Four-point contact ball bearing

四点接触球轴承是一种分离型轴承，也可以说是一套轴承可承受双向轴向载荷的角接触球轴承。其内外圈滚道是桃型的截面，当无载荷或是纯径向载荷作用时，钢球和套圈呈现为四点接触，这也是这个名称的由来;当只有纯轴向载荷作用时，钢球和套圈就成了两点接触，可承受双向的轴向载荷。四点接触球轴承还可以承受力矩载荷，兼有了单列角接触球轴承和双列角接触球轴承的功能。四点接触球轴承只有形成两点接触时才能保证正常的工作。所以一般适用于那些纯轴向载荷或轴向载荷大的合成载荷下呈两点接触的场合,四点接触球轴承极限转速高，也适合于那些高速运转的场合。

Four-point contact ball bearing is a kind of separable bearing, which can also be said to be a set of angular contact ball bearings that can withstand bidirectional axial loads. The inner and outer ring raceways are peach-shaped sections. When no load or pure radial load acts, the steel ball and the ferrule show four-point contact, which is the origin of this name; when only pure axial load acts.The steel ball and the ferrule become two-point contact, which can bear the axial load in both directions. Four-point contact ball bearings can also withstand moment loads, and have both the functions of single-row angular contact ball bearings and double-row angular contact ball bearings.  Four-point contact ball bearings can only ensure normal work when they form two-point contact. Therefore, it is generally suitable for those occasions where there is two-point contact under pure axial load or combined load with large axial load.