JP7310971B1 - stator and rotating machine - Google Patents

Abstract

An object of the present invention is to provide a stator in which the shape of teeth is improved. The stator is a stator of a rotating machine arranged radially outward of a rotor having a shaft extending along a central axis with an air gap interposed therebetween, and has a stator core made of laminated steel plates, the stator core being composed of laminated steel plates. a plurality of teeth extending radially inward from the radially outer side and having a radially inner end as a leading end, at least one of the plurality of teeth having a base portion extending radially inwardly from the radially outer side; The flange portion has a flange extending radially inward of the base and extending to both sides of the base in the circumferential direction. , where θ2 is the rising angle of the groove, t1 is the width of the tooth, t2 is the width of the flange, and w is the distance between the ends of the groove, t2>w>t1 and θ1>θ2. meet. [Selection drawing] Fig. 1

Description

The present invention relates to stators and rotating machines.

2. Description of the Related Art Conventionally, a stator for a rotating machine has a structure in which a stator core has a plurality of teeth extending radially inward from a core back. In Japanese Unexamined Patent Application Publication No. 2002-100000, grooves are provided in portions of the teeth facing the rotor at the radially inner ends, with the aim of making the noise generated during the operation of the rotating electrical machine for a vehicle inconspicuous to the driver. A structure is disclosed in which the number is varied.

JP 2017-118713 A

By the way, it is known that iron loss and NV performance are improved by forming grooves on the radially inner ends of the teeth as described in Patent Document 1. NV is an abbreviation for Noise Vibration, which is caused by torque ripple, radial force, and the like.

The deeper the grooves on the radially inner ends of the teeth, the more the torque ripple and radial force, which affect the NV performance, are improved. was likely to decline.

The stator core is formed of laminated steel sheets obtained by punching electromagnetic steel sheets into a desired shape and laminating them. Since the shape of the radially inner ends of the teeth is highly sensitive to iron loss and NV performance, even a slight deformation has a large effect on the characteristics, and there is concern about an increase in variation and a deterioration in process capability. For this reason, conventionally, there has been room for improvement in the shape of the teeth.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stator with an improved tooth shape.

A stator according to one aspect of the present invention is a stator for a rotating machine disposed radially outward of a rotor having a shaft extending along a central axis with an air gap interposed therebetween, and has a stator core made of laminated steel plates, The stator core extends radially inward from the radially outer side and has a plurality of teeth having radially inner ends as tips, at least one of the plurality of teeth extending radially inwardly from the radially outer side. a base portion; and a flange portion extending radially inward of the base portion and extending to both sides of the base portion in the circumferential direction. When the angle is θ1, the rising angle of the groove is θ2, the width of the tooth is t1, the width of the flange is t2, and the distance between the ends of the groove is w, t2>w>t1 and θ1>θ2. , the rise of the groove is a curve, and the rise angle of the groove is a tangent line of a circle inscribed in the rise of the groove and a straight line passing through the center of the base in the circumferential direction and parallel to the radial direction. It is the angle formed by the reference line and a straight line perpendicular to it .

In the stator of one aspect described above, the rise of the flange is a curved line, and the rise angle of the flange is a tangent line of a circle inscribed in the rise of the flange and a radial direction passing through the center of the base in the circumferential direction. It is the angle formed by the reference line, which is a parallel straight line, and the perpendicular straight line.

In one aspect of the stator described above, the groove portion is one groove portion in which the bottom of the groove arranged on one side in the circumferential direction of the reference line communicates with the bottom of the groove arranged on the other side of the reference line in the circumferential direction. is.

According to one aspect of the present invention, it is possible to provide a stator with improved teeth shape.

