JP5304284B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine including an electric motor or a generator provided with a stator core in which a plurality of electromagnetic steel plates are laminated in the rotor axial direction.

  The rotating electrical machine composed of the electric motor or the generator converts electrical energy into rotational force, or converts rotational force into electrical energy, and contributes to energy saving by effectively improving the conversion efficiency. It is hoped that. For example, in an electric vehicle using an electric motor as a drive source or a hybrid vehicle that obtains driving force by combining an engine and an electric motor, conversion of electric energy and rotational force in a wide load region from light load region to high load region There is a need to reduce the consumption of electrical energy and fuel by improving efficiency.

  For the purpose of improving the performance of the rotating electrical machine, a unidirectional electrical steel sheet having an easy magnetization axis in one direction, a bidirectional electrical steel sheet having easy magnetization axes in two directions orthogonal to each other, or an easy magnetization axis is specified. Forming a stator core of a rotating electrical machine by stamping and forming any of the non-oriented electrical steel sheets that do not have the directionality to a predetermined shape, and stacking and integrating the plurality of punched electrical steel sheets Has been done. For example, when the stator core is formed of a unidirectional electrical steel sheet having excellent magnetic properties in a specific direction, a tooth member formed so as to exhibit excellent magnetic properties in the radial direction of the stator core, Theoretically, the iron loss of the stator core can be effectively reduced by combining with the formed yoke member that exhibits excellent magnetic properties in the circumferential direction.

  However, it is inevitable that an air gap with a large magnetic resistance is generated at the contact portion between the teeth member and the yoke member of the stator core formed of the unidirectional electrical steel sheet, and the magnetic flow is inhibited in this portion. There's a problem. In addition, since the unidirectional electrical steel sheet or the bi-directional electrical steel sheet is more expensive than the non-oriented electrical steel sheet, the stator core is formed of the non-oriented electrical steel sheet and the stator core is used for the purpose of reducing the iron loss. It has been proposed to apply a circumferential tensile stress to the yoke portion.

  For example, in Patent Document 1 below, in an inner rotor type motor having a motor case and a stator core (stator), both of the motor case and the stator core are fixed in a state in which a difference in thermal expansion occurs, or the stator core A structure is suggested in which a tensile stress is applied to the stator core by bringing a holding member into contact with the inner peripheral surface and applying a pressing force to the outer side, thereby obtaining a certain degree of iron loss reduction effect. .

JP 2006-223015 A

  In the first embodiment disclosed in Patent Document 1, the inner diameter of the motor case is made to be slightly larger than the outer periphery of the stator core, and the stator core is heated to expand, or the motor case is cooled to contract. As a result, when the diameters and the fitting parts of both of them are properly fitted, the stator core is inserted into the motor case and fixed, and then returned to room temperature to return the yoke part (relay part) of the stator core. It is comprised so that the tensile stress of radial direction may act on this.

  However, as shown in the first embodiment of Patent Document 1, the tapered fitting portions provided corresponding to the inner peripheral portion of the motor case and the outer peripheral portion of the stator core are fitted in an appropriate state. When it is configured to manage the dimensions and temperature of the stator core or the motor case so that a predetermined tensile stress can be applied to the yoke portion of the stator core later, both of these dimensions and temperature are appropriately managed. It is extremely difficult to do and is not practical.

  Further, in the second embodiment of Patent Document 1, a plurality of holding members integrated with the bottom of the motor case are brought into contact with the stator core from the inside of the slot and pressed outwardly of the stator core to the yoke portion. A configuration is disclosed in which the holding of the stator core and the improvement of the magnetic properties can be achieved simultaneously by applying a tensile stress. Furthermore, Patent Document 1 describes that in order to increase the strength of the holding member, it is preferable to fix the holding member from the upper surface side with an upper surface portion mounting bolt of the motor case.

