Correct installation guide for oil seals: the key to ensuring stable operation of equipment

Careful preparation before installation

Detailed inspection of oil seals

Before installing the oil seal, it is the first priority to conduct a meticulous inspection of the oil seal itself. The oil seal may be damaged by various factors during transportation and storage. First, check whether the oil seal is obviously damaged or deformed. Gently squeeze the oil seal and observe its elastic recovery. If the oil seal is broken, missing pieces or obviously insufficient in elasticity, such an oil seal must not be used, otherwise it will seriously affect the sealing effect and cause a series of problems such as lubricant leakage. Secondly, check whether the skeleton is intact. The skeleton is like the backbone of the oil seal, playing a key role in supporting and maintaining the shape. If the skeleton is broken or deformed, the oil seal will not be able to maintain a stable structure during operation, and the sealing performance will be greatly reduced. Finally, carefully check whether the sealing lip is defective. The sealing lip is the core part of the oil seal to achieve the sealing function. Even extremely small scratches and gaps may become a channel for lubricant leakage.
Cleaning of the shaft and installation parts

The cleanliness of the shaft and installation parts is directly related to the installation quality and service life of the oil seal. During long-term use, the surface of the shaft may be attached with oil, impurities, and rust. These contaminants will not only affect the fit between the oil seal and the shaft, but may also scratch the oil seal during installation. Similarly, if there are impurities in the installation area, the oil seal will be installed unevenly, which will affect the sealing performance. Therefore, before installation, the shaft and the installation area must be thoroughly cleaned with a professional cleaner. For oil stains, organic solvents can be used for cleaning; for rust, sandpaper polishing or rust remover treatment can be used. After cleaning, wipe it with a clean cloth to ensure that the installation surface is clean and flat.
Apply lubricating oil
Applying an appropriate amount of lubricating oil on the sealing lip and shaft of the oil seal is a step that cannot be ignored before installation. Lubricating oil can play a lubricating role during installation, making it easier to install the oil seal on the shaft, reducing the friction between the oil seal and the shaft during installation, and avoiding damage to the oil seal. At the same time, lubricating oil also helps to form a good oil film between the oil seal and the shaft, which is the key to achieving good sealing performance. When the equipment is running, the oil film of appropriate thickness can reduce the wear between the oil seal and the shaft while ensuring the seal, thus extending the service life of the oil seal. In some high-speed motor equipment, the stable oil film formed by the correct application of lubricating oil can ensure that the oil seal still maintains good sealing performance under high-speed operation and reduce the occurrence of equipment failure. ​
Strict control during installation​
Ensure that the oil seal is perpendicular to the axis centerline​
When installing the oil seal, ensuring that the oil seal is perpendicular to the axis centerline is one of the key factors to ensure sealing performance. If the oil seal is not installed vertically, the contact between the sealing lip of the oil seal and the shaft will be uneven, and some areas will be too tight, which may easily lead to increased wear; while some areas will be too loose, which may cause leakage. To ensure verticality, special installation tools can be used. For example, some high-precision oil seal installation tools can accurately install the oil seal on the shaft through a positioning device to ensure that it is perpendicular to the axis centerline. If there are no special tools, some empirical methods can also be used, such as observing the relative position of the oil seal and the shaft from multiple angles during installation, and adjusting it to be completely vertical before fixing it.
Avoid improper external forces on the oil seal

During the installation process, try to avoid excessive squeezing, twisting or scratching of the oil seal. Oil seals are usually made of relatively soft materials such as rubber. These improper external forces can easily damage their structure, thereby losing their sealing performance. When installing the oil seal on the shaft, avoid using brute force to knock or squeeze it. You can use a step-by-step approach to slowly insert the oil seal onto the shaft. At the same time, pay attention to the installation environment and ensure that there are no sharp objects around to prevent scratching the oil seal during operation.

Special installation points for different oil seals

Skeleton oil seal: For skeleton oil seals, the installation position of the self-tightening coil spring is crucial. The self-tightening coil spring provides additional radial tightening force for the oil seal to ensure that the oil seal fits tightly against the shaft. During installation, carefully check whether the self-tightening coil spring is installed in place and whether its opening direction is correct. If the self-tightening coil spring is installed in the wrong position, it will not provide uniform radial tightening force, resulting in a decrease in the sealing performance of the oil seal. For example, during the maintenance of a certain reducer, when the maintenance personnel installed the skeleton oil seal, the opening direction of the self-tightening coil spring was installed in reverse. After the reducer ran for a period of time, the oil seal had a local leakage phenomenon. After disassembling and checking, it was found that it was caused by the installation problem of the self-tightening coil spring. ​
Labyrinth oil seal: When installing the labyrinth oil seal, it is key to strictly control the gap between the rotating part and the fixed part and ensure that the position of the sealing groove is accurate. If the gap is too large, it will reduce the sealing effect and cause the fluid to leak easily; if the gap is too small, friction may occur, affecting the normal operation of the equipment. At the same time, if the position of the sealing groove is inaccurate, the flow path of the fluid in the sealing groove will change, and the flow resistance cannot be effectively used to achieve sealing.
Magnetic oil seal: When installing the magnetic oil seal, ensure that the static ring and the dynamic ring are firmly installed, the direction of the magnetic element is correct, and the dynamic ring can float freely. If the static ring and the dynamic ring are not firmly installed, they are prone to loosening during the operation of the equipment, resulting in sealing failure. If the direction of the magnetic element is wrong, effective magnetic attraction cannot be generated, and the dynamic ring and the static ring cannot fit tightly. If the dynamic ring cannot float freely, it will not be able to adapt to the shaft beating and other situations, which will also affect the sealing performance.
Comprehensive inspection and debugging after installation
Inspection of oil seal installation status
After the installation is completed, the installation status of the oil seal should be checked first. Carefully observe whether the oil seal is installed in place and whether it is skewed or loose. You can check whether the oil seal is firmly fixed on the shaft by gently shaking the oil seal. If the oil seal is found to be skewed, it must be adjusted in time, otherwise the oil seal will wear rapidly due to uneven force during the operation of the equipment, resulting in seal failure.
Equipment trial operation and monitoring
Trial operation of the equipment is an important part of testing the installation effect of the oil seal. During the trial operation, the sealing effect of the oil seal should be closely observed to check whether there is any lubricating oil leakage. At the same time, pay attention to whether the equipment has abnormal heating, vibration, etc. Lubricating oil leakage is the most direct manifestation of improper installation of the oil seal. If leakage is found, the machine should be stopped immediately for inspection. Abnormal heating may be caused by excessive friction between the oil seal and the shaft, which may be caused by excessive installation of the oil seal or verticality problems. Abnormal vibration may be related to unstable installation of the oil seal or the overall balance of the equipment.
Long-term stability monitoring
After the equipment has been in trial operation for a period of time, it is necessary to check the working status of the oil seal again to ensure that it can operate stably in the long term. Some oil seals may perform normally in the initial operation, but over time, due to the influence of various factors, their performance may deteriorate. In some equipment working in high temperature environments, the oil seal may gradually age due to the long-term effect of temperature, resulting in a decrease in sealing performance. Therefore, it is very necessary to regularly inspect and maintain the oil seal. Equipment maintenance files can be established to record the results of each inspection so that problems can be discovered in time and corresponding measures can be taken.