JP2004080996A - Commutator motor and its stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the cooling surface area and emitting the heat of a stator coil, and to improve the cooling and heat-dissipating performance of the coil. <P>SOLUTION: The stator and a commutator motor have high cooling efficiency by being divided into at least two coil ends 2a, which are wound inside a slot of a stator core 1 and protrudes from both ends of the stator core 1 along at least one radial direction of the ends, setting a space 5 between the coil ends 2a, blowing cooling wind along the axial direction inside the space 5, and cooling down a stator coil 2. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a commutator motor used for, for example, an electric tool and capable of efficiently cooling a fixed coil, and a stator thereof.

も の A cooling device that cools a coil end portion of a stator coil protruding from both ends of a stator core has been proposed, for example, in Patent Document 1. However, this configuration can be adopted only for a large motor, and cannot be adopted for the commutator motor of the present invention having a two-pole stator core.

As is well known, the two-pole stator of the commutator motor shown in FIGS. 5 and 6 includes a stator core 1 and a stator coil 2 wound in a slot of the stator core 1. The stator coil 2 has a coil end portion 2a that protrudes axially outward from both ends in the axial direction of the stator core 1, and is connected to a power supply (not shown) through four lead wires 3. Is supplied with electricity.

The stator coil 2 generates heat during motor operation and rises in temperature. For this reason, a cooling fan (not shown) is generally provided to cool the coil end portion 2a by cooling air flowing along the axial direction. Therefore, the sectional shape of the coil bundle 2b of the coil end portion 2a is large. The cooling effect has been improved by forming the shape into a rectangle and increasing the cooling surface area.

JP-A-7-245894

However, for example, the surface area of the conventional coil bundle 2b having a shape in which the ratio of the cross-sectional dimension of the coil bundle 2b in the circumferential direction (vertical) to the axial direction (horizontal) is 1: 1 is made equal to the sectional area by 1.5 In order to make the rectangular shape longer in the axial direction so as to be more than doubled, the axial dimension of the coil bundle 2b must be extended to about 2.6 times or more. Extending the shape of the coil bundle 2b in the axial direction or the radial direction to increase the surface area increases the volume of the motor, and in a design that emphasizes miniaturization of the product, the coil bundle 2b is extended due to dimensional restrictions to reduce the cooling surface area. There was a limit to measures to increase.

The commutator motor and the stator according to claims 1 and 2 have been made in order to solve the above-mentioned problem, and at least one of the coil end portions protruding from the end face of the stator core is reduced to at least two along the radial direction. It is characterized in that a space is provided between the divided coil end portions, through which cooling air flowing along the axial direction passes.

According to the commutator motor or the stator having such a configuration, the stator coil can be reliably cooled without increasing the volume.

The commutator motor according to claim 3 is characterized in that a space is maintained by a spacer interposed in the space.

As described above, according to the present invention, since the space is provided in the coil end portion, the surface of the coil bundle divided by the space becomes a cooling heat radiation surface, the cooling heat radiation surface area of the stator coil increases, and the stator coil is cooled well. become able to. Further, since the coil bundle at the coil end portion is divided into a very simple structure, the manufacturing process is not significantly changed, and a low-cost and effective stator and a commutator motor can be provided.

Hereinafter, the present invention will be described with reference to FIGS. 1 and 2 showing one embodiment. A coil bundle 2b formed by a coil end portion 2a protruding outward in the axial direction from both ends of the stator core 1 of the coil 2 in the axial direction is divided into two or more along the radial direction at a substantially central portion in the circumferential direction and divided. The feature of the present invention is that a space 5 of about 2 to 3 mm is provided between the coil bundles 2b in the radial direction. The space 5 is formed by passing a tool made of plastic, for example, between the single coil bundles 2b so as not to damage the magnet wires constituting the stator coil 2, and is impregnated with a varnish or the like. The shape of the space 5 is fixed. The coil bundle 2b formed by the coil end portion 2a is formed by winding a magnet wire so as to be stacked in substantially constant directions in the axial direction and the radial direction, respectively. It is wound so as to be more than the number of wire stages. According to the above-described embodiment, by providing the space 5 between the coil bundles 2b, the cooling air flowing along the axial direction passes through the space 5, and the coil end portion 2a and, consequently, the stator coil 2 can be efficiently formed. It is cooled and the temperature rise of the stator coil 2 is suppressed.

FIGS. 3 and 4a show another embodiment of the present invention, in which the lead wire 3 is located in a space 5, and the lead wire 3 is used as a spacer. As a result, the space 5 is maintained, and there is no possibility that the space 5 will be closed by any external force, and the stator coil 2 is reliably cooled. In the case of this embodiment, since the lead wire 3 cannot be located in the space 5 of the coil end portion 2a on the back side in FIG. 3, it is necessary to provide some spacer made of an insulating material in place of the lead wire 3.

In the above-described embodiment, the space 5 is provided on both the coil end portions 2a protruding from both axial ends of the stator core 1. However, the space 5 may be provided only on one side of the coil end portion 2a. Is desirably provided on the windward side of the cooling air having a large cooling effect. Alternatively, a magnet wire having a heat-fusible film may be used as the magnet wire, and after forming the space 5 in the same manner as in the above embodiment, the shape of the space 5 may be fixed by heating the magnet wire.

1 is a partial cross-sectional front view illustrating an embodiment of the stator of the present invention. FIG. 2 is a sectional view taken along line AA of FIG. 1. The front view in partial cross section which shows other embodiment of the stator of this invention. FIG. 4 is a partial cross-sectional top view of FIG. 3. The front view with a partial cross section which shows an example of the conventional stator. FIG. 6 is a sectional view taken along line BB of FIG. 5.

Explanation of reference numerals

1 is a stator core, 2 is a stator coil, 2a is a coil end portion, 2b is a coil bundle, 3 is a lead wire, 4 is an armature, and 5 is a space.

Claims (3)

A commutator motor including a stator coil having a coil end portion wound around a stator core and a slot of the fixed core and protruding from both ends of the stator core,
At least one of the coil end portions protruding from the stator core is divided into at least two along the radial direction, and a space is provided between the divided coil end portions for cooling air flowing along the axial direction to pass. Features commutator motor. A stator of a commutator motor including a stator core and a stator coil having coil ends protruding from both ends of the stator core and wound around slots of the stator core,
At least one of the coil end portions protruding from the stator core is divided into at least two along the radial direction, and a space is provided between the divided coil end portions for cooling air flowing along the axial direction to pass. Characteristic stator of commutator motor. The commutator motor according to claim 1, wherein a spacer is interposed in the space to maintain the space.

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