An assist mechanism includes: an electric motor in which a rotor has a magnet and a stator has a winding; a shaft-shaped member in which a worm engaged with a worm wheel is formed; and a coupling that couples an output shaft of the electric motor and the shaft-shaped member to each other. The smallest rotation order among rotation orders of the electric motor and a rotation order of the worm are prime to each other.

A coupling includes first and second annular flanges in spaced relation across a gap. At least one resilient element is disposed in the gap in abutting relation to the first and second annular flanges. A first plurality of fasteners extends from the first annular flange, through the at least one resilient element, to the second annular flange, and a second plurality of fasteners extends from the second annular flange, through the at least one resilient element, to the first annular flange. Fasteners in the first plurality of fasteners is disposed in alternating fashion with fasteners in the second plurality of fasteners.

The torque transmission joint includes an intermediate transmission member, and a first transmission member and a second transmission member that are arranged with one each on both side sections in the axial direction of the intermediate transmission member, with the outer side sections in the radial direction of each engaging with the inside section in the radial direction of the intermediate transmission member. The first transmission member and the second transmission member have a first preliminary engagement section and a second preliminary engagement section at the end sections in the axial direction on sides close to each other. The first preliminary engagement section and the second preliminary engagement section engage with each other with a circumferential gap interposed therebetween that does not disappear when torque transmission is performed between the first transmission member and the second transmission member via the intermediate transmission member.

A coupling assembly includes a flexible coupling and a first adapter. The flexible coupling defines an opening that extends along a central longitudinal axis between a first coupling end and a second coupling end. The first adapter is arranged to be at least partially received within the opening proximate the first coupling end. The first adapter extends between a first adapter first face and a first adapter second face. The first adapter defines a first adapter post and a first adapter hole. The first adapter post that extends from the first adapter first face. The first adapter hole that extends from the first adapter first face towards the first adapter second face.

A coupling assembly includes a flexible coupling and a first adapter. The flexible coupling defines an opening that extends along a central longitudinal axis between a first coupling end and a second coupling end. The first adapter is arranged to be at least partially received within the opening proximate the first coupling end. The first adapter extends between a first adapter first face and a first adapter second face. The first adapter defines a first adapter post and a first adapter hole. The first adapter post that extends from the first adapter first face. The first adapter hole that extends from the first adapter first face towards the first adapter second face.

A system and method for increasing a tooth shear strength without also increasing a torsional rigidity of a flexible spline disposed between two hubs of a flexible coupling for transmitting mechanical motion between two shafts includes attaching a stiffening cap to an end of a flexible spline, between the flexible spline and the hubs and inserting a plurality of dowels into the teeth of the flexible spline to reinforce the flexible spline.

A coupling is disclosed for connecting rotating components of a generator and a prime mover in a power generation system. The coupling comprises a hub, a coupling flange and an elastomeric component located between the hub and the coupling flange. The elastomeric component is removable radially from the coupling.

A coupling is disclosed for connecting rotating components of a generator and a prime mover in a power generation system. The coupling comprises a hub, a coupling flange and an elastomeric component located between the hub and the coupling flange. The elastomeric component is removable radially from the coupling.

A coupling includes first and second annular flanges in spaced relation across a gap. At least one resilient element is disposed in the gap in abutting relation to the first and second annular flanges. A first plurality of fasteners extends from the first annular flange, through the at least one resilient element, to the second annular flange, and a second plurality of fasteners extends from the second annular flange, through the at least one resilient element, to the first annular flange. Fasteners in the first plurality of fasteners is disposed in alternating fashion with fasteners in the second plurality of fasteners.

A torque transmission joint to suppress occurrence of noise when reversing the direction of rotation of a drive shaft. A first transmission member fixed to an output shaft (the drive shaft) is engaged with a first elastic member such that a first gap in a circumferential direction is interposed, as well as with an intermediate transmission member such that a larger gap in the circumferential direction is interposed. A second transmission member fixed to an end portion of a worm is engaged with a second elastic member such that a second gap in the circumferential direction is interposed, as well as with the intermediate transmission member such that a larger gap in the circumferential direction is interposed. First and second annular convex portions are fitted to, respectively, first and second concave portions to prevent separation of the first and second elastic members with respect to the intermediate transmission member.