How does mechanical oil seal work?

Number of hits：4912023-07-20 09:46:14　

　　Mechanical oil seal is a type of seal that is used to prevent oil leakage from rotating shafts or housings in various machines and equipment. Mechanical oil seals are also known as shaft seals, radial lip seals, or rotary shaft seals. They are widely used in automotive, industrial, and petrochemical applications, where they help protect the bearings and other components from oil loss, contamination, and wear.

　　Mechanical oil seal consists of two main parts: a metal case and a rubber lip. The metal case is fixed to the stationary part of the machine, such as the pump casing or the bearing housing. The rubber lip is attached to a spring that presses it against the rotating part of the machine, such as the shaft or the impeller. The rubber lip forms a tight contact with the shaft surface, creating a dynamic seal that prevents oil from escaping or entering the gap between the shaft and the housing.

　　The rubber lip is usually made of synthetic materials, such as nitrile, polyacrylate, silicone, or fluorocarbon, that can resist high temperatures, pressures, and chemical attacks. The rubber lip may also have different shapes and profiles, depending on the application and the operating conditions. Some common types of rubber lip profiles are:

　　1、Single lip: A simple and economical design that provides basic sealing performance for low-pressure and low-speed applications.

　　2、Double lip: A more effective design that provides better sealing performance for medium-pressure and medium-speed applications. The second lip acts as a dust lip that prevents dirt and debris from reaching the main sealing lip.

　　3、Wiper lip: A special design that provides excellent sealing performance for high-pressure and high-speed applications. The wiper lip has a sharp edge that wipes off any oil film or residue from the shaft surface, reducing friction and wear.

　　How to maintain and repair a mechanical oil seal?

　　Mechanical oil seal can wear out over time due to various factors, such as:

　　1、Improper installation or alignment of the seal or the shaft.

　　2、Excessive shaft runout or eccentricity.

　　3、Excessive shaft speed or pressure.

　　4、Insufficient or contaminated lubrication.

　　5、Exposure to harsh environments or corrosive fluids.

　　Some signs of a worn or damaged mechanical oil seal are:

　　1、Oil leakage around the seal or under the machine.

　　2、Increased friction or noise from the seal or the shaft.

　　3、Reduced performance or efficiency of the machine.

　　4、Increased temperature or vibration of the machine.

　　To prevent these problems, it is important to check and replace the mechanical oil seal regularly, according to the manufacturer’s recommendations. Some tips for maintaining and repairing a mechanical oil seal are:

　　1、Choose the right type and size of seal for the application and the operating conditions.

　　2、Clean and inspect the seal and the shaft before installation.

　　3、Use proper tools and techniques to install the seal without damaging it.

　　4、Lubricate the seal and the shaft with compatible oil before operation.

　　5、Monitor the seal condition and performance during operation.

　　6、Replace the seal when it shows signs of wear or damage.

　　Mechanical oil seal is a vital part of many machines and equipment that use rotating shafts or housings. A mechanical oil seal works by creating a dynamic seal between the stationary and moving parts, preventing oil leakage and contamination. A mechanical oil seal requires proper maintenance and repair to ensure its optimal performance and longevity.