Abstract: The resin injection gate is disposed at the pillar part. When the bearing cage is divided into first and second regions by an imaginary line connecting the resin injection gate and a weld to be formed at a position radially facing the resin injection gate, a resin reservoir that can store therein the melted resin is formed at the pillar part in only one of the regions. A circumferential distance between the resin reservoir and the weld is smaller than a circumferential distance between the resin reservoir and the resin injection gate. A cross-sectional area of a communicating part of the resin reservoir, which is configured to communicate with the pillar part, is equal to or less than a quarter of a cross-sectional area of the resin injection gate.

Abstract: The resin injection gate is disposed at the pillar part. When the bearing cage is divided into first and second regions by an imaginary line connecting the resin injection gate and a weld to be formed at a position radially facing the resin injection gate, a resin reservoir that can store therein the melted resin is formed at the pillar part in only one of the regions. A circumferential distance between the resin reservoir and the weld is smaller than a circumferential distance between the resin reservoir and the resin injection gate. A cross-sectional area of a communicating part of the resin reservoir, which is configured to communicate with the pillar part, is equal to or less than a quarter of a cross-sectional area of the resin injection gate.

Abstract: To provide a gear housing comprising a front housing having a structure which can make the front housing lightweight and which can increase the strength of a continuous section of a worm wheel housing portion and a support portion where stress tends to be concentrated. A front-side housing is made of synthetic resin, and includes a housing front plate portion which constitutes a worm wheel housing portion and a support portion integrated with the housing front plate portion. A reinforcing member made of a metal plate is provided at a corner portion between a front surface of the housing front plate portion and a lower surface of the support portion.

Abstract: To provide a gear housing comprising a front housing having a structure which can make the front housing lightweight and which can increase the strength of a continuous section of a worm wheel housing portion and a support portion where stress tends to be concentrated. A front-side housing is made of synthetic resin, and includes a housing front plate portion which constitutes a worm wheel housing portion and a support portion integrated with the housing front plate portion. A reinforcing member made of a metal plate is provided at a corner portion between a front surface of the housing front plate portion and a lower surface of the support portion.

Abstract: A resin reservoir capable of storing the melted resin is provided in the pillar radially facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among a plurality of the pillars not provided with the resin injection gate or the pillar in the vicinity of the pillar facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among the plurality of the pillars not provided with the resin injection gate. A cross-sectional area of a communicating portion of the resin reservoir which communicates with the pillar is smaller than the smallest of cross-sectional areas of a plurality of the resin injection gates.

Abstract: The resin injection gate is disposed at the pillar part. When the bearing cage is divided into first and second regions by an imaginary line connecting the resin injection gate and a weld to be formed at a position radially facing the resin injection gate, a resin reservoir that can store therein the melted resin is formed at the pillar part in only one of the regions. A circumferential distance between the resin reservoir and the weld is smaller than a circumferential distance between the resin reservoir and the resin injection gate. A cross-sectional area of a communicating part of the resin reservoir, which is configured to communicate with the pillar part, is equal to or less than a quarter of a cross-sectional area of the resin injection gate.

Abstract: A resin reservoir capable of storing the melted resin is provided in the pillar radially facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among a plurality of the pillars not provided with the resin injection gate or the pillar in the vicinity of the pillar facing the pillar provided with the resin injection gate having a cross-sectional area larger than those of the other resin injection gates among the plurality of the pillars not provided with the resin injection gate. A cross-sectional area of a communicating portion of the resin reservoir which communicates with the pillar is smaller than the smallest of cross-sectional areas of a plurality of the resin injection gates.

Abstract: A bearing holder is to be formed by injecting a melted resin, from a plurality of resin injection gates provided at a peripheral edge portion of a substantially annular cavity formed in a molding die, into the cavity. At least one column portion is provided with a resin reservoir capable of reserving therein the melted resin. A cross-sectional area of a communication portion of the resin reservoir configured to communicate with the column portion is equal to or smaller than ¼ of a cross-sectional area of the resin injection gate.