JP2021010275A - Rotary electric machine - Google Patents

Abstract

To improve the productivity of a rotary electric machine in which electrolytic corrosion of a bearing is suppressed by preventing damage to an electrically conductive material provided in the collar of a bobbin, and which therefore has improved reliability.SOLUTION: A rotary electric machine comprises: a stator 3 which is fixed to a housing 13 by molding resin and includes a tubular bobbin 4 in which an iron core 7 is inserted into an inner cylinder portion 19, wherein the stator 3 is configured in such a way that a plurality of stator cores 10 having coils 9 wound around an outer cylinder portion of the bobbin 4 are arranged in an annular shape; and a rotor 6 facing the stator 3 through an air gap; a collar portion 5 formed in the bobbin 4 and having a facing surface 51 facing the rotor 6; a groove 11 provided in the facing surface 51 in such a way that the groove 11 is located around an opening 20 formed by the inner cylinder portion 19; and an electrically conductive material 12 disposed inside the groove 11.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotary electric machine.

In a rotary electric machine in which a stator core in which a coil is wound around a laminated iron core via a bobbin is arranged in an annular shape around a rotation axis and fixed to a housing with a mold resin, the stator core is electrically insulated by the mold resin and fixed. The potential of the child core becomes a floating potential. Therefore, the shaft voltage is generated by the capacitance stored between the stator and the rotor. When this shaft voltage is larger than the dielectric breakdown voltage of the oil film of the bearing, electrolytic corrosion occurs in the bearing, which is one of the causes of shortening the life of the bearing. Techniques for reducing this shaft voltage are disclosed in Patent Document 1 and Patent Document 2.

International Publication 2015/0758113 International Publication No. 2014/115255

In Patent Document 1, the core (iron core) is electrically connected to the housing by a conductive ring, and the conductive bar is housed in a groove formed in the flange portion of the bobbin, and the conductive bar and the housing are connected via the conductive ring. An electrically connected bobbin is disclosed. In this rotary electric machine, it is possible to prevent the potentials of the core and the conductive bar from becoming floating potentials, and the electrostatic coupling due to the common mode voltage induced from the coil to the rotor is shielded by the conductive bar to be applied to the bearing. The voltage is reduced and the electrolytic corrosion of the conductor is suppressed.

Further, in Patent Document 2, the conductive paint applied to the inside of the bobbin and the flange portion shields the electrostatic coupling due to the common mode voltage induced from the coil to the rotor, and the stator arranged in the bobbin. A rotary electric machine that reduces the shaft voltage by energizing the core and the ground connection plate installed on the bobbin is disclosed.

However, in general, there is a demand for further improvement in productivity as compared with the rotary electric machine disclosed in Patent Document 1 and Patent Document 2.

An object of the present invention is to improve the productivity of a rotary electric machine having improved reliability, which prevents damage to a conductive material provided on a bobbin collar and suppresses bearing electrolytic corrosion.

In order to achieve the above object, in the present invention, a tubular bobbin having an iron core inserted in the inner cylinder portion and a plurality of stator cores having a coil wound around the outer cylinder portion of the bobbin are arranged in an annular shape. A stator formed on the bobbin and fixed to the housing by a mold resin, a rotor facing the stator via an air gap, and a flange portion formed on the bobbin and having a facing surface facing the rotor. A groove provided on the facing surface so as to be located around the opening formed by the inner cylinder portion, and a conductive material arranged inside the groove are provided.

