Thrust roller bearings are intended for applications requiring high axial load carrying capacity. This type of bearing supports the load at right angles to its direction of application and, thereby, fully utilizes its capabilities in the accommodation of working loads. thrust roller bearings are available in single acting, double acting, self-aligning, combination, cross roller, and other types. They are manufactured in sizes that range from an l.D. of 2 inches (50mm)to an outer diameter of 25 feet (7.6m). Thrust roller bearings can be divided into cylindrical roller bearings(80000 type),thrust taper roller bearings(90000 type),and thrust spherical roller bearings(29000 type).they are separation bearings,have greater rigidity,use small space,can bear greater axial load,have low sensitivity to impact load,they permit low rotating,speed,normally used in the workplace that thrust ball bearings can not applicable to. Thrust roller bearing can bear both axial load and radial load,can use in the heavy load occasion,permit the higher rotating speed,has better self-aliging performance.
Thrust bearings are used in cars because the forward gears in modern car gearboxes use helical gears which, while aiding in smoothness and noise reduction, cause axial forces that need to be dealt with. André Citroën invented a double helical gear which neutralized the thrust caused by normal helical gears.
One specific thrust bearing in an automobile is the clutch "throws out" bearing, sometimes called the clutch release bearing.