Single joint gear couplings are also used to connect two nominally coaxial shafts. In this application the device is called a gear-type flexible, or flexible coupling. The single joint allows for minor misalignments such as installation errors and changes in shaft alignment due to operating conditions. These types of gear couplings are generally limited to angular misalignments of 1/4–1/2°. Geislinger Giubo Grid A grid coupling is composed of two shaft hubs, a metallic grid spring, and a split cover kit. Torque is transmitted between the two coupling shaft hubs through the metallic grid spring element. Like metallic gear and disc couplings, grid couplings have a high torque density. A benefit of grid couplings, over either gear or disc couplings, is the ability their grid coupling spring elements have to absorb and spread peak load impact energy over time. This reduces the magnitude of peak loads and offers some vibration dampening capability. A negative of the grid coupling design is that it generally is very limited in its ability to accommodate the misalignment. Highly flexible Highly flexible couplings are installed when resonance or torsional vibration might be an issue, since they are designed to eliminate torsional vibration problems and to balance out shock impacts. They are used in installations where the systems requires a high level of torsional flexibility and misalignment capacity.This type of coupling provides an effective damping of torsional vibrations, and high displacement capacity, which protects the drive. The design of the highly flexible elastic couplings makes assembly easier. These couplings also compensate shaft displacements (radial, axial and angular) and the torque is transmitted in shear. Depending on the size and stiffness of the coupling, the flexible part may be single and/or multi row. Hirth joints Hirth joints use tapered teeth on two shaft ends meshed together to transmit torque. Hydrodynamic Jaw Jaw coupling is also known as spider or Lovejoy coupling. Magnetic A magnetic coupling uses magnetic forces to transmit the power from one shaft to another without any contact. This allows for full medium separation. Therefore, can provide the ability to hermetically separate two areas whilst continuing to transmit mechanical power from one to the other making these couplings ideal for applications where prevention of cross contamination is essential. Oldham An Oldham coupling has three discs, one coupled to the input, one coupled to the output, and a middle disc that is joined to the first two