Oil resistant seals

OIL SELECTION SHEET CONCEPT

Oil seal, also known as shaft seal, is a device part used in a machine to prevent liquid (mostly lubricating oil) from spilling out of a joint (mainly the joint surface of a part or shaft). Static seals and dynamic seals (generally reciprocating) with seals are called seals. The representative form of the oil seal is the TC oil seal, which is a double oil seal with a self-tightening spring covered with rubber. Generally speaking, the oil seal usually refers to this TC skeleton oil seal.

OIL SELECTION SHEET CONCEPT

Oil seal, also known as shaft seal, is a device part used in a machine to prevent liquid (mostly lubricating oil) from spilling out of a joint (mainly the joint surface of a part or shaft). Static seals and dynamic seals (generally reciprocating) with seals are called seals. The representative form of the oil seal is the TC oil seal, which is a double oil seal with a self-tightening spring covered with rubber. Generally speaking, the oil seal usually refers to this TC skeleton oil seal.

Oil seal is the common name for all types of seals in general, simply a seal that takes oil for lubrication.

Oil seals are generally divided into single type and assembly type. The assembly type is that the frame and lip materials can be freely combined, commonly used for special oil seals.

Oil seals can be divided into many different types and names from the sealing function, characteristics, construction type, working state and sealing mechanism of the oil seal. However, people commonly refer to the rotary shaft oil seal as oil seal, static seal and dynamic seal (generally reciprocating motion). ) The seal is called a seal. The representative form of the oil seal is the TC oil seal, which is a double oil seal with a self-tightening spring covered with rubber. Generally speaking, the oil seal usually refers to this TC skeleton oil seal. The frame oil seal diagram is shown in the figure:

Document Introduction

Commonly used materials for oil seals are: nitrile rubber, fluorine rubber, silicone rubber, acrylic rubber, polyurethane, polytetrafluoroethylene, etc. When selecting the material of the oil seal, consideration must be given to the compatibility of the material with the working medium, its adaptability to the working temperature range and the ability of the medium to follow the high-speed rotation of the shaft. . In general, the temperature of the oil sealant is 20 ~ 50 ℃ higher than the temperature of the working medium when the oil seal is working, and care should be taken when choosing the oil seal material. For details, please refer to: Types and characteristics of rubber. The working range of the oil seal is related to the material used in the oil seal: -40 ~ 120 when the material is nitrile rubber (NBR), -30 ~ 180 ℃ for acrylic rubber (ACM) and – 25~300℃ for fluorine rubber (FPM).

Functional purpose

Engine: Crankshaft – Oil stop valve before and after crankshaft – Valve oil seal (o-ring engine repair kit) (distributor oil seal, water pump oil seal, balance shaft oil seal, oil pump oil seal …); camshaft — camshaft oil seal; Transmission: gearbox front and rear oil seals, shift lever oil seals (o-ring gearbox repair kit) (front shifter seals and rear oil seals); rear axle: difference between speed oil seal-rear axle half oil seal- (front) rear angle oil seal, rear wheel oil seal, front wheel oil seal, direction machine oil seal (repair kit) rudder o-ring), direction assist oil seal (front axle oil seal).

Any part with liquid lubricant in the runner housing and connected to the outside requires an oil seal. Some are rubber, some are metal, and most are steel bonding rubber, such as crankshaft rear oil seal, transmission front and rear oil seal, left and right half shaft oil seal, seal transmission front oil. drive and air compressor crankshaft oil seal.

Preventive measures

Preparation and notes before starting
Thoroughly check that the mechanical washers, attachments and piping installations are complete and that they meet the specifications.
Before starting the mechanical seal, perform a static pressure test to check if the mechanical seal is leaking. If there are too many leaks, find the cause and try to eliminate it. If it is still invalid, it should be disassembled, checked and reinstalled. Generally, the static pressure test pressure is 2~3 kg/cm².
Press the pump to spin and spin the car to check if the car is fast and even. If the handwheel is difficult or does not move, check whether the assembly dimensions are correct and the installation is correct.
Setup and shutdown
Keep the chamber closed with liquid before starting. When transporting solidified media, steam is used to heat the sealed cavity to melt the medium. The car must be cranked before starting to prevent the soft ring from breaking due to sudden start.
For mechanical seals using the pump’s external oil seal system, the oil seal system must be activated first. After stopping, stop the oil sealing system afterwards.
After the hot oil pump is turned off, the cooling water in the oil chamber and the end seal cannot be stopped immediately. The coolant supply should be stopped when the oil temperature at the seal tip drops below 80 degrees to avoid damage to the sealing elements.
Work

If there is a small leak after starting the pump, it should be observed for a period of time. If the leakage does not decrease after 4 hours of continuous operation, the pump should be stopped for inspection.
The operating pressure of the pump should be stable, and the pressure fluctuation should not exceed 1 kg/cm².
During pump operation, inflation should be avoided to avoid dry friction on the sealing surface and damage to the seal.
Sealing condition must be checked regularly. During the operation, when the leakage exceeds the standard, the heavy oil should not be more than 5 drops/min, and the light oil should not be more than 10 drops/min. If there is no tendency to improve within 2-3 days, the pump should be stopped to inspect the sealing device.
Introduction advantage

The oil seal structure is simple and easy to manufacture. Simple oil seals can be cast once and the manufacturing process is not complicated even for more complex oil seals. Metal frame oil seals can be made into required oil seals from only metal and rubber through stamping, gluing, inlaid and casting processes.
Oil seals are lighter in weight and less consumable. Each oil seal is a combination of thin-walled metal parts and rubber parts, the material consumption is very small so the weight of each oil seal is very light.
The installation position of the oil seal is small, the axial length is small, it is easy to process, and the machine is compact.
Oil seal has good sealing function and long service life. It has a certain adaptability to machine vibration and spindle eccentricity.
The oil seal is easy to disassemble and convenient to check.
Cheap oil seals.