It is the side view which looked at the stator core concerning a 1st embodiment of the present invention from one side of the direction of an axis. It is a figure which shows the tooth which concerns on Example 1 of this invention, Comprising: It is a side view which expands and shows the tooth 122 shown in FIG. 7 is a graph showing changes in loss when θ2 is changed under the condition of θ2/θ1<1. 2 is a graph showing changes in electromagnetic force (radial force) when θ2 is changed in the range of θ2/θ1<1. FIG. 11 is a diagram showing a tooth according to Example 2 of the present invention, and is a side view showing an enlarged tooth 1122 corresponding to the tooth 122 shown in FIG. 1; FIG. 10 is a diagram showing a tooth according to Example 3 of the present invention, and is a side view showing an enlarged tooth 2122 corresponding to the tooth 122 shown in FIG. 1. FIG. FIG. 11 is a diagram showing a tooth according to Example 4 of the present invention, and is a side view showing an enlarged flange portion 3131 corresponding to the flange portion 1131 shown in FIG. 1 .

Hereinafter, stators according to embodiments of the present invention will be described with reference to the drawings. It should be noted that, in the drawings below, in order to make each configuration easier to understand, there are cases where the scale, number, etc., of the actual structure and each structure are different.

Also, in the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is parallel to the axial direction of the central axis J shown in FIG. The Y-axis direction is the vertical direction in FIG. The X-axis direction is a direction orthogonal to both the Z-axis direction and the Y-axis direction. In any of the X-axis direction, Y-axis direction, and Z-axis direction, the side indicated by the arrows in the drawing is the + side, and the opposite side is the - side.

Also, in the following description, the positive side (+Z side) in the Z-axis direction is called "one side", and the negative side (-Z side) in the Z-axis direction is called "the other side". Note that the terms "one side" and "the other side" are merely names used for explanation, and do not limit the actual positional relationship and direction. Further, unless otherwise specified, the direction parallel to the central axis J (the Z-axis direction) is simply referred to as the "axial direction", the radial direction about the central axis J is simply referred to as the "radial direction", and the central axis J , that is, the circumference of the central axis J is simply referred to as the "circumferential direction". The side closer to the central axis J in the radial direction is called "radial inner side", and the side farther from the central axis J is called "radial outer side". In the circumferential direction, the side indicated by the arrow in the drawing is the +θ side, and the opposite side is the −θ side.

In this specification, "extends in the axial direction" means not only the case of extending strictly in the axial direction (Z-axis direction), but also the case of extending in a direction inclined within a range of less than 45° with respect to the axial direction. Also includes In addition, in this specification, "extending in the radial direction" means extending strictly in the radial direction, that is, in a direction perpendicular to the axial direction (the Z-axis direction), and in addition to extending in the radial direction by 45 It also includes cases where it extends in a tilted direction within a range of less than °. "Parallel" includes not only the case of being strictly parallel, but also the case of being tilted within a range of less than 45°.

<First Embodiment>
FIG. 1 is a side view of a stator core according to a first embodiment of the present invention, viewed from one side in the axial direction. Stator core 100 is used in a motor stator. A motor is an example of a rotating machine. The motor includes a rotor having a shaft extending along a central axis J, a first bearing that supports the shaft on one axial side of the rotor, and a second bearing that supports the shaft on the other axial side of the rotor. and a stator disposed radially outside the rotor with an air gap therebetween. The stator has a stator core 100 and stator coils.

Stator core 100 is formed by axially laminating a plurality of electromagnetic steel sheets punched into the shape shown in FIG. Stator core 100 has a core back 110 extending radially outward over the entire circumferential circumference, and a plurality of teeth 120 extending radially inward from the inner circumferential side of core back 110 . A slot is formed between each of the plurality of teeth 120 and adjacent teeth 120 . The slots accommodate stator coils. Each of the teeth 121 , 122 and 123 is one of the plurality of teeth 120 .

FIG. 2 is a view showing teeth according to Example 1 of the present invention, and is an enlarged side view showing the teeth 122 shown in FIG. In the following description, the shape of the teeth 122 will be described. At least one of the plurality of teeth 120 may have the shape of teeth 122 described below.

