About Rotary Shaft Oil Seals
Rotary shaft oil seals also known as shaft seals are used in components with oscillating or rotating parts to keep lubricating fluid within them while preventing the ingress of mud and water. Helps improve component life and long-term performance.
Structural composition
Rotary shaft oil seals also known as lip seals, are used to seal rotating elements such as shafts or rotating bores. Common examples include hydraulic pump seals, axle seals, and power steering seals. Early rotating shaft seals used leather as the sealing element. Modern elastomers have replaced leather, and the industry has also added clamping springs that help the sealing lip compensate for lip wear.
The sealing structure consists of a spring main sealing lip in point contact with the shaft. Point contact is formed by two angles, the air side angle is usually smaller than the oil side angle. Depending on the seal type, these two angles vary to create a pressure distribution at the seal contact point that has a steeper slope on the oil side of the seal. The shallower the slope on the oil side of the seal, the wetter the seal will run. The spring is positioned such that the centerline of the spring is axially biased toward the air side of the lip contact point.
To exclude contaminants, a dust lip can be used. To resist wear, the compound typically has a durometer (hardness) of 70 to 85 Shore A.
Advantages
1、Very good static sealing.
2、Very good thermal expansion compensation.
3、Greater roughness is allowed in the housing.
4、Reduced risk of corrosion.
5、Sealing for low and high-viscosity fluids.
6、Modern primary sealing lip with low radial forces.
7、Protection against undesirable air contaminants.
Application industries
Rotary shaft oil seals are a sealing device used to prevent liquid or gas leakage, especially suitable for sealing between the rotating shaft and the external environment. They are widely used in various mechanical equipment and industrial applications. Here are some application examples:
■ Automotive industry: Rotating shaft oil seals are widely used in automotive components such as engines, transmissions, and wheel hubs. They are used to prevent engine oil, coolant and other fluids from leaking into the environment while preventing external dust and contaminants from entering critical components.
■ Industrial Machinery: In various industrial equipment, such as pumps, compressors, gearboxes and motors, rotating shaft oil seals are used to prevent leakage of lubricating oil, liquid or gas. They ensure the proper functioning of the equipment and protect internal parts from external conditions.
■ Agricultural machinery: Rotary shaft oil seals in agricultural equipment prevent the leakage of agricultural machinery lubricants and other fluids, ensuring the reliability and long-term use of agricultural machinery.
■ Aerospace industry: In aviation and aerospace devices, rotating shaft oil seals are used to prevent the leakage of lubricating oil and other media and protect key components from the external environment.
■ Manufacturing: Rotary shaft oil seals are used in various manufacturing industries, such as food and beverage processing, textiles, paper and chemical industries. They are used to maintain equipment reliability and productivity, and to comply with health and safety standards.
Type of oil seals
There are many types of rotary shaft oil seals, and the type chosen depends on the application requirements, operating conditions and environment. Here are some common oil seal types:
1、Single Lip Oil Seal: Single Lip Oil Seal is the simplest and most common type. It consists of a lip to prevent leakage of liquid or gas. Single lip oil seals are suitable for lower pressure and speed applications.
2、Double Lip Oil Seal: Double Lip Oil Seal prevents leakage more effectively than single lip oil seal. It consists of two lips forming a sealing cavity, providing better sealing performance. Double lip oil seals are often used in applications with high leakage requirements.
3、Spring-Loaded Oil Seal: Spring-Loaded Oil Seal adds a spring to the lip to provide better sealing performance. The spring keeps the lip in tight contact with the shaft and maintains pressure, preventing leaks.
4、Non-Contact Oil Seal: Non-Contact Oil Seal uses a special design to form a gas barrier through gas power or lubricant on the shaft, thereby achieving non-contact sealing. This type of oil seal is suitable for high-speed rotating shafts and applications with high friction and wear requirements.
5、Liquid Seal: Liquid seal usually uses liquid as the sealing medium to achieve sealing by forming a liquid layer between the shaft and the oil seal. Liquid seals are suitable for high speed, high temperature or high pressure applications.
6、Magnetic Seal: Magnetic seal uses magnetic force to provide a sealing effect. Sealing performance is achieved by forming a magnetic field between the oil seal and the shaft. Magnetic seals are suitable for applications with extremely high friction and wear requirements.
7、These are just some of the common types of rotary shaft oil seals. There are other specially designed oil seals in practical applications to meet a variety of different needs. Selecting the appropriate rotary shaft oil seal type requires consideration of factors such as operating conditions, speed, pressure, fluid type and environment.
How to choose Rotary shaft oil seals
There are several factors to consider when selecting the appropriate rotary shaft oil seals. Here are some guidelines to help you choose:
- Working conditions: First of all, you need to understand what working conditions the rotating shaft oil seal will be used for. Consider the speed, pressure and temperature range of the rotating axis. These factors will affect the material selection and design requirements of the oil seal.
- Fluid Type: Determines the type of fluid used on the rotating axis. Different liquids may have different requirements for oil seal materials. For example, some liquids may be corrosive to rubber materials, so materials with better corrosion resistance need to be selected.
- Dimensions and geometry: Measure the diameter of the rotating shaft and the dimensions required for the oil seal. Make sure the oil seal selected matches the size of the rotating shaft and provides the required sealing effect.
- Material selection: Select the appropriate oil seal material according to the working conditions and liquid type. Common materials include rubber (such as nitrile rubber, fluorine rubber), polyurethane, polytetrafluoroethylene (PTFE), etc. Different materials have different chemical properties, wear resistance and temperature resistance. Select the appropriate material to meet the application requirements.
- Sealing performance: Choose the appropriate oil seal type according to leakage requirements. If the leakage requirements are high, you can consider designs such as double-lip oil seals or spring-type oil seals that provide better sealing performance.
- Environmental conditions: Consider the environmental conditions in which the rotating shaft oil seal is located, such as humidity, corrosive gases, dust and particles, etc. Make sure the selected oil seal can operate stably over the long term under these conditions.
To sum up, choosing a rotary shaft oil seal requires comprehensive consideration of factors such as working conditions, liquid type, size, material, sealing performance and environmental conditions. Based on these factors, you can select the right rotary shaft oil seal for your application. If you have any doubts, you can contact our professional engineers.
