JP2009296870A - Stator of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator for a rotating electrical machine which secures a sufficient space for winding without reducing the thickness of a back yoke part, improves the alignment of coils and improves the coil space factor. With the goal.
SOLUTION: A restraining portion 5d is provided at a position where a circular arc portion 5a of a connecting recess 5 and an outer line 1b of a back yoke portion 1 on the connecting recess 5 side intersect, and an annular shape centering on a connecting center portion 3 of the back yoke portion 1 is provided. The other back yoke connecting the first rotation angle θ1 when rotated to the outside to the restraining portion 5d with the perpendicular 8 to the tooth portion 2 from the root portion 2a of the tooth portion 2 of the one back yoke portion 1. The rotation angle θ2 is larger than the second rotation angle θ2 when the protrusion 1 is rotated to a position where the protrusion end 2b contacts the portion 1.
[Selection] Figure 8

Description

  The present invention relates to a stator of a rotating electric machine such as a motor used in an electric motor, and more particularly to a stator of a rotating electric machine designed to improve the output and efficiency of the electric motor.

  When a stator of a conventional rotating electrical machine is formed by connecting core pieces, the winding angle between the back yoke parts of the core is changed when winding the tooth parts, so that the spacing between adjacent tooth parts is increased. Widen and secure a space to insert the winding nozzle and supply the conductor. Since the track of the winding nozzle does not become a dead space, the coil space factor can be increased.

  However, for example, when winding with a straight back yoke part, a winding nozzle is inserted between the tooth parts to perform winding, and the lead wire is bent at a right angle at the tip of the nozzle, so that distortion due to plastic deformation is caused. appear. In this case, a problem occurs in the alignment of the coils.

  Therefore, in Patent Document 1, by forming a notch in the outer peripheral portion at the connecting portion of the back yoke portion, the back yoke portion is expanded to a reversely warped state, and the nozzle is adjacent even if the conductive wire circulates around the teeth portion. The method of making it the state which does not interfere with the teeth part to perform is disclosed.

  As a result, the degree of freedom in the angle of the winding nozzle wound around the tooth portion is increased, and the distortion of the conductive wire at the tip of the nozzle in the winding can be reduced and the coil alignment can be improved.

Japanese Patent Laying-Open No. 2002-272027 (stages 0013 to 0020, FIG. 3)

  However, in the conventional stator of a rotating electrical machine, the thickness of the back yoke portion is partially reduced due to the cutout of the outer peripheral portion. In addition, in order to wrap around the teeth portion, the inner peripheral surface of the back yoke portion is often formed perpendicular to the side surface of each tooth portion, and in the connecting portion where the back yoke portions intersect each other The inner peripheral portion has a dogleg shape and the thickness is reduced from the inner peripheral portion side.

  Therefore, there is a problem that the magnetic resistance is increased and the motor torque is reduced by partially reducing the thickness of the back yoke part not only from the inner peripheral part side but also from the outer peripheral part side. Further, when the magnetic flux density is increased, the iron loss is increased and the motor efficiency is reduced.

  The present invention has been made to solve the above-described problems, and ensures sufficient space for winding without reducing the thickness of the outer peripheral portion of the back yoke portion, and the alignment of the coil. An object of the present invention is to provide a stator for a rotating electrical machine that improves the coil space factor and improves the coil space factor.

  A stator of a rotating electrical machine according to the present invention includes a plurality of back yoke portions that are provided with pivotable connection center portions at both ends, connect the connection center portions to form an annular shape, and a center portion of the back yoke portion. It is provided at the intersection of the teeth part projecting in the annular inner direction, the outer part forming the annular outer periphery of the back yoke part and the circumference of the predetermined radius from the coupling center part, and connecting the back yoke part to the coupling center part The first rotation angle when rotating in the annular outer direction around the center of the teeth is the tooth portion protrusion of the other back yoke portion that is connected to the perpendicular to the tooth portion from the root portion of the tooth portion of one back yoke portion. And a deterrence unit that inhibits the rotation at a position larger than the second rotation angle when the unit is rotated to a position where the unit comes into contact.

