**Efficiency** Efficient combustion is essential for optimizing engine performance **Efficiency** Efficient combustion is essential for optimizing engine performanceoil seal
These are comparable to type R and RST, except the outer case does not have a metal reinforcement ring. To compensate, the outside is not made of normal rubber, but a hard, heavy-duty rubber fabric. The advantage is that these types can be made in a split version. They are almost always produced to order, and made of NBR or FKM.
Runouts need to be minimized. The most common causes of the center of rotation movement are shaft whip and bearing wobble. The issue is even worse when there’s misalignment. Contrary to widespread assumption and practice, misalignment cannot be corrected or made up for by using flexible couplings.
Oil seals work by squeezing and retaining lubricant in a thin layer between the lip and the shaft. Perfect sealing is ensured by the hydrodynamic action of the rotating shaft, which in turn produces a slight pump action.
