The so-called vacuum refers to the state of gas with pressure lower than 101325pa in a given space. The noise of rotary vane vacuum pump usually refers to the noise level measured under the limit vacuum when the temperature of the pump is stable. It includes the noise of the pump itself and the noise of the motor. For users, it is also concerned about the noise of the starting stage when the pump temperature is not stable and the noise of the operation under different inlet pressure, as well as the noise of the operation of the gas opening town. Therefore. Many factors should be considered.
How to deal with the noise of the rotary vane vacuum pump. Next, I will show you how to reduce the noise of rotary vacuum pump.
1. Impact of the rotary vane of the rotary vane vacuum pump on the cylinder wall: if the manufacturing, design or materials are not correct, the rotary vane of the rotary vane vacuum pump will not slide smoothly, or the rotary vane head of the rotary vane vacuum pump will not always run close to the cylinder wall due to the existence of exhaust dead gap and the incompressible oil, which will cause the impact of the rotary vane of the rotary vane vacuum pump on the cylinder wall.
Therefore, it is advisable to adopt the structure of circular arc to separate the inlet and outlet. Use the exhaust guide slot to eliminate the dead gap. When the line separation structure is adopted, the distance from the end point of exhaust to the tangent point shall be shortened as far as possible. For the vacuum pump with the rotary vane less than 70L / s, considering the actual thickness of the rotary vane, it is recommended to take 7-lomm, and the larger value for the larger pump. When the rotor is too close, there is only a narrow strip contact between the rotor vane groove and the head of the vane. If the sealing effect is not good when the vane is turned to the tangent position, the pumping speed and even the ultimate pressure of the vane vacuum pump will be affected. It can be seen that this structure can not completely eliminate the exhaust dead gap, which limits the noise reduction level.
2. When the rotary vane vacuum pump reaches the limit pressure, the two pressure oil will shoot into the vacuum chamber at high speed when it is connected with the vacuum chamber, and make a sound when it collides with the rotor and cylinder wall.
3. Impact noise of the valve plate of the rotary vane vacuum pump on the valve seat and supporting parts: the greater the amount of gas inhaled, the greater the noise of the valve plate, the higher the valve jump, the larger the area of the valve, the greater the noise of the valve plate, and the material of the valve plate also have a certain impact. It is recommended to close the valve plate timely and tightly. Pay attention to the material selection and structure of the rotary vane vacuum pump valve.
4. The volume and position of two parts of rotary vane vacuum pump are related to noise.
5. The noise will increase when the echo and bubble breaking sound volume in the rotary vane vacuum pump box increase. Therefore, the noise will increase obviously when the gas is turned on or the atmosphere is opened. If the gas ballast can be adjusted, the gas ballast can be adjusted reasonably.
6. It should be pointed out that too much clearance between vane and groove of vane vacuum pump will reduce performance. Therefore, it is necessary to ensure a reasonable tolerance fit and shape and position tolerance value, pay attention to the thermal expansion of the spinneret, avoid the roughening of the spinneret and the groove, pay attention to the cold oil viscosity of the oil, and design sufficient spring force of the spinneret. When the circular arc surface is used for separation, the additional eccentricity value of the rotor center should not be too large. Otherwise, when the spinner passes through two circular arcs, it will break away from the cylinder wall at the intersection point and cause impact noise instead. Generally, the small pump is 0.20-0.25mm, and the large pump can be increased appropriately. The sound of the pressure oil in the exhaust dead gap and the pressure oil in the residual volume.
The above is the solution to the noise of rotary vane vacuum pump.