A water pump has a pump housing (2) having therein a pump chamber (3); a drive shaft (7) rotatably supported in the pump housing (2); a pulley (5) having a flange wall (5a) fixed to one end portion of the drive shaft (7), the pulley (5) being formed integrally with the drive shaft (7) with synthetic resin material containing glass fiber material (25); and an impeller (8) secured to the other end portion of the drive shaft (7) so as to be able to rotate integrally with the drive shaft (7), the impeller (8) being accommodated in the pump chamber (3). Six penetration holes (23) are formed at the flange wall (5a), and the glass fiber material (25) existing around the penetration hole (23) is oriented at random. With this, decrease in strength of the pulley (5) can be suppressed.

Torsional vibration dampers (TVDs) having a plurality of spokes designed to withstand both torsional and bending forces and vibrations are disclosed. The spokes, which connect a central member to a peripheral rim, include a first end coupled to an outer radial surface of the central member; a second end coupled to an inner radial surface of the rim; and four concave surfaces extending between the first end and the second end. The concave surfaces may be concave from the first end to the second end and may also be concave laterally from front to back or side to side. A TVD having a hub with spokes having one or more concave surfaces is also disclosed herein. A method of designing the spokes for the hub is also disclosed.

Torsional vibration dampers (TVDs) having a plurality of spokes designed to withstand both torsional and bending forces and vibrations are disclosed. The spokes, which connect a central member to a peripheral rim, include a first end coupled to an outer radial surface of the central member; a second end coupled to an inner radial surface of the rim; and four concave surfaces extending between the first end and the second end. The concave surfaces may be concave from the first end to the second end and may also be concave laterally from front to back or side to side. A TVD having a hub with spokes having one or more concave surfaces is also disclosed herein. A method of designing the spokes for the hub is also disclosed.

A bicycle sprocket assembly comprises a sprocket support member. The sprocket support member comprises a central cylindrical portion and a plurality of sprocket support portions. The plurality of sprocket support portions extends radially outwardly from the central cylindrical portion with respect to a rotational center axis of the bicycle sprocket assembly. At least one sprocket support portion of the plurality of sprocket support portions comprises at least one radially extending surface, at least one axially extending surface, and an interior cavity. The at least one radially extending surface extends radially relative to the rotational center axis to support at least one of the at least one sprocket. The at least one axially extending surface extends in an axial direction parallel to the rotational center axis.

A bicycle sprocket assembly comprises a sprocket support member. The sprocket support member comprises a central cylindrical portion and a plurality of sprocket support portions. The plurality of sprocket support portions extends radially outwardly from the central cylindrical portion with respect to a rotational center axis of the bicycle sprocket assembly. At least one sprocket support portion of the plurality of sprocket support portions comprises at least one radially extending surface, at least one axially extending surface, and an interior cavity. The at least one radially extending surface extends radially relative to the rotational center axis to support at least one of the at least one sprocket. The at least one axially extending surface extends in an axial direction parallel to the rotational center axis.

In a torsional damper, a damper mass is connected to a hub through a damper rubber. The hub is provided with a boss fixed to a crankshaft and a rim holding the damper rubber. The boss and the rim are coupled by plurality of spokes. The plurality of spokes each has an inclined shape inclined in the axial direction. Reinforcement portion is provided in the spokes in one direction corresponding to a bending vibration to be input among the plurality of spokes.

In a torsional damper, a damper mass is connected to a hub through a damper rubber. The hub is provided with a boss fixed to a crankshaft and a rim holding the damper rubber. The boss and the rim are coupled by plurality of spokes. The plurality of spokes each has an inclined shape inclined in the axial direction. Reinforcement portion is provided in the spokes in one direction corresponding to a bending vibration to be input among the plurality of spokes.

A bicycle sprocket assembly comprises a sprocket support member. The sprocket support member comprises a central cylindrical portion and a plurality of sprocket support portions. The plurality of sprocket support portions extends radially outwardly from the central cylindrical portion with respect to a rotational center axis of the bicycle sprocket assembly. At least one sprocket support portion of the plurality of sprocket support portions comprises at least one radially extending surface, at least one axially extending surface, and an interior cavity. The at least one radially extending surface extends radially relative to the rotational center axis to support at least one of the at least one sprocket. The at least one axially extending surface extends in an axial direction parallel to the rotational center axis.

A pulley intended to be mounted around a rolling bearing and having an inner web for connecting to an outer race of the rolling bearing, an outer web for connecting to a flexible force-transmitting element, and radial connecting ribs between the outer web and the inner web. The ribs are distributed in several groups, each group providing at least three successive ribs, which form several pairs of adjacent ribs, the midplanes of which are separated two by two at a regular angle, and the angle between the midplanes of two adjacent ribs in one and the same group varies, between two adjacent groups, by at least 5% with respect to the smaller of the two angles.

A pulley intended to be mounted around a rolling bearing and having an inner web for connecting to an outer race of the rolling bearing, an outer web for connecting to a flexible force-transmitting element, and radial connecting ribs between the outer web and the inner web. The ribs are distributed in several groups, each group providing at least three successive ribs, which form several pairs of adjacent ribs, the midplanes of which are separated two by two at a regular angle, and the angle between the midplanes of two adjacent ribs in one and the same group varies, between two adjacent groups, by at least 5% with respect to the smaller of the two angles.