Iron core of motor, motor and the manufacture method for iron core of motor

Abstract

The invention relates to a laminated straight iron core of motor. Wherein, several tooth parts (11) of iron core (1) via the iron core bend part (12) of V-shape cut (13) are connected in band shape; at the direction that closes the V-shape cut (13), the bend part (12) is bended into annular shape; the front part of V-shape cut (13) has hole parts (14); protrusion is arranged opposite to the cut part (13); the part from the hole parts (14) to two sides of front of cut part (13) is parallel cut off, to form stress-proof parts (16, 16'), to improve the service life of punch mould and reduce the stress when bending iron core, to improve the process accuracy.

Description

[0001] This application is a divisional application of the invention patent application filed by Nidec Shibaura Co., Ltd. with the filing date of August 7, 2003 and the application number of "03127561.3". technical field [0002] The present invention relates to a motor core used for a motor such as a brushless DC motor, a motor using the core, and a method for manufacturing the motor core. Background technique [0003] The iron core of a commonly used electric motor is formed in an annular shape by laminating a plurality of straight iron cores, and the straight iron cores are connected with a plurality of teeth punched out of silicon steel plates in a belt shape. [0004] Next, a conventional straight core will be described based on a partial plan view of a strip-shaped straight core 100 shown in FIG. 10 . The straight core 100 is formed by connecting a plurality of tooth portions 111 in a belt shape through a core bending portion 112 having a V-shaped notch portion 113 , a...

AI Technical Summary

Problems solved by technology

For this reason, when the steel plate is punched, the impact strength of the punching die decreases at the protruding parts 116, 116' of the steel plate, the wear and damage of the punching die locally becomes larger, and the life of the die decreases, resulting in depreciation and maintenance costs of the punching die. , Increase in equipment maintenance costs and other cost increases

[0008] When the diameter of the hole portion 114 is increased in order to achieve the above-mentioned uniformity of impact strength, the cross-sectional area of ​​the core bending portion 112 serving as a magnetic path between the tooth portions 111 decreases, the magnetic resistance increases, and the magnetic properties deteriorate. When reducing the reluctance, it is necessary to increase the size of the iron core itself, and there is a problem that the motor becomes larger

[0009] In addition, when the above-mentioned straight core 100 is bent to form an annular core, as shown in FIG. At the bending fulcrum of the core bending portion 112, the deformation pressure is locally concentrated, and the deformation pressure generates a large strain in the steel plate. In addition, the strain deformation region is also enlarged, and the iron loss of the core bending portion 112 serving as a magnetic circuit increases, and the magnetic properties are lowered.

[0010] In addition, the occurrence of processing strain when bending the core bending portion 112 or its deviation reduces the shape accuracy (such as roundness, concentricity, coaxiality, etc.) of the ring core, causing noise and vibration of the motor using it.

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