Though one might not think of gears as being versatile, gear couplings are extremely much considered to be a versatile coupling. A gear coupling is normally a mechanical device made to Scroll Air Compressors transmit torque between two shafts that aren’t collinear. The coupling typically includes two flexible joints, one set to each shaft. These joints are often connected by a third shaft known as the spindle.
Each joint generally consists of a 1:1 gear 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 modified profiles. They are known as 
gears because of the relatively large size of the teeth. Gear couplings are usually limited to angular misalignments of 4 to 5°.
Gear 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 can be positioned on each shaft so 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 collectively and abutted against one another, which are then enveloped by a sleeve. Generally, these sleeves are made from metal, however they can also be manufactured from Nylon.
Single joint gear couplings are used to connect two nominally coaxial shafts. In this application the device is called a gear-type flexible, or flexible coupling. The one joint allows for minimal misalignments such as installation mistakes and changes in shaft alignment due to operating conditions. These types of equipment couplings are generally limited by angular misalignments of 1/4 to 1/2°.