Drive Shaft Assembly with Spline Coupling

A drive shaft assembly for a supercharger, the drive shaft assembly comprising:

• a shaft centered on and extending along a longitudinal axis, the shaft comprising a first end and a second end opposite the first end along the longitudinal axis;
• a spline coupling mounted on the shaft, the spline coupling comprising:
• a first face spline comprising a front surface and a plurality of first teeth extending in a direction away from the front surface and away from the second end of the shaft;
• and
• a second face spline configured to engage with the first face spline, the second face spline comprising back surface and a plurality of second teeth extending in a direction away from the back surface and away from the first end of the shaft and towards the first teeth, the plurality of second teeth configured to slidably engage with the plurality of first teeth;
• wherein each first tooth in the plurality of first teeth has a top surface spaced a distance from the front surface, and an outer surface extending between the front surface and the top surface, the outer surface defining a plane that radially extends away from the longitudinal axis;
• wherein each outer surface defines a contact angle, the contact angle measured between a plane defined by the front surface and the outer surface;
• and
• a spring mounted on the shaft, the spring exerting a force against the spline coupling such that the spring biases the first face spline into engagement with the second face spline, the spring having a spring rate, wherein the spring rate of the spring is selected based on the contact angle;
• wherein, when the first face spline and second face spline are engaged, each first tooth in the plurality of first teeth is engaged with a corresponding second tooth the plurality of second teeth;
• and
• wherein when a rotational load applied to the first face spline exceeds a frictional force defined between the plurality of first teeth and the plurality of second teeth, then the interface between the plurality of first teeth and the plurality of second teeth biases the first face spline and second face spline apart from each other such that the spring compresses allowing the second teeth to slidably disengage from the first teeth.

A drive shaft assembly for a supercharger, the drive shaft assembly comprising:

• a shaft extending along and centered on a longitudinal axis, the shaft comprising a first end and a second end opposite the first end along the longitudinal axis;
• a first spline coupling mounted on the shaft, the first spline coupling comprising a front surface and a plurality of first teeth extending from the front surface away from the second end of the shaft in a direction substantially parallel to the longitudinal axis;
• a second spline coupling mounted on the shaft and configured to engage with the first spline coupling, the second spline coupling comprising a back surface and a plurality of second teeth extending from the back surface away from the first end of the shaft and towards the first teeth in a direction substantially parallel to the longitudinal axis;
• and
• a spring mounted on the shaft, the spring exerting a force against the first spline coupling such that the spring biases the first spline coupling into engagement with the second spline coupling;
• wherein, when a rotational load is applied to the first spline coupling and the first spline coupling and second spline coupling are engaged, the interface between the plurality of first teeth and the plurality of second teeth transmits the rotational load from the first spline coupling to the second spline coupling such that the first spline coupling and the second spline coupling rotate around the longitudinal axis at the same rate;
• wherein, when the rotational load is sufficiently high, the interface between the plurality of first teeth and plurality of second teeth biases the first spline coupling and second spline coupling apart from each other, and compresses the spring;
• and
• wherein when the spring is compressed, the plurality of first teeth slidably disengage from the plurality of second teeth such that the first spline coupling and the second spline coupling are able to rotate around the longitudinal axis at different rates.