JP2015226404A - Press fit fixing structure for dynamo-electric machine, and stator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press fit fixing structure for dynamo-electric machine excellent in magnetic characteristics, by reducing the stress generated at both ends of a back yoke in the circumferential direction.SOLUTION: A press fit fixing structure for dynamo-electric machine includes a laminated core constituted by laminating a plurality of steel sheets, and the other member having a press fit surface to which the radial end face of the laminated core is press fitted. The laminated core is constituted of a plurality of split cores split in the circumferential direction, the radial end face of the split core includes a plurality of core protrusions formed intermittently in the circumferential direction, the press fit surface of the other member includes a plurality of the other member protrusions formed intermittently in the lamination direction of the laminated core. When viewing from the axial direction, the plurality of core protrusions are formed in the central part in the circumferential direction, of the radial end face of the split core.

Description

  The present invention relates to a press-fit fixing structure for a rotating electrical machine and a stator.

  In an electric motor mounted on a vehicle or the like, when a stator core of a stator is press-fitted into a stator holder, a convex portion provided on a press-fit surface and a convex portion provided on a press-fit surface are brought into contact with each other. Is known to engage the other while plastically deforming the other.

  In Patent Document 1, when the stator core of the stator is press-fitted into the stator holder, the convex portions formed on the press-fitting surfaces of both are meshed and plastically deformed. Thus, it is shown that the frictional force generated between the press-fitting surfaces and the shearing force due to plastic meshing are applied, and it can be firmly fixed so as not to move relative to each other.

International Publication No. 2012/157384 (Summary, paragraphs 0020 to 0025, paragraph 0035, see FIG. 9)

  According to the technique described in Patent Document 1, the magnetic characteristics of the stator are improved. For example, when the coil is energized, both end portions in the circumferential direction of the back yoke where the magnetic flux density of the split stator core becomes relatively high There is room for further improvement in the magnitude of the stress generated in.

  Accordingly, the present invention reduces the magnitude of the stress generated at both ends in the circumferential direction of the back yoke and suppresses the occurrence of iron loss during energization, that is, press-fit fixing for a rotating electrical machine with improved magnetic characteristics. An object is to provide a structure and a stator.

  In order to solve the above problems, the present invention comprises a laminated core configured by laminating a plurality of steel plates, and another member having a press-fit surface into which a radial end surface of the laminated core is press-fitted, and The laminated core is constituted by a plurality of divided cores divided in the circumferential direction, and the radial end surface of the divided core includes a plurality of core convex portions formed intermittently in the circumferential direction. The press-fitting surface of the other member includes a plurality of other member protrusions intermittently formed in the stacking direction of the stacked core, and when viewed from the axial direction, the plurality of core protrusions are It is formed in the center part of the said circumferential direction among the end surfaces of the said radial direction of a division | segmentation core, It is characterized by the above-mentioned.

According to such a configuration, when the split core is viewed from the axial direction, the plurality of core convex portions are formed at the center portion in the circumferential direction of the back yoke, of the radial end surfaces of the split core. Therefore, a range in which stress is mainly generated at the time of press-fitting is a portion of the central portion in the circumferential direction of the back yoke in the radial end surface of the split core. Therefore, it is possible to reduce the stress on both ends in the circumferential direction of the back yoke among the radial end faces of the split core, which has a relatively high magnetic flux density when the coil is energized.
Thereby, when the coil is energized, it is possible to suppress the occurrence of energy loss due to the magnetic flux passing through both ends in the circumferential direction of the back yoke among the radial end faces of the split core.

  The split core includes a tooth extending along the radial direction, and a back yoke having a predetermined width in the radial direction and extending in an arc shape in the circumferential direction. The extension line of the both side surfaces of the teeth is formed inside a region where the radial end surface of the back yoke intersects.

  According to such a configuration, the region where the core convex portion is formed is the extension line on both side surfaces of the tooth in the circumferential central portion of the back yoke in the radial end surface of the split core, and the back yoke. It is formed inside the region where the radial end face intersects. Thereby, the stress which generate | occur | produces in the circumferential direction both ends side of a back yoke at the time of coil energization can further be reduced. In addition, it is possible to suppress the occurrence of energy loss due to the magnetic flux passing through both circumferential ends of the back yoke when the coil is energized.