  However, as disclosed in FIG. 5 and FIG. 6 of the above-mentioned Patent Document 1, when a holding member is arranged for each of a plurality of slots provided in the stator core and fixed with bolts, the rotor shaft Due to the dimensional error from the center to the bolt hole position, the pressing force applied from the holding member to the stator core is likely to vary, and as a result, it is possible to avoid applying an uneven tensile stress in the circumferential direction of the stator core. Absent. Furthermore, since each said holding member is being fixed only with the attachment volt | bolt only from the upper surface part side of the motor case, it cannot be given uniform tensile stress to each of each electromagnetic steel plate laminated | stacked on the said rotor axial direction. There was a problem.

  The present invention has been made in view of the above problems, and a rotating electric machine that can improve the effect of reducing the iron loss and the effect of increasing the magnetic flux density by applying a uniform tensile stress to the stator core. It is intended to provide.

  The invention according to claim 1 is a rotating electrical machine having an annular stator core formed by laminating a plurality of electromagnetic steel sheets in the rotor axial direction, and a case member for holding the stator core, the rotor shaft And a press-fitting member having a circular substrate in which an insertion hole is formed, and an edge projecting from the outer periphery of the circular substrate so as to extend in the rotor axial direction along the inner peripheral surface of the yoke part. Is configured to be press-fitted into the yoke portion of the stator core from the radially inner side.

  According to a second aspect of the present invention, in the rotating electric machine according to the first aspect, the protruding dimension of the edge is set to be larger than ½ of the length of the stator core in the rotor axial direction.

  According to a third aspect of the present invention, in the rotating electric machine according to the first or second aspect, the circular substrate is provided with a plurality of openings disposed on an outer side portion of the rotor shaft insertion hole.

  According to a fourth aspect of the present invention, in the rotating electric machine according to any one of the first to third aspects of the present invention, the circular substrate has an auxiliary core installation portion that contacts the end surface in the rotor axial direction of the yoke portion of the stator core. The collar part which has is provided.

  In the invention according to claim 1, since the edge portion of the press-inserting member is configured to be press-inserted from the radially inner side with respect to the yoke portion of the stator core, the periphery of the press-insert member from the press-inserting member to the yoke portion of the stator core. By applying a uniform tensile stress in the direction, there is an advantage that an excellent effect of reducing the iron loss and an effect of increasing the magnetic flux density can be obtained.

  In the invention according to claim 2, since the protruding dimension of the edge portion is set to be larger than ½ of the length in the rotor axial direction of the stator, the edge portion of the press-fitting member extends over the entire length in the rotor axial direction of the yoke portion. Is brought into press contact with each other, there is an advantage that uniform tensile stress can be applied to each of the electromagnetic steel sheets laminated in the rotor axial direction constituting the stator core.

  In the invention according to claim 3, since the plurality of openings are disposed on the outer side portion of the rotor shaft insertion hole formed in the circular substrate, the temperature of the inside of the rolled member, and thus the rotating electrical machine is reduced while reducing the weight. There is an advantage that the rise can be effectively suppressed.

  In the invention which concerns on Claim 4, the space formed in the rotor axial direction both ends of the stator core, ie, the space formed corresponding to the height of the coil wound around the teeth part of the stator core, is used effectively. By providing an auxiliary core, it is possible to effectively increase the cross-sectional area of the back yoke portion necessary for flowing a magnetic flux for generating a desired torque in the rotating electrical machine. There is an advantage that the rotating electrical machine can be downsized by reducing the thickness.

It is sectional drawing which shows embodiment of the rotary electric machine which concerns on this invention. It is sectional drawing which shows the state which decomposed | disassembled the said rotary electric machine. It is the III-III sectional view taken on the line of FIG. It is a top view which shows the specific structure of a press-insertion member. It is a perspective view which shows the specific structure of a press-insertion member. It is the VI-VI sectional view taken on the line of FIG. It is the VII-VII sectional view taken on the line of FIG. FIG. 7 is a view corresponding to FIG. 6 illustrating a modification of the press-fitting member. It is explanatory drawing which shows the action state of the stress in a stator core. FIG. 9 is a view corresponding to FIG. 8 showing a second embodiment of the rotating electrical machine according to the present invention.

