Though one might not think of gears to be flexible, gear couplings are extremely much regarded as a versatile coupling. A gear coupling is normally a mechanical device made to transmit torque between two shafts that are not collinear. The coupling typically consists of two flexible 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/exterior gear set. The tooth flanks and outer diameter of the exterior gear are crowned to allow for angular displacement between your two gears. Mechanically, the gears are equivalent to rotating splines with modified profiles. They are known as gears due to the relatively huge size of the teeth. Equipment 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 equipment couplings consist of short sleeves encircled by a perpendicular flange. One sleeve is normally positioned on each shaft so the two flanges fall into line face to face. A series of screws or bolts in the flanges hold them jointly. 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 from metal, but they can also be manufactured from Nylon.
Single joint equipment couplings are used to connect two nominally coaxial shafts. In this application the device is named a gear-type flexible, or versatile coupling. The single joint permits minor misalignments such as installation errors and adjustments in shaft alignment because of operating conditions. These types of equipment couplings are generally limited to angular misalignments of 1/4 to 1/2°.