Rotary electric machine having temperature sensor for coils and manufacturing method thereof

A stator includes an iron core cylindrical part, multiple teeth, and a coil. The iron core cylindrical part has multiple circular arc-shaped core back parts. The teeth radially inwardly protrude from an inner circumferential wall surface of the iron core cylindrical part. The coil is wound around each of the teeth. A first coil and a second coil are disposed so as to hold a temperature measuring element therebetween. The first coil has an outer surface provided with a gap made of a recess or a space, which is formed by skipping winding a coil wire. The temperature measuring element for measuring temperature of the coil is inserted in the gap and is assembled.

BACKGROUND OF THE INVENTION

Field of the Invention

The present application relates to the field of a rotary electric machine having a temperature measuring element for measuring temperature of a coil and a manufacturing method thereof.

Description of the Related Art

A rotary electric machine may include a stator that has a pair of adjacent divided iron cores with teeth. The teeth are wound with coils between which a temperature measuring element is disposed. The temperature measuring element is brought into contact with one of the coils and has an elastic insulating material that is disposed between the temperature measuring element and the other coil. In this publicly known structure, the elastic insulating member presses the temperature measuring element against the one coil so that the temperature measuring element will be brought into contact with the one coil. Such a structure is disclosed in, for example, Patent Document 1.

In such a conventional rotary electric machine, the temperature measuring element is easily dislocated relative to the coil when being pressed against the coil by the elastic insulating member, and thus, assembling characteristic and accuracy of temperature measurement tend to be deteriorated. To dispose the temperature measuring element and the elastic insulating member between the pair of the adjacent coils, a space for disposing these components is necessary, thereby decreasing a number of layers of the wound coil, resulting in decrease in a space factor.

SUMMARY OF THE INVENTION

The present application has been made to solve the problem and an object of the present application is to provide a rotary electric machine having an improved assembling characteristic of a temperature measuring element, an improved accuracy of temperature measurement, and an improved winding space factor and also to provide a manufacturing method thereof.

A rotary electric machine disclosed in the present application includes a stator having a cylindrical shape, a rotor coaxially disposed with the stator on an inner circumferential side of the stator, and a temperature measuring element that measures temperature of a coil wound around the stator. The stator includes an iron core cylindrical part, multiple teeth that radially inwardly protrude from an inner circumferential wall surface of the iron core cylindrical part, and the coil wound around each of the teeth. The coil wound around one of the multiple teeth is provided with a gap by making a recess on a part of an outer surface of the coil. The temperature measuring element is disposed in the gap.

A manufacturing method for manufacturing the rotary electric machine disclosed in the present application includes forming the gap by making the recess on the part of the outer surface of the coil. The recess is formed by skipping winding the coil wire by a width of at least one coil wire on the outer surface of the coil in winding the coil wire in a staggered arrangement around an outside of the tooth. The manufacturing method also includes inserting and securing the temperature measuring element in the gap.

The rotary electric machine disclosed in the present application includes the temperature measuring element that is disposed in the gap on the outer surface of the coil. Thus, positioning of the temperature measuring element to the coil is easy, thereby improving assembling characteristic. Moreover, the temperature measuring element is disposed in contact with the coil, thereby improving measurement accuracy. Furthermore, the temperature measuring element is assembled to the coil without disposing a special securing part, and therefore, a coil space factor is improved accordingly.

The manufacturing method for manufacturing the rotary electric machine disclosed in the present application includes providing the gap by skipping winding the coil wire in winding and inserting the temperature measuring element in the gap. Thus, the gap is easily provided, and the temperature measuring element is easily disposed between adjacent coils, thereby improving productivity and assembling characteristic.

The foregoing and other objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

A rotary electric machine according to the first embodiment of the present application is described with reference toFIGS. 1 to 8. A rotary electric machine100according to the present application is used in, for example, a generator, an electric motor, and a motor generator. The rotary electric machine100includes a stator10that has a coil16of which the temperature is measured by a temperature measuring element19.

