JP2013132116A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which prevents the deterioration of magnet characteristics of permanent magnets which are caused by an eddy current occurring in the permanent magnets at the rotary electric machine including a stator and a rotor.SOLUTION: A rotary electric machine 2 includes a stator 11 and a rotor 12 supported so as to rotate relative to the stator 11. The rotor 12 includes multiple insertion holes 41a formed at equal predetermined intervals in a circumferential direction of the rotor 12; and permanent magnets 50 respectively inserted into the multiple insertion holes 41a and formed by various kinds of split magnets 51a to 51f having different coercive forces. The coercive force of the split magnet disposed in a portion of the rotor 12 where heat radiation is conducted at a low level is higher than the coercive force of the split magnet disposed in a portion of the rotor 12 where high heat radiation performance is achieved.

Description

  The present invention relates to a rotating electrical machine including a rotor on which magnets are arranged.

  2. Description of the Related Art A rotating electric machine mounted on a hybrid vehicle or an electric vehicle includes a stator around which a coil is wound and a magnet embedded motor in which a rotor having a permanent magnet is arranged on the inner peripheral side of the stator. In such a rotating electrical machine, when the rotor rotates, an eddy current is generated in the permanent magnet due to a change in magnetic flux density. If it does so, a permanent magnet will generate | occur | produce a heat | fever with this eddy current, and there exists a possibility that a permanent magnet may demagnetize and a magnetic characteristic may fall. Thus, for example, Patent Document 1 discloses a rotating electrical machine that suppresses the generation of eddy currents in a permanent magnet by configuring the permanent magnet with a plurality of divided magnets. Further, for example, in Patent Document 2, since eddy current is generated near the surface of the permanent magnet, the coercive force in the vicinity of the surface of each divided magnet is made higher than the coercive force inside the permanent magnet, and the magnetic characteristics are deteriorated due to heat generation. A rotating electrical machine that suppresses the above is disclosed.

JP 2009-148201 A JP 2009-254092 A

During driving of such a rotating electrical machine, the coil and iron core generate heat and the interior of the rotating electrical machine becomes hot, so the rotor is cooled by lubricating oil, heat radiating fins, or the like. However, due to the structure of the rotating electrical machine, there are some parts that are difficult to dissipate. Therefore, in order to prevent deterioration of the magnetic characteristics even when the permanent magnet becomes high temperature, for example, the permanent magnet is constituted by a split magnet having a higher coercive force. It is possible. However, if the coercive force of the permanent magnet is increased, there is a concern that the cost of the permanent magnet will increase.
The present invention has been made in view of the above problems, and provides a rotating electrical machine that can prevent a decrease in magnetic characteristics of a permanent magnet due to an eddy current generated in the permanent magnet in a rotating electrical machine including a stator and a rotor. For the purpose.

In order to solve the above-described problem, an invention according to claim 1 is a rotating electrical machine including a stator and a rotor supported rotatably with respect to the stator,
The rotor includes a plurality of insertion holes formed at equal intervals in the circumferential direction of the rotor, and a permanent magnet that is inserted into each of the plurality of insertion holes and includes a plurality of types of divided magnets having different coercive forces. Have
The coercive force of the divided magnet disposed at a portion having low heat dissipation in the rotor is higher than the coercive force of the divided magnet disposed at a portion having high heat dissipation in the rotor.

  According to a second aspect of the present invention, in the first aspect, the divided magnets are arranged along the axial direction of the rotor.

  According to a third aspect of the present invention, in the first or second aspect, the rotor has an annular shape, and each of the divided magnets is disposed along at least one of a circumferential direction and a radial direction of the rotor.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the permanent magnet is configured by connecting a non-conductor between the divided magnets.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the divided magnets are formed of different magnetic materials.

