| 摘要 |
A pitch transfer gear transmission which enables drive to be transmitted from a gear of having one modulus ( 42 ) to a gear having another modulus ( 46 ) includes at least two gears ( 12,16 ) which have a different number of teeth and which are able to rotate relative to one another, so that the teeth of the two gears ( 12,16 ) can form a gear modulus of a first value at one part of the periphery of the gear, and a gear modulus of another value at another part of the periphery of the gear. Continuously variable transmissions are formed by providing an input or output gear ( 42,46 ) which has a modulus which varies along the length of the gear. Pitch transfer gear assembly ( 30 ) engages with the input or output gear ( 42,46 ), and is moveable by a mechanism ( 59 ) along the length of the gear changing modulus, so as to set the drive ratio of the transmission. |
