Search results
Results from the WOW.Com Content Network
The capstan equation [1] or belt friction equation, also known as Euler–Eytelwein formula [2] (after Leonhard Euler and Johann Albert Eytelwein), [3] relates the hold-force to the load-force if a flexible line is wound around a cylinder (a bollard, a winch or a capstan).
The discovery and underlying research is usually attributed to Richard Stribeck [1] [2] [3] and Mayo D. Hersey, [4] [5] who studied friction in journal bearings for railway wagon applications during the first half of the 20th century; however, other researchers have arrived at similar conclusions before. The mechanisms along the Stribeck curve ...
Belt friction is a term describing the friction forces between a belt and a surface, such as a belt wrapped around a bollard.When a force applies a tension to one end of a belt or rope wrapped around a curved surface, the frictional force between the two surfaces increases with the amount of wrap about the curved surface, and only part of that force (or resultant belt tension) is transmitted ...
Nikolai Pavlovich Petrov's method of lubrication analysis, which assumes a concentric shaft and bearing, was the first to explain the phenomenon of bearing friction.This method, which ultimately produces the equation known as Petrov's law (or Petroff's law), is useful because it defines groups of relevant dimensionless parameters, and predicts a fairly accurate coefficient of friction, even ...
Bearing pressure is a particular case of contact mechanics often occurring in cases where a convex surface (male cylinder or sphere) contacts a concave surface (female cylinder or sphere: bore or hemispherical cup). Excessive contact pressure can lead to a typical bearing failure such as a plastic deformation similar to peening.
Fluid bearings generally have very low friction—far better than mechanical bearings. One source of friction in a fluid bearing is the viscosity of the fluid leading to dynamic friction that increases with speed, but static friction is typically negligible. Hydrostatic gas bearings are among the lowest friction bearings even at very high speeds.
The updated model offers life calculations also for hybrid bearings, i.e. bearings with steel rings and ceramic (silicon nitride) rolling elements. [ 21 ] [ 22 ] Even if the 2019 GBLM release was primarily developed to realistically determine the working life of hybrid bearings, the concept can also be used for other products and failure modes.
Journal (friction, radial or rotary) bearing: This is the most common type of plain bearing; it is simply a shaft rotating in a hole. [3] In locomotive and railroad car applications a journal bearing specifically referred to the plain bearing once used at the ends of the axles of railroad wheel sets, enclosed by journal boxes .