Device and application of mechanical seal of vacuum pump and diaphragm pump

The device and application of mechanical seal of vacuum pump and diaphragm pump 1. The requirement of mechanical seal for machine accuracy: (take the mechanical seal of vacuum pump as an example) (1) The radial mechanical seal of the shaft (or sleeve) of the mechanical seal part of the device bounces The maximum public service does not exceed 0.04～0.06mm. (2) The axial movement of the rotor does not exceed 0.3mm. (3) The maximum runout of the mechanical seal positioning end facing the shaft (or sleeve) between the seal cavity and the seal end cover shall not exceed 0.04～0.06mm. 2. Recognition of seals: (1) Recognize whether the installed seal is the same as the required type. (2) Check carefully with the final assembly drawing before installation to see if the number of parts is complete. (3) Choose mechanical seals driven by parallel springs. The mechanical seals of the springs are divided into left and right rotations, which must be selected according to the rotation history of the shaft. 3. The installation method of the seal: the installation method varies with the type of mechanical seal and the type of the machine, but the installation method is almost the same. The installation process and precautions are as follows: (1) Determination of the device size: installation At the same time, the size of the mechanical seal should be ensured in accordance with the operation manual or sample of the product. (2) Before installation, the shaft (sleeve) and gland should be free of burrs, and the bearing should be in good condition; the seals, shaft, seal cavity, and gland should all be clean. In order to reduce frictional resistance, the part of the mechanical seal on the shaft should be coated with a thin layer of oil for lubrication. Taking into account the compatibility of rubber O-rings, if oil is not suitable, soapy water can be used. Floating static ring has no anti-rotation pin structure, so it is not suitable to be oiled and should be dry installed in the gland. (3) Install the static ring and gland on the shaft first, taking care not to collide with the shaft, and then install the moving ring assembly. The tightening screws of the spring seat or transmission seat should be evenly tightened in several rounds. Before fixing the gland, push the compensation ring by hand to axially tighten it. After loosening, the compensation ring can automatically spring back to the appearance of no jamming, and then the gland bolts are evenly locked. Keywords: mechanical seals, mechanical seals, mechanical shaft seals