The plane oil seal factory found that when the machine is working, the radial force of the oil seal lip on the shaft causes an oil film with a thickness of about 2.5mm between the interfaces, which is the essence of the sealing effect of the skeleton oil seal.

　　First of all, The plane oil seal factory recommends to check the appearance quality, the surface of the oil seal must be smooth and free of defects such as burrs, cracks, air bubbles, missing corners and impurities embedded; the edge of the oil lip is sharp, without gaps, burrs and unevenness; The contact width between the lip and the shaft is generally 0.13 to 0.5 mm, and the optimum width is 0.25 mm.

　　Secondly, The plane oil seal factory reminds to use a vernier caliper to measure the size of the oil seal. It is best to use a standard plug gauge to measure the inner diameter to check whether the tightness is appropriate.

　　The plane oil seal factory According to the needs and conditions, the oil resistance test can be carried out. After soaking in No. 25 transmission oil at (70±5)℃ for 24h, the weight change should be -3%～+5%; at (20±5) After soaking in the mixture of No. 120 gasoline (75%) and benzene (25%) at ℃ for 24h, the weight change should not exceed +20%.

　　According to the requirements of The plane oil seal factory, the oil seal edge should have an appropriate amount of interference with the matching journal. If it is too large, it will affect its service life, and if it is too small, the sealing performance will deteriorate.