  When the end surface in the radial direction of the laminated core is press-fitted into the press-fitting surface of the other member, the core convex portion deforms the other member convex portion to make it more than the surface of the press-fitting surface of the other member. It is characterized by entering inside.

According to such a configuration, the core convex portion is press-fitted while the other member convex portions are plastically deformed, so that a frictional force generated between the press-fit surfaces and a shearing force due to plastic meshing are applied, and the core convex portion And the protrusions of the other members can be firmly fixed so as not to move relative to each other.
For this reason, even if the region where the core convex portion is formed is a limited range, that is, the central portion in the circumferential direction of the back yoke in the radial end surface of the split core, it is between the laminated core and the other member. The slip torque can be secured at a high value.

  ADVANTAGE OF THE INVENTION According to this invention, the magnitude | size of the stress which generate | occur | produces in the circumferential direction both ends of a back yoke can be reduced, and the press fit fixing structure for rotary electric machines excellent in the magnetic characteristic, and a stator can be provided.

It is a disassembled perspective view of the stator of the electric motor which concerns on 1st Embodiment. It is a cross-sectional perspective view which shows a part of division | segmentation core and a stator holder. FIG. 3 is a cross-sectional view taken along the line XX in FIG. 2 and shows a state in which a stator core is press-fitted into a stator holder. (A) is a figure before press-fitting, (b) is a figure which shows in press-fitting. (A) is a figure explaining the characteristic of the stress for every magnetic flux density, and an iron loss. (B) is the figure which drew typically magnetic flux density distribution in the stator core which concerns on 1st Embodiment. It is a figure explaining the stress distribution in the stator core which concerns on 1st Embodiment. It is a figure explaining the stress distribution in the stator core which concerns on 2nd Embodiment. It is a figure explaining the stress distribution in the stator core which concerns on a comparative example.

Hereinafter, a press-fit fixing structure for a rotating electrical machine according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
In the following, the press-fit fixing structure for a rotating electrical machine according to the embodiment will be described by taking as an example a stator of an electric motor mounted on a vehicle, particularly an automobile, but is not limited thereto. The embodiment of the present invention can also be applied to a stator of an electric motor mounted on a device other than an automobile, such as an industrial machine.
Moreover, although the case where a stator core and a stator holder are fixed by press-fitting among electric motors will be described below as an example, the present invention is not limited thereto. The present invention can also be applied to the case where the rotor yoke of the electric motor is press-fitted and fixed to the rotor shaft.
Further, in the following description, the direction axes such as the axial direction, the circumferential direction, and the radial direction are as described in each drawing unless otherwise specified.

(First embodiment)
FIG. 1 is an exploded perspective view of the stator of the electric motor according to the first embodiment.
As shown in FIG. 1, the stator 11 of the electric motor according to this embodiment includes a substantially annular stator core 12 and a stator holder 13.

  The stator core 12 is configured by connecting a plurality of substantially identically divided cores 14 in the circumferential direction so that the distance to the outer peripheral surface 12a is a predetermined value, for example, R, with the axis as the center. That is, the divided cores 14 are connected in a substantially annular shape so that the radial distance from the axis L is the radius R. The details of the split core 14 will be described later with reference to FIG. 2, but the back yoke 15, the teeth 16, a substantially annular yoke annular portion 17 configured by connecting the back yoke 15 in the circumferential direction, and the yoke annular portion 17. The inner peripheral surface 17a and the dowel portion 24 are provided.

  The stator core 12 has been described as being configured by connecting a plurality of divided cores 14, but is not limited thereto. That is, the core may not be divided, that is, an integral core may be used.

  The stator holder 13 has a substantially hollow cylindrical shape centered on the axis, and includes an inner peripheral surface 13a that serves as a press-fit surface when the stator core 12 is press-fitted, and a flange portion 13b.

  The flange portion 13b is formed so as to protrude radially outward from one axial end portion of the stator holder 13, and is fixed by bolting to a housing or the like.

  The stator 11 is configured such that, for example, the stator core 12 is pressed into the stator holder 13 so that the axis of the stator core 12 and the axis of the stator holder 13 coincide with each other at L.

FIG. 2 is a cross-sectional perspective view showing a part of the split core and the stator holder.
As shown in FIG. 2, the split core 14 is configured by laminating a plurality of substantially T-shaped steel plates 18 punched by a press in the axis L direction. The plurality of steel plates 18 are connected to each other, for example, by caulking or bonding.

