Screw vacuum pump and claw type vacuum pump are both dry vacuum pumps, but due to their different working principles, their structures are different. In order to obtain the lowest pressure, the two pumps are made into four stages. However, the claw type pump is separated from the stage by the diaphragm, and the screw pump is separated by the cross of the screw, so there is a big difference between the two phases.

1、 The difference of using technology:

1. The screw pump has the shortest gas channel, and the gas transmission position between stages remains unchanged, which is conducive to the rapid discharge of gas out of the pump, reducing the change and condensation of gas in the pump, and facilitating the discharge of solid particles.

Claw type pump due to the existence of stage partition, gas channel is long and curved, gas is easy to condense and easy to block the channel.

2. The pump body and rotor of screw pump are single, so it is easy to carry out anti-corrosion treatment.

The surface treatment of the diaphragm of claw pump is almost impossible, and the anti-corrosion coating on the rotor surface is also easy to be damaged during assembly.

2、 The difference in service reliability:

1. The rotor and pump shaft can not be integrated due to the existence of interstage diaphragm in claw vacuum pump. The rotor is installed on the shaft at the rear. In order to facilitate the installation and disassembly, the fit can not be too tight, so the rolling key and rotor are easy to loose after operation.

The shaft and rotor of the screw pump are cast and processed as a whole, which is completely integrated and there is no assembly problem.

2. There are many gaps in claw vacuum pump, such as the clearance between the rotor and the rotor, the clearance between the rotor and the pump body, the clearance between the rotor and the end cover and the diaphragm, and each clearance is independent. As long as any one of the gaps fails, the pump can not work normally.

Only the clearance between the exhaust end and the rotor determines the working performance of the screw pump, and the clearance between the rotor and the rotor is interrelated, so the operation reliability is very high.

3、 Differences in Maintainability:

1. Disassembly

It is difficult to disassemble claw pump: due to the multi-stage structure, all disassembly needs multi-stage decomposition, and the rotor disassembly is the real difficulty. At the same time, the accuracy will be reduced in different degrees after each disassembly. Even simple cleaning must be completely disassembled and reassembled.

Screw pump disassembly is simple: screw pump disassembly only needs to remove the rear cover bearing, the rotor can be disassembled from the front end, which is extremely simple. If it is only for cleaning and dismantling, after cleaning, just install the rotor back into the pump body, without any adjustment.

2. Installation

It is difficult to assemble claw pump: during the installation of claw pump, 8 clearances of rotor end face and clearance between rotors of 8 rotors should be controlled for stage 4 rotor. If any gap is not adjusted properly, rework must be carried out again. If the rotor is to be installed on the shaft, the rotor must be knocked, which is easy to damage parts.

Screw pump assembly simple: screw pump assembly, only need to control the screw exhaust end face and the clearance between the exhaust wall, as well as screw concave clearance, only need to adjust two simple clearance.