Application of Sealing on Oil Film Bearing of Rolling Mill

Aug 09, 2021

Oil film bearings are also called liquid friction bearings. During the working process of the rolling mill, liquid lubrication is used to form a complete pressure oil film between the cone sleeve and the bushing. The oil film completely separates the bushes and the cone sleeves that are relatively running at high speed without direct metal contact.

Sealing device is a very important part of oil film bearing.

The characteristics of the oil film bearing rotary seal of mainly have three points:

1) Sealing of two-way media (water or emulsion and lubricating oil);

2) The pressure difference on both sides, but there is jet or splash;

3) The seal rotates with the roll at high speed.

The rotary seals of oil film bearings of rolling mills are all lip seals. The lip type seal mainly relies on the sharp corners of the sealing lip to compress the sealing coupling surface. In theory, it should be a line contact, but in fact it is a narrow-band contact, with sufficient pressing force, and the contact stress is in a peak shape.

For the lip type seal, it cannot be pressed too hard, and the contact belt cannot be too wide. Analyzed from the dual angle of lubrication and sealing, that is: if the pressure is too strong, the seal and the coupling surface will be in a semi-dry friction state, which will aggravate the wear and heat of the seal and shorten the service life

if the contact belt is too wide, it may form a thick wax lubrication state, and thus leak oil to the outside, reducing the sealing effect