Teeth 122 have bases 140 extending radially inward from the inner peripheral side of core back 110 . The tooth 122 has a flange portion 131 radially inside the base portion 140 and extending to both sides in the circumferential direction from the base portion 131 . In FIG. 2, the reference line K is a straight line passing through the center of the base 140 in the circumferential direction and parallel to the radial direction. The tooth 122 has a symmetrical shape with the reference line K as an axis of symmetry. Since the teeth 122 are line-symmetrical, the shape of the teeth 122 on the -θ side of the reference line K will be mainly described in the following description.

The −θ side edge of the base 140 is formed by a straight line 141 . A radially outer end of the straight line 141 connects to the inner circumference of the core back 110 . A straight line 141 extends radially inward from the radially outer end. The straight line 141 is closer to the reference line K on the radially inner side than on the radially outer side. A straight line connecting the −θ side edge and the +θ side edge of the radially inner end of the base portion 140 intersects the reference line K at right angles. The length of the straight line connecting the −θ side edge and the +θ side edge of the radially inner end of the base portion 140 (hereinafter also referred to as “tooth width”) is t1.

The −θ side edge of the flange portion 131 is formed by a straight line 132 and a straight line 138 . The radial outer end of the straight line 132 connects to the radial inner end of the straight line 141 . A straight line 132 extends radially inward from the radially outer end. The straight line 132 is closer to the reference line K on the radially outer side than on the radially inner side. The angle formed by the straight line 132 and the straight line orthogonal to the reference line K (hereinafter also referred to as the "rising angle of the flange portion") is θ1.

The radially outer end of straight line 138 connects to the radially inner end of straight line 132 . A straight line 138 extends radially inward from the radially outer end. Straight line 138 is parallel to reference line K. FIG.

A radially inner edge of the flange portion 131 is formed by a straight line 139 , a straight line 133 , a straight line 134 and a straight line 136 . The −θ side end of the straight line 139 connects to the radial inner end of the straight line 138 . A straight line 139 extends from the -θ side to the +θ side. A straight line 139 is parallel to the reference line K.

The −θ side end of the straight line 133 is connected to the +θ side end of the straight line 139 . A straight line 133 extends from the -θ side to the +θ side. The straight line 133 is closer to the core back 110 on the +θ side than on the -θ side. The angle formed by the straight line 133 and the straight line orthogonal to the reference line K (hereinafter also referred to as the "rising angle of the groove") is θ2.

The −θ side end of the straight line 134 is connected to the +θ side end of the straight line 133 . A straight line 134 extends from the -θ side to the +θ side. The straight line 134 is closer to the core back 110 on the -θ side than on the +θ side.

The −θ side end of the straight line 136 is connected to the +θ side end of the straight line 134 . A straight line 136 extends from the -θ side to the +θ side. A straight line 136 is orthogonal to the reference line K. FIG.

The flange portion 131 has a groove portion 135 formed by straight lines 133 and 134 and recessed radially outward from the radial positions of the straight lines 139 and 136 . The collar portion 131 has a groove portion 137 corresponding to the groove portion 135 on the +θ side of the reference line K. As shown in FIG.

A straight line connecting the −θ side end of the groove portion 135 and the +θ side end of the groove portion 137 intersects the reference line K at right angles. The length of the straight line connecting the −θ side end of the groove portion 135 and the +θ side end of the groove portion 137 (hereinafter also referred to as “the distance between the ends of the groove portions”) is w.
A straight line connecting the −θ side end and the +θ side end of the radially inner end of the flange portion 131 intersects the reference line K at right angles. The length of a straight line connecting the −θ side end and the +θ side end of the radially inner end of the flange portion 131 (hereinafter also referred to as “width of the flange portion”) is t2.