  The split core 14 includes a back yoke 15 extending along the circumferential direction and teeth 16 extending radially inward from a circumferential intermediate portion of the back yoke 15 on the radially outer side.

  A fitting recess is formed at one circumferential end of the back yoke 15, and a fitting projection corresponding to the fitting recess is formed at the other circumferential end of the back yoke 15. Yes. Adjacent back yokes 15 are connected by fitting these fitting recesses and fitting projections together. In other words, the split cores 14 are connected to each other by fitting the fitting recesses and the fitting projections to form the stator core 12.

  The stator holder 13 is made of a metal material lower than the hardness of the stator core 12, that is, the split core 14. Therefore, the hardness of the stator core 12, that is, the divided core 14 is higher than the hardness of the stator holder 13. In FIG. 2, white arrows indicate the press-fitting direction when the split core 14 is press-fitted into the stator holder 13.

  The outer peripheral surface 12a of the stator core 12 (see also FIG. 1), that is, the outer peripheral surface of the yoke annular portion 17, is formed intermittently in the circumferential direction and extends in the stacking direction of the steel plates 18, that is, in the axis L direction. Core convex part 25 and core concave part 26, and a curved surface part without irregularities.

  The core recessed part 26 is formed between the core convex parts 25 and 25 adjacent in the circumferential direction.

  The plurality of core convex portions 25 and core concave portions 26 are formed only in the center portion in the circumferential direction of the back yoke 15 on the end surface in the radial direction of the split core 14 when viewed from the direction of the axis L.

  In other words, the split core 14 includes a tooth 16 extending along the radial direction, and a back yoke 15 having a predetermined radial width and extending in a circumferential arc shape. The recess 26 is formed only in a region where the extension line on both side surfaces of the tooth 16 intersects the radial end surface of the back yoke 15.

  Further, the other region, that is, the region other than the center portion in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14 is a curved surface portion without unevenness.

In other words, the region provided with the plurality of core convex portions 25 and the plurality of core concave portions 26 has a substantially spline shape due to the convexities of the core convex portions 25 and the plurality of core concave portions 26.
On the other hand, both end portions in the circumferential direction of the end surface in the radial direction of the back yoke 15 do not exhibit a substantially spline shape, and a curved surface portion without unevenness is formed.

Of the radial end surfaces of the split cores 14, the central portion of the back yoke 15 at the center in the circumferential direction, that is, the back yoke corresponding to the longitudinal central axis of the teeth 16 of the radial end surfaces of the split cores 14. A dowel portion 24 is recessed in the portion 15.
That is, a plurality of dowel portions 24 are recessed in the outer circumferential surface 12a of the stator core 12 at predetermined intervals in the circumferential direction (see also FIG. 1).

  The dowel portion 24 is formed to have a larger circumferential width and radial width than the core recess 26. The dowel portion 24 is used for positioning when the stator core 12 is press-fitted and fixed to the stator holder 13.

  In addition, the core convex part 25, the core recessed part 26, and the dowel part 24 can be processed by press punching, wire cutting, etc., for example.

Next, the sectional shape of the stator holder 13 will be described with reference to FIG.
As shown in FIG. 2, a plurality of holder protrusions 27 formed on the inner peripheral surface 13 a of the stator holder 13 intermittently in the stacking direction of the steel plates 18, that is, intermittently formed in the axis L direction. Is formed.

  A holder recess 28 is formed between adjacent holder projections 27 in the direction of the axis L.

  Due to the holder convex portions 27 and the holder concave portions 28, the cross-sectional shape of the inner peripheral surface 13a of the stator holder 13 is a flat knurled mountain or valley, that is, a substantially sine wave shape.

  The holder protrusion 27 or the holder recess 28 can be processed by rolling or cutting, for example.

  In the inner peripheral surface 13 a of the stator holder 13, the end portions 29 on both sides in the stacking direction of the steel plates 18, that is, in the direction of the axis L, have a substantially cylindrical shape formed flat in the stacking direction of the steel plates 18.

Next, the manner in which the stator core 12 is press-fitted and engaged with the stator holder 13 will be described with reference to FIGS. 3 (a) and 3 (b) (FIGS. 2 to 5, abstract and paragraph of Patent Document 1). (See also the engagement method described in paragraphs 0020 to 0028).
FIGS. 3A and 3B are cross-sectional views taken along the line XX in FIG. FIG. 3A shows a state before press-fitting. Further, the dimensional relationships of the radial radii R, R1, R2, R3, R4, and R5 from the axis L on the outer peripheral surface 12a of the stator core 12 and the inner peripheral surface 13a of the stator holder 13 are also shown.

