claw design. The claw vacuum pumps are based on a static compression system. In contrast to rotary lobes, compression happens internally by volume contraction. A claw pump consists of two rotors. They turn in opposite directions in a compressor housing without contact observing very tight clearances. They are synchronized via precision gear. As the claw moves over the suction connection and the axial suction channel inlet gas is sucked into the compression chamber. The gas is pre-compressed within the compressing chamber and is then discharged.

Rotary Screw

A screw vacuum pump consists of two parallel, screw-shaped rotors, one with a right-hand thread and the other with a left-hand thread. Both screws turn in the compressor housing without friction and at very tight clearances. They are synchronized via precision gear. The compression housing and the special shape of the screws form the compression chambers. Due to the opposite rotation of both screws, the chamber connected with the suction port is enlarged and the gas is transported into the compression chamber. Then the chamber moves axially from the suction side to the pressure side (arrow). In variable pitch models, the gas is compressed at each pitch change and cooled before the next pitch change, resulting in greater efficiency. On the pressure side, the chamber is moved against the axial housing wall and the volume is reduced until the front surface of the screw opens the pressure channel and the pre-compressed gas is discharged through the pressure connection. Cooling is achieved using a water-cooled outer chamber. For some pump sizes additional cooling gas can be introduced into the pump.

Rotary Vane Vacuum Pumps

A rotary vane pump is a positive-displacement pump that consists of vanes mounted to a rotor that rotates inside a cavity. In some cases, these vanes can have variable length and/or be tensioned to maintain contact with the walls as the pump rotates. It was invented in 1874. There have been various improvements, including a variable vane pump for gases They are considered less suitable than other vacuum pumps for high-viscosity and high-pressure fluids, and are complex to operate. They can endure short periods of dry operation and are considered good for low-viscosity fluids.

Regenerative Blowers

Regenerative blowers move air using non-positive displacement. They allow some air to pass over a blade and then forward using another blade. This is different from machines that use positive displacement that work by trapping air and forcing it to move.