a constant torque power transmission consisting of a rotating mass , or gyroscope , rotating around a first axis and supported by a frame or enclosure in turn pivotally supported about a second axis at right angle to the first axis by a gimbal , the gimbal being pivotably supported around a third axis disposed at a right angle to the second axis . a reciprocating power input oscillates the gimbal and the rotating mass about the third axis , causing the rotating mass frame or enclosure to develop a precessional force oscillating about the second axis .