FIG. 1is a sectional side view showing a main part of one side of the stator10of the rotary electric machine100according to the first embodiment.FIG. 2is a perspective view of the stator10as viewed from one end side in an axial direction.FIG. 3is a sectional view along the axial direction of the stator10.FIG. 4is a plan view showing one end surface of the stator10as viewed from the one end side in the axial direction.FIG. 5is a perspective view of the stator10as viewed from the other end side in the axial direction.FIG. 6is a perspective view showing a bobbin14to be used in the stator10.FIG. 7is a perspective view showing a divided iron core12wound with the coil16.FIGS. 8, 9A, and 9Bare sectional views of a main part of the stator10of the rotary electric machine100and show states of holding the temperature measuring element19between two coils16.

As shown inFIG. 1, the rotary electric machine100has a housing1that is constituted of a frame2and an end plate3. The frame2includes a cylindrical part2aand a bottom2b, thereby having a cylindrical shape with a bottom, and the frame2is made of an aluminum material or other material. The end plate3covers an opening of the frame2. The housing1houses the stator10and a rotor5. The stator10is inserted and fixed in the cylindrical part2aof the frame2. The rotor5is firmly fixed to a rotation shaft6and is rotatably disposed on an inner circumferential side of the stator10. The rotation shaft6is rotatably supported by the bottom2bof the frame2and the end plate3via bearings4.

The rotor5is, for example, a permanent magnet rotor, and includes a rotor core7and permanent magnets8. The rotor core7is inserted at an axial center position of the rotation shaft6and is firmly fixed to the rotation shaft6. The permanent magnets8are buried in an outer circumferential surface side of the rotor core7and are arranged at a predetermined pitch in the circumferential direction, and the permanent magnets8constitute magnetic poles.

The rotor5is not limited to the permanent magnet rotor and may use a cage rotor or a wound rotor. The cage rotor may include uninsulated rotor conductors that are contained in slots of a rotor core and that are shorted by a short-circuit ring at each side. The wound rotor may include insulated conductors that are fitted to slots of a rotor core.

Next, a structure of the stator10is specifically described with reference toFIGS. 2 to 7.

As shown inFIGS. 2 to 5, the stator10includes a stator core11, coils16of U phase, V phase, and W phase, and bus rings25,26, and27for the U phase, the V phase, and the W phase. The stator core11is constituted of multiple divided iron cores12that are arranged in a circle. The coils16are respectively wound around the divided iron cores12via both bobbins14and15. The bus rings25,26, and27are used for connecting the coils16of the U phase, the V phase, and the W phase and are adjacently arranged.

The divided iron core12is obtained by equally dividing the circular-shaped stator core11in the circumferential direction into 18 parts. The divided iron core12is made of a predetermined number of electromagnetic steel sheets that are integrally laminated. The divided iron core12has a core back part12awith a circular arc-shaped cross section and has a tooth12bthat protrudes from an inner circumferential wall surface of the core back part12atoward a radial inside of the core back part12a. The multiple core back parts12aare arranged so as to be fitted to an inside of a yoke13in a circumferential direction, thereby constructing an iron core cylindrical part as a whole.

The bobbin14is made of a resin material such as a PBT resin or a PPS resin so as to have electrical insulating properties. As shown inFIG. 6, the bobbin14includes a coil winding part14a, a flange part14bthat is provided on a radially outward of the coil winding part14a, and a wall part14cthat is arranged on a radially inward of the core back part12arelative to bus ring holding parts20,21, and22. The bobbin14is disposed on one end surface in the axial direction of the divided iron core12.

More specifically, as shown inFIGS. 3 and 4, the coil winding part14ais disposed on one end surface in the axial direction of the tooth12b, whereas the flange part14bis disposed on one end surface in the axial direction of the core back part12a. The bus ring holding parts20,21, and22are concentrically formed to the flange part14bso as to have groove shapes and are respectively used for the U phase, the V phase, and the W phase. The bobbin15is made of a resin material such as a PBT resin or a PPS resin and is provided with a coil winding part15a. The bobbin15is disposed on the other end surface in the axial direction of the divided iron core12. More specifically, the coil winding part15ais disposed on the other end surface in the axial direction of the tooth12b, as shown inFIGS. 3 and 7.

