JP2016052200A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine capable of suppressing occurrence of vibration and increase of iron loss.SOLUTION: In a rotary electric machine 10 including a plurality of split cores 31 arranged annularly and a housing 23 in which a cylindrical core storage unit 53 for storing the plurality of split cores 31 and which has a thermal expansion coefficient different from that of the split cores 31, the core storage unit 53 has a contact inner wall 53t brought into contact with the plurality of split cores 31 in an axial direction of the plurality of split cores 31 and a non-contact inner wall 53s not brought into contact with the plurality of split cores 31.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rotating electrical machine having a plurality of divided cores arranged in an annular shape.

  Conventionally, a rotary electric machine is known in which an annular stator core is formed by a plurality of divided cores, and an outer peripheral surface portion of the stator core is fitted into an inner peripheral surface portion of a housing by press-fitting or shrink fitting (see, for example, Patent Document 1). .

JP 2009-131006 A

In such a configuration in which the entire outer peripheral surface portion of the stator core is fitted to the entire inner peripheral surface portion of the housing by press fitting or shrink fitting, vibration and rotational noise generated from the stator core and the rotor are easily transmitted directly to the housing. Therefore, there is a disadvantage that vibration and noise of the rotating electrical machine increase.
Further, when the entire outer peripheral surface portion of the stator core is fitted to the entire inner peripheral surface portion of the housing by press fitting or shrink fitting, the housing and the stator core are likely to be distorted due to the compressive stress generated by the press fitting or shrink fitting. Therefore, there is a disadvantage that electrical loss, so-called iron loss, increases.

  A rotating electrical machine according to the present invention for solving the above-described problems is formed of a plurality of divided cores arranged in an annular shape and a cylindrical core housing portion that houses the plurality of divided cores, and is different from the divided cores. A rotating electrical machine including a housing having a thermal expansion coefficient, wherein the core housing portion is in contact with the plurality of divided cores in the axial direction of the plurality of divided cores, and the plurality of divided cores. A non-contact inner wall that does not contact.

  According to the rotating electrical machine according to the present invention, a plurality of divided cores arranged in an annular shape are accommodated in the core accommodating portion, and a contact inner wall where the core accommodating portion and the plurality of divided cores contact is partially formed. Generation of vibration and noise, and increase in iron loss can be suppressed.

FIG. 1 is a cross-sectional view of a rotating electrical machine according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a state in which each component of the rotating electrical machine according to the embodiment of the present invention is disassembled. FIG. 3 is a plan view of the main body of the rotating electrical machine according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of the main body of the rotating electrical machine according to the embodiment of the present invention. FIG. 5 is a partial enlarged cross-sectional view in which the portion A shown in FIG. 2 is enlarged. FIG. 6 is a plan view of the stator core of the rotating electrical machine according to the embodiment of the present invention.

  Hereinafter, a rotating electrical machine 10 according to an embodiment to which the rotating electrical machine according to the present invention is applied will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, the rotating electrical machine 10 includes a main body 11, a cover 12, and a plurality of bolts 13 that fix the cover 12 to the main body 11. The rotating electrical machine 10 is not particularly limited as long as it has a structure including a split core. It is constituted by a motor.

  As shown in FIG. 2, the main body 11 includes a stator core 21, a rotor 22, a housing 23, an insulator 25, a lead wire 26, and a plurality of bolts 27 that fix the stator core 21 to the housing 23. The

  As shown in FIGS. 3 and 4, the stator core 21 is composed of twelve divided cores 31 having the same structure, and each divided core is arranged in an annular shape adjacent to each other. The twelve split cores 31 are held in an annular shape by a circular jig with reference to the inner peripheral side peripheral wall or outer peripheral side peripheral wall of each split core arranged in an annular shape. Further, the twelve divided cores 31 may be held in an annular shape by partially laser welding the peripheral wall on the outer diameter side, and the contact portions of the divided cores are bonded by bonding. Thus, it may be held in an annular shape. Thereby, the annular stator core 21 in which the twelve divided cores 31 are integrated is formed.

