Regular inspection and structural working principle of Roots pump

{1} Regular Inspection of LC Roots Pump

Regular inspection of the Roots pump can keep it in good working condition for a long time and reduce the failure rate of LC Roots pump, etc. Therefore, regular inspection work is very important. But this regular inspection work also needs to be carried out correctly, otherwise the wrong inspection method will not have any effect. Therefore, let's talk about how to carry out the inspection work of the vacuum pump

1. Daily inspection of LC Roots pump

1. Motor load inspection: Use a power meter or current/voltage meter to measure the motor load.

2. Temperature check: Use a thermometer to check the temperature of each part

3. Oil level inspection: Excessive oil level causes temperature increase; The oil level is too low, causing poor lubrication

Secondly, LC Roots pumps are checked monthly

The tension of the coupling elastomer or triangular tape is checked.

3. Check quarterly whether the lubricating oil in the gearbox has deteriorated

4. LC Roots pump should be inspected every six months

1. Check if the seal is damaged.

2. Check if the lubricating oil inside the front cover bearing box has deteriorated

5. Vacuum pump inspection every year

1. Does the slight wear of the gears have an impact on the normal operation of the rotor, and does it need to be adjusted?

2. Check if the piston rings and piston ring liners are worn

3. Check if the bearings are worn

Therefore, it is crucial to establish a reasonable and planned inspection time, so that the inspection work forms a good "cycle", which can greatly reduce the possibility of LC Roots pump failure that has not been detected for a long time, solve problems in a timely manner, and reduce adverse effects

{II} Structure and Working Principle of Roots Pump

In the pump chamber, there are two "8" shaped rotors installed perpendicular to each other on a pair of parallel shafts, and a pair of gear belts with a transmission ratio of 1 act to rotate synchronously in opposite directions to each other.

. There is a certain gap between the rotors and the inner wall of the pump casing, which can achieve high-speed operation

Due to the fact that Roots pumps are vacuum pumps without internal compression, the compression ratio is usually very low, so high and medium vacuum pumps require a front stage 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. In order to improve the vacuum degree of the pump, the Roots pump can be used in series

Working principle of Roots pump

When extracting air, the two rotors are driven by a pair of gears with a transmission ratio of 1, and they rotate synchronously in opposite directions to each other.

. The rotors are not in contact with each other and there are gaps between them

There is a large pumping speed within a wide pressure range

There is a gap between the rotors and between the rotor and the pump chamber wall. The moving parts in the pump chamber have no friction and do not require lubrication. There is no oil in the pump chamber

The rotor shape is symmetrical, with good dynamic balance performance and smooth operation. High precision gear transmission is selected, resulting in low noise during operation; Can achieve higher rotational speed (pumping speed)

During the pumping process, the working space volume of a Roots pump remains unchanged, that is, "no internal compression", which is different from most variable capacity vacuum pumps

Gas discharge: When the top of the rotor rotates past the edge of the exhaust port and the enclosed space is connected to the exhaust side, due to the high gas pressure on the exhaust side, a portion of high-pressure gas rushes back into the enclosed space, causing the gas pressure in the space to suddenly increase to the exhaust pressure, which is known as the "external compression process". When the rotor continues to rotate, the gas is discharged from the pump