  According to the present invention, the depressing portion is provided at the intersection between the outer portion forming the annular outer periphery of the back yoke portion and the circumference of the predetermined radius from the coupling center portion, and the annular shape is formed around the coupling center portion of the back yoke portion. The tooth part protrusion of the other back yoke part connected to the perpendicular to the tooth part from the root part of the tooth part of one of the back yoke parts when the first turning angle is turned to the outside to the restraining part; By making the angle larger than the second rotation angle when rotating to the position where it contacts, it is possible to ensure a sufficient space for the winding without reducing the thickness of the outer peripheral portion of the back yoke portion. Thus, the motor torque can be enhanced and the motor efficiency can be improved.

It is a top view which shows the structure of embodiment of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows a part of structure which has arrange | positioned the core piece in linear form in embodiment of the stator of the rotary electric machine which concerns on this invention. It is sectional drawing which shows a part of structure which has arrange | positioned the core piece in linear form in embodiment of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows a part of structure of the state which closed the core piece in embodiment of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows a part of structure of the state which opened the core piece in embodiment of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the structure of the connection part of the state which closed the core piece in embodiment of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the structure of the connection part of the state which opened the core piece in embodiment of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the structure of the state which opened the core piece at the time of the winding in embodiment of the stator of the rotary electric machine which concerns on this invention. It is a schematic diagram which shows an example of the winding process in the winding apparatus in embodiment of the stator of the rotary electric machine which concerns on this invention. It is a cross-sectional schematic diagram which shows the structure of the motor in the Example of the stator of the rotary electric machine which concerns on this invention. It is a connection diagram of the stator of the rotating electrical machine in the embodiment of the stator of the rotating electrical machine according to the present invention. It is a schematic diagram which shows the winding order in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the structure of the stator of the rotary electric machine in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the other structure of the stator of the rotary electric machine in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the other structure of the stator of the rotary electric machine in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the structure of the core piece in the Example of the stator of the rotary electric machine which concerns on this invention. It is a dimension example of the core piece in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the structure of the connection part of the core piece in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view which shows the structure of the analysis model in the Example of the stator of the rotary electric machine which concerns on this invention. It is a figure which shows the result of the strength analysis in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view explaining the position of the connection center part of the core piece in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view explaining the relationship between the position of the connection center part of a core piece in the Example of the stator of the rotary electric machine which concerns on this invention, and an expansion angle. It is a figure explaining the relationship between the position of the connection center part of a core piece, and an expansion angle in the Example of the stator of the rotary electric machine which concerns on this invention. It is a top view explaining the relationship between the position of the connection center part of a core piece in the Example of the stator of the rotary electric machine which concerns on this invention, and an expansion angle. It is a figure explaining the relationship between the position of the connection center part of a core piece, and an expansion angle in the Example of the stator of the rotary electric machine which concerns on this invention.

Hereinafter, various embodiments of a stator for a rotating electrical machine according to the present invention will be described with reference to the drawings.
Embodiment FIG. 1 is a plan view showing a configuration of a stator of a rotating electric machine according to an embodiment of the present invention, and FIG. 2 is a plan view showing a part of a configuration in which core pieces in FIG. 1 are linearly arranged. FIG. 3 is a cross-sectional view taken along the arrow AA in FIG.

  In FIG. 1, the stator 100 of the rotating electrical machine of the present embodiment is configured by connecting a plurality of core pieces in a substantially annular shape. The core piece 50 includes a back yoke portion 1 and a tooth portion 2, and is connected to a connecting convex portion 4 having a connecting center portion 3 rotatably connected to both ends of the back yoke portion 1, as shown in FIG. The recessed part 5 is provided, and the teeth part 2 protrudes from the center part in the center O direction inside the annular shape. Although the stator 100 of the rotating electrical machine has a substantially circular ring shape, it may have a substantially polygonal ring shape.

  As shown in FIG. 3, the core piece 50 includes first laminated plates 50a-1, 50a-3,..., 50a- (n + 1) (n is an integer) and second laminated plates 50b-1, 50b-. 2,..., 50b-n are alternately stacked.

  .., 50a- (n + 1) and the second laminated plates 50b-1, 50b-2,... Corresponding fixing concave portions 6 and fixing convex portions 7 are provided, and are fixed by being press-fitted and caulked during lamination.