  In addition, although the stator core 21 is comprised by the 12 division | segmentation cores 31 of the same structure, you may be comprised by structures other than this. For example, the number other than 12 may be 3 to 20 or more. Further, each of the divided cores 31 may have an annular stator core similar to the stator core 21 with a different structure instead of the same structure.

The split core 31 includes a core body 41 including a circular arc portion 31a constituting a part of the ring of the stator core 21, and a protruding portion 31b protruding from the inner peripheral portion of the circular arc portion 31a toward the center of the circular arc, and a protruding portion And coil winding 42 wound around 31b.
The coil windings 42 of the twelve divided cores 31 constitute a three-phase coil of a U-phase coil, a V-phase coil, and a W-phase coil, and a magnetic field is formed in the three-phase coil by supplying three-phase AC power. Is done.

  The core body 41 is formed of a laminated core in which a core laminated plate 41a made of a magnetic material such as an electromagnetic steel plate is laminated, fixed and integrated, and a through hole 41b through which the bolt 27 is passed is formed. ing. The core body 41 may be formed of a dust magnetic material.

  The core body 41 is formed of a material having a thermal expansion coefficient different from that of the housing 23. Specifically, when the temperature of the rotating electrical machine 10 rises, the heat of the core body 41 is increased so that the gap between the outer peripheral surface of the core body 41 accommodated in the housing 23 and the inner peripheral surface of the housing 23 is increased. A material whose expansion coefficient is smaller than the thermal expansion coefficient of the housing 23 is selected.

  The insulating property of the core body 41 is enhanced by fitting an insulating member formed so as to cover the core body 41 into the core body 41. Alternatively, the insulation is enhanced by covering the core body 41 with an insulating member formed by outsert molding of an insulating resin.

  As shown in FIG. 2, the rotor 22 is disposed on the inner peripheral side of the stator core 21, and includes a shaft 22a that outputs power and a rotor 22b that is fixed to the shaft 22a and rotates together with the shaft 22a. . The rotor 22 further rotatably supports the shaft 22 a by a main body side bearing 22 c accommodated in the housing 23 of the main body 11 and a cover side bearing 22 d accommodated in the cover 12.

  The clearance between the outer peripheral surface of the rotor 22 and the inner peripheral surface of the stator core 21 is a clearance that allows the rotor 22 to rotate smoothly without resistance in the stator core 21, and the rotation axis represented by the center line CL. The rotor 22 and the stator core 21 are formed so as to be uniform in the circumferential direction centering on the center.

  A plurality of permanent magnets (not shown) are embedded in the rotor 22b. When the permanent magnets in the rotor 22b are attracted to a magnetic field excited by the three-phase coil of the stator core 21, the rotor 22b is driven to rotate. The

  On the other hand, when the permanent magnet provided on the rotor 22b rotates around the rotation axis along with the rotation of the rotor 22b, a magnetic field is formed, and an induced current flows in the three-phase coil of the stator core 21 by this magnetic field. Due to this induced current, electric power is generated at both ends of the three-phase coil, and the rotating electrical machine 10 functions as a generator.

  The rotating electrical machine 10 is configured as a permanent magnet synchronous motor (Interior Permanent Magnet) in which a permanent magnet is embedded in a rotor 22b, and is controlled by, for example, a variable voltage variable frequency control (VVVF) inverter. . The rotating electrical machine 10 may have a configuration other than the permanent magnet synchronous motor. That is, the rotor 22b may be composed of a structure other than the permanent magnet, for example, an electromagnet, or may be composed only of an iron core.

  As shown in FIGS. 2, 3, and 4, the housing 23 includes a mounting portion 51, a bearing housing portion 52, a core housing portion 53, a connection portion 54, and a cover fixing portion 55. These parts are integrally formed.

  The housing 23 is formed of a material having a thermal expansion coefficient different from that of the core body 41 of the split core 31. Specifically, when the temperature of the rotating electrical machine 10 rises, the gap between the outer peripheral surface of the core body 41 of the split core 31 accommodated in the housing 23 and the inner peripheral surface of the housing 23 is increased. A material having a thermal expansion coefficient larger than that of the core body 41 is selected.