  According to the first aspect of the present invention, the permanent magnet is composed of a plurality of types of divided magnets having different coercive forces. And the coercive force of the split magnet arrange | positioned in a site | part with low heat dissipation in a rotor shall be higher than the coercive force of the split magnet arrange | positioned in a site | part with high heat dissipation. As a result, the divided magnets arranged in the portion having low heat dissipation in the rotor generate heat due to eddy currents, and even if the temperature rises, the divided magnets have a relatively high coercive force, so that the magnetic characteristics can be prevented from being lowered. On the other hand, since the divided magnets arranged in the portion with high heat dissipation in the rotor are easy to dissipate heat even if they generate heat due to eddy current, temperature rise is suppressed. Therefore, even if it is a divided magnet with a comparatively low coercive force, the fall of a magnetic characteristic can be prevented. Further, the coercive force of the split magnet is set according to the heat dissipation property of the portion of the rotor to be arranged. Thereby, it can prevent that a permanent magnet is comprised by the division | segmentation magnet of an excessively high coercive force. Therefore, it is possible to reduce the manufacturing cost as compared with a permanent magnet constituted by a divided magnet having a high coercive force with reference to a divided magnet arranged at a portion having low heat dissipation. The rotating electrical machine of the present invention can prevent deterioration of the magnetic characteristics of the permanent magnet due to the eddy current generated in the permanent magnet.

  According to the invention which concerns on Claim 2, each division | segmentation magnet is arrange | positioned along the axial direction of a rotor. Here, the rotor in the rotating electrical machine is cooled by lubricating oil, heat radiating fins, or the like housed in the rotating electrical machine. Further, since the rotor is disposed with its peripheral surface facing the peripheral surface of the stator, the axial range facing the stator may have low heat dissipation. Alternatively, when the rotating electrical machine is housed in the housing together with the clutch device, many heating elements may be arranged close to the rotating electrical machine. If it does so, the heat dissipation of the site | part which adjoins a heat generating body may become low. Therefore, in consideration of the positional relationship with the low heat dissipation part as described above, by adopting the configuration as in the present invention, it adapts to the heat dissipation of each member located around the rotor, and the magnetic characteristics of the permanent magnet Can be efficiently prevented.

  According to the invention which concerns on Claim 3, each division | segmentation magnet is arrange | positioned along at least one direction among the circumferential direction and radial direction of an annular rotor. In a rotor in a rotating electrical machine, the temperature of the permanent magnet may rise due to heat generated by a coil or an iron core constituting the rotating electrical machine. In addition, the rotor core in which the insertion hole to which the permanent magnet is fixed differs depending on the fixing position of the permanent magnet with respect to the insertion hole, but the circumferential end and the circumferential center of the permanent magnet, and the radial outer side and the diameter. The heat dissipation is different on the inner side. Therefore, by adopting the configuration as described above, it is possible to adapt to the heat dissipation of each part of the rotor and to effectively prevent the deterioration of the magnetic characteristics of the permanent magnet.

  According to the invention which concerns on Claim 4, the permanent magnet is comprised by interposing a nonconductor between each division | segmentation magnet. Here, the plurality of divided magnets constituting the permanent magnet can more effectively prevent the generation of eddy currents in the respective divided magnets by preventing the eddy current from flowing across the adjacent divided magnets. . Therefore, it is preferable that the adjacent divided magnets are electrically insulated. Therefore, as described above, by connecting a non-conductor between the divided magnets, generation of an eddy current flowing across a plurality of magnets can be prevented. Accordingly, since the amount of heat generated by the eddy current can be reduced, it is possible to prevent the magnetic characteristics of the permanent magnet from being lowered by suppressing the temperature rise of the divided magnets.

  According to the invention which concerns on Claim 5, each division | segmentation magnet is formed with the mutually different magnetic material. The coercive force of the permanent magnet is determined by the magnetic anisotropy indicating the degree of influence of the external magnetic field on the domain wall, and thus changes depending on the composition of the magnetic material. Therefore, a plurality of types of divided magnets are formed of different magnetic materials, that is, a hard magnetic material for a divided magnet having a high coercive force, and a soft magnetic material for a divided magnet having a low coercive force. The permanent magnet can adapt to the difference in heat dissipation in the rotor by magnetizing such a divided magnet. Further, by using a generally expensive hard magnetic material only in a portion having low heat dissipation, an increase in manufacturing cost as a permanent magnet can be suppressed.

