Introduction to the Most Comprehensive Oil Seal Knowledge

Introduction to the Most Comprehensive Oil Seal Knowledge.

Oil seal is a mechanical component used for sealing, also known as a rotating shaft lip seal ring. The friction part of the machinery is protected from oil entering during operation, and oil seals are used to prevent oil leakage from the machinery. Common ones are skeleton oil seals.

1、 Oil seal representation method

Common representation methods:

Oil seal type – inner diameter – outer diameter – height – material

For example, TC30 * 50 * 10-NBR represents a double lip inner skeleton oil seal with an inner diameter of 30, an outer diameter of 50, and a thickness of 10, made of nitrile rubber.

2、Material of skeleton oil seal

Nitrile rubber (NBR): wear-resistant, oil resistant (cannot be used in polar media), temperature resistant: -40~120 ℃.

Hydrogenated nitrile rubber (HNBR): Wear resistance, oil resistance, aging resistance, temperature resistance: -40~200 ℃ (stronger than NBR temperature resistance).

Fluorine adhesive (FKM): acid and alkali resistant, oil resistant (resistant to all oils), temperature resistant: -20~300 ℃ (better oil resistance than the above two).

Polyurethane rubber (TPU): Wear resistance, aging resistance, temperature resistance: -20~250 ℃ (excellent aging resistance).

Silicone rubber (PMQ): heat-resistant, cold resistant, with small compression permanent deformation and low mechanical strength. Temperature resistance: -60~250 ℃ (excellent temperature resistance).

Polytetrafluoroethylene (PTFE): has good chemical stability, resistance to various media such as acid, alkali, and oil, wear resistance and high temperature resistance, high mechanical strength, and good self-lubricating properties.

Generally speaking, the materials commonly used for skeleton oil seals are nitrile rubber, fluororubber, silicone rubber, and polytetrafluoroethylene. Due to its good self-lubricating properties, especially when added to bronze, the effect is even better. They are all used to make retaining rings, Glee rings, and stemsticks.

3、 Distinguishing the model of skeleton oil seal

The C-type skeleton oil seal can be divided into five types: SC oil seal  type, T Coi seal  type, VC oil seal   type, KC oil seal   type, and DC  oil seal  type. They are single lip inner skeleton oil seal, double lip inner skeleton oil seal, single lip spring free inner skeleton oil seal, double lip spring free inner skeleton oil seal, and double lip spring free inner skeleton oil seal. (We recommend you pay attention to the “Mechanical Engineer” official account to grasp dry goods knowledge and industry information at the first time)

The G-type skeleton oil seal has a threaded shape on the outside, which is the same type as the C-type. However, it is modified to have a threaded shape on the outside in the process, similar to the function of an O-ring, which not only enhances the sealing effect but also helps to fix the oil seal from loosening.

The B-type skeleton oil seal has adhesive material on the inner side of the skeleton or there is no adhesive material inside or outside the skeleton. The absence of adhesive material will improve the heat dissipation performance.

A-type skeleton oil seal is an assembled oil seal with a relatively complex structure compared to the above three types, characterized by better and superior pressure performance.