  The mounting portion 51 is formed flat and has mounting holes 51a, 51b, 51c, and 51d. Mounting bolts (not shown) are inserted into the mounting holes 51a, 51b, 51c, and 51d, and the rotating electrical machine 10 is mounted. It comes to be attached to the part.

A protrusion 52a is formed in the bearing housing 52 from the mounting portion 51 toward the inside, and a recess 52b for housing the main body side bearing 22c is formed in the protrusion 52a.
Further, the bearing housing portion 52 is formed with a through hole 52c that penetrates the recess 52b, and the shaft 22a of the rotor 22 is passed through the through hole 52c.

  As shown in FIG. 2, the core housing portion 53 is formed in a cylindrical shape that projects in the same direction as the projecting direction of the projecting portion 52 a of the bearing housing portion 52, and the core housing portion 53 accommodates the annular stator core 21. The inner peripheral surface of the cross section of the portion 53 has a cross-sectional shape formed of a circle centered on the same axis as the axis of the stator core 21 when the stator core 21 is accommodated. As shown in FIG. 5, the inner wall that accommodates the stator core 21 of the core accommodating portion 53 includes a contact inner wall 53 t that contacts each divided core 31 of the stator core 21, and a non-contact inner wall 53 s that does not contact each divided core 31 of the stator core 21. have.

  In the present embodiment, the contact inner wall 53t and the non-contact inner wall 53s are formed in a structure that is continuous in the circumferential direction around the axis of the core housing portion 53. In other embodiments, the shaft It may be a discontinuous structure that is partially formed in the circumferential direction around the center. In this case, it is only necessary to fix each divided core 31 of the stator core 21 by the contact inner wall 53t. For example, four contact inner walls 53t arranged at an interval of about 90 ° are intermittently arranged, or about 120 ° is arranged. Three contact inner walls 53t arranged at intervals are intermittently arranged.

Further, the axial length of the inner wall of the core housing portion 53 that faces the core body 41 of the divided cores 31 is L, the axial length of the contact inner wall 53t as L _1, the axial direction of the non-contact inner wall 53s of the length and _{L 2, L =} has a L 1 + _{L 2,} the length _{L 1 is L} 1 <L × (1/2), i.e. the length _{L 1} is a half of the length L It is formed with an arbitrary dimension within a range not exceeding, for example, a dimension within a range of L × (1/2) to L × (1/5).

In the contact inner wall 53t, between the outer peripheral surface of the stator core 21 and the inner peripheral wall surface of the cylinder, for example, a gap of about an intermediate fit, in which the reference hole based on JIS standard is H6 and the axis crossing is js5 or k5c. The diameter of the inner circumference of the cylinder is formed so that an equivalent gap is created.
In the non-contact inner wall 53s, the gap between the outer peripheral surface of the stator core 21 and the inner peripheral wall surface of the cylinder is, for example, equivalent to a clearance of a clearance fit degree in which a reference hole based on JIS standard is H9 and an axis intersection is c9. The diameter of the inner circumference of the cylinder is formed so that a gap of slightly larger than the gap is formed.

  Further, screw holes 53a are formed at positions corresponding to the divided cores 31 below the core housing portion 53, and the bolts 27 are screwed to the screw holes 53a.

The connecting portion 54 has a protruding portion 54 a that is formed to protrude partially outward in the radial direction from the core housing portion 53, and a recessed portion 54 b that is recessed to receive the connecting portion of the lead wire 26. .
Here, the radial direction indicates the radial direction of the split core 31 and the housing 23, and indicates the radial direction centering on the central axis of the ring formed by the above-described 12 split cores 31.

  The cover fixing portion 55 is formed so as to protrude radially outward from the core housing portion 53, and has a plurality of screw holes 55a. The bolts 13 are screwed into the screw holes 55a, and the cover 12 is connected to the main body. 11 is fixed.

As shown in FIGS. 2 and 4, the insulator 25 functions as an insulating member formed in a cylindrical shape with a material having high insulating properties such as plastic and ceramics. The insulator 25 is formed with a plurality of through holes and slits on the side wall.
The insulator 25 is arranged on the upper side of the stator core 21, and has a function of further ensuring insulation between the core body 41 of the split core 31 constituting the stator core 21 and the coil winding 42 wound around the core body 41. And has a function that can be held in a through-hole or slit in the side wall by a holding member such as a strap so that the wiring line of the coil winding 42 is surely contained in the insulator 25 when the coil winding 42 is routed. Have.