According to the present invention, it is possible to improve productivity, prevent damage to the conductive material provided on the collar of the bobbin, and improve the reliability of suppressing bearing electrolytic corrosion. Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

It is sectional drawing of the rotary electric machine which concerns on 1st Embodiment of this invention. It is sectional drawing of the stator and the rotor which concerns on 1st Embodiment of this invention. It is a perspective view of the bobbin which concerns on 1st Embodiment of this invention. It is a perspective view which shows the other embodiment of the bobbin which concerns on 1st Embodiment of this invention. It is a perspective view of the bobbin and the earth connection plate which concerns on 1st Embodiment of this invention. It is a perspective view of the stator core and the earth connection plate which concerns on 1st Embodiment of this invention. It is a perspective view which shows the state which combined the stator core and the earth connection plate which concerns on 1st Embodiment of this invention. It is a schematic perspective view which shows the state which provided the conductive material in the groove provided in the flange part of the bobbin which concerns on 1st Embodiment of this invention. It is sectional drawing of the groove provided in the flange part of the bobbin which concerns on 1st Embodiment of this invention, and the sectional perspective of the conductive material. It is sectional drawing of the groove provided in the collar part of the bobbin which concerns on 2nd Embodiment of this invention, and the sectional perspective of the conductive material. It is a schematic perspective view which shows the state which provided the conductive material in the groove provided in the flange part of the bobbin which concerns on 3rd Embodiment of this invention. It is a top view of the stator which concerns on 4th Embodiment of this invention. It is sectional drawing of the rotary electric machine which concerns on 5th Embodiment of this invention. It is sectional drawing of the stator which concerns on 5th Embodiment of this invention. It is a perspective view of the bobbin which concerns on 5th Embodiment of this invention.

Hereinafter, the configuration and operation of the rotary electric machine according to the first to fifth embodiments of the present invention will be described with reference to the drawings. In each figure, the same reference numerals indicate the same parts.

(First Embodiment)
FIG. 1 is a cross-sectional perspective view of a rotary electric machine according to the first embodiment of the present invention. As shown in FIG. 1, the rotary electric machine 1 according to the first embodiment of the present invention is a double rotor type axial gap type rotary electric machine.

The rotary electric machine 1 includes a stator 3, a rotor 6, a housing 13, a central shaft 15, a bearing 16, a front housing 17, and a back housing 18.

In the stator 3, a plurality of stator cores 10 (see FIG. 2) arranged in an annular shape are fixed to the housing 13 by a mold resin (not shown). The stator core 10 includes an iron core 7, a tubular bobbin 4 in which the iron core 7 is inserted into the inner cylinder portion 19 (see FIGS. 3a, 3b, etc.), and a coil 9 wound around the outer cylinder portion of the bobbin 4. Is equipped with.

In the rotor 6, a plurality of fan-shaped magnets 62 are annularly fixed to one end surface of a disk-shaped base 61, and the magnets 62 face the stator 3 via an air gap. The rotor 6 is coupled to a front housing 17 coupled to both ends of the housing 13 and a central shaft 15 supported by a bearing 16 provided in the back housing 18, respectively. Therefore, the rotor 6 rotates together with the central axis 15.

The rotating electric machine 1 configured in this way rotates the rotor 6 by supplying power to the stator 3 to generate a rotating magnetic field, and outputs torque by a central shaft 15 rotating together with the rotor 6. The rotary electric machine 1 can also be used as a generator by supplying rotational power to the rotor 6 without supplying electric power to the stator 3.

FIG. 2 is a cross-sectional perspective view of the stator 3 and the rotor 6 according to the present embodiment. Note that, in FIG. 2, the mold resin provided in the stator 3 is omitted as in FIG. As shown in FIG. 2, the stator 3 includes a conductive material 12 arranged inside a groove 11 (see FIGS. 3a and 3b) provided on a surface facing the rotor 6 and facing the rotor 6. A ground connection plate 14 is attached to the surface to be used. The ground connection plate 14 is a conductor that electrically connects the iron core 7, the housing 13, and the conductive paint 12.