The bobbins14and15may be fixed to the divided iron core12from a point of view of easiness of winding the coil16. For example, the bobbins14and15may be fixed to the divided iron core12in an engaging manner or in an adhesive manner using an adhesive material. Alternatively, the bobbins14and15may be integrally formed with the divided iron core12by mold forming.

As shown inFIG. 7, the coil16is structured by winding a conductive wire by a predetermined number of turns around the tooth12band the coil winding parts14aand15aof the bobbins14and15, which are respectively disposed at both end surfaces in the axial direction of the tooth12b. The conductive wire is an insulation-covered copper round wire, which corresponds to a coil wire. An insulator (not shown) is provided on each side surface in the circumferential direction of the tooth12bto provide insulation between the coil16and the divided iron core12.

As shown inFIGS. 2 to 5, the 18 divided iron cores12that are wound with the coils16are circularly arranged while the teeth12bare radially inwardly directed and side surfaces in the circumferential direction of the core back parts12aare abutted on each other. In this condition, the 18 divided iron cores12are inserted and fixed in the cylindrical yoke13by press fitting, shrinkage fitting, or other methods. The yoke13is formed by cutting or drawing a metal material of a single component such as iron. However, the yoke13may be formed by integrally laminating steel sheets, such as electromagnetic steel sheets.

The coils16are wound around the divided iron cores12and are circularly arranged repeatedly in the circumferential direction of the stator core11in the order of the coil16of the U phase, the coil16of the V phase, and the coil16of the W phase. Each of the coils16has an end16athat is led out to the bobbin14side. Each of the coils16has the other end16bthat is led out to the bobbin15side.

The bus rings25,26, and27for the U phase, the V phase, and the W phase are respectively formed by bending a strip-shaped flat sheet made of a material such as oxygen-free copper, deoxidized copper, or tough pitch copper, into a cylindrical shape with a partially open part. As shown inFIGS. 2 and 4, the bus rings25,26, and27for the U phase, the V phase, and the W phase are respectively fitted and held in the bus ring holding parts20,21, and22shown inFIG. 6by being fixed with an adhesive or other material as necessary.

As shown inFIGS. 2 and 4, the end16aof the coil16of the U phase is led out in the axial direction to the bobbin14side, bent at a right angle, further led out in a radial outward direction of the stator core11, and connected to a coil connecting part of the bus ring25for the U phase. The end16aof the coil16of the V phase is led out in the axial direction to the bobbin14side, bent at a right angle, further led out in the radial outward direction, and connected to a coil connecting part of the bus ring26for the V phase. The end16aof the coil16of the W phase is led out in the axial direction to the bobbin14side, bent at a right angle, further led out in the radial outward direction, and connected to a coil connecting part of the bus ring27for the W phase. The ends16aof the coils16of the U phase, the V phase, and the W phase and the coil connecting parts of the bus rings25,26, and27are respectively electrically connected to each other by means of TIG welding, laser welding, resistance welding, soldering, resistance brazing, or other methods.

As shown inFIG. 5, the ends16bof the coils16of the U phase, the V phase, and the W phase, that is, the ends16bof the coils16on the common side are led out in the axial direction to the bobbin15side, collected together, and electrically connected by means of TIG welding, laser welding, or other methods. The connected part on the common side of the coils16of the U phase, the V phase, and the W phase is covered with an insulating tube17. The connected part on the common side may be covered with a resin mold, an insulating tape, or other insulating material, instead of the insulating tube17. Although the common side structural parts of the coils16of the U phase, the V phase, and the W phase are collected together and are joined by welding or other methods, these common side structural parts may be connected by using bus rings for the common side that are held by bus ring holding parts for the common side formed to the bobbin15.

