JPS61203851A - Motor - Google Patents

Abstract

PURPOSE:To enhance a motor efficiency by disposing permanent magnets on the inner and outer peripheral surfaces to hold a stator winding, opposing at different polarities, mounting on the same rotational shaft to rotate, thereby forming a coreless stator winding to eliminate an iron loss. CONSTITUTION:A rotor core 2 and the first permanent magnet 3 are mounted on a rotational shaft 1, and a stator winding 10 is provided through the prescribed air gap at the outer peripheral side. Further, the second permanent magnet 14 is disposed through the prescribed air gap at the outer peripheral side of the winding 10, and opposed in different polarity to the first magnet 3. The magnet 14 is coupled by a holder 15 with the shaft 1, and the first and second magnets 3, 14 are simultaneously rotated to hold the winding 10. Thus, the winding 10 is formed in a coreless state, and the decrease in a magnetomotive force is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an electric motor having a permanent magnet (in particular, to an electric motor in which reduction in efficiency due to iron loss is suppressed).

(b) Prior Art Generally, as a conventional electric motor, there is one described in Japanese Patent Publication No. 55-23019. This electric motor includes a rotating shaft, a rotor provided on the rotating shaft and having multiple pole permanent magnets on the outer periphery, and a stator winding provided on the outer periphery of the rotor with a predetermined air gap in between. Ta. In this case, the stator winding was provided on the iron core.

(c) Problems to be Solved by the Invention In such conventional electric motors, there is a problem in that iron loss occurs due to changes in magnetic flux generated in the iron core, resulting in a decrease in efficiency of the electric motor.

Furthermore, when the iron core is made of soft ferrite to reduce iron loss, since this soft ferrite has a low saturation magnetic flux density, it is necessary to increase the thickness of the soft ferrite, which causes the problem that the motor becomes larger.

In view of these problems, the present invention provides an electric motor that is highly efficient by eliminating iron loss.

(b) Means for Solving the Problems The electric motor of the present invention includes a rotating shaft, a rotor attached to the rotating shaft and having a first permanent magnet on the outer periphery, and a predetermined air gap between the outer periphery of the rotor. A second permanent magnet is provided on the outer periphery of the stator winding with a predetermined air gap therebetween and rotates co-coincidentally with the rotor, the second permanent magnet facing the first permanent magnet. 2. The polarity of the permanent magnet is different.

(e) Function If the electric motor is constructed in this way, the iron core rotates in synchronization with the rotor, so there is no change in magnetic flux, preventing iron loss, and increasing the efficiency of the electric motor.

(F) Embodiment Below, an embodiment of the present invention will be described based on the drawings. First, FIGS. 1 and 2 are sectional views of main parts, and the same constituent elements are given the same reference numerals. (1) is the rotating shaft, (2) is the rotor core made of multiple electrical iron plates laminated and attached to the rotating shaft (1), and (3) is the 4 poles provided on the outer periphery of this rotor core (2). A rotor consisting of a first permanent magnet, this rotating shaft (1), a rotor core (2), and a first permanent magnet (3) is supported by bearings (4) and (5) and rotates. .

These bearing parts (4) and (5) are attached to the end bracket (6).
, (7) via spacers (8) and (9).

(A) is a coreless stator winding installed on the outer periphery of the rotor through a predetermined air gap, and is attached to a support member α° C. made of insulating resin. This support member α is attached to the end bracket (7) at the flange portion. This attachment can be done using adhesives, rivets, screws, etc. There are various winding methods for this stator winding (G), such as single-phase full-wave, two-phase half-wave, four-phase half-wave, two-phase full-wave, three-phase half-wave, and three-phase full-wave, depending on the purpose of use. It can be determined accordingly.

Further, the winding distribution may include concentrated winding, distributed winding, lap winding, wave winding, etc., but is not particularly limited. (6) is the stator winding α
This is a protection part for the lead wire @ of O, and is integrally molded with the support member (b), but it may be an eyelet method of a separate member. α
Chrysanthemum is a second permanent magnet that is provided on the outer periphery of the stator core αO with a predetermined air gap, and has different poles facing each pole of the first permanent magnet (3), and is one rotor (1). It is attached to a holder fixed to the rotor and rotates together with the rotor. still.

(to) is a frame.

Also, as a control circuit that drives this motor.

It can be driven using a generally known DC brushless motor control circuit. For example, one that magnetically detects the rotational position of the rotor and switches the energization to the stator windings (see the prior art section of JP-A-59-139883). Alternatively, the energization of the stator winding is switched based on the induced voltage generated in the non-energized stator winding due to the rotation of the rotor (see the embodiment section of JP-A-59-139883). The detailed explanation will be omitted since it can be easily driven using the following.

When the electric motor configured as described above is driven, the stator winding (to) does not have a stator core like the conventional one, so eddy currents occur due to changes in magnetic flux from the first permanent magnet (3) of the rotor. does not occur. In other words, iron loss is eliminated.

In addition, by making the stator winding (A) coreless, the air gap becomes wider and the magnetomotive force loss of the first permanent magnet increases. is provided to prevent loss of magnetomotive force.

Therefore, the efficiency of the motor is improved by reducing the iron loss. Also, there is no need to use soft ferrite, and the size of the motor can be suppressed.

(g) Effects of the invention The electric motor of the present invention includes a rotating shaft, a rotating shaft attached to the rotating shaft,
and a rotor having a first permanent magnet on the outer periphery, a stator winding provided on the outer periphery of the rotor through a predetermined air gap, and a stator winding provided on the outer periphery of the stator winding with a predetermined air gap therebetween. Since the second permanent magnet is provided and rotates together with the rotor, it is possible to make the stator winding coreless and prevent a decrease in efficiency due to iron loss. Further, since the first and second permanent magnets are provided to sandwich the stator winding and have different magnetic poles, it is possible to suppress a decrease in magnetomotive force due to the coreless stator winding.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an electric motor showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along line n-I in FIG. (1)...rotating shaft, (3)...first permanent magnet,
(G)...Stator winding, (2)...Support member,
(2)...Second permanent magnet.

Claims (1)

[Claims] 1) A rotating shaft, a rotor attached to the rotating shaft and having a first permanent magnet on the outer periphery, a stator winding provided on the outer periphery of the rotor through a predetermined air gap, and the stator winding. a second permanent magnet provided on the outer periphery of the wire via a predetermined air gap and rotating together with the rotor;
An electric motor characterized in that a second permanent magnet facing the first permanent magnet has a different polarity.