FIG. 3a is a perspective view of the bobbin 4 according to the first embodiment of the present invention. As shown in FIG. 3a, the bobbin 4 includes a collar portion 5 having a facing surface 51 facing the rotor 6. As the material of the bobbin 4, for example, polybutylene terephthalate, polyethylene terephthalate, polypropylene, polyethylene, polyphenylene sulfide, polystyrene, polycarbonate, polyamide, epoxy resin, phenol resin, unsaturated polyester resin and the like are used alone or in combination. There is. In addition, organic fibers, inorganic fibers, fillers and the like can be mixed with the tree species and used. Further, the bobbin 4 has a bending strength of 100 Mpa or more so as to be able to withstand the insertion pressure of the resin during the molding process.

A groove 11 is provided on the facing surface 51 of the flange portion 5 so as to be located around the opening 20 of the inner cylinder portion 19. In the present embodiment, grooves 11 are provided on both sides of the stator 3 in the circumferential direction with respect to the opening 20 along the legs 201 and 202 of the trapezoidal opening 20, respectively. A conductive material is arranged inside the groove 11.

FIG. 3b is a perspective view showing another embodiment of the bobbin 4. As shown in FIG. 3b, the grooves 11 are provided on both sides of the stator 3 in the circumferential direction with respect to the opening 20 together with two first groove portions 11a provided along the legs 201 and 202 of the opening 20 having a trapezoidal shape. The stator 3 has a second groove portion 11b provided along the lower bottom 203 of the trapezoidal opening 20 on the outer side in the radial direction.

FIG. 3c is a perspective view of the bobbin 4 and the ground connection plate 21 according to the first embodiment of the present invention. As shown in FIG. 3c, the ground connection plate 21 is an arch-shaped thin plate, the bottom side 211 is in contact with the lower bottom 203 of the opening 20, the arch side 212 protrudes from the flange portion 5, and the back surface is electrically connected to the conductive material 12. It is provided on the facing surface 51 so as to be connected.

FIG. 3d is a perspective view of the stator core 10 and the ground connection plate 14 according to the first embodiment of the present invention. As shown in FIG. 3d, the ground connection plate 14 is attached to the facing surface 51, the bottom 141 is in contact with the iron core 7, the back surface is in contact with the conductive material 12, and the iron core 7 and the conductive material 12 are electrically connected. ..

Further, a concave portion is formed in the first end portion 143 and a convex portion is formed in the second end portion 144 so that the stator core 10 can be connected to the adjacent stator core 10 as shown in FIG. 3e.

Non-magnetic conductive members such as aluminum alloys are used for the ground connecting plates 14 and 21. Although a magnetic material may be used as the conductive member, it is desirable to use a non-magnetic conductive member in order to effectively pass the magnetic flux through the stator core 10.

FIG. 4a is a schematic perspective view showing a state in which the conductive material 12 is provided in the groove 11 provided in the flange portion 5 of the bobbin 4 according to the first embodiment of the present invention. As shown in FIG. 4a, the groove 11 is provided on the facing surface 51 and has a bottom surface 111 and side walls (front side wall 112, rear side wall 113, right side wall 114, and left side wall 115) surrounding the bottom surface 111. The bottom surface 111 faces the rotor 6 like the facing surface 51, and the front side wall 112, the rear side wall 113, the right side wall 114, and the left side wall 115 are substantially orthogonal to the rotor 6.

Further, FIG. 4b is a cross-sectional perspective view of the groove 11 provided in the collar portion of the bobbin and the conductive material 12 according to the present embodiment. The bottom surface 111 of the groove 11 shown in FIG. 4b is smooth.

In addition, in FIGS. 4a and 4b, although the surface of the conductive material 12 is lower than the facing surface 51, it is conductive with the facing surface 51 so that the flow of the injected molding resin is not obstructed by the groove 11. It is desirable that the materials 12 have the same surface. The depth of the groove 11 is preferably 0.05 mm to 1 mm in consideration of the thickness to which the conductive paint is applied, but is not limited to the above value because the resistance value differs depending on the conductive paint.