The stator10thus structured has six three-phase alternating current windings each constituted of the coils16of the U phase, the V phase, and the W phase that are Y-connected.

The rotary electric machine100is supplied with alternating current at the bus rings25,26, and27for the U phase, the V phase, and the W phase via an external inverter (not shown). This occurs a rotating magnetic field in the stator10. The rotating magnetic field generates an attractive force and a repulsive force that cause the rotor5to be rotationally driven. The rotary electric machine100can be used in an electric motor such as a motor equipped in a household electric appliance and a motor equipped in an industrial machine.

Next, examples of winding the coil16so as to have a gap18and examples of holding the temperature measuring element19are described by using coil winding models inFIGS. 8, 9A, and 9B. The coil16includes a first coil160aand a second coil160b.

As shown in the sectional view of the main part of the stator10inFIG. 8, one divided iron core12that is positioned on a right side inFIG. 8is wound with the first coil160aof one of the coils16, whereas another divided iron core12that is positioned on a left side inFIG. 8adjacent to the one divided iron core12is wound with the second coil160bof another of the coils16.FIGS. 8, 9A, and 9Bshow cross sectional structures in which the temperature measuring element19is disposed at facing parts of the first coil160aand the second coil160b.

In the example of the coil winding model inFIG. 8, a gap18is provided to a surface part of the wound coil of the first coil160a, which faces the second coil160b. This surface part functions as a surface part for holding the temperature measuring element19. The gap18is formed by skipping winding the coil wire of the first coil160aby one turn at a fourth stage that is the uppermost layer of the wound coil wound in a staggered arrangement. The uppermost layer functions as an outer surface of the first coil160aand is an adjacent layer facing the adjacent second coil160b. The gap18is shaped by making a recess along the axial direction on a part of the outer surface of the first coil160a. The part in which the coil wire is not wound at the outer surface of the first coil160a, that is, at the surface part of the wound coil16, corresponds to the gap18. The gap18is provided so as to have the same width in the axial direction, for example. The gap18causes exposure of the coil wire that is wound one stage under the outer surface of the first coil160a.

The coil winding model is exemplified in the present application to describe the winding manner of the coil16, and it is obvious that the number of turns of winding of the coil wire can differ from that actually used.

The gap18is easily formed as follows. For example, after the coil wire is wound and reaches a part to be formed with the gap18, during winding the coil wire around the tooth12b, a spacer is disposed at this part, and the coil wire is then wound so as to hold the spacer. The spacer has a dimension corresponding to a width of the turn that is skipped. The spacer is removed after the coil wire is wound.

In another example, it is possible to form the gap18without using the spacer or another component such that the coil wire is obliquely wound at a desired angle relative to a regular winding direction before reaching an area to be formed with the gap18during winding. The width of the gap18is adjusted in accordance with the oblique angle, and thus, winding of the coil wire is skipped by a predetermined width on the outer surface of the coil16.

The temperature measuring element19is inserted in the gap18of the first coil160a. The temperature measuring element19has a diameter greater than that of the coil wire, and thus, the temperature measuring element19is disposed in contact with the coil wire of the outer surface of the first coil160aat each end of the gap18. The temperature measuring element19is brought into contact with both of the two coils16that face each other, that is, both of the first coil160aand the second coil160b.

The coil wire is densely wound in an area other than the area of the gap18in the outer surface of the first coil160a. That is, the coil wire is wound next so that an outer circumference of the coil wire will be partially brought into contact with an outer circumference of the coil wire that is already wound.

The outer surface of the coil16is made by stacking the coil wire higher in a part in which the temperature measuring element19is not disposed than in the part in which the temperature measuring element19is disposed. This structure improves the space factor.

The layer of the outer surface of the coil16, that is, an adjacent layer, is a surface part of the coil16facing the adjacent coil16. This layer may include a part other than the outermost layer of the coil wire that is wound around the tooth12bat the highest stage.

