A splined shaft is a piece mechanical component that can perform two functions; it can provide anti-rotation when functioning as a linear guide. And it can also transmit torque when functioning as a nonlinear guide. Splined shafts are built with splines, grooves or tongues that are machined along the length of the shaft. They mate with the female splined bore, gear bearing or another mating component. Then they transfer rotary motion in rotary drive applications or function as function as a linear guide when paired with an internally-splined bearing or bushing.
There are different types of a splined shaft according to grooves or tongues that transmit torque. Below is a list of the different types of splined shaft designs that are currently used today.
- Parallel Key - A type splined shaft that features a square profile and ridges
- Involute Splines - They are built with tapered ridges that have the ability to reduce stress concentrations
- Crowded - This is a type of splined shaft that features modified teeth that taper towards the end face allowing angular misalignment
- Serrations - It has a tooth that is non-involute. Featuring teeth that are in the form of an included angle that allows more teeth on a smaller diameter shaft.
- Helical Splines - Built with either parallel or involute teeth and with ridges that form a helix pattern around the shaft. Allowing both rotary and linear motion. It also minimizes stress concentrations for a stationary joint under high load.
Those are the different types of splined shafts designs used various industries today. Each of them offers benefits and functionalities that make them the ideal component for a specific task or application. They differ on the types of grooves and tongues that allow them to transmit different amounts of torque making them suitable for any application. Choosing the right type of spline shaft will depend on the application.