Embodiment: It is sectional drawing of an IPM motor. It is the fragmentary top view seen from the rotating shaft direction of the IPM motor. It is AA sectional drawing of FIG. Modified embodiment: a view showing a permanent magnet in which a plurality of divided magnets are arranged in the rotation axis direction. It is a figure which shows the permanent magnet which has arrange | positioned the some division magnet to the rotating shaft direction. It is a figure which shows the permanent magnet which has arrange | positioned the some division | segmentation magnet to the circumferential direction of a rotor. It is a figure which shows the permanent magnet which has arrange | positioned the some division magnet to the radial direction of a rotor.

<Embodiment>
(Configuration of front module 1)
Hereinafter, a front module 1 according to an embodiment embodying a rotating electrical machine of the present invention will be described with reference to the drawings. The rotating electrical machine of the present invention is a permanent magnet embedded motor (hereinafter referred to as an “IPM (Interior Permanent Magnet) motor”), and will be described as a synchronous motor for driving in a vehicle on which it is mounted. The front module 1 is a device applied to the power train in the front portion of the vehicle, and includes an IPM motor 2, a clutch device 3, a control valve (not shown), and the like. The hybrid vehicle is a hybrid vehicle using the IPM motor 2 and the engine as drive sources. The engine is a normal internal combustion engine that generates output from a hydrocarbon-based fuel.

  As shown in FIG. 1, the IPM motor 2 of the front module 1 is integrally formed with a clutch device 3 that is a wet multi-plate clutch, and the clutch device 3 transmits or blocks driving force to or from the engine. It has been switched. In the description, “rotational axis direction” or “axial direction” means a direction along the rotational axis Cr of the clutch device 3, that is, a horizontal direction in FIG. A vehicle transmission is connected in series to the driving IPM motor 2 in the hybrid vehicle. This transmission is a normal automatic transmission, and is connected to the left and right drive wheels of the vehicle via a differential device.

  In a hybrid vehicle using the front module 1 as a part of the power train, the clutch device 3 is disconnected when starting, and the left and right drive wheels are rotated mainly by the IPM motor 2 via the transmission. Further, when it is necessary to accelerate while the vehicle is traveling, the clutch device 3 is connected and the vehicle is driven by the driving force of the engine in addition to the IPM motor 2. When the brake operation of the vehicle is performed, regenerative braking is performed after the clutch device 3 is disconnected. Furthermore, the IPM motor 2 is driven by the engine via the clutch device 3 and also functions as a generator.

  The IPM motor 2 includes a stator 11 and a rotor 12 that is rotatably supported with respect to the stator 11. The motor housing 13 of the IPM motor 2 is integrally formed of an aluminum alloy or the like, and the front is sealed with a motor cover 14 with the stator 11 and the rotor 12 built therein. An engine is attached to the front of the motor cover 14, and a transmission is disposed behind the motor housing 13. The clutch device 3 is interposed between the rotor 12 constituting the IPM motor 2 and the engine. The IPM motor 2, the engine, and the clutch device 3 are arranged so that their rotational axes are coaxial.

  An input shaft 21 is connected to a flywheel of the engine via a damper (both the flywheel and the damper are not shown). A clutch inner 21 a that forms the clutch device 3 is integrally formed on the outer peripheral surface of the input shaft 21. The clutch device 3 is formed so that the driving force of the engine can be input to the clutch inner 21a. The input shaft 21 is an input member that is rotatably supported by the motor cover 14 via a bearing 14 a and can transmit the driving force of the engine to the clutch device 3. A reservoir 15 for storing oil is formed in the internal space formed by the motor housing 13 and the motor cover 14 as shown in FIG. The reservoir 15 stores oil so that at least a part of the rotor 12 of the IPM motor 2 is immersed in the oil when the front module 1 is in operation.

  The clutch inner 21a is supported in a state where a plurality of friction plates 22 are overlapped in the rotation axis direction in a plurality of spline grooves formed on the outer peripheral surface. Each friction plate 22 is formed in a ring shape, and a protrusion formed on the inner peripheral end thereof is engaged with a spline groove of the clutch inner 21a. Thereby, each friction plate 22 is engaged with the clutch inner 21a while restricting relative rotation. That is, each friction plate 22 is configured to be movable in the direction of the rotation axis Cr with respect to the clutch inner 21a and to be rotatable together with the clutch inner 21a. A friction material (not shown) is formed on the front and back surfaces of the friction plate 22.

