Though one may not think of gears to be versatile, gear couplings are extremely much considered to be a versatile coupling. A equipment coupling is a mechanical device 
designed to transmit torque between two shafts that aren’t collinear. The coupling typically includes two versatile joints, one set to each shaft. These joints are often linked by a third shaft called the spindle.
Each joint generally includes a 1:1 equipment ratio internal/external gear pair. The tooth flanks and external size of the external equipment are crowned to permit for angular displacement between the two gears. Mechanically, the gears are equal to rotating splines with altered profiles. They are called gears due to the relatively large size of one’s teeth. Equipment couplings are generally limited by angular misalignments of 4 to 5°.
Gear couplings ordinarily come in two variations, flanged sleeve and continuous sleeve. Flanged gear couplings consist of short sleeves encircled by a perpendicular flange. One sleeve is usually positioned on each shaft so the two flanges line up in person. A number of screws or bolts in the flanges hold them collectively. Continuous sleeve gear couplings feature shaft ends coupled collectively and abutted against each other, which are after that enveloped by a sleeve. Generally, these sleeves are made from metal, however they can also be manufactured from Nylon.
Single joint equipment couplings are accustomed to connect two nominally coaxial shafts. In this application these devices is called a gear-type flexible, or flexible coupling. The solitary joint allows for minimal misalignments such as installation errors and adjustments in shaft alignment due to operating conditions. These types of gear couplings are generally limited to angular misalignments of 1/4 to 1/2°.