  Further, both ends of the back yoke portion 1 of the first laminated plates 50a-1, 50a-2,... 50a- (n + 1) and the second laminated plates 50b-1, 50b-2,. The convex part 4 and the connection recessed part 5 are provided alternately. In each layer of the core piece 51 connected to the core piece 50, the connection recesses 5 and the connection protrusions 4 are alternately provided so as to correspond to the connection connection protrusions 4 and the connection recesses 5 of each layer of the core piece 50. Yes.

  On both the front and back surfaces of the connecting convex portion 4 of the core pieces 50, 51, a columnar turning concave portion 3a and a rotating convex portion 3b are provided at the position of the connecting central portion 3, and the core pieces 50, The connecting convex portions 4 of the 51 back yoke portions 1 are fitted with a slight gap (about 5 μm) therebetween so as to rotate via the rotating concave portion 3a and the rotating convex portion 3b.

  4 to 7 are plan views for explaining the operation of the connecting portion of the core pieces 50 and 51 in the stator 100 of the rotating electrical machine in the embodiment of the present invention. FIG. 4 shows the state of the core pieces 50 and 51 when the stator 100 of the rotating electrical machine is closed in an annular shape, and FIG. 5 shows the case where a part of the stator 100 of the rotating electrical machine is disconnected and reversely warped. The state of the core pieces 50 and 51 is shown. 6 and 7 are enlarged plan views of the connecting portion of FIGS. 4 and 5, respectively.

  As shown in FIG. 6, the connecting recess 5 at the end of the back yoke portion 1 includes a rotating recess 3 a centering on the connecting center portion 3 and an arc portion 5 a that is substantially concentric with the rotating protrusion 3 b, and the back yoke portion. It is formed from a straight line portion 5b from a point 5c where one inner peripheral portion 1a intersects. The connection convex part 4 is formed of an arc part 4a corresponding to the arc part 5a and a straight part 4b that contacts the straight part 5b of the connection recess 5 in a state where the back yoke part 1 is connected in an annular shape.

  The core piece 50 is rotated from the state of forming the annular shape in FIG. 4 to the reversely warped state of FIG. 5 in the annular outer direction by rotating the concave portion 3a for rotation and the convex portion 3b for rotation about the connection center portion 3. When opened, the outer shell portion 1b on the outer side of the connecting convex portion 4 side back yoke portion 1 expands until it comes into contact with the restraining portion 5d at the end portion of the connecting concave portion 5 that restrains rotation. This deployment angle is defined as the first rotation angle θ1 with the maximum deployment angle.

  Here, the outer portion 1b of the back yoke portion 1 is an outer portion that forms an outer peripheral circle when the back yoke portion 1 is connected in an annular shape. And the suppression part 5d exists in the position where the circular arc part 5a of the connection recessed part 5 and the outer shell part 1b of the connection recessed part 5 side back yoke part 1 cross | intersect.

  FIG. 8 is a plan view for explaining the connection state of core pieces 50 and 51 during winding of stator 100 of the rotating electrical machine according to the embodiment of the present invention. As shown in FIG. 8, in the core pieces 50 and 51, the inner peripheral portion 1 a of the back yoke portion 1 is provided perpendicular to the teeth portion 2.

  Thereby, the core piece 51 is rotated to the root part 2a of the teeth part 2 by rotating the flyer 22 carrying the nozzle 21 around the teeth part 2 in a circular orbit using, for example, the winding device 200 (see FIG. 9). The conductor 23 is densely wound.

  In FIG. 8, the core piece 50 connected to the core piece 51 to be wound is opened by rotating the turning concave portion 3 a and the turning convex portion 3 b around the connection center portion 3. The perpendicular line 8 from the root part 2a of the tooth part 2 to the tooth part 2 is in contact with the protruding end part 2b of the tooth part 2 of the core piece 50. This deployment angle is set as the second rotation angle θ2 with the minimum deployment angle.

  As shown in FIG. 9, when winding is performed by the winding device 200, in the stator 100 of the rotating electrical machine in the embodiment of the present invention, the first rotation angle θ1 is larger than the second rotation angle θ2. The restraining portion 5d is provided at a position where it becomes larger, and a sufficient space is ensured in which the winding conductor 23 and the tooth portion 2 of the core piece 50 do not interfere with each other.