  1 to 3 show an embodiment in which a rotating electrical machine according to the present invention is applied to an electric motor used in an electric vehicle. The rotating electrical machine includes a pair of case members 1, 2 made of a nonmagnetic material such as an aluminum alloy material and having a predetermined rigidity, a stator core (stator) 3 held by the case members 1, 2, and A pair of press-fitting members 4 and 4 for applying a tensile stress to the stator core 3 and a rotor (rotor) 5 rotatably supported by bearings 1a and 2a disposed on the case members 1 and 2 are provided. ing. The case members 1 and 2 are formed integrally with a transmission case or a differential case mounted on the vehicle.

  The stator core 3 has a yoke portion (body portion) 6 formed in an annular shape and a plurality of teeth portions (tooth portions) 7 protruding from the inner peripheral surface thereof toward the center of rotation. A coil (armature winding) 8 is wound around 7. A plurality of extending portions 9 extending outward in the radial direction protrude from the outer peripheral portion of the yoke portion 6, and the stator core 3 is connected to the case members 1 and 2 in the extending portion 9. An installation hole 11 for the fixing bolt 10 to be fixed to is formed.

  As shown in FIGS. 4 and 5, the press-fitting member 4 has a circular substrate 15 formed by, for example, machining an aluminum alloy material having a predetermined rigidity. A plurality of edges 16 extending in the axial direction of the rotor along the inner peripheral surface of 6 are arranged at regular intervals. The edge portions 16 are provided in a number corresponding to the number of slot portions 12 (see FIG. 3) formed between adjacent teeth portions 7, 7 of the stator core 3, and the width dimension of the edge portion 16 is determined by the slot size. It is formed slightly shorter than the width dimension of the portion 12.

  Further, the protruding dimension S (see FIG. 2) of the edge portion 16 is set to be larger than ½ of the length L of the stator core 3 in the axial direction of the rotor. Specifically, the protrusion dimension S of the edge 16 is set to a value slightly larger than the sum of 1/2 of the rotor axial length L of the stator core 3 and the installation height of the coil 8, Interference is avoided. Further, the outer diameter D of the edge portion 16 is formed to be about 100 μm to 300 μm larger than the yoke portion inner diameter d of the stator core 3, that is, the diameter of the slot portion 12. Then, as shown in FIGS. 3 and 6, the press-inserting member 4 is assembled to the stator core 3, whereby the edge 16 of the press-inserting member 4 from the radially inner side with respect to the yoke portion 6 of the stator core 3. It is designed to be press-fitted.

  The circular substrate 15 of the press-inserting member 4 has a rotor shaft insertion hole 17 formed at the center thereof, and a plurality of radially extending openings 18 are provided around the rotor shaft insertion hole 17. Yes. The opening 18 of the circular substrate 15 is provided to reduce the weight of the rotating electrical machine and to prevent the temperature inside thereof from rising, and corresponds to the installation portion of the teeth portion 7 of the stator core 3. It is arranged at the position and has a width dimension corresponding to the tooth portion 7. The radial length of the opening portion 17 can be set as appropriate, but it is preferable that the opening portion 17 is open in the radial direction to the extent that at least half of the protruding length of the tee portion 7 is exposed. Further, as shown in FIG. 7, the side wall surface 18 a of the opening portion 18 has a spiral wind F so that the spiral wind F generated corresponding to the rotation direction K of the rotor 5 can be smoothly discharged to the outside. It is formed on an inclined surface along the flow direction. However, the present invention is not limited to these configurations.

