A belt tuning device to an accessory belt drive system (ABDS) that utilizes a torsional spring to connect the belt pulley to the shaft of a motor generator unit to isolate the system and allow the pulley to advance ahead of the motor or to be behind the motor. The tuning device also has a free running zone providing a decoupling function for the system, allowing the tuning device to be both a driver and a generator of power. The tuning device has all of the belt pulley, a spring retainer, a torsion spring, a stop ring, and a shaft fixed in relation to each other.

Torsional vibration dampers (TVDs) having a plurality of spokes that are asymmetric by having a changing spoke thickness in the angular direction with the greatest thickness at the position where the belt torque and the dynamic torque of the TVD act in unison are disclosed. The spokes, which connect a central member to a peripheral rim, include an asymmetrical thickness in an angular direction, as evidenced by a cross-section view transverse to a radial length of each of the plurality of spokes. Engine systems having one of the disclosed TVDs mounted to a shaft are also disclosed, for example a TVD mounted to a crankshaft.

In an aspect, a system is provided for controlling tension in an endless drive member, and including an isolation device and a tensioning system. The isolation device is positioned on an accessory drive shaft and has a pulley and a biasing member to transfer force from the pulley to the accessory drive shaft. The isolation device pulley is engaged with the endless drive member, such that a first span of the endless drive member is on a first side of the isolation device pulley and a second span of the endless drive member is on a second side of the isolation device pulley. The tensioning system has a first tensioner pulley engaged with the first span and a second tensioner pulley engaged with the second span. The first and second tensioner pulleys are urged by first and second tensioner pulley biasing forces towards the first and second spans respectively.

An isolator is provided for use with an engine and in particular an engine that is assisted or started by MGU (Motor-Generator Unit) or a motor through an endless drive member. It comprises a double acting spring system for isolating crankshaft pulley from torsion vibration at the crankshaft, and in extreme conditions, such as during engine startup and accelerations or decelerations of the engine crankshaft relative to the pulley and when isolator operates in an “engine-driven” mode with the engine crankshaft is driven by the belt.

An isolating decoupler comprising a shaft having an outer surface, a pulley rotationally engaged about the shaft, a torsion spring having a first section having a major diameter and a second section having a minor diameter, the major diameter is greater than the minor diameter, the torsion spring engaged with the pulley, a wrap spring having an inner diameter less than an outer surface outer diameter, the wrap spring frictionally engaging the outer surface, the torsion spring having an end fixedly connected to the wrap spring, the torsion spring loaded in a winding direction whereby the diameter of each coil of the torsion spring decreases in a progressive sequence as a load increases, the second section is disposed radially outboard of the wrap spring such that the second section moves radially inward to clamp the wrap spring during a load condition, and the pulley comprising a member disposed to progressively release the wrap spring from the shaft outer surface upon occurrence of a predetermined load condition.

A pulley structure may be equipped with an outer rotating body, an inner rotating body, and a coil spring provided between the outer rotating body and the inner rotating body. The coil spring is configured so as to undergo torsional deformation in a diameter-expanding or a diameter-contracting direction, thereby engaging the outer rotating body and the inner rotating body and transmitting torque, and to undergo torsional deformation in the direction opposite the direction in which torque is transmitted, thereby entering a disengaged state in which the coil spring slides with the outer rotating body or the inner rotating body, thus interrupting the transmission of torque. The number of windings of the coil spring is in a range between [M-0.125] and M (both inclusive), where M is a natural number.

Torsional vibration dampers are disclosed that have a hub defining a plurality of fastener-receiving openings and an inertia member concentric about and spaced a radial distance apart from a shaft-receiving member of the hub and having a plurality of receptacles defining a bore oriented axially. Each receptacle aligns with one of the plurality of fastener-receiving openings, and receives one of a plurality of elastomeric rings with a fastener seated therein and received in the fastener-receiving openings to operatively connect the inertia member to the hub through compression of the elastomeric rings. The height of each elastomeric ring is greater than the axial width of the receptacles, and compression of the elastomeric rings deforms each radially into a first gap between the hub and the inertia member and a second gap between the inertia member and the fastener, thereby axially locking the inertia member to the hub for rotation together.

The present patent application discloses an overrunning alternator damping pulley. The overrunning alternator damping pulley includes a pulley body, two ball bearings provided on both ends of a shaft hole of the pulley body; and a hub for supporting the two ball bearings. At least one spring holder is provided on the hub. At least one friction spring is installed on the spring holder. One end of the friction spring is inserted to the spring holder. Another end of the friction spring forms a free end spirally extending along an axial direction of the hub. The outer ring of the friction spring is in contact with an inner wall of the pulley body. A damping groove corresponding to the friction spring is provided on the inner wall of the pulley body.

A device for noise vibration reduction of an alternator's pulley includes a pulley part combined with a rotating shaft of the alternator and also has a pendulum damper adapter part inserted into the pulley. In particular, the pendulum damper adapter part includes a pendulum pamper part and rotate or reciprocate the pendulum damper part to generate a vibration having the same frequency as but an opposite phase to a vibration of the pulley part so as to reduce the vibration of the pulley part.

Methods and systems are provided for a crankshaft damper cover for a crankshaft damper of a crankshaft in an engine. In one example, a crankshaft damper cover shaped to fit within a cavity of a crankshaft damper and including an inset and an annular ring embedded within the inset, where the annular ring includes tabs adapted to mate with an inner surface of the crankshaft damper. As one example, the inset may be comprised of a damping material, such as plastic or foam.