  In the description of the operation and the connected state of the connecting portion, the structure of the first laminated plate of the core pieces 50 and 51 is described. However, the structure of the second laminated plate is the connection center portion 3 having an annular shape. This is the same except that the line is symmetrical with respect to the center line passing through.

  As described above, in the present embodiment, the restraining portion 5d is provided at a position where the arc portion 5a of the connecting recess 5 intersects the outer portion 1b of the back yoke portion 1 on the connecting recess 5 side, and the connection center of the back yoke portion 1 is provided. The first rotation angle θ1 when rotating to the restraining portion 5d around the portion 3 around the annular shape is perpendicular to the tooth portion 2 from the root portion 2a of the tooth portion 2 of one back yoke portion 1. The thickness of the back yoke portion is reduced because it is made larger than the second rotation angle θ2 when it is rotated to the position where the protruding end portion 2b of the other back yoke portion 1 that is connected to the contact portion is in contact. It is possible to secure a sufficient space for the winding without doing so.

  Further, the amount of magnetic flux can be increased, and in that case, the motor torque can be increased. On the other hand, for example, when the same amount of magnetic flux as that in the conventional method is used, the magnetic flux density can be reduced, so that the influence of saturation of the magnetic flux density can be reduced, thereby improving the motor efficiency.

  In the present embodiment, the rotating electric machine stator 100 forming a substantially circular ring is used, but the present invention is not limited to this. For example, a stator of a rotating electric machine that forms a polygonal ring may be used. Also in this case, the same effect as in the present embodiment can be obtained.

  Next, examples of the present invention will be described in more detail. In this embodiment, the stator of the rotating electric machine of the present invention is applied to an electric power steering device (hereinafter referred to as EPS) for a vehicle.

  An EPS motor is required to reduce cogging torque and generate large torque in order to improve steering feeling. The cogging torque is greatly affected by the frequency determined by the least common multiple of the number of motor slots and the number of permanent magnet poles. By increasing this frequency, vibration and torque pulsation can be reduced.

  Further, in-vehicle motors such as EPS are driven by a power source having a relatively low driving voltage of 12 V or 24 V, and a large current needs to flow through the coil in order to achieve high output. A 10 pole 12 slot motor is suitable as a structure that achieves both the reduction of cogging torque and the torque of the motor. In addition, delta connection is suitable for reducing the resistance value between the power feeding sections.

  FIG. 10 is a schematic cross-sectional view showing the configuration of a 10-pole 12-slot motor used in this embodiment. As shown in FIG. 10, a 10-pole 12-slot motor includes a rotating electrical machine stator 100 in which 12 core pieces forming 12 slots 9 are arranged in a substantially annular shape, and a rotating electrical machine stator 100. The rotor 150 is composed of 10-pole permanent magnets 10 arranged alternately in an annular shape on the inner periphery.

  FIG. 11 shows a connection diagram of a stator 100 of a rotating electric machine used for a 10 pole 12 slot motor. Each phase is shown separately as a U phase, a V phase, and a W phase for each corresponding coil group. As shown in FIG. 11, the conductors 23 are delta-connected as a whole corresponding to a three-phase power source, and a group of coils connected in series for each phase are connected in a so-called two-series / two-parallel configuration.

  That is, focusing on the U phase, the coils of U1 + and U1- are connected in series, and U2- and U2 + are connected in series. Furthermore, these two series connections are connected in parallel to each other. Here, the signs of + and − are given to each coil, which indicates that the direction in which the conductive wire 23 is wound around the tooth portion is opposite between + and −.

  FIG. 12 is a schematic diagram showing the winding order of the conductive wire 23 to the tooth portion 2 when realizing the connection diagram shown in FIG. 11. Each phase is a view as seen from the tooth portion 2 side of the core piece, B indicates the direction of connection order of each phase in the winding, and C indicates the winding direction of the coil in each phase. In the direction of C, R is clockwise (clockwise) and L is counterclockwise (counterclockwise).

  As shown in FIG. 12, in the case of connection as shown in FIG. 11, the coils U1 +, U1-, V1-, V1 +, W1 +, W1-, U2-, U2 +, V2 +, V2-, W2- -, W2 +, and winding end 12 can be continuously wound with one conductor.