  R1 is a radius from the axis L to the bottom of the holder recess 28. A radius from the axis L to the end portions 29 on both sides in the axis L direction of the inner peripheral surface 13a of the stator holder 13 is R2. A radius from the axis L to the top of the tip of the core convex portion 25 is R3.

  Furthermore, the radius from the axis L to the top of the tip of the holder convex portion 27 is R4. Similarly, let R be the radius from the axis L to the bottom of the core recess 26. That is, R has a value equal to the radius from the axis L to the curved surface portion having no irregularities in the outer peripheral surface 12a of the stator core 12. The radius from the axis L to the bottom of the dowel 24 is R5.

  At this time, R, R1, R2, R3, R4, and R5 satisfy the relationship of R1> R3> R2> R4> R> R5, for example.

  In this state, as shown in FIG. 3B, the stator core 12 is press-fitted into the stator holder 13 in the direction of the axis L indicated by the white arrow.

  Then, since the relationship between the radius R3 of the core convex portion 25 and the radius R4 of the holder convex portion 27 satisfies R3> R4, the length corresponding to the difference Δ = R3-R4 (> 0) The thickness becomes the surplus, and plastic deformation occurs as shown in the holder convex portion 27B of FIG.

  In other words, when the outer peripheral surface 12a of the stator core 12 is press-fitted in the axis L direction into the inner peripheral surface 13a of the stator holder 13, the tip of the core convex portion 25 and the tip of the holder convex portion 27 overlap. Thus, plastic deformation occurs and press-fitting is performed.

  At this time, as shown in FIG. 3B, the tip of the core convex portion 25 of the outer peripheral surface 12 a of the stator core 12 engages with the tip of the holder convex portion 27 of the inner peripheral surface 13 a of the stator holder 13.

Here, the hardness of the stator core 12 is higher than the hardness of the stator holder 13, and the core convex portion 25 of the stator core 12 extends in the press-fitting direction, that is, the direction parallel to the axis L direction, and has a high collapse rigidity.
On the other hand, the holder convex portion 27 of the stator holder 13 extends in a direction (circumferential direction) orthogonal to the press-fitting direction, and falls down and has low rigidity.

  Therefore, as shown in FIG. 3 (b), the core protrusion 25 of the stator core 12 hardly undergoes plastic deformation, and the holder protrusion 27 of the stator holder 13 undergoes large plastic deformation, and the press-fitting is completed in a form of being tipped over. To do.

  As a result, the holder convex portion 27 of the inner peripheral surface 13a of the stator holder 13 is plastically deformed in a spline shape following the shape of the spline-shaped outer peripheral surface 12a of the stator core 12.

  And the core convex part 25 of the outer peripheral surface 12a of the stator core 12 penetrates inside the surface of the inner peripheral surface 13a of the stator holder 13. More specifically, it enters the inner side in the radial direction from the tip of the holder projection 27 of the stator holder 13 (see the holder projection 27B in FIG. 3B).

  In this way, the core convex portion 25 and the holder convex portion 27 are engaged with each other so that a large resistance is exerted in the rotational direction. That is, a frictional force generated between the press-fitting surfaces and a shearing force due to plastic meshing are applied, so that it can be firmly fixed so as not to be relatively movable.

  Further, since the holder convex portion 27 of the stator holder 13 that has been tilted functions as “return”, the outer peripheral surface 12 a of the stator core 12 is prevented from coming off from the inner peripheral surface 13 a of the stator holder 13.

  Further, as shown in FIG. 3A, the relationship between the radius R2 of the end portion 29 of the inner peripheral surface 13a of the stator holder 13 and the radius R3 of the core convex portion 25 is set to R2 <R3. Therefore, when the stator core 12 is press-fitted into the stator holder 13, the end portion 29 of the inner peripheral surface 13 a of the stator holder 13 and the core convex portion 25 are tightly fitted.

  Therefore, when the outer peripheral surface 12 a of the stator core 12 is press-fitted into the inner peripheral surface 13 a of the stator holder 13, it can be fitted with almost no press-fitting allowance (tightening allowance) between the end portion 29 and the core convex portion 25. it can. For this reason, it is possible to prevent the stator core 12 or the stator holder 13 from being shaved and generating shavings.

