Abstract: An isolating device (10) isolates fluctuations in torque of a drive shaft about a nominal torque value. The device comprises a first annular member (11) for connection to a rotary driving shaft and a second annular member (12) designed for connection to a driven piece of equipment such as a fan or alternator in an internal combustion engine. The first (11) and second (12) annular members are interconnected by a plurality of elastomeric elements (23) which are pre-compressed in a circumferential direction between retaining plates fixed to the first and second annular members (11, 12). The pre-compression permits a minimum torque of the drive shaft for a nominal torque level to be transmitted to the driven member load substantially without deflection of the elastomeric element (33). Hence there is little or no relative rotational displacement of the first and second members (11, 12) of the isolating device (10) during start up until the working range of the device is reached.

Abstract: An improved torsional vibration isolator assembly for an engine is provided which includes a non-linear spring device which effectively minimizes the transmission of torsional vibrations to the engine's gear train throughout all engine operating frequencies and conditions while limiting relative movement between the engine's crankshaft and crank gear so as to maintain timing error within acceptable limits. The improved torsional vibration isolator is designed to absorb torsional vibrations transmitted from the crankshaft so as to substantially isolate the entire engine gear train, including the crank gear, from the torsional vibrations throughout all engine operating conditions and frequencies, including at and below the natural frequency, i.e. crank resonance, of the crankshaft. The crank gear isolator includes resilient elements positioned in cavities formed between engaging projections formed on inner and outer rings of the assembly.

Abstract: A torsional vibration damper has a rotational axis and an annular housing having inner and outer members. The housing has an annular channel in which an inertia member is received. The channel has axially extending walls and is closed by an annular cover plate to retain the inertia member The inner edge of the cover plate is received in a rabbet in the inner channel wall and is joined to the wall by means of a weld. The inner and outer members are connected by an annular weld at a central hub. The weld may extend between two radial extremes which are separated by a distance substantially greater than the thickness of weld. The damper is easier to manufacture and assemble and has greater structural integrity.

Abstract: A fuel pump drive gear assembly is provided which includes torsional absorption elements positioned between a drive gear and a fuel pump hub. The drive gear includes a plurality of apertures for receiving a plurality of projections formed on the fuel pump hub. The torsional absorption elements are positioned in the apertures between the projections and the drive gear so as to frictionally engage a surface of both the projection and the drive gear, thus creating a mechanical driving connection between the rotating drive gear and the fuel pump hub. The torsional absorption elements have adequate stiffness to provide the necessary torque to drive the fuel pump, while retaining sufficient flexibility to permit relative rotational movement between the driving gear and the fuel pump hub for absorbing the vibratory loads imposed upon the gear assembly by the fuel pump without compromising the timing between the fuel pump and engine.