The skeleton oil seal structure consists of three parts: the oil seal body, the reinforced skeleton and the self-tightening coil spring. The sealing body is divided into bottom, waist frame oil seal structure diagram, cutting edge and sealing lip according to different parts. Generally, the inner diameter of the skeleton oil seal in the free state is smaller than the shaft diameter, that is, it has a certain interference. Therefore, after the oil seal is installed on the oil seal seat and the shaft, the pressure of the oil seal edge and the contraction force of the self-tightening coil 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, adding a spring can compensate for the self-tightening force of the oil seal at any time.
Oil seals are used to keep chemicals apart from lubricants such as oil/fat or water away to keep spinning shafts or bearings in proper working condition. Rotary shaft Seals are among the most commonly used seals for sealing lubricating oil, water or grease in different applications.
Oil seals are used in a great many devices for steel production equipment.
Figure 7 shows the places where each seal type is used in a rolling mill.
Rubber type
No single physical property of rubbers is responsible for the successful performance of an oil seal or ‘O’ ring. The ultimate tensile strength, breaking elongation, modulus, shore hardness, creep and stress relaxation in tension and compression loads are all important physical properties that characterize a seal or ‘O’ ring. Compression strength and set together with stress relaxation or decay are important for effective sealing. The difference in these properties in a swollen seal is highly critical. An optimum swelling value in a fluid medium is a desirable feature. De-swelling decreases the seal pressure against the wall of the housing where the seal is fixed, leading to leakage. Over swelling minimizes the physical properties of the rubber. Seals made of polysulfide rubbers have extreme fuel resistance but undesirably high compression set. The effect of temperature on the seal is an important factor. Swelling under stress can increase at higher temperatures and a suitable compounding technique should be adopted to reduce this effect.