As shown in the examples inFIGS. 8, 9A, and 9B, whereas a stacking height of the coil wire increases on a side close to the core back part12aof the tooth12bbecause a greater space for winding the coil wire is obtained as a distance to the shaft increases, the stacking height of the coil wire decreases on a side away from the core back part12aof the tooth12b. That is, whereas the coil wire is wound in a four-stage staggered arrangement on the side close to the core back part12aof the tooth12b, the coil wire is wound in a three-stage staggered arrangement on the side away from the core back part12aof the tooth12b, resulting in decrease of one stage compared with the area close to the core back part12aof the tooth12b. Thus, the layer of the outer surface of the coil16that is wound on the side away from the core back part12aof the tooth12bincludes a layer of which the stage number of the coil wire wound in the staggered arrangement is small. It is possible to improve the space factor by appropriately adjusting the number of the stages of winding in accordance with a space between the pair of the adjacent teeth12b.

In the example inFIG. 9A, the temperature measuring element19is disposed on a tip side of the tooth12baway from the core back part12a. In this coil winding model, the gap18is formed by skipping winding a third layer from the tip of the tooth12bof a third stage functioning as the outer surface of the first coil160a, to generate a space, and the temperature measuring element19is set in this gap18. This third stage is an area in which the number of stages of the coil wire wound in the staggered arrangement is not maximum. The winding of the coil wire is skipped by a width corresponding to the diameter of one coil wire.

FIGS. 8 and 9Ashow examples of disposing the temperature measuring element19in an area other than an end part of the coil16, more exactly, an end part on the tip side of the tooth12b. However, as in another example of the coil winding model shown inFIG. 9B, it is also possible to dispose the temperature measuring element19in the gap18that is provided to the outer surface of the first coil160aat a position closest to the tip of the tooth12b. In the case inFIG. 9B, one part of each of the first coil160aand the second coil160bis brought into contact with the temperature measuring element19. The coil19and the temperature measuring element19may be fixed by an adhesive such as a silicone adhesive or an epoxy adhesive to reliably bring them into contact with each other.

The coil16generates heat that is transmitted primarily through the iron core. In view of this, the temperature measuring element19is desirably disposed on the outer surface of the coil16to measure the temperature because the outer surface of the coil16is away from the iron core and thereby tends to increase in temperature. For this reason, the structure of the present application as shown inFIG. 8, 9A, or9B enables disposition of the temperature measuring element19on the outer surface of the coil16and is suitable for measuring temperature of the coil16.

The examples described above have the structure in which the temperature measuring element19is brought into contact with the pair of the coils16, which are the first coil160aand the second coil160b. However, it is also possible to correctly measure the temperature of the coil16in the structure in which the temperature measuring element19is brought into contact with one of the coils16, and the other coil16is disposed around the temperature measuring element19in a noncontact manner.

The pair of the adjacent coils16have a space in which the coil wire is not wound around the gap18for containing the temperature measuring element19. This space is adjusted so that the temperature measuring element19will not come off from the gap18and will not deviate in the gap18.

Thus, in the rotary electric machine100according to the first embodiment of the present application, the gap18is formed by winding the coil wire so as to generate a space at at least one part of one or both of the adjacent layers of the pair of the adjacent coils16, which are the first coil160aand the second coil160b, and the temperature measuring element19is disposed in the gap18.

The first embodiment provides effects as described below.

(1) Disposing the temperature measuring element19in contact with the coil16enables easy positioning of the temperature measuring element19, thereby improving the assembling characteristic.

(2) Disposing the temperature measuring element19in contact with the coil16enables fixing the position of the temperature measuring element19, thereby decreasing variation in temperature measurement and improving the measurement accuracy.

