Innenring

Innenring is a German term that translates to “inner ring” and is used in technical and geometric contexts. In everyday German engineering language it commonly refers to the inner component of a bearing, while in geometry it denotes the inner boundary of an annulus.

In geometry, the Innenring describes the interior circle of an annulus, the ring-shaped region between two concentric circles. The inner radius defines the inner boundary, and together with the outer radius it determines the width and area of the annulus. This concept is fundamental in discussions of circular sections, tolerances, and spatial calculations.

In mechanical engineering, the Innenring is the inner race or inner component of a rolling-element bearing. It is designed to be mounted on a shaft and carries the rolling elements—such as balls or rollers—that run along its raceway. The surface finish, hardness, and dimensional tolerances of the Innenring are critical for ensuring smooth rotation, bearing life, and load distribution. The Innenring is typically manufactured from hardened steel and may be press-fitted onto a shaft or clamped to a rotating assembly, while the corresponding Außenring (outer ring) is housed in the bearing’s stationary part.

Bearings are characterized by the interaction of the Innenring, the rolling elements, and the Außenring. Proper lubrication, appropriate fits, and correct alignment are essential to minimize wear and ensure reliable performance under radial and axial loads.

The term Innenring can thus refer either to the inner boundary in geometric contexts or to the inner race in bearing technology, depending on the disciplinary usage.