  Furthermore, since the holder convex portion 27 is plastically deformed when the stator core 12 is press-fitted, a part of the holder convex portion 27 may be broken. However, in the present embodiment, there is no gap between the end portions 29 on both sides in the axis L direction and the core convex portion 25 (R2 <R3). And falling out to the outside through the gap between the core protrusions 25 is prevented.

  The reason why the relationship between the radius R of the core recess 26 and the radius R4 of the holder projection 27 is R <R4 is that when the stator core 12 is press-fitted into the stator holder 13, the holder projection 27 In order to prevent interference with the core recess 26, a slight clearance gap is provided.

  The reason why the relationship between the radius R4 of the holder convex portion 27 and the radius R2 of the end portion 29 is R4 <R2 is that when the stator core 12 is press-fitted into the stator holder 13, FIG. This is because plastic deformation of the holder protrusion 27 is likely to occur as shown in FIG.

  As described above, the core convex portion 25 causes the holder convex portion 27 to be plastically deformed like the holder convex portion 27B, whereby the core convex portion 25 and the holder convex portion 27 are firmly engaged.

Next, the stress and iron loss characteristics for each magnetic flux density will be described with reference to FIG.
FIG. 4A is a graph showing the relationship between stress and iron loss for each of the four types of magnetic flux densities B1, B2, B3, and B4 (where B1>B2>B3> B4).

  Here, the horizontal axis represents the stress axis. The right side from 0 indicates tensile stress, and the left side from 0 indicates compressive stress. The vertical axis represents the iron loss axis. It shows that the iron loss increases as the value of the shaft increases, and the iron loss decreases as the value of the shaft decreases.

  As shown in FIG. 4A, generally, the smaller the value of magnetic flux density, the smaller the value of iron loss, regardless of the magnitude of stress. That is, the decrease in magnetic properties is slight.

  In other words, for example, even under a situation where stress is greatly applied in the tension or compression direction, if the magnetic flux density is small, it can be said that the iron loss, that is, the deterioration of the magnetic characteristics can be minimized.

  Therefore, it can be said that the magnetic flux density is preferably as small as possible in order to minimize the iron loss, that is, the decrease in magnetic properties.

Next, the magnetic flux density distribution in the stator core 12 according to the present embodiment will be described with reference to FIG.
FIG. 4B is an enlarged view of the split core 14 in the stator core 12 of the present embodiment, and schematically shows the state of magnetic flux lines when a coil (not shown) wound around the split core 14 is energized. It was drawn in a typical way.
That is, the magnetic flux density distribution can be known by looking at the density state of the magnetic flux lines in FIG.

  As can be seen from this figure, the core convex portion 25 and the core concave portion 26 of the present embodiment are installed in a portion where the interval between the magnetic flux lines is the smallest, that is, a portion where the value of the magnetic flux density is the smallest.

  This will be described in more detail. The intervals between the magnetic flux lines in the portion of the teeth 16 are increased by the flow of a plurality of magnetic flux lines from other adjacent divided cores 14. For this reason, the magnetic flux density of the split core 14 is higher in the portion of the teeth 16 than in the other portions.

  The magnetic flux lines exiting the teeth 16 are oriented along the circumferential direction of the back yoke 15 such that the magnetic flux lines on the left side of the center line of the teeth 16 are counterclockwise and the magnetic flux lines on the right side are clockwise. Change and separate as you move away from each other.

  That is, when viewed from the direction of the axis L, the central portion in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14 is a region where magnetic flux lines diverge, and therefore the magnetic flux lines are spaced apart and the magnetic flux The density is the lowest.

  Therefore, it is considered that the core convex portion 25 and the core concave portion 26 are installed only in a place where the magnetic flux density is the lowest. That is, the core convex part 25 and the core concave part 26 are formed only in the center part in the circumferential direction of the back yoke 15 in the radial end face of the split core 14 when viewed from the axis L direction.

  In this way, when the stator core 12 is press-fitted into the stator holder 13, a range in which a large stress is generated is concentrated on the central portion in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14. Can do.

