Rolling contact type bearings

The auxiliary bearing may be of the rolling element type, which is cm rently most common, or the dry lubricated bushing. The auxiliary bearing, which normally does not contact the shaft, is used to protect the Totaling components from loss of the servo amplifiers (see Figure 5-4.5). The ui -... 

C = basic dynamic load rating in kg or N (provided by the bearing manufacturer). It is the load which will give a life of 1 million revolutions P - equivalent dynamic bearing load in kg or N p = exponent of the life equation, which depends upon the type of contact between the races and the rolling elements. It is recommended as 3 for ball bearings and 10/3 for roller bearings = speed of the machine in r.p.m. 

When solid nonconforming surfaces are brought into contact in machine elements such as gears, cams, rolling element bearing, sdl the load is concentrated over a small contact area. A small concentrated contact, point or line, results in high pressure which leads to elastic deformation of the surfaces. Since the shape of contact determines the pressure distribution, the elastic deformation has to be taken into consideration. This type of lubrication is called elastohydrodynamic lubrication. 

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