  The stator 11 of the IPM motor 2 is attached to the inner peripheral portion of the motor housing 13 with a screw. The stator 11 has a cylindrical stator core 31 and a coil 32. The stator core 31 is formed by stacking electromagnetic steel plates in the rotation axis direction. As shown in FIG. 2, the stator core 31 has a plurality of teeth 31a formed at a predetermined pitch in the circumferential direction. The stator 11 can generate a magnetic field inside the stator 11 by passing a current through the coil 32 wound around each tooth 31a.

  The rotor 12 has an annular shape as a whole, and includes a rotor core 41, an adhesive sheet 42, an end plate 43, a fixing pin 44, and a permanent magnet 50. The rotor 12 is provided to be rotatable with respect to the stator 11 with an air gap interposed inside the stator 11. The rotor 12 receives a magnetic force from the teeth 31a of the stator core 31 that has become a magnetic pole when an electric current is passed through the coil 32 of the stator 11, and rotates about the axis of a rotating shaft (not shown). Thereby, the IPM motor 2 outputs a predetermined torque from the rotating shaft.

  The rotor core 41 is formed by laminating electromagnetic steel plates in the rotation axis direction. In the rotor core 41, a plurality of magnet insertion holes 41 a are penetrated in the axial direction at a predetermined pitch in the circumferential direction of the rotor 12 in the rotor core 41. A permanent magnet 50 described later is inserted into the magnet insertion hole 41 a and is adhered to the inner peripheral surface by the adhesive sheet 42. Thereby, the site | part located in the radial direction outer side of the magnet insertion hole 41a among the rotor cores 41 becomes a magnetic pole.

  The adhesive sheet 42 is a fixing means for bonding the outer surface of the permanent magnet 50 to the inner peripheral surface of the magnet insertion hole 41a and fixing the permanent magnet 50 to the magnet insertion hole 41a. The adhesive sheet 42 is affixed to the outer peripheral surface of the permanent magnet 50 before being inserted into the magnet insertion hole 41a. And after inserting the permanent magnet 50 in the magnet insertion hole 41a, it adhere | attaches by heating the rotor core 41 and making the adhesive sheet 42 foam.

  As shown in FIG. 3, the end plate 43 is a plate-like member attached so as to support the rotor core 41 at both axial ends of the rotor core 41. The end plate 43 is made of a nonmagnetic material in order to prevent leakage of magnetic lines of force in the axial direction of the rotor core 41 generated from the stator 11. The end plates 43 at both ends are integrally fixed by fixing pins 44 that are inserted through the rotor core 41.

  The permanent magnet 50 is a magnet that is formed in a flat plate shape as a whole and is magnetized in the thickness direction. The permanent magnets 50 are inserted into the plurality of magnet insertion holes 41a of the rotor core 41 so that the polarity is reversed with respect to the permanent magnets 50 inserted into the adjacent magnet insertion holes 41a. The permanent magnet 50 is composed of a plurality of types of divided magnets having different coercive forces. In the present embodiment, the permanent magnet 50 is formed by connecting six divided magnets 51 a to 51 f with a non-conductive adhesive 52 in the rotation axis direction. As shown in FIGS. 1 and 3, each divided magnet is arranged along the axial direction of the rotor 12, and the divided magnet is located on one side (left side in FIG. 1) of the rotation axis Cr in the rotor 12. 51a and divided magnets 51b to 51f in order toward the other side of the rotation axis Cr.