  For this reason, the central portion in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14 provided with the core convex portion 25 and the core concave portion 26 has a relatively low stress compared to the end portions on both sides. Large value. However, since the magnetic flux density in this region is low as described above, for example, as shown by the graph characteristic of the magnetic flux density B4 in FIG. 4B, the iron loss, that is, the decrease in magnetic characteristics can be suppressed.

  In addition, the portion where the core convex portion 25 and the core concave portion 26 are not provided, that is, the portion of the curved portion having no irregularities at both ends in the circumferential direction of the back yoke 15 among the radial end surfaces of the split core 14 is It is only in contact with the holder projection 27 provided on the inner peripheral surface 13a of the stator holder 13, and the press-fit stress can be reduced as compared with the central portion.

  Therefore, even if the coil of the split core 14 is energized and the magnetic flux lines pass through both ends in the circumferential direction of the back yoke 15, the stress is reduced in this region as described above. The deterioration of characteristics can be suppressed.

Next, the stress distribution in the stator core according to the present embodiment will be described with reference to FIG. FIG. 5 schematically shows a result of analyzing the stress distribution of the split core 14 mainly by numerical calculation in the stator core 12.
FIG. 7 is a diagram for mainly explaining the stress distribution of the split core 14 in the stator core 12 according to the comparative example. From now on, I would like you to read while comparing and contrasting both figures as appropriate.
In the comparative example, the outer peripheral surface 12a of the stator core 12 and the inner peripheral surface 13a of the stator holder 13 are respectively formed with spline-like irregularities and knurled peaks and valleys formed over the entire peripheral surface. Yes. As a specific example of the comparative example, a known structure described in, for example, paragraph 0035 of FIG.

Here, the total of the circumferential lengths of the tops of the core protrusions 25 in the divided core 14 is defined as a press-fit contact length T. That is, T represents the total circumference of the protrusions of the core protrusion 25.
Moreover, the circumferential length of the circumferential direction of the back yoke 15 among the radial direction end surfaces of the split core 14 is set to s.

  At this time, in this embodiment, for example, T = (1/3) · s is satisfied, but this is not a limitation. If the core convex portion 25 and the core concave portion 26 are provided only at the center portion in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14, the press-fitting contact length T and the circumferential length s The ratio is not particularly limited.

  Further, in the comparative example, for example, T = (1/2) · s is satisfied. However, the present invention is not limited to this, and if the core convex portion 25 and the core concave portion 26 are formed over the entire circumferential surface, the press fitting is performed. The ratio between the contact length T and the circumference s is not questioned.

  In this embodiment and the comparative example, the viewpoints other than the positions of the core convex portion 25 and the core concave portion 26 are formed so as to satisfy the same conditions.

  As shown in FIG. 5, the split core 14 according to the present embodiment has a stress at a curved surface portion where the core convex portion 25 and the core concave portion 26 are not provided at both ends in the circumferential direction of the back yoke 15 in the radial end surface. A reduction range D has appeared.

  On the other hand, in the comparative example shown in FIG. 7, the stress reduction range D did not appear in the same part as in FIG. That is, the stress reduction range D did not appear at both ends in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14.

  Further, when the stress distributions of FIG. 5 which is the present embodiment and FIG. 7 which is the comparative example are compared, no significant difference is recognized regarding the portion other than the stress reduction range D.

  Therefore, the average value of the stress of the back yoke 15 was obtained. Then, it turned out that the stress of the magnitude | size of 56.5 MPa is applied to the back yoke 15 of the split core 14 of this embodiment shown in FIG. 5 on the average in the compression direction.

  On the other hand, the comparative example was 58.0 MPa in the compression direction on average. Thereby, in this embodiment, it turned out that the reduction of the average value of stress was succeeded.

(Action / Effect)
The actions and effects of the present embodiment are summarized as follows.
The split core 14 of the stator core 12 according to the present embodiment includes a tooth 16 extending along the radial direction, and a back yoke 15 having a predetermined radial width and extending in a circumferential arc shape.

  And the core convex part 25 and the core recessed part 26 are formed only in the area | region where the extension line of the both sides | surfaces of the teeth 16 and the radial direction end surface of the back yoke 15 cross | intersect.

  In other words, the plurality of core convex portions 25 and the core concave portions 26 are formed only in the center portion in the circumferential direction of the back yoke 15 on the radial end surface of the split core 14 when the stator core 12 is viewed from the axis L direction. It has come to be.

  Further, the other region, that is, the region other than the center portion in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14 is a curved surface portion without unevenness.