  After the coil has been wound, the winding start 11, the transition portion 41f, and the winding end 12 are connected by the connecting member 42a, the connecting portion 41d and the connecting portion 41j are connected by the connecting member 42b, and the connecting portion 41b and the connecting portion 41h are connected by the connecting member 42c. To do.

  Therefore, when the stator of the rotating electrical machine according to the present invention is used for an EPS motor having 10 poles and 12 slots connected in delta connection, not only can the motor torque be enhanced and the motor efficiency improved, but also one conductor It exhibits excellent productivity such as transportability and winding performance when winding coils continuously.

  Since the EPS motor is mounted near the steering handle of the vehicle, it is necessary to reduce the size of the main body. Actually, a rotating electrical machine stator having an outer peripheral diameter D0 of 50 mm to 100 mm is used. Moreover, in order to obtain a required output, it is necessary to flow a current of 70 to 100 A (ampere).

  First, the cross-sectional area of the slot required for the EPS motor is obtained. When delta connection is performed with 10 poles and 12 slots as shown in FIG. 11, currents flow in parallel in the four coil groups. For example, when the current flows from the lead wire portion 13, current flows in parallel through the U-phase coil groups U2 and U1 and the W-phase coil groups W1 and W2.

Since a current of 70 to 100 A flows through the lead wire portion 13, a current flowing through one coil group is 17.5 to 25 A. Since an insulating film is damaged by Joule heat generated when a large current is passed through the conductor 23 made of copper wire, the allowable current value that can be passed through the conductor 23 is limited to 8 A / mm ² . Therefore, a conductor having a cross-sectional area of 25 ÷ 8≈3.1 mm ² is required to pass a current of 25 A at the maximum.

  In the EPS motor, since a large current with a low voltage is passed as compared with home appliances and FA devices, it is preferable to use a thick conductor and a small number of turns in order to reduce the resistance value of the coil. The electrical steel sheet of the stator of a rotating electrical machine is magnetically saturated when a magnetic field of about 2T (Tesla) or more is generated. In addition, if a magnetic field of about 2T or more is generated, the efficiency of the motor deteriorates.

For these reasons, the EPS motor uses about 7 to 20 turns. Therefore, in order to wind at least 7 turns, it is necessary to ensure that the cross-sectional area of the slot for winding is 3.1 mm ² × 7 pieces × 2 (both sides) ≈43 mm ² or more.

  Next, the minimum development angle θ2 required for the winding is obtained. The thickness of the back yoke portion is about 50% to 100% of the width of the teeth portion 2 in view of the rigidity of the core piece. Moreover, if it is 50% or more, the back yoke part 1 will not raise | generate a magnetic saturation.

When the outer peripheral diameter D0 of the stator 100 of the rotating electric machine of the EPS motor is 100 mm at the maximum and the sectional area of the slot 9 is 43 mm ^{2 at} the minimum, the ratio of the thickness T of the back yoke part 1 to the width W of the tooth part 2 is 50. The shape of the stator 100 of each rotating electrical machine at%, 75%, and 100% is shown in FIGS.

  FIGS. 13A to 15A are plan views showing the overall configuration of the stator 100 of each rotating electrical machine, and FIGS. 13B to 15B are the stator 100 of each rotating electrical machine. It is an enlarged plan view of the state which opened the core piece 50 connected with the core piece 51 of.

  From FIG. 13B, the radius R1 of the inner periphery of the stator 100 of the rotating electrical machine when the ratio of the thickness T of the back yoke part 1 to the width W of the tooth part 2 is 50% is 31.9 mm, and the core piece 51 The second rotation angle θ2 is 85.8 ° as the minimum deployment angle between the core piece 50 and the core piece 50.

  14B, the radius R1 of the inner periphery of the stator 100 of the rotating electrical machine when the ratio of the thickness T of the back yoke portion 1 to the width W of the tooth portion 2 is 75% is 29.2 mm, and the core piece 51 The second rotation angle θ2 is 80.1 ° as the minimum deployment angle between the core piece 50 and the core piece 50.

  From FIG. 15 (b), when the ratio of the thickness T of the back yoke part 1 to the width W of the tooth part 2 is 100%, the radius R 1 of the inner periphery of the stator 100 of the rotating electrical machine is 28.7 mm, and the core piece 51 As a minimum deployment angle between the core piece 50 and the core piece 50, the second rotation angle θ2 is 76.6 °.

