Though one may not think about gears to be flexible, gear couplings are very much regarded as a versatile coupling. A equipment coupling is definitely a mechanical gadget 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 contains a 1:1 equipment ratio internal/exterior gear pair. The tooth flanks and outer size of the exterior gear 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 because of 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 gear couplings contain short sleeves encircled by a perpendicular flange. One sleeve is definitely placed on each shaft so the two flanges line up face to face. A series of screws or bolts in 
the flanges keep them jointly. Continuous sleeve equipment couplings feature shaft ends coupled collectively and abutted against one another, which are after that enveloped by a sleeve. Generally, these sleeves are made of metal, but they can also be made of 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 minor misalignments such as installation mistakes and adjustments in shaft alignment due to operating conditions. These kinds of gear couplings are usually limited by angular misalignments of 1/4 to 1/2°.