In this embodiment, the groove portion 135 is provided so that θ1>θ2, that is, the flange portion 131 is tapered, and the relationship among t1, t2, and w is t2>w>t1. In this embodiment, the grooves 135 and 137 are provided so as to be symmetrical about the reference line K, but another groove may be provided between the grooves 135 and 137 . In addition, in this embodiment, the lines are symmetrical with respect to the reference line K, but the shape may be asymmetrical if θ1>θ2. Further, the groove portion 135 and the groove portion 137 are not limited to those formed by two straight lines. may be formed.

According to this embodiment, by widening the base of the flange portion 131 with θ1>θ2, sufficient rigidity against deformation can be ensured. With this configuration, iron loss and NV performance can be reduced more than when there is no groove.

As the depth of the groove 135 is increased, iron loss and NV performance tend to improve, but as the depth increases, the effective gap length increases, resulting in a decrease in torque. In other words, if the same torque is to be produced, the current must be increased, which increases the copper loss. Therefore, when considering not only the NV performance but also the motor efficiency, it is desirable to determine the depth of the groove portion 135 with a balance between the two.

FIG. 3 is a graph showing changes in loss when θ2 is changed under the condition of θ2/θ1<1. In FIG. 3, the horizontal axis is θ2/θ1, and the vertical axis is loss. FIG. 4 is a graph showing changes in electromagnetic force (radial force) when θ2 is changed under the condition of θ2/θ1<1. In FIG. 4, the horizontal axis is .theta.2/.theta.1, and the vertical axis is the radial force. In FIGS. 3 and 4, θ2/θ1=0, that is, the change in loss and radial force when there is no groove 135 is normalized as 1. FIG.

As can be seen from FIG. 3, the stator iron loss improves as θ2/θ1 increases (the groove 135 becomes deeper). loss), the change is small. When the iron loss is separated into the stator iron loss and the rotor iron loss, it can be confirmed that the rotor iron loss is improved in the range of θ2/θ1≦0.6 as compared with the case without the groove 135 . Since the rotor, which is a rotating body, is difficult to cool, improving the rotor loss is thermally advantageous. Regarding the radial force, it can be confirmed that in the range of θ2/θ1<1, the deeper the groove portion 135, the more the radial force is improved. From the above, by setting θ1>θ2, it is possible to improve the NV performance while ensuring the rigidity, and more preferably, by setting θ2/θ1≦0.6, it is possible to simultaneously improve the NV performance, efficiency, and thermal performance.

FIG. 5 is a view showing a tooth according to Example 2 of the present invention, and is a side view showing an enlarged tooth 1122 corresponding to the tooth 122 shown in FIG.

Base 1140 corresponds to base 140 in FIG. The brim portion 1131 corresponds to the brim portion 131 in FIG. A straight line 1141 corresponds to the straight line 141 in FIG. A straight line 1132 corresponds to the straight line 132 in FIG. Line 1138 corresponds to line 138 in FIG. Straight line 1139 corresponds to straight line 139 in FIG. A straight line 1133 corresponds to the straight line 133 in FIG. Line 1134 corresponds to line 134 in FIG. The groove 1135 corresponds to the groove 135 in FIG. The groove portion 1137 corresponds to the groove portion 137 in FIG.

In Example 2, the flange portion 1131 has a groove portion 1136 between the groove portion 1135 and the groove portion 1137 . Also in Example 2, by setting θ1>θ2, the NV performance can be improved while ensuring the rigidity, and more preferably, by setting θ2/θ1≦0.6, the NV performance improvement, efficiency, and thermal performance can be improved at the same time. can.

FIG. 6 is a diagram showing a tooth according to Example 3 of the present invention, and is a side view showing an enlarged tooth 2122 corresponding to the tooth 122 shown in FIG.

Base 2140 corresponds to base 140 in FIG. The brim portion 2131 corresponds to the brim portion 131 in FIG. A straight line 2141 corresponds to the straight line 141 in FIG. A straight line 2132 corresponds to the straight line 132 in FIG. Line 2138 corresponds to line 138 in FIG. Straight line 2139 corresponds to straight line 139 in FIG. A straight line 2133 corresponds to the straight line 133 in FIG.