Therefore, the development angle required for the winding in the stator of the rotating electric machine of the EPS motor is
θ2 = 76.6 ° Formula 1
It becomes.

Next, the radius Ra of the arc portion 5a is obtained. FIG. 16 is a plan view for explaining the relationship between the width W of the tooth portion 2 of the core piece 51 of the stator 100 of the rotating electrical machine constituting 12 slots and the thickness T of the back yoke portion 1. In the case of 12 slots, the angle formed by each core piece is 30 °, and therefore the width W of the tooth portion 2 is given by the following equation 2 from FIG.
W = {R1 ÷ 2 × sin (30 ° ÷ 2)} × 2 Equation 2
Here, R1 is the radius of the inner periphery of the stator.

Further, the thickness T of the back yoke portion 1 is given by Equation 3 shown below.
T = W × K Equation 3
However, K is the ratio of the thickness T of the back yoke part 1 to the width W of the tooth part 2.

  Here, when the ratio of the thickness T of the back yoke part 1 to the width W of the tooth part 2 is 50%, 75%, and 100%, the width W of the tooth part 2 and the thickness T of the back yoke part 1 are If it calculates | requires using Formula 2 and Formula 3, it will become a result shown in FIG. From FIG. 17, the thickness T of the back yoke portion 1 becomes maximum when the ratio of the thickness T of the back yoke portion 1 to the width W of the tooth portion 2 is 100%, and T = 14.8 mm.

  FIG. 18 shows an enlarged plan view of a connecting portion between the core piece 51 and the core piece 50 shown in FIG. As shown in FIG. 18, the connecting recess 5 at the end of the back yoke portion 1 is formed by an arc portion 5a and a straight portion 5b. In order to maintain the angle between adjacent teeth in a state where the core piece 51 and the core piece 50 are closed, and the stator 100 of the rotating electrical machine forms a substantially annular shape, it is essential to include the straight portion 5b.

  In order to provide the straight portion 5b, the maximum value Ramax of the radius Ra of the arc portion 5a is the intersection of the inner peripheral portion 1a of the back yoke portion 1 from the position of the connecting central portion 3 of the turning concave portion 3a or the turning convex portion 3b. It is necessary to make it smaller than the distance Rb to the point 5c.

  The distance Rc from the position of the connection center portion 3 to the outer shell portion 1b of the back yoke portion 1 was obtained by performing strength analysis using the analysis model shown in FIG. FIG. 19A is a side view of the analysis model, and FIG. 19B is a front view.

  As shown in FIG. 19, a hole 14b having a diameter D1 is provided on a plate piece 14 that is sufficiently long in the vertical direction as viewed in the drawing at a distance d from the end 14a of the plate piece 14, and the end 14a is formed on the wall surface of the hole 14b. The strength of the plate piece 14 when a load was applied to the side was evaluated. The plate thickness of the plate piece 14 is t.

  In order to secure the strength of the rotating convex portion 3b against the shearing stress at the time of rotating, the diameter of the rotating convex portion 3b needs to be equal to the plate thickness. The diameter D1 of the hole 14b as the turning recess 3a is the same as the diameter of the turning projection 3b, and the diameter D1 of the hole 14b needs to be equal to the plate thickness.

  In electromagnetic steel sheets for motors, the thickness of laminated steel sheets is standardized by JIS, and those with t = 0.35 mm or t = 0.5 mm are generally used. FIG. 20 shows the result of strength analysis using the plate pieces 14 of t = 0.35 mm and t = 0.50 mm as analysis models.

  In FIG. 20, the vertical axis represents the strength, and the horizontal axis represents the ratio of the distance d to the plate thickness t. The graph of I shows the change in intensity with the distance d when t = D1 = 0.35 mm. Moreover, the graph of II shows the change of the intensity | strength by the distance d in case of t = D1 = 0.50mm.

  As a result of the strength analysis, the strength of the plate piece 14 decreases in the region of d / t <1, but since a stable strength is obtained in the region of d / t ≧ 1, from the end 14a of the plate piece 14 At the distance d to the hole 14b, a relationship of d ≧ t is necessary.