(3) Disposing the coil16around the temperature measuring element19enables measuring temperature of the coil16at a higher accuracy because the temperature in the vicinity of the temperature measuring element19comes close to the temperature of the coil16.
(4) The coil wire is stacked higher in the area other than the gap18in which the temperature measuring element19is disposed than in the gap18. This increases the number of turns of winding compared with that of winding in an ordinary staggered arrangement, thereby increasing the space factor.
(5) The gap18is formed such that the coil wire is wound in the staggered arrangement around the outside of the tooth12bby skipping winding the coil wire by a width of at least one coil wire on the outer surface of the coil16, thereby making a recess on a part of the outer surface of the coil16. The coil16is, for example, the first coil160a. Thus, the gap18is formed without using a special tool or an additional part, whereby the productivity is improved.

It is obvious that effects similar to those described above are obtained also in cases such as the coil wire uses a rectangular copper wire, and the temperature measuring element19has a rectangular parallelepiped shape.

Second Embodiment

FIG. 10is a sectional view showing a main part of a coil winding model of the stator10of the rotary electric machine100according to a second embodiment. In the example of the first embodiment, the gap18is provided only on the first coil160aside, and the gap18is not provided to the second coil160bthat faces the first coil160a. On the other hand, in the second embodiment, the gap18is provided to a surface part of the wound coil of a first coil160c, and another gap18is also provided to a surface part of the wound coil, that is, a surface part facing the coil, of a second coil160dthat faces the first coil160cas in the case of the first coil160c. The gap18of the first coil160cand the gap18of the second coil160dare symmetrically arranged to have a space therebetween, in which the temperature measuring element19is inserted.

As in the case of the first embodiment, it is obvious that the gap18can be provided in an area other than the area of the uppermost layer of the coil16at the highest stage of winding, in the second embodiment.

Thus, the rotary electric machine100according to the second embodiment has the temperature measuring element19that is disposed in the space formed by the two gaps18. The gaps18are respectively provided at symmetrical positions of the facing outer surfaces of the pair of the adjacent coils16, which are the first coil160cand the second coil160d.

The second embodiment provides an effect as described below.

(1) At least two coils16are brought into contact with the outer circumference of the temperature measuring element19, and thus, the temperature in the vicinity of the temperature measuring element19comes close to the temperatures of the coils16. This structure enables measuring temperature of the coil16at a higher accuracy.

Third Embodiment

FIG. 11is a side view of the divided iron core12of the rotary electric machine100according to a third embodiment. As shown inFIG. 11, the coil16that is wound around the tooth12bhas a long-side crossing part161at the gap18of the outer surface. The long-side crossing part161is wound so as to cross along the long side of the outer surface of the coil16. The tooth12bhas a rectangular cross section along the coil winding direction. The coil wire is wound in the axial direction on the long-side side and faces an adjacent coil16. The coil wire is wound so as to cross the axial direction on the short-side side. The long-side crossing part161that is provided in the gap18divides the gap18into two spaces18aand18b. As shown inFIG. 11, the gap18has a rectangular plane shape with a width corresponding to at least two coil wires, and the long-side crossing part161is obliquely arranged relative to the rectangular shape. The long-side crossing part161is linearly provided so as to be oblique at a predetermined angle to the axial direction, which is a regular winding direction. The spaces18aand18bthat are divided by the long-side crossing part161respectively have plane shapes of long narrow right triangles that face different directions. In the example inFIG. 11, the space18ais provided so that the width will decrease from an end to the other end, that is, from a lower end to an upper end, of the surface part of the wound coil, whereas the space18bis provided so that the width will gradually decrease from an end to the other end, that is, from an upper end to a lower end, of the surface part of the wound coil. That is, in the condition in which the inserting direction of the temperature measuring element19is the axial direction, the spaces18aand18bare formed so as to gradually decrease in dimension along the inserting direction of the temperature measuring element19.

