Motor and method of manufacturing the motor

Abstract

The utility model provides a motor which is capable of preventing one or two of a rotation shaft and a rotation part from being damaged when the rotation shaft is going through the rotation element, and which is capable of preventing an overlarge interval from being generated between an internal circumferential surface of the rotation element and an external circumferential surface of the part, where the rotation element is fixed, of the rotation shaft. In the motor (1), the rotation element (8) is pressed in and fixed at a second shaft part (54) of the rotation shaft (50), the external diameter of the second shaft part is larger than the external diameter of the first shaft (53) on which a helical groove (58) is formed, and the second shaft part is formed at a position which is closer to a stator (40) compared with the first shaft part (53). Thus, even if an internal diameter of the rotation element is the same with an external diameter (phi2) of the second shaft part, the internal diameter of the rotation shaft is much larger than an external diameter (phi1) of the first shaft. Therefore, when the rotation shaft is allowed to go through the rotation element, and the first shaft part is allowed to go through the rotation part, the external circumferential surface of the first shaft part is prevented from contacting with the internal circumferential surface of the rotation shaft.

Description

technical field [0001] The present invention relates to a motor in which a spiral groove is formed on a portion of a rotating shaft protruding from a stator, and a method for manufacturing the motor. Background technique [0002] The motor has a permanent magnet fixed to the outer peripheral surface of the rotary shaft and a stator radially opposed to the outer peripheral surface of the permanent magnet, and outputs rotational force from a portion of the rotary shaft protruding from the stator. For example, when this motor is used in a lens driving device or an optical head driving device, a helical groove for engaging a rack or nut on the driven side is formed on the outer peripheral surface of a portion of the rotating shaft protruding from the stator. In this motor, a rotating member may be attached to a position closer to the stator than a portion of the rotating shaft in which the helical groove is formed. For example, there has been proposed a structure in which an in...

AI Technical Summary

Problems solved by technology

[0004] When manufacturing a motor with a rotating shaft mounted with a rotating part, after assembling the rotor, insert the rotating part from the tip side of the rotating shaft, but at that time, if the inner peripheral surface of the rotating part comes into strong contact with the spiral groove, a spiral The groove part is damaged and excessive burrs are generated, which may hinder the drive of the rack or nut.

In addition, there is also a problem that the inner peripheral surface of the rotating member is damaged.

Even so, if the inner diameter of the rotating member is set to be larger than the outer diameter of the portion where the spiral groove is formed, when the rotating member is fixed to the rotating shaft, there will be a gap between the inner peripheral surface of the rotating member and the outer periphery of the rotating shaft. Create large gaps between faces

As a result, there are problems that the rotating member cannot be fixed to the rotating shaft by a simple structure such as press-fitting or bonding, and the concentricity between the rotating member and the rotating shaft is lowered.

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