Hoist and method for manufacturing hoist

A method for manufacturing a hoist comprising a brake motor including

• a brake mechanism that supplies a braking force to rotations of a motor shaft, wherein:
• the brake motor includes:
• a pull rotor attached to the motor shaft and arranged to face a stator in the radial direction of the motor shaft;
• a movable core that is arranged to face the pull rotor and to be attracted by the pull rotor when a magnetic flux from the stator flows to the pull rotor;
• a motor cover including an outer wall portion that is provided so as to increase an inner diameter of an inner peripheral portion thereof with proximity to one side in an axial direction of the motor shaft from other side;
• a drum member that is fixed to the motor cover side of the movable core, and including an outer peripheral portion that is located radially inward relative to the inner peripheral portion of the outer wall portion and faces the inner peripheral portion;
• a brake shoe that is attached on the outer peripheral portion, and
• the method comprising:
• forming the motor cover to have a tolerance of a surface angle of the inner peripheral portion regarding to a reference angle that is inclined toward the axial direction, the tolerance being −0.25 degrees or more and less than 0 degrees, and configuring the brake mechanism;
• scraping-off the inner peripheral portion upon impact by media that contain large amounts of sharp edges among media, wherein projecting portions are formed so that a degree of the projecting portions becomes smaller in a portion with a small inner diameter of the motor cover than in a portion with a large inner diameter of the motor cover;
• forming the drum member configuring the brake mechanism;
• attaching the brake shoe configuring the brake mechanism on the outer peripheral portion so that a tolerance of a surface angle of the brake shoe regarding to the reference angle is more than 0 degrees and less than or equal to +0.25 degrees;
• and
• assembling the motor cover and the drum member in a state where the brake shoe faces the inner peripheral portion,
• wherein
• a combination of an inclination angle of the inner peripheral portion within the tolerance range on the inner peripheral portion side and an inclination angle of the brake shoe within the tolerance range on the brake shoe side is set so that, in an assemble initial state where the drum member provided with the brake shoe and the motor cover are assembled, the brake shoe is brought into an outer radial side contact state in which the brake shoe contacts with the inner peripheral portion on outer diameter side rather than on inner diameter side.