The conductive material 12 is formed by applying a conductive paint to the groove 11 and drying and curing the groove 11. For the base base material of the conductive coating material, for example, an epoxy resin, an acrylic resin, a urethane resin, a polyester resin, a silicone resin, or the like is used alone or in combination. Further, the conductive particles of the conductive coating material may be any material having conductivity, for example, silver, copper, gold, nickel, aluminum, carbon or the like is used, and silver or copper having a low electric resistance value is particularly preferable. .. The paste-like conductive particles applied to the groove 11 may be melted and then solidified to form a conductive material.

In the rotary electric machine 1 according to the present embodiment, the conductive material 12 is arranged inside the groove 11. Therefore, the pressure due to the injected mold resin is not applied to the side surface or the bottom surface of the conductive material 12. Therefore, it is possible to prevent the conductive material 12 from being peeled off or damaged. Therefore, it is possible to provide an axial gap type rotary electric machine 1 having high reliability for bearing electrolytic corrosion.

Further, in the rotary electric machine 1 according to the present embodiment, since the conductive material 12 can be formed by applying the conductive paint to the groove 11, the productivity can be improved.

Further, since the grooves 11 are provided on both sides of the stator 3 in the circumferential direction with respect to the opening 20 and the conductive material 12 is arranged, electrostatic coupling due to the common mode voltage induced from the coil 9 to the rotor 6 is performed. It is possible to efficiently shield and reduce the voltage applied to the bearing and suppress the electrolytic corrosion of the bearing.

Further, the groove 11 has two first groove portions 11a provided on both sides of the stator 3 in the circumferential direction with respect to the opening 20, and a second groove portion 11b provided on the radial outer side of the stator 3. Since the conductive materials 12 are arranged respectively, the electrostatic coupling due to the common mode voltage induced from the coil 9 to the rotor 6 is further shielded to reduce the voltage applied to the bearing and further suppress the electrolytic corrosion of the bearing. can do. Further, since the groove 11 is not provided inside the stator 3 in the radial direction and the conductive material 12 is not provided, it is possible to prevent the conductive material 12 from generating an eddy current and prevent the occurrence of an eddy current loss. be able to.

Further, in the ground connection plate 14, the bottom side 141 is in contact with the iron core 7, the back surface is in contact with the conductive material 12, the arch side 142 is in contact with the housing 13, and the iron core 7, the conductive material 12, and the housing 13 are electrically connected. ing. Therefore, it is possible to prevent the potentials of the iron core 7 and the conductive material 12 from becoming floating potentials, and it is possible to suppress electrolytic corrosion of the bearing.

Further, a concave portion is formed in the first end portion 143 and a convex portion is formed in the second end portion 144 so that the stator core 10 can be connected to the adjacent stator core 10 as shown in FIG. 3e.

Further, since the groove 11 has the bottom surface 111 and the side walls surrounding the bottom surface 111 (front side wall 112, rear side wall 113, right side wall 114, and left side wall 115), the contact area between the conductive material 12 and the groove 11 can be increased. Can be wide. Therefore, the peeling of the conductive material 12 can be further prevented.

(Second Embodiment)
Next, the rotary electric machine according to the second embodiment of the present invention will be described with reference to the drawings.

FIG. 4c is a cross-sectional perspective view of a groove provided in the collar portion of the bobbin according to the second embodiment and a conductive material. The difference between the present embodiment and the first embodiment is that the bottom surface 111 of the groove 11 formed on the facing surface 51 is roughened (regardless of mechanical, chemical, or electrical method), and is conductive with respect to the groove 11. The anchor effect of the sex material 12 is improved. In addition to the bottom surface 111, the front side wall 112, the rear side wall 113, the right side wall 114, and the left side wall 115 surrounding the bottom surface 111 may be roughened.

(Third Embodiment)
Next, the rotary electric machine according to the third embodiment of the present invention will be described with reference to the drawings.

