A coupling device according to an embodiment is a coupling device for connecting a first shaft and a second shaft that includes a primary inner ring member mounted on the first shaft, a primary outer ring member disposed on an outer circumferential side of the primary inner ring member, a primary elastic member for connecting the primary inner ring member and the primary outer ring member, a secondary inner ring member mounted on the second shaft, a secondary outer ring member disposed on an outer circumferential side of the secondary inner ring member, a secondary elastic member for connecting the secondary inner ring member and the secondary outer ring member, and a weight attaching plate interposed between the primary outer ring member and the secondary outer ring member, the weight attaching plate including a weight attaching portion capable of attaching and detaching an additional weight to and from the outer circumferential side of the primary outer ring member and the outer circumferential side of the secondary outer ring member.

A coupling device according to an embodiment is a coupling device for connecting a first shaft and a second shaft that includes a primary inner ring member mounted on the first shaft, a primary outer ring member disposed on an outer circumferential side of the primary inner ring member, a primary elastic member for connecting the primary inner ring member and the primary outer ring member, a secondary inner ring member mounted on the second shaft, a secondary outer ring member disposed on an outer circumferential side of the secondary inner ring member, a secondary elastic member for connecting the secondary inner ring member and the secondary outer ring member, and a weight attaching plate interposed between the primary outer ring member and the secondary outer ring member, the weight attaching plate including a weight attaching portion capable of attaching and detaching an additional weight to and from the outer circumferential side of the primary outer ring member and the outer circumferential side of the secondary outer ring member.

An object of the present invention is to provide an SBR composition for a torsional damper in which the SBR composition has a good physical property balance of high load-bearing properties, low CS properties, and the kneadability and roll processability of a rubber material, and to provide a torsional damper. The object is achieved in such a manner that the SBR composition for the torsional damper comprises at least:(a) an SBR polymer having a combined styrene content of 10 wt % to 50 wt %; (b) carbon black comprising FEF grade carbon black and HAF grade carbon black blended at a ratio of FEF:HAF=1:3 to 3:1; (c) a crosslinking system including sulfur, a sulfur-donating compound, and an organic peroxide compound; and (d) a co-crosslinking agent, wherein 60 parts by weight to 100 parts by weight of the carbon black as total parts by weight of the FEF grade carbon black and the HAF grade carbon black is blended based on 100 parts by weight of the SBR polymer, 0.4 part by weight to 2.5 parts by weight of the sulfur is blended based on 100 parts by weight of the SBR polymer, the sulfur-donating compound is blended at 0.625 time to 12.5 times the blending amount of the sulfur, the organic peroxide compound is blended at 1.25 times to 12.5 times the blending amount of the sulfur, and 4 parts by weight to 16 parts by weight of the co-crosslinking agent is blended based on 100 parts by weight of the SBR polymer.

Provided is a torque-transmission joint 15a that is able to reduce the thrust force that is transmitted between the output shaft 12a of an electric motor 8 and a worm shaft 6a without generating noise. A shock-absorbing member 18a that is made using an elastic material is assembled between a driving-side transmission member 16a that is supported by the output shaft 12a and a driven-side member 17a that is supported by the worm shaft 6a. Held sections 33a, 33b of the shock-absorbing member 18a are located between the side surfaces in the circumferential direction of driving-side arm sections 21a of the driving-side transmission member 16a and side surfaces in the circumferential direction of driven-side arm sections 23a of the driven-side transmission member 17a. A damper section 26 is integrally provided with the shock-absorbing member 18a, and that damper section 26 is elastically held between the tip-end surface of the output shaft 12a and the base-end surface of the worm shaft 16a.

Provided is a torque-transmission joint 15a that is able to reduce the thrust force that is transmitted between the output shaft 12a of an electric motor 8 and a worm shaft 6a without generating noise. A shock-absorbing member 18a that is made using an elastic material is assembled between a driving-side transmission member 16a that is supported by the output shaft 12a and a driven-side member 17a that is supported by the worm shaft 6a. Held sections 33a, 33b of the shock-absorbing member 18a are located between the side surfaces in the circumferential direction of driving-side arm sections 21a of the driving-side transmission member 16a and side surfaces in the circumferential direction of driven-side arm sections 23a of the driven-side transmission member 17a. A damper section 26 is integrally provided with the shock-absorbing member 18a, and that damper section 26 is elastically held between the tip-end surface of the output shaft 12a and the base-end surface of the worm shaft 16a.

A steering device includes: a coupling including a first coupling member, a second coupling member, and an elastic member, the elastic member which is made from a resin, and which includes an elastic member base portion, a first rotation direction elastic portion, a second rotation direction elastic portion, a third rotation direction elastic portion, a fourth rotation elastic portion, and an axial elastic portion, the axial elastic portion which is provided to the elastic member base portion, and which is arranged to be bent in a direction to be inclined with respect to the first axis when a clearance between the first shaft member assembly and the second shaft member assembly in the direction of the first axis is decreased.

A steering device includes: a coupling including a first coupling member, a second coupling member, and an elastic member, the elastic member which is made from a resin, and which includes an elastic member base portion, a first rotation direction elastic portion, a second rotation direction elastic portion, a third rotation direction elastic portion, a fourth rotation elastic portion, and an axial elastic portion, the axial elastic portion which is provided to the elastic member base portion, and which is arranged to be bent in a direction to be inclined with respect to the first axis when a clearance between the first shaft member assembly and the second shaft member assembly in the direction of the first axis is decreased.

The disclosed invention is a novel method for constructing a Torsional Vibration Damper (TVD). The traditional means used to construct the hub of the TVD was to employ a single material. The disclosed invention essentially discretizes the construction of the TVD hub into three regions: nose, spokes, and flange, and simultaneously aligns unique materials and manufacturing methods for each region with the structural loads borne thereby. Consequently, the invention helps in reduces four unwanted characteristics: (1) mass; (2) polar mass moment of inertia; and (3) casting scrap; and (4) cost. Furthermore, because of this construction other enhancements to the axial and angular structural integrity of the TVD can be reaped in certain cases.

The disclosed invention is a novel method for constructing a Torsional Vibration Damper (TVD). The traditional means used to construct the hub of the TVD was to employ a single material. The disclosed invention essentially discretizes the construction of the TVD hub into three regions: nose, spokes, and flange, and simultaneously aligns unique materials and manufacturing methods for each region with the structural loads borne thereby. Consequently, the invention helps in reduces four unwanted characteristics: (1) mass; (2) polar mass moment of inertia; and (3) casting scrap; and (4) cost. Furthermore, because of this construction other enhancements to the axial and angular structural integrity of the TVD can be reaped in certain cases.

A low frequency torsional vibration damper has an annular inertia member defining an annular recess for receiving an elastomeric O-ring in a radial outer surface or a radial inner surface thereof and defining opposing annular recesses for receiving elastomeric O-rings, one each, in the top and bottom surfaces thereof, an elastomeric O-ring seated in each annular recess, and a hub defining an annular receptacle with opposing sidewalls that each comprise a plurality of spaced apart tabs permanently deformed against the plurality of elastomeric O-rings, thereby operatively coupling the hub to the inertia member for rotation together. When the inertia member defines the outer diameter of the torsional vibration damper, the hub is mountable on a shaft, and when the inertia member defines the inner diameter of the torsional vibration damper, the hub is mountable inside a shaft.