The role of the skeleton oil seal is generally the transmission components in the need for lubrication of the components and power components to isolate, so as not to let the lubricant leakage, usually used for rotating shafts, is a rotating shaft lip seal. The skeleton is just like the steel reinforcement inside the concrete member, which plays the role of strengthening, and makes the oil seal can keep the shape and tension. According to the skeleton type, it can be divided into inner skeleton oil seal, outer skeleton oil seal, inner and outer exposed skeleton oil seal. The skeleton oil seal is made of high quality nitrile rubber and steel plate, with stable quality and long service life. Widely used in automobile, motorcycle crankshaft, camshaft, differential, shock absorber, engine, axle, front and rear wheels and other parts.

The sealing ability of the oil seal depends on the thickness of the oil film on the sealing surface, if the thickness is too large, the oil seal leaks; if the thickness is too small, dry friction may occur, causing wear of the oil seal and the shaft; there is no oil film between the sealing lip and the shaft, which is prone to cause heat and wear.　Therefore, when installing, some oil must be applied to the seal, and at the same time, ensure that the skeleton oil seal is perpendicular to the shaft centerline; if it is not perpendicular, the sealing lip of the oil seal will drain the lubricant from the shaft, which will also lead to excessive wear of the sealing lip. In operation, the lubricant in the shell slightly oozing out a little to achieve the formation of an oil film at the sealing surface of the most ideal state.

The role of the skeleton oil seal:

1, to prevent sediment, dust, moisture, etc. from outside the invasion of the bearing;

2, to limit the lubricant leakage in the bearing. Requirements for the oil seal is the size (inner diameter, outer diameter and thickness) should be in accordance with the provisions; requirements for proper elasticity, can be properly carded shaft, play a sealing role; to be heat-resistant, abrasion-resistant, good strength, resistance to media (oil or water, etc.), long service life.

Reasonable use of oil seals, should pay attention to the following points:

(1) Shaft speed due to design and structural reasons, high speed oil seals should be used for shafts with high rpm, low speed oil seals for shafts with low rpm, low speed oil seals can not be used for high speed shafts, and vice versa.　

(2) ambient temperature in the use of higher temperatures, should be selected polypropylene ester or silicon, fluorine, silicofluoroelastomer. And should try to reduce the oil temperature in the tank. In the case of use temperature is too low, should be selected cold-resistant rubber.　

(3) pressure general oil seals to withstand poor pressure capacity, excessive pressure when the oil seal will be deformed. In the use of excessive pressure conditions should be used under pressure support ring or strengthen the pressure-resistant oil seal.　

(4)Installation of the degree of eccentricity of the oil seal and the shaft with the eccentricity is too large, then its sealing will deteriorate, especially in the high speed of the shaft is particularly serious. If the eccentricity is too large, can be used "W" section of the oil seal.　

(5)The surface finish of the shaft directly affects the service life of the oil seal, i.e., high shaft finish, the service life of the oil seal will be long.　(6) Note that in the lip of the oil seal should have a certain amount of lubricant.　

(7) Pay special attention to prevent dust from soaking into the oil seal.

Leakage causes and elimination methods:

The skeleton oil seal belongs to the dynamic sealing elements, "critical oil film" exists, is a sufficient condition for the oil seal seal, no leakage seal is not allowed, is also impossible. Because the existence of lubricant film is to ensure that the oil seal edge to realize the lubrication friction lock indispensable, and the existence of lubricant film, make a certain amount of leakage is unavoidable. For rotary oil seals, in the process of using, if in the operation of the initial 50~100 hours within the occurrence of a small amount of leakage is permissible. As the running time increases, the leakage will stop gradually, and often the life of such oil seals is relatively long. In the effective use of the period, a small amount of leakage is allowed, otherwise should find the oil seal parts leakage causes and to exclude, and in the future installation and use of the process to pay attention to.

Common causes of oil seal failure and troubleshooting methods:

No. Failure Cause Analysis Remedy

1 Poor lip poor manufacturing quality, edge burrs or defects Remove the burrs or replace the oil seal

2 Poor quality or failure of the spring Poor quality of the manufacturing quality Replacement of the spring of the oil seal

3 Radial pressure is too small The spring is too loose, the clamping force is too small. Adjust oil seal spring