  As shown in FIGS. 2, 3, 4, and 6, the lead wire 26 has a U-phase coil, a V-phase coil, and a coil winding 42 wound around the core body 41 of the split core 31. The W-phase coil and the neutral point are collected, and are composed of a U-phase lead wire 26a, a V-phase lead wire 26b, a W-phase lead wire 26c, and a neutral point lead wire 26d provided with terminals at the ends.

  As shown in FIG. 6, the U-phase lead line 26a, the V-phase lead line 26b, the W-phase lead line 26c, and the neutral point lead line 26d are arranged in this order, but this order of arrangement is an arbitrary order. May be. These U-phase lead wire 26a, V-phase lead wire 26b, W-phase lead wire 26c and neutral point lead wire 26d are electrically connected to a motor controller (not shown).

  This motor controller includes, for example, a variable voltage variable frequency control inverter, and motor control for outputting torque based on a torque command value to be output by the rotating electrical machine 10 sent from a control device (not shown). A current is generated, and the motor control current is supplied to the coil winding 42 of the split core 31 via the lead wire 26.

  As shown in FIGS. 1 and 2, the cover 12 includes a fixing portion 71 that fixes the cover 12 to the housing 23 of the main body 11, a bearing housing portion 72 that houses the cover-side bearing 22 d of the rotor 22, and a bearing housing portion 72. A closing part 73 that closes the opening of the fixed part 71 and a bearing accommodating part 72 are formed integrally.

  A through hole 71a is formed in the fixed portion 71 so that the bolt 13 can be passed therethrough. The bearing accommodating portion 72 is formed with a protruding portion 72a toward the inside, and the protruding portion 72a is formed with a recess 72b for accommodating the cover-side bearing 22d.

Further, the bearing housing portion 72 is formed with a through hole 72c that penetrates the recess 72b, and the shaft 22a of the rotor 22 is passed through the through hole 72c.
The closing portion 73 has a lid 73 a that closes the through hole 72 c of the bearing housing portion 72, and the lid 73 a closes the opposite side of the protruding portion 72 a of the bearing housing portion 72.

  Next, a method for incorporating the stator core 21 of the rotating electrical machine 10 of the present embodiment into the housing 23 will be briefly described.

First, the stator core 21 shown in FIGS. 2 and 6 is prepared.
The stator core 21 is formed as follows. A laminated core in which core laminated plates 41 a having a certain thickness are laminated and integrated is formed as the core body 41.

An insulating member formed so as to cover the core body 41 is fitted into the core body 41.
Then, a wire is wound around the protruding portion 31 b of the core body 41 to form a coil winding 42. In this way, the split core 31 is formed. Similarly, a coil winding 42 is formed on a core body 41 fitted with an insulating member, and twelve divided cores 31 are prepared. The twelve divided cores 31 are arranged in an annular shape, and the contact portions are bonded to each other, whereby the annular stator core 21 is formed.

Next, bolts 27 are passed through the through holes 41b of the split cores 31 constituting the stator core 21, and the bolts 27 and the screw holes 53a of the housing 23 formed at positions corresponding to the split cores 31 are screwed. As a result, the stator core 21 is fixed to the housing 23.
At this time, the stator core 21 is fitted into the contact wall surface 53t of the core housing portion 53 by press fitting or shrink fitting.

  The U-phase lead wire 26a, V-phase lead wire 26b, W-phase lead wire 26c, and neutral point lead wire 26d of the lead wire 26 drawn from the winding of the stator core 21 are the housing 23 shown in FIGS. 4 is set in the connection portion 54 shown in FIG. When each lead wire is set in the connection portion 54, the assembly of the stator core 21 into the housing 23 is completed.