  In addition, the permanent magnet 50 is configured by arranging divided magnets having different coercive forces according to the heat dissipation of each part of the rotor 12. In other words, the coercive force of the plurality of types of divided magnets 51a to 51f is set according to the heat dissipation performance of the portion arranged in the rotor 12. And in this embodiment, since the heat dissipation of the rotor 12 inside the motor housing 13 of the IPM motor 2 differs in the rotation axis direction, the permanent magnet 50 includes a plurality of types of divided magnets 51a to 51f having different coercive forces. Connected in the direction of the rotation axis. Here, each of the divided magnets 51 a to 51 f is formed of different magnetic materials so as to have a coercive force corresponding to the heat dissipation of the rotor 12. That is, since the coercive force of the permanent magnet varies depending on the composition of the magnetic material, the divided magnets 51a to 51f are formed by magnetizing different magnetic materials after forming them into a predetermined shape. Details of setting the coercive force of each of the divided magnets 51a to 51f will be described later.

  In the IPM motor 2 having the above-described configuration, for example, a three-phase alternating current is supplied to the coil 32 from a vehicle battery via an inverter. Thereby, a rotating magnetic field is generated in the stator 11, and the rotor 12 is rotated with respect to the stator 11 by an attractive force or a repulsive force caused by the rotating magnetic field. One end portion of the clutch outer 23 in the axial direction is attached to the inner end of the end plate 43 on one side of the rotor 12 with a bolt so as to transmit the driving force due to this rotation. The clutch outer 23 is formed so as to be rotatable relative to the clutch inner 21a about the rotation axis Cr.

  A plurality of separate plates 24 formed in a substantially ring shape are arranged on the inner peripheral surface side of the cylindrical portion formed on the radially outer side of the clutch outer 23. And the protrusion part formed in the outer peripheral part of the separate plate 24 is engaging with the some spline groove | channel formed in the internal peripheral surface of the cylindrical part of the clutch outer 23. FIG. As a result, the separate plate 24 can be moved in the direction of the rotation axis Cr with respect to the clutch outer 23 and can be rotated together with the clutch outer 23. Each separate plate 24 is alternately interposed between the plurality of friction plates 22 described above.

  The clutch outer 23 extends radially inward and is spline-fitted with a turbine shaft 25 of a torque converter included in the transmission of the vehicle at the inner end. This torque converter is a device that transmits a rotational force by an oil flow accompanying the rotation of the turbine shaft. Further, a connecting member connected to the pump impeller is attached to an end portion in the axial direction of the turbine shaft 25 so as to be integrally rotatable. As a result, the driving force of the clutch outer 23 can be input to the torque converter of the transmission. The clutch outer 23 is supported on the motor housing 13 via a bearing 26 at its inner end.

  Further, the clutch outer 23 is formed with a concave portion bent in a U-shape, and the inner peripheral surface of the cylindrical member 27 is fluid-tightly fitted to the outer peripheral surface located on the radially inner side of the concave portion. . The cylindrical member 27 is regulated by a snap ring fitted to the outer peripheral surface of the recess of the clutch outer 23 so as not to move to one side (left side in FIG. 1) from a predetermined position in the direction of the rotation axis Cr. . Here, the clutch device 3 has a cylinder portion Cyl formed by a part of the concave portion of the clutch outer 23 and the surface on the other side (right side in FIG. 1) of the cylindrical member 27 as shown by a thick dotted line in FIG. Is formed. A piston member 28 is accommodated in the cylinder part Cyl so as to be slidable in the direction of the rotation axis Cr. The piston member 28 is formed in a substantially annular shape, and is fluid-tightly fitted to the cylinder portion Cyl at the inner peripheral end.

  In the piston member 28, the piston upper surface 28a located on one side (left side in FIG. 1) in the direction of the rotation axis Cr faces the inner surface of the cylinder portion Cyl. Thereby, a pressure chamber PC to which oil is supplied is defined between the cylinder portion Cyl and the piston upper surface 28a of the piston member 28. As shown in FIG. 1, a piston spring 29 is interposed between the piston lower surface 28b located on the other side (right side in FIG. 1) of the piston member 28 in the rotation axis Cr direction and the inner surface of the cylinder part Cyl. Yes. The piston spring 29 is in contact with the piston lower surface 28b of the piston member 28 on the side where the pressure chamber PC is formed and the opposite side of the rotation axis Cr direction. As a result, the piston spring 29 biases the piston member 28 in the direction in which the cylindrical member 27 is positioned.