  With such a configuration, when the stator core 12 is press-fitted into the stator holder 13, the main stress generation range can be the central portion in the circumferential direction of the back yoke 15. As shown in the holder convex portion 27B of FIG. 3 (b), only the top portion of the core convex portion 25 provided in the center portion in the circumferential direction of the back yoke 15 in the split core 14, This is because the holder convex portion 27 provided on the inner peripheral surface 13a of the stator holder 13 is plastically deformed so as to fall down during press-fitting.

  For this reason, when the coil wound around the teeth 16 of the split core 14 is energized, stress is reduced at both ends in the circumferential direction among the radial end surfaces of the back yoke 15 having a relatively high magnetic flux density. be able to.

  Thereby, at the time of electricity supply, generation | occurrence | production of the iron loss by a magnetic flux line passing through this part, ie, the fall of a magnetic characteristic, can be suppressed.

  Moreover, as demonstrated in FIG.3 (b), the core convex part 25 plastically deforms the holder convex part 27 like the holder convex part 27B. Thereby, since the core convex part 25 and the holder convex part 27 engage completely, backlash does not arise between both convex parts.

  For this reason, even if the area | region where the core convex part 25 is formed is only the center part of the circumferential direction among the radial direction both ends of the split core 14, it is between the stator core 12 and the stator holder 13. The slip torque can be secured as a relatively large value.

  Here, the slip torque is the torque generated when the press-fitted stator core 12 and the stator holder 13 are rotated so as to give a torsion angle on the axis L. The torque at the start. That is, the larger the slip torque, the stronger the both are coupled.

(Second Embodiment)
FIG. 6 is a diagram for explaining mainly the stress distribution of the split core 14 in the stator core 12 according to the second embodiment. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted. From this point onward, the reader should read as appropriate in comparison with FIG. 7 as a comparative example.

  In the first embodiment, the core convex portion 25 and the core concave portion 26 are provided only at the center portion in the circumferential direction of the back yoke 15 on the radial end surface of the split core 14, and the contact length T during press-fitting and the circumference of the back yoke 15 are The relationship with the circumferential length s in the direction is set to satisfy, for example, T = (1/3) · s.

  However, in this embodiment, the relationship between the press-fitted contact length T and the circumferential length s of the back yoke 15 in the circumferential direction is the same as that in the comparative example. That is, for example, T = (1/2) · s is satisfied. The other parts are created in the same manner as in the first embodiment.

  Even if comprised in this way, the effect | action and effect similar to 1st Embodiment were acquired. That is, as shown in FIG. 6, also in the present embodiment, in the split core 14, the stress reduction range D appears on the curved surface portion where the core convex portion 25 and the core concave portion 26 of the back yoke 15 are not provided. That is, the stress reduction range D appeared in the curved surface portions having no irregularities at both ends in the circumferential direction of the back yoke 15 among the radial end surfaces of the split cores 14.

  On the other hand, in the comparative example shown in FIG. 7, the stress reduction range D did not appear in the same part as in FIG. That is, the stress reduction range D did not appear at both ends in the circumferential direction of the back yoke 15 in the radial end surface of the split core 14.

  Further, when the stress distributions of FIG. 6 which is the present embodiment and FIG. 7 which is the comparative example are compared, no significant difference is recognized regarding the portion other than the stress reduction range D.

  Therefore, the average value of the stress of the back yoke 15 was obtained. Then, it turned out that the stress of the magnitude | size of 56.8 MPa is applied to the back yoke 15 of the split core 14 of this embodiment shown in FIG. 6 on the average in the compression direction. On the other hand, the comparative example, on average, was 58.0 MPa in the compression direction as described above.

  From the above, it was found that the average value of stress was successfully reduced also in this embodiment.

  Therefore, also in the present embodiment, as in the first embodiment, in the radial end surfaces of the split cores 14, the portions of the curved surface portions having no irregularities at both ends in the circumferential direction of the back yoke 15 are energized during energization. The effect of suppressing the occurrence of iron loss due to the passage of the magnetic flux lines, that is, the deterioration of the magnetic properties can be exhibited.

  Further, similarly to the first embodiment, there is an effect that the slip torque between the stator core 12 and the stator holder 13 can be secured as a relatively large value.

  The above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the described configurations.

  In addition, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and a part or all of the configuration of another embodiment can be added to the configuration of one embodiment. It is.

