Wheel Hub Oil Seal: A Key Sealing Component In The Automotive Transmission System.
The hub seal is a key sealing component installed in the automobile hub assembly. Its main function is to prevent the leakage of lubricating grease and block external pollutants (such as water, dust, mud, etc.) from entering the bearing system. As an important part of the automobile transmission system, the performance of the hub seal directly affects the vehicle's driving safety, fuel economy and maintenance cost.
-Metal skeleton: provides structural strength and installation stability
-Elastic sealing lip (usually fluororubber or nitrile rubber): realize dynamic sealing
-Spring ring: maintain constant contact pressure between sealing lip and shaft
-Dust lip: as the second line of defense to block external pollutants
-Special coating: some high-end oil seals have low friction coating to reduce rotation resistance
The hub oil seal forms an initial seal through the interference fit between the elastic sealing lip and the rotating shaft, and forms a stable oil film (about 1-2μm thick) when the shaft rotates with the radial pressure provided by the spring ring, which can both maintain lubrication and prevent leakage. When the shaft rotates at high speed, the micro-bevel design of the sealing lip will produce a pumping effect, pushing the grease that attempts to leak back into the sealing cavity.
1. Classification by structure
Single lip oil seal: only main sealing lip, used in clean environment
Double lip oil seal: main sealing lip + dust lip, standard configuration
Triple lip oil seal: add extra protection, used in harsh working conditions
Unit oil seal: integrated bearing and sensor, modern trend
2. Classification by material
NBR (nitrile rubber): economical, good oil resistance
FKM (fluoro rubber): high performance, high temperature resistance (up to 200℃)
ACM (acrylic rubber): balance performance and cost
PTFE (polytetrafluoroethylene): ultra-low friction, used in electric vehicles.
-Regularly check the oil seal area for grease leakage
-When replacing the bearing, always replace the oil seal at the same time
-Use special tools to install to avoid lip damage
-Choose original or equivalent replacement parts