Circular ring with designations
A circular ring is the area between two concentric circles , i.e. H. between two circles with a common center. Its area is
where is the number of circles and and mean the radii as well as and the diameter of the outer and inner circle.
The area can also be calculated from the inside diameter or outside diameter and ring width :
This information can be found e.g. B. with pipe cross-sections; where is the wall thickness.
Furthermore, the area can be calculated
using the annulus width and the mean annulus diameter
The effective hydraulic diameter for a circular ring for hydraulic applications is
Should z. For example, for brake discs , a frictional torque to the axial force and the coefficient of friction by
are determined, the friction-relevant radius calculated or diameter by
Torus , hollow cylinder , spherical shell
^ H. Hinzen: machine elements . Volume 2. Oldenbourg Verlag, 2001