一、 Why does double stage rotary vane vacuum pump have high temperature?

High motor power and high working current lead to high temperature of vacuum pump. The number of fan blades is less and the air volume is small. Fan speed is low, air pressure, air volume is small. The voltage of the bus where the vacuum pump motor is located is 380V. Due to the cable voltage drop and uneven load distribution, the actual voltage applied by the motor is only 365v. The low voltage results in large operating current. Motor with dust, oil, reduce the heat dissipation capacity, resulting in high temperature vacuum pump. And so on will lead to high temperature of vacuum pump.

二、 High temperature solution of double stage rotary vane vacuum pump

The motor power and speed are matched with the vacuum pump and cannot be changed. The fan is installed on the main shaft of the motor. The speed of the motor determines the speed of the fan and cannot be replaced. Although increasing the number of fan blades can play a certain role, but the dynamic balance is not easy to find after the number of blades is increased. If the alignment is not good, the motor vibration will increase.

(1) The fan cover of the original double-stage rotary vane vacuum pump was lengthened by 40 cm, and an axial fan with the same diameter as the fan cover was installed inside. The motor power of the axial flow fan was 850W, the speed was 1489r / min, and the voltage was 380V. The original fan remains. The axial flow fan is equipped with another power supply control, and the axial flow fan is not interlocked with the main motor. After the vacuum pump is started, the axial flow fan is started in time, and the axial flow fan is stopped 30 minutes after the vacuum pump is shut down, so that the main motor can be fully cooled.

(2) Regularly remove the dust on the vacuum pump motor, keep the motor heat sink clean and increase its heat dissipation capacity.

(3) Adjust the bus voltage of vacuum pump to 400V.

We all know that vacuum pump oil plays a very important role in rotary vane vacuum pump, especially the performance of 2x rotary vane vacuum pump is closely related to vacuum pump oil, especially the limit vacuum pressure and service life of vacuum pump. Vacuum pump oil is not only used as a medium to obtain vacuum, but also for lubrication, cooling and sealing of vacuum pump friction points.

三、 The main performance requirements of double stage rotary vane vacuum pump oil are as follows:

1. This is the most important performance of vacuum pump oil. Because the vacuum degree of rotary vane vacuum pump is very high, paraffin based narrow fraction lubricating oil is generally used.

2. Good thermal oxidation stability; vacuum pump is developing to a high speed. Due to the high-speed friction between sliding vane and pump body, the oil temperature increases, and the oil is easy to be oxidized and decomposed. Especially, the diffusion pump often works in a very high temperature environment, which increases the vapor pressure in the system and reduces the vacuum degree. Therefore, the vacuum pump oil is required to have good thermal oxidation stability.

3. Appropriate viscosity and good viscosity temperature characteristics: the volume of vacuum pump cavity changes constantly and forms exhaust effect, which requires the lubricating oil to have appropriate viscosity and viscosity temperature characteristics.