spline shaft

Splines are ridges or the teeth[1][2][3] on a drive shaft that mesh with grooves in a mating piece and transfer torque to it, maintaining the angular correspondence between them.

For instance, a equipment mounted on a shaft might use a man spline on the shaft that matches the female spline on the apparatus. The splines on the pictured drive shaft match with the female splines in the center of the clutch plate, as the smooth suggestion of the axle is supported in the pilot bearing in the flywheel. An planetary gearbox alternative solution to splines is certainly a keyway and important, though splines give a longer fatigue life.[2]