Therefore, the distance Rc from the position of the connection center portion 3 to the outer portion 1b of the back yoke portion 1 is
Rc = d + (D1) /2=d+t/2≧t+t/2=1.5t Equation 4
This relationship is required.

The maximum value Ramax of the radius Ra of the circular arc part 5a is that the position radius of the connection center part 3 (distance from the connection center part 3 to the center O) is R2, and the outer peripheral radius of the stator 100 of the rotating electrical machine is R0 (= D0 / 2). ) From FIG. 16 and FIG. 18, Ramax = R2- (R0-T) = (R0-Rc)-(R0-T) Equation 5
It becomes.

Here, using the relationship of Equation 4,
Ramax ≦ (R0−1.5t) − (R0−T) = T−1.5t Equation 6
In order to provide the straight portion 5b,
Ra <T-1.5t Formula 7
It becomes.

Development necessary for winding when the outer peripheral diameter D0 of the stator 100 of the rotating electric machine of the EPS motor is 100 mm and the ratio K of the thickness T of the back yoke part to the width W of the tooth part is 100%. The angle is θ2 = 76.6 °, and the thickness T of the back yoke at that time is T = 14.8 mm.
Ramax ≦ T−1.5t = 14.8−1.5t Equation 8
It becomes.

Here, in the electromagnetic steel sheet for motors, the thinnest one with t = 0.35 mm is generally used.
Ramax ≦ 14.8−1.5t = 14.8−1.5 × 0.35≈14.3 Equation 9
Equation 7 becomes
Ra <14.3 Formula 10
It becomes.

Ra is obtained as a ratio r1 to the outer peripheral radius R0 (= D0 / 2) of the stator 100 of the rotating electrical machine.
r1 = Ra / R0 <14.3 / 50≈0.29 Equation 11
It becomes. Therefore, in order to provide the straight portion 5b, the radius Ra of the arc portion 5a is smaller than the ratio r1 of the outer peripheral radius R0 of the stator 100 of the rotating electrical machine less than 0.29.

Next, the position radius R2 of the connection center portion 3 (the distance from the connection center portion 3 to the center O) is obtained. In FIG. 21, the top view for demonstrating the position of the connection center part 3 of the core piece 51 of the stator 100 of the rotary electric machine which comprises 12 slots is shown. The maximum value R2max of the position radius R2 of the coupling center portion 3 is as shown in FIG.
R2max = R0-Rc Formula 12

Here, using the relationship of Equation 4,
R2 ≦ R0−1.5t Formula 13
It becomes.

The outer peripheral diameter D0 of the stator 100 of the rotating electric machine of the EPS motor is 100 mm (R0 = D0 / 2 = 50 mm), and the thickness t is the thinnest t = 0.35 mm generally used in electromagnetic steel sheets for motors. If Equation 13 is
R2 ≦ R0−1.5t = 50−1.5 × 0.35≈49.5 Equation 14
It becomes.

When R2 is obtained as a ratio r2 to the outer peripheral radius R0 (= D0 / 2) of the stator 100 of the rotating electrical machine,
r2 = R2 / R0 <49.5 / 50 = 0.99 Equation 15
It becomes. Therefore, the position radius R2 of the connection center portion 3 is such that the ratio r2 to the outer peripheral radius R0 of the stator 100 of the rotating electrical machine is smaller than 0.99.

  As described above, when the stator 100 of the rotating electrical machine of the present invention is used for an EPS motor having 10 poles and 12 slots connected in delta connection, the first rotation angle θ1 is larger than the second rotation angle θ2. In order to configure the deterring unit 5d at the position, it is necessary to satisfy the following conditions.