(Operation of front module 1 and setting of coercivity of split magnet)
Next, the operation of the front module 1 having the above configuration will be described. The motor housing 13 and the clutch outer 23 are formed with an oil passage that communicates an electric oil pump (not shown) and the pressure chamber PC. Then, when oil is sucked from the reservoir 15 by the electric oil pump and supplied to the pressure chamber PC through the oil passage, the hydraulic pressure of the pressure chamber PC increases. Then, the piston member 28 moves against the urging force of the piston spring 29 in the direction in which the bottom portion of the cylinder portion Cyl is located. As a result, the friction plate 22 and the separate plate 24 are separated and the clutch is disengaged. Therefore, transmission of the driving force from the clutch inner 21a to the clutch outer 23 is interrupted.

  On the other hand, when the supply of oil to the pressure chamber PC by the electric oil pump is stopped, the piston member 28 is biased toward the cylindrical member 27 by the piston spring 29, and the oil is discharged from the pressure chamber PC. As a result, the hydraulic pressure in the pressure chamber PC is lowered, and the piston member 28 presses the friction plate 22 and the separate plate 24 toward one side in the direction of the rotation axis Cr by the biasing force of the piston spring 29. If it does so, the friction plate 22 and the separate plate 24 will press-contact, and will be in the state of a clutch connection. Therefore, the friction plate 22 and the separate plate 24 rotate integrally, and the driving force can be transmitted from the clutch inner 21 a to the clutch outer 23.

  Here, in the front module 1 having such a configuration, the oil discharged by the electric oil pump is not only supplied to the pressure chamber PC, but also each member accommodated in the motor housing 13 as lubricating oil or cooling oil. To be supplied. The oil stored in the reservoir 15 is pumped up by the rotation of the rotor 12 and supplied to each member accommodated in the motor housing 13 as lubricating oil or cooling oil. However, the front module 1 may have a difference in the cooling performance of each part due to its configuration or operation. For example, the cooling performance of the part changes depending on whether the coil 32 of the stator 11 is close to a member that can be a heating element in the operating state, or is separated from other members and the oil as the cooling oil easily circulates.

  Here, in the IPM motor 2, when the rotor 12 rotates, an eddy current is generated in the permanent magnet 50 due to a change in magnetic flux density, and the permanent magnet 50 generates heat. That is, the permanent magnet 50 is a member that can be a heating element when the IPM motor 2 is driven. Moreover, since the permanent magnet 50 may be demagnetized at a high temperature and the magnetic characteristics may be deteriorated, it is necessary to appropriately promote cooling. However, as described above, the cooling performance of the front module 1 has a difference in height depending on each part. Therefore, a part having high heat dissipation and a part having low heat dissipation are generated in each part of the rotor 12 that holds the permanent magnet 50. It may be difficult to improve the cooling performance of 50. In the front module 1 of the present embodiment having the above-described configuration, the rotor 12 has gradually increased heat dissipation from one side of the rotating shaft Cr toward the other side (left side to right side in FIG. 1). That is, the part located on the front side of the front module 1 among the parts of the rotor 12 is likely to become hot when the front module 1 is operated because the heat dissipation is low.

  Therefore, by forming the permanent magnet 50 with a plurality of divided magnets, the generation of eddy current is suppressed, and the temperature rise of the permanent magnet 50 is suppressed in the first place. However, as the permanent magnet 50 is subdivided, the eddy current path is more likely to be cut off, so that the generation of eddy currents can be suppressed. On the other hand, however, the manufacturing cost is increased and the magnetic properties are decreased due to the decrease in the magnet volume. Concerned. On the other hand, the magnetic characteristics can be prevented from deteriorating even when the temperature becomes high by disposing a magnet having a high coercive force in a state where the permanent magnet 50 is set to a certain number of divisions. However, in general, a magnet having a high coercive force is more expensive than a magnet having a low coercive force, which may increase the manufacturing cost. Therefore, as shown in FIG. 3, the IPM motor 2 of the front module 1 of the present embodiment forms a permanent magnet 50 by a plurality of divided magnets 51 a to 51 f having different coercive forces in the rotation axis direction.

