The Hirth toothed coupling system is used in all our toothed clutches. It consists of having the machined teeth of both parts fit with each other.

It is the ideal system when you need to join shafts that must transmit a high torque because it offers great reliability and robustness.

60º Teeth Hirth coupling detail.

Hirth coupling design

The design of the coupling is defined by the outer diameter, the tooth quantity, the angle between teeth, and its depth. Additionally, teeth can be machined with asymmetric distributions to limit the number of positions where they fit. This is an ideal solution when the shafts need to be engaged and disengaged repeatedly, but the synchronism must be maintained at all times.

Key features

120º Teeth Hirth coupling detail.

• Very high loads can be transferred using a small and simple clutch, that being composed by just 3 pieces (2 discs and a screw) is more economic than other coupling solutions.
• There is no backlash.
• The coupling is self-centering; thanks to which it’s commonly used in very high RPM gas turbines.
• If there is some friction and the screws loosen, screwing them down again would restore the firmness.
• A more complex system can be developed using pneumatic cylinders.

Main applications

This system is widely used in the manufacturing industry. Hirth Couplings were first used in aircraft engine crankshafts. Many cylinders had to be connected, often together with a reducer or a transmission booster. This made it complicated to manufacture a one-piece crankshaft, so Hirth Couplings were used to joint the different sections.

They are also used in gas turbine shafts, in accessories for surgical operating tables, in agriculture machines and bicycle parts and frames, such as the bicycle crankset.

Large diameter Hirth Couplings can perform extremely accurate and repeatable rotational positioning. For this reason, they are used in indexing heads and rotary tables for precision machining and inspection tasks.

Finally, but not less important, in electromagnetic clutches and pneumatic clutches.

Custom design

At EIDE, we can offer custom designs. If you have an application where you use this system, do not hesitate and contact us. We will quote the product that best suits your needs.

For more information about Hirth Couplings please contact the commercial department.