Selection of Oil Seal Material Based on Operating Conditions: Speed and Temperature Considerations

The selection of rubber material for skeleton oil seals is critical, as it significantly influences the performance and operational effectiveness of the seals. When determining the appropriate material for the construction of skeleton oil seals, several factors must be taken into account, including:

- Operating temperature
- Pressure
- Linear velocity
- Chemical medium

Additionally, the manufacturing processes associated with various rubber types differ, necessitating a careful consideration of the production method employed for the skeleton oil seal. While several mainstream elastomers, such as nitrile rubber, acrylic rubber, fluorinated rubber, and silicone rubber, are suitable for skeleton oil seal fabrication, the following criteria should guide the selection process:

1. The maximum operative temperature of the working environment.

This refers to the ambient temperature conditions surrounding the skeleton oil seal during its operational phase.

2. The minimum operational temperature during functioning.

At lower temperatures, the rubber material of the oil seal exhibits increased hardness and brittleness, leading to reduced resilience. Consequently, the oil seal lip exerts greater radial force on the shaft center, thereby augmenting friction. Nevertheless, as the shaft rotates, the frictional heat generated increases due to the heightened holding force, allowing the oil seal lip to gradually regain its original elasticity. Thus, the skeleton oil seal can maintain normal functionality despite the brittleness of the rubber at low temperatures or in instances where temperature is artificially depressurized, contingent on achieving a sufficiently high shaft rotational speed.

3. The influence of shaft velocity on the composition of the skeleton oil seal material.

Shaft speed plays a critical role in determining the appropriate material for skeleton oil seals. Elevated shaft speeds can generate significant thermal energy due to friction at the lip interface. This increased temperature can accelerate the degradation of the rubber lip, thereby reducing the operational lifespan of the skeleton oil seal.

4. Selection of Oil Seal Material Based on Sealing Medium

It is essential to select oil seal materials that are compatible with the specific sealing medium. The chosen material must effectively prevent the components of the medium from adversely affecting the rubber, such as causing fouling or combustion, while also resisting erosion caused by the chemical properties of the medium.

5. Selection of Skeleton Oil Seal Material Based on Operating Conditions

Oil seals can be categorized based on their operating conditions into reciprocating and rotary types. Rotary oil seals are typically employed in mechanical shaft applications, while reciprocating oil seals are used in rod systems. The selection of materials for each type of sealing application must be tailored to their specific operational requirements.

When selecting the material for an oil seal, it is imperative to evaluate the aforementioned factors from a multifaceted perspective rather than a singular viewpoint. The selection of the appropriate skeleton oil seal material should encompass a comprehensive analysis of all relevant variables.

The operating speed of a typical skeleton oil seal is influenced by the design parameters, including the geometry and applied pressure of the seal. The maximum design velocity for conventional rubber oil seals is approximately 15 m/s, whereas for PTFE lip seal rotary oil seals, the maximum operational speed can reach 30 m/s. Furthermore, an increase in the operational pressure during rotation correlates with a decrease in allowable rotation speed. Additionally, variations in temperature, whether elevated or decreased, can significantly impact both the operational speed and the service life of the oil seal.