Abstract: A speed-increasing spindle device in an assembly structure in a separable form of device main body and shank, capable of using a coupling bolt of large diameter, high in rigidity, and sufficient in strength. The head of the coupling bolt is rotatably engaged in a bolt head engaging part provided at one side of the device main body and shank, while the threaded part of the coupling bolt is engaged with a screw hole provided at the other side of the device main body and shank, and the engaging part for rotary operation tool provided on the outer end plane in the axial direction of the coupling bolt confronts outside through the insertion hole of the shank. The bolt head engaging part has a bolt head accommodating space larger than the maximum hole diameter permitted in the shank in terms of strength, and therefore the shaft diameter of the coupling bolt may be set, at least, as large as the maximum hole diameter of the shank.

Abstract: A power steering apparatus provided with an electromagnetic clutch disposed between an output shaft of a steering assisting motor and a transmission shaft connected to a steering mechanism, an intermediate transmission shaft supported between the output shaft and transmission shaft and supporting an armature part of the electromagnetic clutch, and a biasing member to bias the intermediate transmission shaft in the axial direction. The intermediate transmission shaft is pressed to the side of the output shaft by the biasing member and a fixed initial gap is formed between a friction plate fixed to the output shaft and another friction plate fixed to the armature part. In addition, this power steering apparatus is provided with a shielding member between a reduction unit and the electromagnetic clutch for shielding these two from each other. Lubricant scattering from the reduction unit is prevented from reaching the electromagnetic clutch owing to the presence of the shielding member.

Abstract: An electric motor having a frictional planetary speed reducer comprises a hollow cylindrical rotor disposed inside a stator. The speed reducer is at least partly accommodated in the rotor.