Reuleaux Triplexer

By Spencer Connor

An interesting little arrangement that I have not seen implemented nor found a use for, admittedly. As a Reuleaux triangle is a shape of constant width this is theoretically a zero backlash device, although in practice some clearance would be needed. It actually does produce sinusoidal motion but not in the generally desired way: for 1/6th of the rotation the motion of a larger amplitude sinusoid is followed, then after 1/6th rotation the motion transitions to another sinusoid. In effect, only the peaks of the sine wave are followed as shown in the graph below. Additionally, the period of the generated signal is 1/3 the input rotation period.