This mechanism demonstrates the transmission of a hyperboloid gear pair. A hyperboloid of revolution is the surface developed by a straight-line generatrix, tangent to a base cylinder and at an angle to the axis of the base cylinder, as it is revolved about the axis of the base cylinder. The hyperboloid gear is generated based on formulating the straight-line, which is used to generate a hyperboloid of revolution, as its tooth profile. The hyperboloid gear pair is equivalent to a rolling and sliding contact between two hyperboloids. It can transmit the motion between two crossed axes. However, since the contact of two meshing hyperboloid gears is a line contact, there will be a slipping motion along the tooth profile of the hyperboloid gears when transmission. Thus the transmission of hyperboloid gears has the problem of greater frictions.