JP2005269782A - Stator structure of motor and manufacturing method of motor stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator structure of a motor improvable in radiation efficiency by a cooling medium, and to provide a manufacturing method of a motor stator. <P>SOLUTION: The stator structure of the motor is formed with a slot, impregnates varnish 8 into a coil 6 after inserting the coil 6 into the slot, and cures the varnish by heating. The varnish surface of the coil end of the coil 6 is made large by being formed into an irregular shape such as, for example, a crater shape. By this, when cooling the structure by using the cooling medium, the flow of the cooling medium on the surface can be turbulized, whereby cooling efficiency is improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a stator structure of an electric motor and a method for manufacturing the electric motor stator, and more particularly to a technique for improving the cooling efficiency of a coil by a refrigerant.

In a conventional stator of an electric motor, an insulating paper and a coil are inserted into a slot and fastened with a racing material, and then the coil is impregnated with a varnish as a thermosetting resin. Thereafter, the varnish is heated to about 150 ° C. and solidified. As a result, the coil is fixed, and the thermal conductivity of the coil is further improved (see, for example, JP-A-9-322495 and JP-A-2003-189523).
Japanese Patent Laid-Open No. 9-322495 JP 2003-189523 A

  However, in the conventional motor stator structure, since the varnish portion on the surface of the coil end portion is smooth, the surface area of the varnish is reduced, and when the coil is cooled by flowing a refrigerant such as air or oil, There was a drawback that the flow became laminar and the heat dissipation characteristics were poor.

  The present invention has been made to solve such a conventional problem. An object of the present invention is to provide a stator structure of an electric motor capable of improving the heat dissipation efficiency by the refrigerant, and a method of manufacturing the electric motor stator. It is to provide.

  To achieve the above object, according to the present invention, there is provided a stator structure of an electric motor comprising a slot, the coil being inserted into the slot, the coil being impregnated with a thermosetting resin, and solidified by heating. The surface of the varnish of the portion is made uneven to increase the surface area.

  In the electric motor stator structure and electric motor stator manufacturing method according to the present invention, the surface of the thermosetting resin impregnated in the coil end portion is formed into an uneven shape such as a crater. Therefore, when cooling the stator core using a refrigerant, The surface layer flow of the refrigerant can be turbulent, and the heat dissipation performance from the coil end portion can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of an electric motor having a stator structure of an electric motor to which the present invention is applied. As shown in the figure, this electric motor is provided with a cylindrical stator 1 and a rotor 2 arranged concentrically with the stator 1, and a rotating magnetic field is generated by passing an electric current through a coil wound around the stator 1. Thus, the rotor 2 having permanent magnets is rotated, so that the rotating shaft 12 connected to the rotor 2 can be driven to rotate.

  FIG. 2 is an explanatory view showing general processing steps when the stator 1 is manufactured by winding the coil 6 around the stator core 3 and further impregnating the stator core 3 with a varnish (thermosetting resin) 8. As shown in FIG. 1A, first, the insulating paper 4 is inserted into the slots between the cores of the stator cores 3, and the coil 6 is wound around the stator cores 3. Further, the wedge 5 is covered so that the wound coil 6 does not come out of the slot.

  Thereafter, as shown in FIG. 5B, the coil end portion is fastened with the racing material 7. Next, as shown in FIG. 4C, the wound portion of the coil 6 is impregnated with the varnish 8, and as shown in FIG. 5D, the varnish 8 is heated to about 150 ° C. To cure. Thereby, the coil 6 is fixed inside the slot, and the heat dissipation of the coil 6 can be further improved.

  In the first embodiment of the present invention, as shown in FIG. 3, the surface of the varnish 8 impregnated in the coil end portion is formed into a crater shape (uneven shape) to increase the surface area, and air or oil is used. The cooling efficiency at the time of cooling the stator 1 by flowing a refrigerant is improved.

  Hereinafter, with reference to FIG. 4, the process sequence at the time of forming the varnish 8 surface of a coil end part in a crater shape is demonstrated. First, as shown in FIG. 2A, air is fed into the varnish 8 using an air pump 10 while stirring the liquid varnish 8 with a stirrer 9.