The tooth12bhas a rectangular cross section along the axial direction, which has a long side and a short side. The coil16is wound along the outer circumference of the rectangular shape. Thus, to form the gap18in forming the coil16, a space must be provided between two coil wires that are sequentially wound, by skipping winding the coil wire at either part of the outer circumferential surface. For this reason, as shown inFIG. 11, the coil wire is arranged in the crossing manner on one of the four outer circumferential surfaces of the tooth12bto skip winding the coil16. In the first embodiment and the second embodiment, whether the coil wire is arranged in the crossing manner in the gap18is not important as long as the gap18is provided for disposing the temperature measuring element19. On the other hand, in the third embodiment, the gap18of the coil16is divided by the long-side crossing part161to form the spaces18aand18brespectively at both sides in the width direction of the long-side crossing part161.

FIG. 12is a side view of the stator10of the rotary electric machine100according to the third embodiment and shows a state of disposing the temperature measuring element19to the divided iron core12wound with the coil16. The temperature measuring element19is disposed in the gap18from an end toward the other end of the surface part that faces the coil16, that is, from a lower side toward an upper side inFIG. 12. The space18ahas the width that gradually decreases from a front side toward a depth side along the inserting direction. The temperature measuring element19includes a temperature sensing part19a. The temperature sensing part19ais, for example, disposed on a tip side of the tubular temperature measuring element19. The tip side of the temperature measuring element19that is provided with the temperature sensing part19ais disposed on the deep side in which the space18ahas a small width, whereby tightness between the tip side of the temperature measuring element19and the coil16is improved.

Thus, in the third embodiment, the long-side crossing part161is wound at one part of the adjacent layer of the outer surface of the coil16to provide the space18aor18bso that the width will gradually decrease along the axial direction, and the temperature measuring element19is inserted and is secured in the space18aor18b.

The long-side crossing part161is provided in the gap18of the coil16, on one or both of the facing surface parts of the wound coils of the two coils16. This structure provides advantageous effects compared with a structure in which the crossing part is provided on the short-side side of the rectangular cross section of the tooth12b. As shown inFIG. 11, in the case of forming the space18aby using the long-side crossing part161, the length in the axial direction of the space18adepends on the length of the long side of the rectangular shape of the tooth12band is thereby longer than the length of the short side of the rectangular shape. Thus, in the condition in which the temperature measuring element19is inserted from an end of the space18a, a contact area between the coil wire and the temperature measuring element19is sufficiently obtained, thereby enabling more stably holding the temperature measuring element19and measuring the temperature correctly.

The third embodiment provides effects as described below.

(1) Disposing the temperature measuring element19in the space18aor18bof which the width gradually decreases enables easy positioning in the axial direction of the temperature measuring element19, thereby improving the assembling characteristic.

(2) Disposing the temperature measuring element19in the space18aor18bof which the width gradually decreases reliably makes the temperature measuring element19and the coil19in close contact with each other, thereby enabling measuring temperature of the coil16at a higher accuracy.
(3) Disposing the temperature sensing part19aof the temperature measuring element19on the deep side in which the space18aor18bhas a small width enables measuring the temperature of the coil16at a higher accuracy.

In the case of providing the space18aor18bto one of the coils16that face each other, the other coil16may not be provided with the gap18(first pattern), the other coil16may be provided with the gap18with a constant width (second pattern), or the other coil16may be provided with the space18aor18b(third pattern). In the second pattern, the temperature measuring element19is inserted on the coil16side by using the gap18with the constant width as a guide groove, while the tightness between the coil16and the temperature measuring element19is improved in the space18a.

Fourth Embodiment

FIGS. 13A and 13Bare sectional views showing main parts of the wound coil models of the stator10of the rotary electric machine100according to a fourth embodiment.FIG. 13Ashows a structure of providing insulating members30aand30bsurrounding the coils16in the structure inFIG. 8.FIG. 13Bshows a structure of providing insulating members30cand30din the structure inFIG. 10.

As shown inFIG. 13A, the temperature measuring element19is directly brought into contact with the first coil160awhile the first coil160aof one of the coils16and the temperature measuring element19are surrounded by the one insulating member30a, and the temperature measuring element19is indirectly brought into contact with the second coil160bvia the insulating members30aand30bwhile the second coil160bof the other coil16is surrounded by the other insulating member30b.

