What is mechanical seal? What is a skeleton oil seal? What are the types of gaskets? Mechanical seal is a device used to solve the problem of sealing between rotating shaft and body. It is a device to prevent fluid leakage by at least one pair of end faces perpendicular to the rotating axis, under the action of the fluid pressure and the elastic force (or magnetic force) of the compensation mechanism and the coordination of the auxiliary seal, so as to prevent fluid leakage. It is commonly used in rotary fluid machinery such as pumps, compressors, reaction agitators, and also used for the sealing of gear boxes, valves, rotary joints, stern shafts of ships, etc.
Skeleton oil seal is a typical representative of oil seal. Generally speaking, oil seal refers to framework oil seal. The function of oil seal is to isolate the parts that need to be lubricated in the transmission parts and the output parts, so as not to let the lubricating oil leak. The skeleton is like the steel bar in the concrete component, which plays a reinforcing role and keeps the shape and tension of the oil seal. According to the structure, it can be divided into single lip framework oil seal and double lip framework oil seal. The secondary lip of double lip framework oil seal plays a dust-proof role to prevent external dust and impurities from entering into the machine. According to the framework type, it can be divided into inner framework oil seal, exposed framework oil seal and assembled oil seal. According to the working conditions, it can be divided into rotating framework oil seal and reciprocating framework oil seal. Widely used in gasoline engine crankshaft, diesel engine crankshaft, gearbox, differential, shock absorber, engine, axle and other parts. There are two types of gaskets.
Static seal and dynamic seal. Comparison of traditional rotary seal: traditional rotary seal mainly includes skeleton oil seal, labyrinth seal and traditional mechanical seal.
1) Framework oil seal. Short term cost performance is high, but long-term operation cost is high, service life is short, leakage rate is high, linear speed is low, wear journal, lubricating oil is easy to lose or pollute. Therefore, it is not suitable for continuous operation.
2) Labyrinth seal. Compared with the framework oil seal, it has better performance and no contact; the sealing structure and linear speed of equipment have a great relationship with the medium viscosity; the axial oil leakage still exists, so it can not be used in the condition of vertical sealing. After long-term use, the oil leakage is still large, and it is difficult to control the environmental pollution and oil consumption.
3) The traditional mechanical seal has the advantages of tight structure, less leakage, long service life, less friction power consumption, no wear on shaft or shaft sleeve, no sensitivity to vibration and deflection of rotating shaft and deflection of shaft to sealing cavity, good floating performance, safety and reliability, long operation cycle, wide application range. But the first time investment is high, the installation cost is time-consuming, and the installation precision is high; the precision of processing and manufacturing is high, the processing is complex, and the installation size is large. Skeleton oil seal and mechanical seal framework oil seal: just like the steel bar in the concrete component, it can strengthen the oil seal and keep the shape and tension of the oil seal.
According to the structure, it can be divided into single lip framework oil seal and double lip framework oil seal. The secondary lip of double lip framework oil seal plays a dust-proof role to prevent external dust and impurities from entering into the machine. According to the framework type, it can be divided into inner framework oil seal, exposed framework oil seal and assembled oil seal. According to the working conditions, it can be divided into rotating framework oil seal and reciprocating framework oil seal.
Framework oil seal structure: there are three parts: oil seal body, reinforced framework and self tightening coil spring. Generally, the inner diameter of the framework oil seal in free state is smaller than the shaft diameter, that is, it has a certain "interference amount". Therefore, when the oil is sealed into the oil seal seat and shaft, the pressure of the oil seal edge and the contraction force of the self tightening spiral spring will produce a certain radial tightening force on the shaft. After a period of operation, the pressure will rapidly decrease or even disappear. Therefore, the spring can compensate the self tightening force of the oil seal at any time.