Abstract: Provided are: an impact fastening tool which prevents a torque detector from missing a signal and extends service life by adopting a fixed connector that prevents the trouble of being instantaneously separated (bounced) from a rotating electrode by intermittent impacts and has a shape allowing the progression of friction to be delayed structurally; and a torque tester. Both end portions of the fixed connector are fixed, and at least two protrusion portions are formed between the both end portions. The rotating electrode is disposed between one protrusion portion and the other protrusion portion such that the rotating electrode contacts the fixed connector at two or more points or in a line form. A signal required for the torque detecting means is transmitted through the contact between the rotating electrode and the fixed connector.

Abstract: Provided are: an impact fastening tool which prevents a torque detecting means from missing a signal and extends service life by adopting a fixed connector that prevents the trouble of being instantaneously separated (bounced) from a rotating electrode by intermittent impacts and has a shape allowing the progression of friction to be delayed structurally; and a torque tester. Both end portions of the fixed connector are fixed, and at least two protrusion portions are formed between the both end portions. The rotating electrode is disposed between one protrusion portion and the other protrusion portion such that the rotating electrode contacts the fixed connector at two or more points or in a line form. A signal required for the torque detecting means is transmitted through the contact between the rotating electrode and the fixed connector.

Abstract: A storage disk drive motor 12 includes a stator unit 2, a rotor unit 3, a shaft 41 arranged in a coaxial relationship with a center axis 9, a sleeve unit 22 including a flange portion 223, and a base member 21, having a through-hole, fixed to the sleeve unit 22 by caulking. The flange portion 223 includes a flange lower surface 223b making contact with an upper surface 21a of the base member 21 and a jut 24 protruding downwards from a radial inner side of the flange lower surface 223b. The jut 24 includes a first outer circumferential surface 241 opposed to the inner circumferential surface 21c of the base member 21, a second outer circumferential surface 242 positioned below the first outer circumferential surface 241, and a groove 243 radially inwardly indented from the first outer circumferential surface 241 and the second outer circumferential surface 242.

Abstract: A storage disk drive motor 12 includes a stator unit 2, a rotor unit 3, a shaft 41 arranged in a coaxial relationship with a center axis 9, a sleeve unit 22 including a flange portion 223, and a base member 21, having a through-hole, fixed to the sleeve unit 22 by caulking. The flange portion 223 includes a flange lower surface 223b making contact with an upper surface 21a of the base member 21 and a jut 24 protruding downwards from a radial inner side of the flange lower surface 223b. The jut 24 includes a first outer circumferential surface 241 opposed to the inner circumferential surface 21c of the base member 21, a second outer circumferential surface 242 positioned below the first outer circumferential surface 241, and a groove 243 radially inwardly indented from the first outer circumferential surface 241 and the second outer circumferential surface 242.