Though one might not think about gears as being flexible, gear couplings are very much considered to be a flexible coupling. A gear 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 fixed to 
each shaft. These joints tend to be connected by a third shaft called the spindle.
Each joint generally consists of a 1:1 gear ratio internal/external gear set. The tooth flanks and external size of the external gear are crowned to permit for angular displacement between your two gears. Mechanically, the gears are equal to rotating splines with modified 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°.
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 certainly positioned on each shaft so the two flanges fall into line in person. A number of screws or bolts in the flanges hold them together. 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 may also be made of Nylon.
Single joint gear couplings are accustomed to connect two nominally coaxial shafts. In this application the device is called a gear-type flexible, or flexible coupling. The one joint permits minor misalignments such as for example installation mistakes and changes in shaft alignment because of operating conditions. These kinds of equipment couplings are generally limited to angular misalignments of 1/4 to 1/2°.