The −θ side end of the straight line 2134 connects to the +θ side end of the straight line 2133 . A straight line 2134 extends from the -θ side to the +θ side. A straight line 2134 is orthogonal to the reference line K. The groove portion 2135 of this embodiment has a shape in which the groove portions 135 and 137 in FIG. 2 are connected to each other at the bottoms of the grooves. That is, in this embodiment, the flange portion 2131 is located on the bottom of the groove (corresponding to the groove portion 135) arranged on the −θ side (one side in the circumferential direction) of the reference line and on the +θ side of the reference line (the other side in the circumferential direction). ) has one groove portion (groove portion 2135) communicating with the bottom of the groove (corresponding to the groove portion 137) arranged in the groove. Also, in this embodiment, the flange portion 2131 has a groove portion 2136 that is recessed radially outward from the straight line 2134 . Also in Example 2, by setting θ1>θ2, it is possible to improve the NV performance while ensuring the rigidity. can.

FIG. 7 is a diagram showing a tooth according to Example 4 of the present invention, and is a side view showing an enlarged flange portion 3131 corresponding to the flange portion 1131 shown in FIG. In FIG. 2, the groove 135 is formed by two straight lines, the straight lines 133 and 134, but the present invention is not limited to this. is also applicable. In this case, the angle formed by the tangent line of the circle 3135a inscribed in the -θ side end of the groove portion 3135 (rising of the groove portion 3135) and the straight line 3136 (the straight line perpendicular to the reference line K) of the radially inner end of the flange portion 1131 is As θ2, the relationship between θ1 and θ2 described above may be applied.

The present invention can also be applied to a case where the straight line 132 in FIG. In this case, the angle formed by the tangent line of the circle inscribed at the edge of the curve on the -θ side (rising of the groove) and the straight line perpendicular to the reference line K is defined as θ1, and the relationship between θ1 and θ2 described above can be applied. .

The present invention can also be applied to the case where the straight lines 132 and 138 in FIG. can be done. In this case, the angle formed by the tangent line of the circle inscribed at the edge of the curve on the -θ side (rising of the groove) and the straight line perpendicular to the reference line K is defined as θ1, and the relationship between θ1 and θ2 described above can be applied. .

The present invention is not limited to the above embodiments, and various improvements and design changes may be made without departing from the scope of the present invention. In addition, the embodiments disclosed this time should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning of equivalents to the scope of the claims.

100... Stator core, 110... Core back, 120... Teeth

Claims (3)

A stator of a rotating machine arranged radially outward of a rotor having a shaft extending along a central axis with an air gap therebetween,
having a stator core made of laminated steel plates,
The stator core has a plurality of teeth extending radially inward from the radially outer side and having radially inner ends as tips,
at least one of the plurality of teeth has a base portion extending radially inward from the radially outer side;
The flange has a groove recessed radially outward at the radially inner end,
When the rising angle of the flange portion is θ1, the rising angle of the groove portion is θ2, the width of the tooth is t1, the width of the flange portion is t2, and the distance between the ends of the groove portion is w,
t2>w>t1, and θ1>θ2,
satisfy the relationship of
The rise of the groove is a curve,
The rising angle of the groove is an angle formed by a tangent line of a circle inscribed in the rising of the groove and a straight line perpendicular to a reference line, which is a straight line passing through the center in the circumferential direction of the base and parallel to the radial direction.
stator. The rise of the flange portion is a curve,
The rising angle of the flange is an angle formed by a tangent line of a circle inscribed in the rising of the flange and a straight line perpendicular to a reference line, which is a straight line passing through the center in the circumferential direction of the base and parallel to the radial direction.
A stator according to claim 1 . The groove portion is one groove portion in which the bottom of the groove arranged on one side in the circumferential direction of the reference line communicates with the bottom of the groove arranged on the other side of the reference line in the circumferential direction.
A stator according to claim 1 .

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