These insulating members30aand30bare, for example, insulating papers. The insulating papers are bent and compressed due to elasticity, and thus, the temperature measuring element19is pressed against the second coil160bwhile also being pressed against the first coil160a.

As shown inFIG. 13B, the temperature measuring element19is directly brought into contact with the first coil160cwhile the first coil160cof one of the coils16and the temperature measuring element19are surrounded by the one insulating member30c, and the temperature measuring element19is indirectly brought into contact with the second coil160dvia the insulating members30cand30dwhile the second coil160dof the other coil16is surrounded by the other insulating member30d. Moreover, due to the gap18provided to the outer surface of the second coil160d, the insulating members30cand30dare bent at supporting points on the two coil wires adjacent to the gap18. Thus, the temperature measuring element19is pressed against the second coil160dand at the same time pressed against the first coil160c.

In one embodiment of the insulating members30aand30bor the insulating members30cand30das shown inFIG. 13A or 13B, one of the coils16and the temperature measuring element19may be unified in the condition in which the temperature measuring element19is set to the one coil16, and a surface of this structure may be entirely covered with the insulating member30aor30c. In addition, for example, the surface part of the adjacent other coil16may be entirely covered with the another insulating member30bor30d.

In the structure in which the insulating members30aand30bor the insulating members30cand30dare provided, for example, the temperature measuring element19is brought into contact with both of the two coils16such that the temperature measuring element19is indirect contact with one of the coils16and is in indirect contact with the other coil16via the insulating members30aand30bor the insulating members30cand30d.

It is obvious that the insulating member is able to be used by appropriately changing an area for providing the insulating member, the material, and the thickness depending on a product specification.

Thus, in the structure according to the fourth embodiment, the insulating members30aand30bor the insulating members30cand30dare provided, thereby pressing the temperature measuring element19to the gap18of the coil16while insulating the coils16. This structure reliably makes the temperature measuring element19in close contact with the coils16.

FIG. 13Ashows the example of surrounding the two coils16with the respective insulating members30aand30b.FIG. 13Bshows the example of surrounding the two coils16with the respective insulating members30cand30d. However, it is also possible to obtain electric insulation by disposing the insulating members30aand30bor the insulating members30cand30dso as to cover at least the facing surface parts of the coils16.

Alternatively, the insulating member30aor30bor the insulating member30cor30dmay be disposed to only one of the two coils16, and no insulating member may be disposed to the other coil16.

In the above-described example, the temperature measuring element19and the coil16are unified by surrounding with the insulating member30aor30cin the condition in which the temperature measuring element19is set to one of the coils16. However, the temperature measuring element19may not be unified with the coil16. That is, one of the coils16may be surrounded by the insulating member30aor30c, the other coil16may be surrounded by the insulating member30bor30d, and the temperature measuring element19may be interposed between the two insulating members30aand30bor the two insulating members30cand30d. This structure makes both of the two coils16have equal degree of tightness to the temperature measuring element19.

Thus, the rotary electric machine100according to the fourth embodiment includes the insulating members30aand30bor the insulating members30cand30dthat are interposed between one of the coils16with the gap18in which the temperature measuring element19is disposed and the facing other coil16that is provided to face the gap18.

The fourth embodiment provides effects as described below.

(1) The temperature measuring element19is pressed against the coil16and is reliably brought into close contact with the coil16due to the elasticity of the insulating members30aand30bor the insulating members30cand30d, thereby enabling measuring temperature of the coil16at a higher accuracy.
(2) The temperature measuring element19is pressed against the coil16and is stably held due to the elasticity of the insulating members30aand30bor the insulating members30cand30d, thereby enabling a correct temperature measurement.

It is therefore understood that numerous modifications which have not been exemplified can be devised without departing from the scope of the present application. For example, at least one of the constituent components may be modified, added, or eliminated. At least one of the constituent components mentioned in at least one of the preferred embodiments may be selected and combined with the constituent components mentioned in another preferred embodiment.