  As a result, as shown in FIG. 5B, a liquid varnish 8 in which a large number of bubbles are generated is generated. Then, as shown in FIG. 2C, the wound portion of the coil 6 inside the slot is impregnated with a normal varnish 8 (varnish containing no bubbles) (according to the processing procedure up to FIG. 2C). The coil end portion is impregnated with the varnish 8 in which bubbles are generated as shown in FIG. Then, the varnish 8 is hardened by heating to about 150 degreeC. As a result, as shown in FIG. 4D, a crater-like uneven portion is formed on the surface of the varnish 8 impregnated in the coil end portion.

  Thus, in the stator structure of the electric motor according to the present embodiment, the surface of the varnish 8 impregnated in the coil end portion is crater-like, so that the surface layer flow of the refrigerant is turbulent when the stator core is cooled using the refrigerant. It is possible to improve the heat dissipation performance from the coil end portion.

  It is also possible to use a procedure in which when the ordinary varnish 8 is impregnated in the coil 6, the varnish 8 is once heated and solidified, and then the coil end portion is impregnated with the varnish 8 containing bubbles and solidified. is there.

  Next, a second embodiment of the present invention will be described. In 2nd Embodiment, as shown in FIG. 5, the granular member 11 which has high thermal conductivity at normal temperature adheres to the surface of the varnish 8 which impregnates a coil end part. As shown in FIG. 7A, the granular member 11 has a spherical shape. And since the granular member 11 adheres, an unevenness | corrugation arises in the surface of the varnish 8 and a refrigerant | coolant can be made turbulent, Therefore Heat dissipation performance can be improved.

  Hereinafter, a processing procedure for fixing the granular member 11 will be described with reference to FIG. First, as shown in FIG. 5A, the granular member 11 is mixed while stirring the liquid varnish 8 with the stirrer 9.

  As a result, as shown in FIG. 5B, a liquid varnish 8 in which a large number of granular members 11 are mixed substantially uniformly is generated. Then, as shown in FIG. 2C, the coil 6 is impregnated with the varnish 8 in which the granular member 11 is mixed. Then, the granular member 11 moves to the coil end portion by capillary action, and the granular member is fixed to the coil end portion. Then, the varnish 8 is hardened by heating to about 150 degreeC. As a result, as shown in FIG. 4D, a varnish 8 mixed with the granular member 11 is formed at the coil end portion, and the surface area can be increased.

  Thus, in the stator structure of the electric motor according to the second embodiment, since the granular member 11 is mixed into the varnish 8 impregnated in the coil end portion, irregularities are formed on the surface of the varnish 8 at this portion, and the surface area is increased. Therefore, when the stator core is cooled using the refrigerant, the surface layer flow of the refrigerant can be turbulent, and the heat dissipation performance from the coil end portion can be improved.

  Further, since the spherical shape of the granular member 11 is used, the shape is simple and inexpensive, and the coil 6 is scratched when impregnating the varnish 8 mixed with the granular member 11 with no corners. There is no.

  Further, if the granular member 11 is made of a non-conductive member such as a resin member, the magnetic field generated by the coil 6 can be prevented from being disturbed. That is, by using the granular member 11 as a non-conductive member, no eddy current is generated inside the granular member 11 even under the influence of the rotating magnetic field excited by the coil 6, so that the granular member 11 itself generates heat. Thus, the efficiency of the electric motor can be prevented from decreasing.

  Next, a modification of the second embodiment will be described. In the second embodiment described above, an example in which a spherical member as shown in FIG. 7A is used as the shape of the granular member 11 has been described. However, as a modification of the shape of the granular member 11, FIG. As shown in b), it is also possible to use a complex toe shape, or as shown in FIG.

  Further, by using a complex tow shape, the surface area can be increased and the heat radiation efficiency can be improved. Moreover, since it does not have a corner | angular part, when impregnating the varnish 8, the coil 6 is not damaged.

  Moreover, by using a tube-shaped thing, a surface area can be enlarged similarly to the complex tow shape mentioned above, and heat dissipation efficiency can be improved.

