轴承的基本原理brg+basic课稿.ppt

轴承的基本原理 轴承的负荷 B-13 Cylindrical Roller Bearing Variants ? The range of bearing variants and their characteristics is illustrated in this slide. Note that the speed is relatively high in relation to the high load capability. ? Logarithmic profiles of the raceway and rollers prevent high edge stresses as rollers and raceways elastically deform under high loads. ? Sliding friction occurs in the contact area between roller end and flange, and it is critical to make sure that this area is properly lubricated. SKF developments in the flange/roller geometry have greatly improved the effectiveness of the supply of lubrication to this area. SKF Reliability Maintenance Institute ?B-14 Taper Roller Bearing Capabilities ? The taper roller bearing design allows true rolling. The enlarged view at top shows the beneficial effects of logarithmic profiles on the stress concentrations in the raceway; this can be compared to stresses resulting from straight-line contact. . The lower enlargement shows the detail of the flange to roller contact, where sliding friction occurs. ? Like the angular contact ball bearing, these bearings can only carry loads in one direction and for this reason they are generally fitted in pairs. Care must be taken to establish the correct amount of clearance or preload in these assemblies, which must be established at the assembly stage. SKF Reliability Maintenance Institute B-15 Spherical Roller Bearing Capabilities ? SKF is a world leader in bearing designs, and the spherical roller bearing is a good example of this. The bearing is the work-horse of the industrial world due to its self-aligning ability, its great axial and radial load carrying ability, and its ability to withstand shock loads. Special heat treatment enables this bearing to operate at temperatures of up to 200 oC (392 °F) with no detriment to the material. ? The high load carrying ability is a function of the bearing design, the use of high quality materials and manufacturing quality. T