FIG. 4d is a schematic perspective view showing a state in which the conductive material is provided in the groove provided in the collar portion of the bobbin according to the third embodiment of the present invention. The difference between this embodiment and the first embodiment is that a step 116 is provided on the bottom surface 111 of the groove 11. By providing the step 116 on the bottom surface 111 of the groove 11 to which the ground connection plate (not shown) is attached, the conductive material 12 can be raised only at the portion in contact with the ground connection plate.

(Fourth Embodiment)
Next, the rotary electric machine according to the fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 5 is a plan view of a stator of a rotary electric machine according to a fourth embodiment of the present invention. The difference between this embodiment and the first embodiment is that the conductive material 121 is provided on the surface of the mold resin 22.

As shown in FIG. 5, in the stator 31 according to the present embodiment, the conductive material 121 is arranged on the surface of the mold resin 22 in which the end 71 of the iron core 7 of the stator core 10 is exposed, and the end of the iron core 7 is arranged. The portion 71 and the housing 13 are electrically connected. Therefore, the reliability of bearing electrolytic corrosion can be further improved.

(Fifth Embodiment)
FIG. 6 is a cross-sectional perspective view showing a rotary electric machine according to a fifth embodiment of the present invention. As shown in FIG. 6, the rotary electric machine 100 according to the fifth embodiment of the present invention is a radial gap type rotary electric machine.

The rotary electric machine 100 includes a stator 103, a rotor 106, a housing 1013, a central shaft 1015, a bearing 1016, a front housing 1017, and a back housing 1018.

In the stator 103, a plurality of stator cores 1010 arranged in an annular shape are fixed to the housing 1013 by a mold resin (not shown).

In the rotor 106, a plurality of arc-shaped magnets 1062 are fixed to the side surface of the columnar base 1061, and the magnets 1062 face the stator 103 via an air gap. The rotor 106 is coupled to a front housing 1017 coupled to both ends of the housing 1013 and a central shaft 1015 supported by bearings 1016 provided in the back housing 1018, respectively. Therefore, the rotor 106 rotates together with the central axis 1015.

The rotary electric machine 100 configured in this way rotates the rotor 106 by supplying power to the stator 103 to generate a rotating magnetic field, and outputs torque by a central shaft 1015 that rotates together with the rotor 106. The rotary electric machine 100 can also be used as a generator by supplying rotational power to the rotor 106 without supplying electric power to the stator 103.

FIG. 7 is a cross-sectional perspective view showing the stator 103 of the rotary electric machine 1 according to the present embodiment. In FIG. 7, the mold resin provided in the stator 103 is omitted as in FIG. As shown in FIG. 7, the stator core 1010 provided in the stator 103 includes an iron core 107 and a tubular bobbin 104 in which the core teeth portion 1071 of the iron core 107 is inserted into the inner cylinder portion 1019 (see FIG. 8). It is formed by a coil 109 wound around an outer cylinder portion of the bobbin 104.

The core back portion 1072 of the iron core 107 is in contact with the inner wall of the housing 1013 and is electrically connected. Further, the bobbin 104 includes a collar portion 105 having a facing surface 1051 facing the rotor 106. The collar portion 105 includes a conductive material 112 on the facing surface 1051. Further, the conductive material 112 is in contact with the core teeth portion 1071 of the iron core 107 and is electrically connected.

FIG. 8 is a perspective view of the bobbin 104 according to the fifth embodiment of the present invention. As shown in FIG. 8, the bobbin 104 includes a collar portion 105 having a facing surface 1051 facing the rotor 106.

The facing surface 1051 has a groove 1011 and an outer frame 1052 surrounding the groove 1011, an inner frame 1053 surrounding the opening 1020 of the inner cylinder portion 1019, and a crosspiece 1054 connecting the outer frame 1052 and the inner frame 1053. .. Therefore, a groove 1011 is formed around the opening 1020 excluding the crosspiece 1054. Further, the inner frame 1053 has a cutting portion 10111, which is connected to the groove 1011. A conductive material 1012 is provided inside the groove 1011 and the cut portion 1011. The conductive material 1012 is in contact with the core teeth portion 1071 of the iron core 107 by the cutting portion 10111 and is electrically connected.

