ZJP Roots vacuum pump

Introduction to ZJP series Roots vacuum pump

Roots vacuum pump is a type of positive displacement vacuum pump,also known as a mechanical booster pump.It is currently one of the main pumping equipment for obtaining medium and high vacuum.Its working principle is similar to Roots blower,which uses an 8-shaped rotor to rotate synchronously in the opposite direction inside the pump casing,thereby completing suction and exhaust.It cannot be used alone(air-cooled Roots pump can be used alone),and needs to be connected in series with mechanical pumps(front-end pumps)such as water ring vacuum pump,rotary vane vacuum pump,reciprocating vacuum pump,etc.,to solve the problem of low vacuum degree and small pumping volume of a single mechanical pump.

The ZJP series Roots vacuum pump is an improved equipment of the ZJ series Roots vacuum pump.Its performance parameters are the same as those of the ZJ series Roots vacuum pump,but the difference is that the ZJP type Roots vacuum pump is connected between the inlet and outlet through a valve body with self weight.When used in series with the front stage pump,the atmosphere in the system enters the Roots pump.When the pressure difference between the inlet and outlet is higher than the design pressure difference of the pump,the self weight valve automatically opens,and gas flows back from the outlet to the inlet,balancing the pressure between the inlet and outlet and protecting the Roots pump motor from overload and rotor breakage.

The air-cooled Roots vacuum pump can work independently,but the generated vacuum degree is low,and the motor power is high,with a small range of use.

The principle of ZJP series Roots vacuum pump

Roots vacuum pump uses a pair of"8"-shaped rotors to rotate in opposite directions at a constant speed in the pump chamber to produce suction and exhaust.During the rotation process,a certain gap is always maintained between the rotors and between the rotors and the pump body.(See Figure 1)

The two rotors of the Roots vacuum pump are supported in rolling bearings on both sides of the pump body end caps,relying on a pair of adjustable synchronous gears to maintain a certain mutual position and gap between the two rotors during high-speed rotation.The gap between the rotor and the end cap is adjusted by a metal gasket under the fixed end bearing pressure cap.The pump works because the heated rotor can only expand to one side.(See Figure 2)As the Roots pump is a vacuum pump without internal compression,it usually has a low compression ratio and requires a front-end pump.The vacuum of a Roots pump depends not only on the structure and manufacturing accuracy of the pump itself,but also on the vacuum of the preceding pump