  In order to produce the stator core 3, first, a magnetic steel plate having a thickness of about 0.1 to 1.0 mm is punched, whereby a plurality of protrusions constituting the tooth portion 7 and the extending portion 9 are formed on the inner peripheral surface. And a plurality of electromagnetic steel plates 20 each formed of an annular plate provided on the outer peripheral surface. Next, each time the magnetic steel sheets 20 are laminated while positioning the magnetic steel sheets 20 so that the positions of the protrusions that become the teeth portion 7 and the extending portion 9 are matched, the surface of the laminated electromagnetic steel plates 20 By providing a minute concave portion such that the minute convex portion protrudes toward the back surface at a predetermined position, each electromagnetic steel sheet 20 is caulked and temporarily joined, and a plurality of electromagnetic sheets are welded by welding the outer peripheral surface portion. The stator core 3 in which the steel plates 20 are laminated and integrated in the rotor axial direction is produced.

  Then, after the coil 8 is wound around the teeth portion 7 of the stator core 3, the press-inserting members 4 are installed on both end sides in the rotor axial direction in a state where the rotor 5 is disposed in the stator core 3. The edge portion 16 is press-fitted into the yoke portion 6 of the stator core 3 from the radially inner side. Specifically, the outer diameter D of the edge portion 16 is made smaller than the inner diameter d of the yoke portion 6 by heating and expanding the stator core 3 or cooling and compressing the press-fitting member 4. In the state, the edge portion 16 is installed in the yoke portion 6. Thus, the edge 16 of the press-inserting member 4 is brought into pressure contact with the inner peripheral surface of the yoke portion 6 by returning the press-inserting member 4 to room temperature in a state where the press-inserting member 4 is assembled to the stator core 3.

  As shown in FIG. 8, when a tapered surface 19 having a tapered shape is formed on the outer surface of the tip of the edge portion 16, press-fitting is facilitated, and the magnetic steel sheet is not chipped on the inner peripheral surface of the yoke portion 6. Such inconveniences can be prevented. In other words, according to this configuration, the edge portion 16 is moved from the radially inner side to the yoke portion 6 of the stator core 3 without heating and expanding the stator core 3 or cooling and shrinking the press-fitting member 4. It is possible to press-fit.

  As described above, the rotor 5 is disposed on the inner side of the annular stator core 3 formed by laminating a plurality of electromagnetic steel plates 20 in the rotor axial direction, and a pair of stator cores 3 are disposed at both ends in the rotor axial direction. With the press-in members 4 and 4 installed, they are disposed between the case members 1 and 2. The case members 1 and 2 are connected to each other via the fixing bolt 10, the stator core 3 is fixed to the case members 1 and 2, and the rotor 5 is rotatably supported. Can be manufactured easily and appropriately.

  That is, as in the first embodiment of Patent Document 1, the tapered fitting portions provided corresponding to the inner peripheral portion of the cylindrical motor case and the outer peripheral portion of the stator core are fitted in an appropriate state. The press-fitting member 4 is installed on both ends of the stator core 3 in the axial direction of the rotor without requiring a complicated operation such as the above, and the edge 16 is radially inward with respect to the yoke 6 of the stator core 3. By simply press-fitting from the side, a uniform pressure P is applied to the stator core 3 in the direction of increasing its diameter (see FIG. 3). As shown in FIG. A tensile stress Q in the circumferential direction is applied.

  In this way, a uniform tensile stress Q in the circumferential direction corresponding to the pressure P applied through the press-fitting member 4 can be applied to the yoke portion 6 of the stator core 3. Even when the stator core 3 is configured using a steel plate, there is an advantage that an excellent effect of reducing the iron loss and an effect of increasing the magnetic flux density can be obtained. Moreover, since the press-fitting member 4 is configured by projecting the edge 16 on the outer periphery of the circular substrate 15, the outer diameter of the edge 16 is set with high accuracy by cutting using a lathe or the like. be able to.

  Therefore, a dimensional error from the center of the rotor shaft to the bolt hole position is caused as in the second embodiment of Patent Document 1 in which a holding member is provided for each of a plurality of slots provided in the stator core and fixed with bolts. As a result, the edge 16 of the press-fitting member 4 is brought into pressure contact with the yoke portion 6 of the stator core 3 from the radially inner side without variation in the pressing force applied to the stator core from the holding member. Thus, uniform tensile stress in the circumferential direction can be easily and appropriately applied to the yoke portion 6 of the stator core 3.

