Though one might not think about gears to be flexible, gear couplings are extremely much regarded as a flexible coupling. A equipment coupling is a mechanical device designed to transmit torque between two shafts that are not collinear. The coupling typically includes two versatile joints, one fixed to each shaft. These joints are often connected by a third shaft called the spindle.
Each joint generally includes a 1:1 equipment ratio internal/external gear set. The tooth flanks and outer diameter of the external gear are crowned to permit for angular displacement between your two gears. Mechanically, the gears are equal to rotating splines with altered 
profiles. They are known as gears due to the relatively large size of one’s teeth. Gear couplings are generally 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 contain short sleeves surrounded by a perpendicular flange. One sleeve can be placed on each shaft so the two flanges fall into line in person. A series of screws or bolts in the flanges keep them jointly. Continuous sleeve gear couplings feature shaft ends coupled together and abutted against one another, which are after that enveloped by a sleeve. Generally, these sleeves are made from metal, but they may also be made of Nylon.
Single joint gear couplings are accustomed to connect two nominally coaxial shafts. In this application these devices is named a gear-type versatile, or versatile coupling. The single joint permits minimal misalignments such as for example installation errors and changes in shaft alignment due to operating circumstances. These types of gear couplings are generally limited to angular misalignments of 1/4 to 1/2°.