  More specifically, each of the divided magnets 51a to 51f is set to a coercive force corresponding to the heat dissipation because the heat dissipation of the rotor 12 gradually increases from one side to the other side of the rotating shaft Cr. Has been. That is, the coercive force of the split magnet 51a disposed in the portion of the rotor 12 with low heat dissipation (one side of the rotation shaft Cr) is disposed in the portion of the rotor 12 with high heat dissipation (other side of the rotation shaft Cr). It is higher than the coercive force of the split magnet 51f. Therefore, in the present embodiment, a hard magnetic material is magnetized to the divided magnet 51a arranged on one side of the rotor 12 of the permanent magnet 50 so that the coercive force becomes the highest, and conversely on the other side of the rotor 12. The divided magnet 51f to be arranged is magnetized with a soft magnetic material so as to have the lowest coercive force.

(Effects of front module 1)
According to the IPM motor 2 of the front module 1 of the present embodiment, the permanent magnet 50 is composed of a plurality of types of divided magnets 51a to 51f having different coercive forces. And the coercive force of the split magnet arrange | positioned in the site | part with low heat dissipation in the rotor 12 shall be higher than the coercive force of the split magnet arrange | positioned in a site | part with high heat dissipation. Thereby, even if the divided magnets 51a to 51f arranged in the portion having low heat dissipation in the rotor 12 generate heat due to eddy current and the temperature rises, the coercive force of the divided magnets 51a to 51f is relatively high, so that the magnetic characteristics are reduced. Can be prevented. On the other hand, the split magnet 51f arranged at a portion with high heat dissipation in the rotor 12 is easy to dissipate heat even if it generates heat due to eddy current, so that temperature rise is suppressed. Therefore, even if it is the division magnets 51a-51f with a comparatively low coercive force, the fall of a magnetic characteristic can be prevented.

  The divided magnets 51a to 51f are set to have a coercive force according to the heat dissipation property of the portion of the rotor 12 to be arranged. Thereby, it can prevent that the permanent magnet 50 is comprised with the division | segmentation magnet of an excessively high coercive force. Therefore, the manufacturing cost can be reduced as compared with the case where the magnet is configured by a segmented magnet having a coercive force set with respect to the segmented magnet 51a disposed in a portion with low heat dissipation. Therefore, the IPM motor 2 of the present invention can efficiently prevent the deterioration of the magnetic characteristics of the permanent magnet 50 due to the eddy current generated in the permanent magnet 50 as compared with the conventional case.

  Each of the divided magnets 51 a to 51 f is disposed along the axial direction of the rotor 12. Here, the rotor 12 in the IPM motor 2 is cooled by oil stored in the IPM motor 2. Further, since the rotor 12 is disposed with its peripheral surface facing the peripheral surface of the stator 11, the axial range facing the stator 11 may have low heat dissipation. In addition, since the IPM motor 2 is housed in the motor housing 13 together with the clutch device 3, many heating elements other than the IPM motor 2 are arranged close to each other. If it does so, the heat dissipation of the part which the rotor 12 adjoins to a heat generating body may become low. Therefore, in consideration of the positional relationship with the low heat dissipation part as described above, the structure of the present invention is adapted to the heat dissipation of each member located around the rotor 12, and the permanent magnet 50 It is possible to efficiently prevent a decrease in magnetic characteristics.

  Furthermore, the permanent magnet 50 is configured by connecting a non-conductive adhesive 52 between the divided magnets 51a to 51f. Here, the plurality of divided magnets 51a to 51f constituting the permanent magnet 50 prevent the eddy current from flowing across the adjacent divided magnets 51a to 51f, so that the eddy current in each of the divided magnets 51a to 51f is reduced. Occurrence can be prevented more effectively. Therefore, it is preferable that the adjacent divided magnets 51a to 51f are electrically insulated. Thus, as described above, by connecting the divided magnets 51a to 51f with nonconductors interposed therebetween, it is possible to prevent the generation of eddy currents that flow across a plurality of magnets. Accordingly, since the amount of heat generated by the eddy current can be reduced, it is possible to prevent the magnetic characteristics of the permanent magnet 50 from being lowered by suppressing the temperature rise of the divided magnets 51a to 51f.