  Furthermore, as shown in the above embodiment, when the protruding dimension S of the edge portion 16 provided on the outer peripheral portion of the circular substrate 15 is set to be larger than ½ of the length L in the rotor axial direction of the stator core. By installing a pair of press-inserting members 4, 4 at both ends of the stator core 3 in the axial direction of the rotor, the edges 16 of the press-inserting members 4, 4 are pressed against the entire length of the yoke 6 in the axial direction of the rotor. Therefore, there is an advantage that uniform tensile stress can be applied to each of the electromagnetic steel sheets 20 laminated in the rotor axial direction. Alternatively, without interfering with the coil (armature winding) 8 wound around the yoke portion 6 protruding toward the rotor central axis direction in the stator core 3, the circular substrate 15 and the rotor axial end surface portion of the yoke portion 6 The coil 8 can be accommodated in between.

  FIG. 10 shows a second embodiment of the rotating electrical machine according to the present invention. In the second embodiment, a flange portion 22 having a concave groove 21 having an opening facing the rotor axial end surface of the yoke portion 6 is formed on the outer peripheral portion of the press-fitting member 4. The arranged auxiliary core 23 is configured to contact the end surface in the rotor axial direction of the yoke portion 6 of the stator core 3. The auxiliary core 23 is formed by laminating the electromagnetic steel plates in the radial direction of the rotor by, for example, winding a belt-shaped body made of electromagnetic steel plates in the circumferential direction of the rotor shaft and fixing the start and end portions thereof by spot welding or the like. In this state, it is held in the concave groove 21 of the edge portion 16.

  When the auxiliary core 23 that contacts the end surface in the rotor axial direction of the yoke portion 6 of the stator core 3 is provided on the press-fitting member 4 as described above, the coil 8 is wound around the tooth portion 7 of the stator core 3. As a result, the auxiliary core 23 can be disposed by effectively using the spaces formed at both ends of the stator core 3 in the rotor axial direction. This can effectively increase the cross-sectional area of the back yoke portion necessary to flow a magnetic flux for generating a desired torque in the rotating electrical machine, so the radial thickness of the back yoke portion is reduced. There is an advantage that downsizing of the rotating electrical machine can be realized.

  Note that a structure may be adopted in which protrusions that function as the edge 16 of the press-fitting member 4 are integrally provided on the wall surfaces of the case members 1 and 2 that cover the end surface of the stator core 3 in the axial direction of the rotor. In this case, there is an advantage that uniform tensile stress can be applied to the yoke portion 6 of the stator core 3 without increasing the number of parts, and the assembly work of the rotating electrical machine can be simplified effectively.

DESCRIPTION OF SYMBOLS 1, 2 Case member 3 Stator core 4 Press-insertion member 5 Rotor 6 Yoke part 15 Circular substrate 16 Edge part 17 Rotor shaft insertion hole 18 Opening part 21 Gutter part 23 Auxiliary core

Claims (4)

  A rotary electric machine having an annular stator core formed by laminating a plurality of electromagnetic steel plates in the rotor axial direction and a case member for holding the stator core, and a circular substrate having a rotor shaft insertion hole formed And a press-inserting member having an edge projecting from the outer peripheral portion along the inner peripheral surface of the yoke portion so as to extend in the rotor axial direction, and the edge portion of the press-inserting member is against the yoke portion of the stator core. A rotating electric machine characterized by being configured to be press-fitted from the radially inner side.   2. The rotating electrical machine according to claim 1, wherein the protruding dimension of the edge is set to be larger than ½ of the length of the stator core in the rotor axial direction.   The rotating electrical machine according to claim 1 or 2, wherein the circular substrate has a plurality of openings disposed on an outer side portion of the rotor shaft insertion hole.   The rotation according to any one of claims 1 to 3, wherein the circular substrate is provided with a flange portion having an auxiliary core installation portion that abuts against a rotor axial end surface of the yoke portion of the stator core. Electric.

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