Abstract: A diagnostic driveline vibration analyzing tool for measuring and characterizing the torsional vibrations in a vehicle driveline. An electronic control unit and sensor cooperate to measure speed fluctuations occurring between the passing of adjacent teeth of a rotating gear. These time measurements are the basis for displacement, velocity and acceleration calculations which, combined with driveshaft rotational order information, can be used to pinpoint the source of excessive driveline torsional vibrations.

Abstract: A rotary pump (10) is disclosed of the type including a rotating cylinder block (25) defining a plurality of cylinders (27), each defining an imaginary axis (a), which are uniformly spaced about an axis of rotation (A) of the cylinder block. A piston (29) is disposed for reciprocation within each cylinder (27) as the cylinder block rotates. The housing defines a fluid inlet (43) and a fluid outlet (45). In open communication with each cylinder (27) is a cylinder port (47), disposed for serial communication with the fluid inlet and fluid outlet as the cylinder block (25) rotates. Each cylinder port (47) defines a leading edge (L) which are disposed randomly relative to their respective imaginary axis (a).