  In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Specifically, for example, in both the first embodiment and the second embodiment, the hardness of the stator core 12 is set to be higher than the hardness of the stator holder 13, but the core convex portion 25 of the stator core 12 is fixed to the stator holder when press-fitted. It is only necessary that the 13 holder protrusions 27 can be plastically deformed, and the hardness of the stator core 12 and the hardness of the stator holder 13 may be set substantially equal.

  Moreover, although both 1st Embodiment and 2nd Embodiment described in the example which press-fits the stator core 12 to the stator holder 13 in the axis line L direction, also when press-fitting a rotor core to a rotor shaft in the axis line L direction, Can be applied.

  Further, both the stator cores 12 in the first embodiment and the second embodiment are divided stator cores configured by connecting a plurality of divided cores 14 in the circumferential direction, but the plurality of divided cores 14 are integrated. It is good also as an integrated stator core formed in this.

  Moreover, the electric motor according to the embodiment of the present invention is not particularly limited in the mounting position of the rotor. That is, an inner rotor type in which the rotor is arranged on the inner peripheral side of the stator 11 or an outer rotor type in which the rotor is arranged on the outer peripheral side of the stator 11 may be used.

  Further, the embodiment of the present invention can be applied to a generator, an alternator and the like in addition to the electric motor.

11 Stator (Press-fit fixing structure for rotating electrical machine)
12 Stator core (laminated core)
12a Outer peripheral surface (radial end surface)
13 Stator holder (other members)
13a Inner peripheral surface (press-fit surface)
13b Flange 14 Split core 15 Back yoke 16 Teeth 17 Yoke annular part 17a Inner peripheral surface 18 Steel plate 24 Dowel part 25 Core convex part 26 Core concave part 27, 27B Holder convex part (other member convex part)
28 Holder recess 29 End L Axis (axis)
R, R1, R2, R3, R4, R5 Radius B1, B2, B3, B4 Magnetic flux density T Contact length at press-fit s Perimeter D Stress reduction range

Claims (6)

A laminated core constructed by laminating a plurality of steel plates;
Other members having a press-fitting surface into which the radial end surface of the laminated core is press-fitted,
With
The laminated core is composed of a plurality of divided cores divided in the circumferential direction,
The radial end face of the split core is:
Comprising a plurality of core protrusions intermittently formed in the circumferential direction;
The press-fitting surface of the other member is
A plurality of other member convex portions formed intermittently in the laminating direction of the laminated core,
When viewed from the axial direction, the plurality of core convex portions are formed at a central portion in the circumferential direction of the radial end surfaces of the divided cores. Press-fit fixing structure. The split core includes a tooth extending along the radial direction, and a back yoke having a predetermined width in the radial direction and extending in an arc shape in the circumferential direction,
2. The rotation according to claim 1, wherein the core convex portion is formed in a region where an extension line on both side surfaces of the tooth intersects with the radial end surface of the back yoke. Press fit fixing structure for electric machine. When the radial end surface of the laminated core is press-fitted into the press-fitting surface of the other member,
3. The rotating electrical machine according to claim 1, wherein the core convex portion deforms the other member convex portion and enters inside the surface of the press-fitting surface of the other member. Press-fit fixing structure. A laminated core constructed by laminating a plurality of steel plates;
Other members having a press-fitting surface into which the radial end surface of the laminated core is press-fitted,
With
The laminated core is composed of a plurality of divided cores divided in the circumferential direction,
The radial end face of the split core is:
Comprising a plurality of core protrusions intermittently formed in the circumferential direction;
The press-fitting surface of the other member is
A plurality of other member convex portions formed intermittently in the laminating direction of the laminated core,
When viewed from the axial direction, the plurality of core protrusions are formed at a central portion in the circumferential direction of the radial end surfaces of the divided cores. The split core includes a tooth extending along the radial direction, and a back yoke having a predetermined width in the radial direction and extending in an arc shape in the circumferential direction,
5. The stator according to claim 4, wherein the core convex portion is formed in a region where an extension line of both side surfaces of the tooth intersects with the radial end surface of the back yoke. . When the radial end surface of the laminated core is press-fitted into the press-fitting surface of the other member,
6. The stator according to claim 4, wherein the core convex portion deforms the other member convex portion and enters inside the surface of the press-fitting surface of the other member.

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