Though one may not think of gears to be flexible, gear couplings are extremely much considered to be a versatile coupling. A equipment coupling is usually a mechanical device designed to transmit torque between two shafts that aren’t collinear. The coupling typically contains two versatile joints, one set to each shaft. These joints tend to be linked by a third shaft called the spindle.
Each joint generally includes a 1:1 gear ratio internal/exterior gear pair. The tooth flanks and external size of the exterior equipment are crowned to allow for angular displacement between your two gears. Mechanically, the gears are equivalent to rotating splines with altered profiles. They are known as gears due to the relatively large size of one’s teeth. Equipment couplings are usually limited to angular misalignments of 4 to 5°.
Equipment couplings ordinarily can be found in two variations, flanged sleeve and continuous sleeve. Flanged equipment couplings consist of short sleeves encircled by a perpendicular flange. One sleeve is usually positioned on each shaft therefore the two flanges line up in person. A number of screws or bolts in the flanges keep them together. Continuous sleeve equipment couplings feature 
shaft ends coupled jointly and abutted against one another, which are then enveloped by a sleeve. Generally, these sleeves are constructed with metal, but they may also be made of Nylon.
Single joint gear couplings are used to connect two nominally coaxial shafts. In this application these devices is named a gear-type versatile, or flexible coupling. The solitary joint permits minimal misalignments such as for example installation errors and adjustments in shaft alignment because of operating conditions. These kinds of equipment couplings are generally limited by angular misalignments of 1/4 to 1/2°.