In the mechanical world, splines are teeth or ridges formed on a drive shaft. These when created are called spline shafts and work by locking together with a mirror image. Once these two spline shaft pieces lock and are turned, they release torque.
There are several kinds of spline shafts and these are the most common ones found today.
- Parallel Key Spline. This group of spline shafts have the common characteristic of having the splines equally spaced from each other and the two spline shafts run parallel in both directions, namely radial and axial.
- Involute Spline. This group of spline shafts would have involute splines or grooves that are not equally spaced from each other. This design reduces stress concentrations thus increasing overall strength in the long run.
- Crowned Spline. This group of spline shafts have the characteristics of involute spline shafts as to spacing but the male splines are modified or customized to allow for misalignment.
- Serrations. This group of spline shafts have equally spaced grooves whose sides form the letter ‘V’. Often, these kinds of spline shafts have small diameters.
- Helical Splines. This group of spline shafts have grooves that are equally spaced. The overall design is helical or forms a helix around the shaft. Depending on the design, the sides can be involute or parallel. This is the most flexible design, as it allows stress to be minimized for a specific joint carrying a heavy load. This can also allow for both rotary and linear motion to produce torque.
- Ball Splines. This group of spline shafts utilizes a ball bearing implement to allow linear motion even at high torque production.