The restraining part 5d provided in the outer peripheral part 1b outside the connection center part 3 and the respective back yoke part 1 of the adjacent core pieces 50 and 51,
From Equation 1 θ1> θ2 = 76.6 ° Equation 16
From Equation 11 r1 <0.29 Equation 17
From Equation 15 r2 <0.99 Equation 18
It is composed of areas that satisfy all of

Here, as shown in FIG. 22, when the outer peripheral radius R0 of the stator 100 of the rotating electrical machine is R0 = 1, the position radius R2 of the coupling center portion 3 is R2 = r2, and the radius Ra of the circular arc portion 5a is Ra = r1. The maximum expansion angle that can be opened when the adjacent tooth portions 2 are expanded is θ1. From the cosine theorem, the following equation holds:
r1 ² + r2 ² −2r1 · r2 · cos (π−θ1 / 2) = 1 Equation 19

  FIG. 23 shows the quadratic curve graph III of Equation 19 when θ1 = 76.6 °. The vertical axis represents r1 and the horizontal axis represents r2. The region of θ1> 76.6 ° is upward of the quadratic curve graph III toward the drawing. Accordingly, the region satisfying the equations 16, 17, and 18 is the region S1 shown in FIG.

  FIG. 24 is a plan view for explaining the positional relationship between the core piece 51 and the core piece 50 when θ1> θ2 = 120 °. FIG. 24A shows a state where the core piece 51 and the core piece 50 are closed (θ2 = 0 °). FIG. 24B shows a state (θ2 = 30 °) in which the back yoke portion 1 between the core piece 51 and the core piece 50 is horizontal. FIG. 24C shows a state where the core piece 51 and the core piece 50 are open (θ2 = 120 °).

  As shown in FIG. 24C, in the opened state where θ2 is 120 ° from the closed state (FIG. 24A), the tooth portion 2 between the core piece 51 and the core piece 50 has an angle of 90 °. Form. Therefore, if θ1> 120 °, the perpendicular 8 to the tooth portion 2 from the root portion 2a of the tooth portion 2 and the projecting end portion 2b of the tooth portion 2 of the core piece 50 do not interfere with each other in the core piece 51.

  FIG. 25 shows the quadratic curve graph IV of Equation 19 when θ1 = 120 °. A region satisfying θ1> 120 ° and Equations 17 and 18 is a region S2 shown in FIG.

  In the present embodiment, the case where the stator of the rotating electrical machine of the present invention is used in an EPS motor having 10 poles and 12 slots connected in a delta connection has been described. However, the present invention is not limited to this. The same effect can be obtained with the same configuration even when used for a motor using 10 poles and 12 slots, for example, a servo motor, a compressor motor, or the like.

DESCRIPTION OF SYMBOLS 1 Back yoke part 1b Outer part 2 Teeth part 2a Root part 2b Projection end part 3 Connection center part 5a Arc part 5d Suppression part 8 Perpendicular line 100 Stator of rotary electric machine

Claims (6)

A plurality of back yoke portions that are provided with pivotable connection center portions at both end portions and connect the connection center portions to form an annular shape;
Teeth portion projecting in the annular inner direction from the center portion of the back yoke portion,
Provided at the intersection of the outer line forming the annular outer periphery of the back yoke part and the circumference of a predetermined radius from the connection center part, and connecting the back yoke part and rotating in the annular outer direction around the connection center part The first rotation angle in the case of letting it go to the position where the tooth portion protrusion of the other back yoke portion connected to the perpendicular to the tooth portion from the root portion of the tooth portion of one of the back yoke portions comes into contact A stator for a rotating electrical machine, comprising: a deterring unit that inhibits rotation at a position that is larger than a second rotation angle when the rotation is performed.   The stator of the rotating electrical machine according to claim 1, wherein the plurality of back yoke portions form a substantially circular ring shape.   The stator of the rotating electrical machine according to claim 1, wherein the plurality of back yoke portions form a polygonal annular shape.   The stator of the rotating electric machine according to claim 2 or 3, wherein the back yoke portion is formed by connecting twelve back yoke portions to form an annular shape.   The restraining portion has a relation Ra <T−1.5t between a distance Ra to the connection center portion and a thickness T of the back yoke portion and a plate thickness t of the steel plate of the back yoke portion formed by laminating steel plates. The stator of the rotating electrical machine according to claim 4, wherein The restraining part has a ratio r1 of the distance Ra between the restraining part and the connecting center part to a radius of the annular outer periphery of the back yoke part, and a ratio r2 of the position radius of the connecting center part such that r1 <0.29 and r2 <0.99. In this case, the first rotation angle θ1 exists in a region satisfying θ1> 76.6 ° in the relationship of r1 ² + r2 ² −2r1 · r2 · cos (π−θ1 / 2) = 1. A stator for a rotating electrical machine according to claim 5.

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