  In the second embodiment described above, an example in which the coil 6 is impregnated with the varnish 8 mixed with the granular member 11 having high conductivity and the granular member 11 moves to the coil end portion by capillary action has been described. After impregnating the coil 6 with a normal varnish 8 in which the granular member 11 is not mixed, the highly conductive granular member 11 may be sprinkled on the coil end portion and then heated and solidified. .

  Furthermore, after the coil 6 inside the slot is impregnated with a normal varnish 8 and heated and solidified, the coil end portion can be impregnated with the varnish 8 mixed with the granular member 11 and heated and solidified again. It is.

  As mentioned above, although the stator structure of the motor of this invention and the manufacturing method of the motor stator were demonstrated based on embodiment of illustration, this invention is not limited to this, The structure of each part has the same function. It can be replaced with any configuration.

  For example, in the first embodiment, the case where the varnish surface of the coil end portion is made crater-like as an example of making the varnish surface uneven is described as an example, but the present invention is not limited to this, The shape may be a varnish surface uneven shape to increase the surface area.

  Further, in the second embodiment, as the shape of the granular member 11, the spherical shape, the complex toe shape, and the tube shape as illustrated in FIGS. The invention is not limited to this, and it is also possible to increase the surface area by forming irregularities on the varnish surface using other shapes.

  Further, in each of the above-described embodiments, the varnish 8 has been described as an example of the thermosetting resin. However, the present invention is not limited to this, and the same curing can be performed even when other thermosetting resins are used. Can be obtained.

  This is extremely useful for improving the cooling efficiency of the stator.

It is explanatory drawing which shows the structure of the electric motor by which the stator structure of the electric motor which concerns on this invention is employ | adopted. It is explanatory drawing which shows the general procedure at the time of winding a coil and impregnating a varnish to a stator core. It is explanatory drawing which shows a mode that the crater-like uneven | corrugated | grooved part was formed in the varnish of a coil end part. It is explanatory drawing which shows the procedure at the time of forming a crater-like protrusion on the varnish of a coil end part. It is explanatory drawing which shows a mode that a granular member mixed in the varnish of a coil end part. It is explanatory drawing which shows the procedure at the time of mixing a granular member in the varnish of a coil end part. It is explanatory drawing which shows the shape of a granular member, (a) is a spherical shape, (b) is a complex shape, (c) shows a tube shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator 2 Rotor 3 Stator core 4 Insulating paper 5 Wedge 6 Coil 7 Racing material 8 Varnish (thermosetting resin)
9 Stirrer 10 Air pump 11 Granular member 12 Rotating shaft

Claims (9)

In a stator structure of an electric motor comprising a slot, and after inserting a coil into the slot, impregnating the coil with a thermosetting resin and heating and solidifying the coil,
A stator structure for an electric motor, wherein the surface of the varnish of a coil end portion of the coil is made uneven to increase the surface area.   The stator structure for an electric motor according to claim 1, wherein the uneven shape is a crater shape.   The stator structure for an electric motor according to claim 1, wherein the surface of the varnish is made uneven by mixing a highly heat-conductive granular member into the varnish.   The stator structure for an electric motor according to claim 3, wherein the granular member is made of a non-conductive material.   The stator structure for an electric motor according to claim 3, wherein the granular member has a spherical shape.   The stator structure for an electric motor according to claim 3, wherein the granular member has a complicated shape.   The stator structure for an electric motor according to claim 3, wherein the granular member has a tube shape. In a manufacturing method for manufacturing an electric motor stator,
Inserting a coil into the slot, impregnating the coil with a thermosetting resin, impregnating the end portion of the coil with a thermosetting resin mixed with air bubbles, and applying heat to the heat And a step of solidifying the curable resin. In a manufacturing method for manufacturing an electric motor stator,
Inserting a coil into the slot;
A method of manufacturing an electric motor stator, comprising: impregnating the coil with a thermosetting resin mixed with a highly heat-conductive granular member; and applying heat to cure the thermosetting resin. .