In the rotary electric machine 100 according to the present embodiment, the conductive material 1012 can be formed by applying the conductive paint to the groove 1011, so that the productivity can be improved. Further, the conductive material 1012 is provided inside the groove 1011. Therefore, the contact area between the conductive material 1012 and the flange portion 105 is wide, and the adsorption force of the conductive material 1012 on the collar portion 105 can be increased. Further, since the conductive material 1012 is provided inside the groove 1011 so that the pressure due to the injected mold resin is not applied to the side surface or the bottom surface of the conductive material 1012. Therefore, it is possible to prevent the conductive material 1012 from peeling off or being damaged from the flange portion 105 of the bobbin 104. Therefore, it is possible to provide the rotary electric machine 1 having high reliability for bearing electrolytic corrosion.

The present invention is not limited to each of the above embodiments, and includes various modifications within a range not deviating from the gist thereof. For example, the present invention is not limited to the one including all the configurations described in each of the above embodiments, and includes the one in which a part of the configurations is deleted. In addition, a part of the configuration according to one embodiment can be added or replaced with the configuration according to another embodiment.

1,100 ... Rotor, 3,103 ... Stator, 4,104 ... Bobbin, 5,105 ... Flange, 6,106 ... Rotor, 7,107 ... Iron core, 9,109 ... Coil, 10,1010 ... Stator core, 11,1011 ... Groove, 12,1012 ... Conductive material, 13,1013 ... Housing, 14,1014 ... Earth connection plate, 15,1015 ... Central shaft, 16,1016 ... Bearing, 17,1017 ... Front Housing, 18,1018 ... Back housing, 19,1019 ... Inner cylinder, 20,1020 ... Opening

Claims (11)

A tubular bobbin having an iron core inserted in the inner cylinder portion and a plurality of stator cores having a coil wound around the outer cylinder portion of the bobbin are arranged in an annular shape and fixed to the housing by a mold resin. With the stator
With the rotor facing the stator through the air gap,
A collar formed on the bobbin and having a facing surface facing the rotor,
A groove provided on the facing surface so as to be located around the opening by the inner cylinder portion, and
A rotary electric machine including a conductive material arranged inside the groove. In the rotary electric machine according to claim 1,
A rotary electric machine characterized in that the conductive material is a conductive paint. In the rotary electric machine according to claim 1,
A rotary electric machine characterized in that the grooves are provided on both sides of the stator in the circumferential direction with respect to the opening. In the rotary electric machine according to claim 1,
The groove has two first groove portions provided on both sides of the stator in the circumferential direction with respect to the opening, and a second groove portion provided on the radial outer side of the stator. A characteristic rotary electric machine. In the rotary electric machine according to claim 1,
A rotary electric machine which is attached to the facing surface and includes a ground connection plate which electrically connects the iron core, the housing, and the conductive material. In the rotary electric machine according to claim 1,
The rotary electric machine is characterized in that the groove has a bottom surface and a side wall surrounding the bottom surface. In the rotary electric machine according to claim 1,
A rotary electric machine characterized in that the surface forming the groove is roughened. In the rotary electric machine according to claim 1,
A rotary electric machine characterized in that a step is provided on the bottom surface of the groove. In the rotary electric machine according to claim 1,
A rotary electric machine characterized in that the rotary electric machine is an axial gap type rotary electric machine. In the rotary electric machine according to claim 1,
A rotary electric machine arranged on the surface of the mold resin and provided with another conductive material that electrically connects the iron core and the housing. In the rotary electric machine according to claim 1,
A rotary electric machine characterized in that the rotary electric machine is a radial gap type rotary electric machine.

Images