Click：Principle of Roots Vacuum Pump

ZJP/ZJPC roots vacuum pumps with overflow valve achieve suction and exhaust functions through a pair of figure-8 rotors rotating in opposite directions at a constant speed within the pump casing. Each rotor is supported by two bearings, and a pair of synchronous gears ensures a constant relative position between the rotors. Clearances are maintained between the rotors, the rotor and the pump body, as well as the rotor and the side covers, resulting in friction-free operation of the working chamber and no lubrication required. The rotor support adopts a reliable anti-backlash structure. Rotating components undergo precision dynamic balancing, coupled with high-precision helical gears, ensuring smooth operation, low noise, and high operational reliability, enabling long-term service under high pressure differentials. The dynamic sealing section adopts proprietary patented technology combined with imported oil seals, limiting shaft seal runout to ≤ 0.02 mm, thus eliminating oil leakage at the shaft seal. A gravity-operated valve is installed between the suction and exhaust ports. The valve opens automatically when the pressure differential between the exhaust and suction ports exceeds the preset value of the valve’s dead weight, which defines the maximum allowable pressure differential for reliable pump operation. Consequently, roots pumps equipped with overflow valves feature an automatic overload protection function.

Performance Characteristics:

ZJP/ZJPC roots vacuum pumps deliver a high pumping speed at low inlet pressures and are equipped with automatic overload protection. Key components of this series are manufactured with CNC machining centers. The pump body, side covers and end covers are sealed with O-rings and positioned by cylindrical pins, ensuring excellent parts interchangeability and convenient maintenance. Roots pumps are not intended for standalone operation and must be used in series with a backing pump. Various vacuum pumps can be applied as backing pumps, including screw pumps, oil-sealed pumps and liquid ring pumps. Notably, when configured with screw pumps or liquid ring pumps as backing units, the system is particularly suitable for applications involving the extraction of large volumes of condensable gases.

The ZJC/ZJPC series roots vacuum pumps are improved based on the original coupling torque transmission, adopting magnetically driven technology. Compared with ordinary roots pumps, it has the following advantages:

1、Magnetic drive transmits torque, converting the main shaft's dynamic seal into static seal-no need for skeleton oil seals or mechanical seals, achieving zero leakage;

2、No mechanical contact friction in the transmission part, avoiding friction noise and vibration during power transmission;

3、Compared with rigid couplings, magnetic drive features lower noise, no impact noise, and stable start-up and operation;

4、It cancels dynamic seals, fundamentally solving the oil leakage problem of roots pumps;

5、It cancels dynamic seals, fundamentally solving the oil leakage problem of roots pumps。