Comparison of fluid-lubricated bearings and oil-impregnated bearings

First, the connected porosity is about 20% (volume fraction), and the effective gas permeability is about 10 x 10-1. m. Under the condition of low pressure and high speed of oil-containing imported bearings, the leakage of lubricating oil is very small, and the oil film does not become very thin, so it is mainly controlled by fluid lubrication. Under such low pressure and high speed conditions. Oil-impregnated bearings have a slightly lower coefficient of friction than fluid-lubricated bearings and conventional bearings that are constantly supplied with oil. This is because the air in the cavity formed in the upper portion of the inner diameter of the bearing forms bubbles in the lubricating oil, thereby lowering the apparent viscosity of the lubricating oil.

However, under high pressure and low speed conditions, the phenomenon of lubricating oil leakage is serious, the oil film is thinned, and boundary lubrication and solid contact friction are added in the fluid lubrication area, so that the friction coefficient sharply rises. Figure 6. The critical point for this phenomenon. This critical point is 6. Compared with the critical point c in a conventional bearing, it is more biased toward the low pressure, high speed side. This is because, in the case of a conventional imported bearing, the leakage of the lubricating oil only occurs at both ends of the bearing, and for the oil-impregnated bearing, in addition to the both ends, the lubricating oil leaks through the pores of the porous body. Next, the connectivity 孑L gap is about 30% (volume fraction), and the effective gas permeability is about 100×10-1. m. Oil-bearing bearing II, the connected porosity is 1.5 times that of the oil-impregnated bearing I, and the oil content is also 1.5 times. However, the leakage of lubricating oil is related to the effective gas permeability, that is, the leakage amount of the lubricating oil of the oil bearing II is an order of magnitude higher than that of the oil bearing. That is to say, for the oil-impregnated bearing II, it is more difficult to maintain the thickness and lubrication performance of the oil film, so the critical point 6 is more biased toward the low pressure and high speed side.

For more information and purchase please visit: https://www.supplyforever.com

Some knowledge of bearing heating failure

Bearing consultation to form a knowledge of bearing heating failure

The bearing is a fixed part of the machine and is the main body of the machine. Its function is basically to maintain the center position of the shaft and the mechanism for controlling the movement. Bearings play a decisive role in any machine. If there are no imported bearings, the machine will not work.

Many users have reported that when using bearings, the failure of bearing heating is the most common, and this failure will also affect the life and performance of the bearing. So how is this failure formed? Below, is the knowledge that is summarized for everyone.

1. The oil level is too low and the lubricant is lost from the oil seal;

2. The grease in the bearing housing is completely filled or the oil level is too high. This can lead to excessive lubrication, high temperature or oil leakage;

3. The contact type (friction) oil seal is too dry or the spring is too tight;

4. The inner hole of the bearing box is not round; the bearing box is twisted and deformed; the bearing surface is not flat; the inner diameter of the box hole is too small;

5. The contact type (friction) oil seal is too dry or the spring is too tight.

For more information and purchase please visit: https://www.supplyforever.com