Motor

Abstract

A motor includes a rotor shaft 7 which is fixed in the inside diameter portion of a magnet 6, a first coil 2 which is arranged adjacently to the magnet in the axial direction of the rotor shaft, a first outside magnetic pole portion 1a which is excited by the first coil, is inserted on the inner periphery side of the first coil, and is arranged so as to be opposed to a predetermined angle range of the outer peripheral surface of the magnet with a predetermined gap being provided between the first outside magnetic pole portion and the outer peripheral surface of the magnet, a second coil 4 which is arranged on almost the same plane as the first coil so as to be adjacent to the magnet in the axial direction of the rotor shaft, and a second outside magnetic pole portion 1b which is excited by the second coil, is inserted on the inner periphery side of the second coil, and is arranged so as to be opposed to a predetermined angle range of the outer peripheral surface of the magnet with a predetermined gap being provided between the second outside magnetic pole portion and the outer peripheral surface of the magnet in a state in which the phase shifts through (180 / N) degree with respect to the magnetization portion of the magnet from the first outside magnetic pole portion.

Description

technical field [0001] The present invention relates to an electric motor suitable for being configured in a small cylindrical shape. Background technique [0002] 7A is a schematic longitudinal sectional view showing a configuration example of a conventional stepping motor, and FIG. 7B is a schematic partial sectional view schematically showing a state of magnetic flux flowing from a stator of the stepping motor in FIG. 7A. [0003] In FIG. 7A , two bobbins 101 in which the stator coil 105 is wound concentrically are arranged side by side in the axial direction, and the two bobbins 101 are clamped and fixed to different stator yokes 106 , respectively. Stator teeth 106 a and 106 b arranged alternately in the circumferential direction are formed on the inner diameter surface of each stator yoke 106 along the inner diameter surface of the bobbin 101 . The stator yokes 106 integrated with the stator teeth 106a or 106b are respectively fixed to the two cases 103 . In this way...

AI Technical Summary

Problems solved by technology

[0015] However, in the solution proposed by the above-mentioned patent document, a predetermined interval is required between the inner diameter of the magnet and the inner magnetic pole facing it, and the management at the time of its manufacture leads to an increase in cost.

[0016] In addition, even as the shape of the stator, cylindrical inner magnetic pole parts and outer magnetic pole parts are required, and it is difficult to manufacture them integrally.

In addition, when it is manufactured separately and then assembled into one body, the number of parts increases, resulting in an increase in cost.

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