Below, the effect of the rotary electric machine 10 of this embodiment is demonstrated.
The rotating electrical machine 10 according to the present embodiment includes twelve divided cores 31 arranged in an annular shape and a core accommodating portion 53 that accommodates twelve divided cores 31, and has a thermal expansion coefficient different from that of the divided core 31. The core housing portion 53 includes a housing 23 and includes a contact inner wall 53t that contacts the plurality of divided cores 31 and a non-contact inner wall 53s that does not contact the plurality of divided cores 31.

  According to the rotating electrical machine 10 according to the present embodiment, the twelve split cores 31 arranged in an annular shape are equivalent to the contact inner wall 53t formed to be equivalent to an intermediate fit fit intersection and a fit fit intersection of a clearance fit. Since it is accommodated in the core accommodating part 53 having the non-contact inner wall 53 s formed on the shaft, the shaft eccentricity between the stator core 21 composed of the twelve divided cores 31 and the core accommodating part 53 is alleviated. That is, compared with a structure in which a non-contact inner wall is not formed and the fit between the split core and the core housing portion is performed by press fitting including an intermediate fit or shrink fitting including an interference fit. In the rotating electrical machine 10, since the dimension of the contact inner wall 53 t is less than ½ of the total dimension of the non-contact inner wall 53 s and the contact inner wall 53 t, the shaft eccentricity becomes difficult and the shaft eccentricity is reduced. .

  Note that the dimensional tolerance of the fit is defined in the JIS standard as described above, but the JIS standard defines a fit between the fits, an intermediate fit, and a fit. In this embodiment, The same fit as in JIS standard is used. In this embodiment, the gap fit refers to a fit in which a gap is ensured even at a high temperature, or a gap in which no gap is required and precise movement is required. An interference fit includes press fit and shrink fitting, and refers to a fit that is difficult to disassemble without damaging a part that has undergone a fit, for example. Intermediate fit refers to an intermediate fit between a gap fit and a fit fit, and includes a fit that can be disassembled and assembled without damaging the part, including indentation and light press fit.

Further, according to the rotating electrical machine 10 according to the present embodiment, since the contact inner wall 53t is partially formed in the core housing portion 53, when the stator core 21 is fitted into the core housing portion 53, both axes are arranged. Positioning to match is facilitated. That is, when the stator core 21 is fitted into the core housing portion 53, the non-contact inner wall 53s on the opening side of the core housing portion 53 is formed to be equivalent to the gap fitting intersection, so that the stator core 21 can be easily housed in the core. The stator core 21 can be easily fitted into the core housing portion 53 by simply inserting the stator core 21 into the contact inner wall 53t formed equivalent to the intermediate fitting fit intersection.
Note that the stator core 21 is fitted into the contact wall surface 53t of the core housing portion 53 by press fitting or shrink fitting.

  Further, according to the rotating electrical machine 10 according to the present embodiment, as the temperature of the rotating electrical machine 10 rises, the heat of the housing 23 is reduced so that the contact pressure between the split core 31 on the contact inner wall 53t and the inner wall of the core housing portion 53 decreases. The expansion coefficient is set to be larger than the thermal expansion coefficient of the split core 31. Thereby, the compressive stress in the contact inner wall 53t can be reduced as the temperature of the rotating electrical machine 10 increases. As a result, the rotational vibration of the rotor 22 inside the core housing portion 53 in the housing 23 and the vibration of the stator core 21 are suppressed from being transmitted to the housing 23, and the generation of vibration and noise can be suppressed. Generation can be suppressed and increase in iron loss can be suppressed.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

10 Rotating electric machine 21 Stator core (several split cores arranged in an annular shape)
23 Housing 31 Split core 53 Core housing part 53s Non-contact inner wall 53t Contact inner wall

Claims (2)

A plurality of split cores arranged in an annular shape;
A rotating electrical machine including a cylindrical core housing portion that accommodates the plurality of divided cores, and a housing having a thermal expansion coefficient different from that of the divided cores,
The rotating electrical machine, wherein the core housing portion includes a contact inner wall that contacts the plurality of divided cores and a non-contact inner wall that does not contact the plurality of divided cores in an axial direction of the plurality of divided cores.   The contact inner wall is formed continuously in a circumferential direction of the core housing portion, and the non-contact inner wall is formed continuously in a circumferential direction of the core housing portion. The rotating electrical machine described.

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