Abstract
The parallel-shaft type of adjustable cone pulley consists of two parallel shafts on which are mounted a pair of adjustable cone pulleys, with a belt as the connecting medium. Provision is made for adjusting the spacing between the faces of the cones by a movement of one or both halves of the pulley in such a manner that, when the spacing of the pulley opening on one shaft is being increased, the spacing of the pulley opening on the opposite shaft is being decresed. Thus when the effective diameter of the pulley on the first shaft is being decreased, that of the opposing pulley is increased, and the length of belt necessary to encompass the two pulleys is substantially the same. In this sort of variable speed control mechanism, acccording to the speed changing ratio, the tension of the belt and the contact condition between the belt and the pulleys change very little and we can not get a constant transmissive torque regardless of the changing speed ratio. However if we maintain a constant tension in the belt and a constant condition of contact between the belt and the pulley regardless of the changing speed ratio, a constant transmissive torque is produced. As a means of maintaining these condition, one possible idea would be to turn the cone faces of the pulley into certain special surfaces of revolution. This paper deals with this subject theoretically.
