Though one might not think of gears as being flexible, gear couplings are extremely much regarded as 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 fixed to each shaft. These joints tend to be linked by a third shaft known as the spindle.
Each joint generally consists of a 1:1 equipment ratio internal/exterior gear set. The tooth flanks and outer size of the external gear 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 huge size of one’s teeth. Equipment couplings are usually limited by angular misalignments of 4 to 5°.
Gear couplings ordinarily can be found in two variations, flanged sleeve and continuous sleeve. Flanged gear couplings consist of short sleeves surrounded by a perpendicular flange. One sleeve is usually positioned on each shaft therefore the two flanges line up face to face. A series of screws or bolts in the flanges keep them collectively. Continuous sleeve gear couplings feature shaft ends coupled together and abutted against one another, which are then enveloped by a sleeve. Generally, these sleeves are made of metal, but they can also be manufactured from Nylon.
Single joint gear couplings are used to connect two nominally coaxial shafts. In this Low Backlash Reducers application the device is called 
a gear-type versatile, or versatile coupling. The one joint allows for minimal misalignments such as for example installation mistakes and changes in shaft alignment due to operating circumstances. These types of equipment couplings are usually limited to angular misalignments of 1/4 to 1/2°.