What are the common causes of oil seal repair kit failure?

Oil seals are generally molded with oil-resistant rubber, and nitrile rubber is the most common oil seal and ring at present. Fault Cause Analysis Elimination Method Poor lubrication, serious wear of the lip working surface, width more than 1 3.

Hello, the replacement of the oil seal is mainly due to the aging of the oil seal, deformation, and the seal is not tight, resulting in the leakage of the relevant assembly parts, in addition to the overhaul of the engine or transmission, the relevant oil seal also needs to be replaced, and the oil seal is one-time and non-reusable.

There are three kinds of high noise failures that often occur in the mechanical operation of the excavator repair package seals and hydraulic pump work, namely pipeline noise, relief valve noise, and hydraulic cylinder noise.

Drawing on experience, we have found that when the oil is mixed into the air, cavitation is easy to form in the high-pressure area of the oil seal repair kit. It can be seen that the oil filter of the hydraulic pump, the oil inlet pipe is blocked or the oil viscosity is too high, which can cause the vacuum at the oil inlet of the pump to be too high and make the air infiltrate. Secondly, the repair kit of the oil seal at the shaft end of the hydraulic pump and the pilot pump is damaged, or the oil inlet pipe is poorly sealed, resulting in air ingress.

The oil level of the oil tank is too low, so that the hydraulic pump inlet pipe is directly emptied, that is, the phenomenon of adsorption of air, and the rotation of pressure causes oil oscillation, resulting in noise inside the mechanical system.

It can be seen that the fault of the noise of the oil seal repair kit is sent from the pipeline, and the bending of the pipeline, the fixed pipeline, the dead angle, the loose fixed clip and other abnormalities will also produce vibration and cause noise. Therefore, it is necessary to check whether the clamp of the pipeline is loose, tighten and strengthen it in time, and ensure the dredging of the pipeline by the car to avoid dust blockage or dead bends. If it is a mixture of air, at this time, the air should be exhausted in time and the outside air should be prevented from re-entering.

The wear or damage of the needle valve also needs to be replaced in time, or the fatigue deformation of the spring causes the instability of its pressure regulating function, and the deformation of the oil seal repair kit, the oil seal repair kit or piston rod should be replaced in time. The noise of the hydraulic cylinder may be caused by the air mixed in the oil or the air in the hydraulic cylinder is not completely exhausted, and the cavitation phenomenon is generated under the action of high pressure, which causes a large noise, so it can be solved by exhausting the air in time.

Fault one, poor oil seal.

Manifestations: Poor lip and mouth, early leakage; Poor quality or failure of springs, early leakage; The radial pressure is too small, and it leaks early;

Causes: Poor build quality, burrs or defects on the cutting edge; The spring is too loose, the holding force is too small, etc.;

Solution: Remove burrs or replace oil seals; Replace the oil seal spring; Adjust oil seal springs, etc.

Fault two, poor assembly.

Manifestations: Obvious scars on the lips and early leakage; The oil seal is butterfly-shaped deformed; If the lip of the oil seal is reversed in the direction of assembly or the spring falls off, the machine will leak;

Reason: During assembly, the oil seal passes through the keyway or thread, scratching the lip; Improper oil seal installation tools; Improper chamfering of the shaft end, too low smoothness, or too much assembly force, resulting in the flipping of the oil seal lip or the fall off of the spring, etc.;

Solution: Replace the oil seal, when reinstalling the oil seal, use a sheath to protect the oil seal lip; Redesign and manufacture of oil seal installation tools; Use fine sandpaper to polish the chamfer of the shaft end, apply grease, and install carefully;

Fault 3: Lip wear.

Performance: poor lubrication, serious wear of the working surface of the lip, width of more than 1 3, matte; The lubricating oil contains dust, impurities or no dust-proof device, and dust, foreign matter, etc.

Causes: Poor lubrication, dry friction of the lips; The oil is not clean, and the hydraulic piping system is too dirty; Abnormal wear and tear caused by dust and other intrusion into the lips; Powder hard granules adhere to the shaft; During assembly, iron filings and the like pierce the lip; Casting sand intrudes into the lip; Misapplied paint on the shaft or oil seal lip, oil seal spring held too tightly, etc.;

Solution: Ensure lubrication; Ensure the cleanliness of the lubricating oil and strengthen the cleaning of the pipeline system; In order to prevent dust and other intrusion into the lips, a dust-proof device is added; Pay attention to cleaning during assembly and remove misapplied paint;

Fault 4: Rubber aging.

Manifestations: overheating, hardening or cracking of the lip; Poor lubrication, hardening, cracking of the lip; swollen, softened lips;

Reason: The temperature of the working medium is higher than the design value, which exceeds the durability limit of the rubber; Poor lubrication, dry friction occurs; Poor compatibility of rubber to working media; The oil seal is immersed in washing oil or gasoline for a long time, which makes the lips swell, etc.;

Solution: reduce the temperature of the working medium, or replace it with a heat-resistant rubber oil seal; Guaranteed lubrication; Selection of rubber materials compatible with the working medium or selection of working media suitable for rubber materials; Do not wash the oil seal with washing oil or gasoline, otherwise wipe it dry immediately after washing.