  Each of the divided magnets 51a to 51f is formed of different magnetic materials. The coercive force of the permanent magnet 50 is determined by the magnetic anisotropy indicating the degree of influence of the external magnetic field on the domain wall, and therefore varies depending on the composition of the magnetic material. Therefore, the plurality of types of divided magnets 51a to 51f are formed of different magnetic materials, that is, a hard magnetic material is used for the divided magnet 51a having the highest coercive force, and a soft magnetic material is used for the divided magnet 51f having the lowest coercive force. And about the split magnets 51b-51e located between the split magnet 51a and the split magnet 51f, the material ratio is changed gradually. The permanent magnet 50 can adapt to the difference in heat dissipation in the rotor 12 by magnetizing the divided magnets 51a to 51f. Further, by using a generally expensive hard magnetic material only in a portion having low heat dissipation, an increase in manufacturing cost as the permanent magnet 50 can be suppressed.

<Modification of Embodiment>
The front module 1 according to the embodiment of the rotating electrical machine of the present invention has been described above. Then, the deformation | transformation aspect of embodiment is demonstrated with reference to FIGS. In the present embodiment, the permanent magnet 50 is composed of six types and six divided magnets 51a to 51f. On the other hand, you may comprise the permanent magnet 50 so that the division | segmentation magnet of the same coercive force may be included. For example, as shown in FIG. 4, it is assumed that the permanent magnet 50 has three types and six divided magnets 51b, 51d, and 51f. At this time, the coercive forces of the divided magnets 51b, 51d, and 51f are set so as to gradually decrease. Even in such a configuration, the same effect can be obtained. In addition, the manufacturing cost can be reduced by reducing the number of types of divided magnets.

  Moreover, in the front module 1 of this embodiment, since the heat dissipation of the rotor 12 is gradually increased from one side of the rotating shaft Cr to the other side (left side to right side in FIG. 1), the split magnet 51a. The coercive force of ˜51f was set to be gradually lowered. However, depending on the configuration of the front module 1 and the IPM motor 2, for example, it is assumed that the heat dissipating property of the part located on both ends of the rotating shaft Cr is high and the heat dissipating characteristic of the part located on the central side is low or vice versa. Is done. In such a case, you may set so that the coercive force of a division | segmentation magnet may become high gradually toward the center side from the both ends side of the rotating shaft Cr of the rotor 12. FIG. For example, as shown in FIG. 5, it is assumed that the permanent magnet 50 has four types of eight divided magnets 51g to 51j. Then, the divided magnets 51j having the lowest coercive force are arranged on both ends of the rotation axis Cr, and the divided magnets 51g having the highest coercive force are arranged on the center side. Thereby, it can adapt to the rotor 12 from which heat dissipation differs in the both ends side and center side of a rotating shaft direction, and can prevent the fall of the magnetic characteristic of the permanent magnet 50 efficiently.

  As described above, the permanent magnet 50 is configured such that the coercive forces of the plurality of divided magnets divided in the axial direction of the rotor 12 are different from each other. Here, the rotor 12 supports the permanent magnet 50 inserted in the magnet insertion hole 41 a penetrating the rotor core 41. The rotor core 41 may have a shape including a magnet insertion hole 41a in order to reduce leakage magnetic flux that does not contribute to the rotational drive of the rotor 12. The leakage magnetic flux is a magnetic flux that is short-circuited with a part of the magnetic flux generated by the permanent magnet 50 inserted into the adjacent magnet insertion hole 41a out of the magnetic flux generated by the permanent magnet 50 inserted in the magnet insertion hole 41a.

  For this reason, if the thickness is different at each circumferential portion of the rotor core 41, a difference in thermal conductivity may occur. In such a case, since the heat dissipation of the rotor 12 is different in the circumferential direction, the permanent magnet 50 may be configured by a plurality of divided magnets divided in the circumferential direction of the rotor 12. For example, as shown in FIG. 6, it is assumed that there are four types of eight divided magnets 51k to 51n. At this time, the coercive force of the divided magnets 51k to 51n is set so as to gradually decrease from the circumferential center of the magnet insertion hole 41a toward both circumferential ends. Thereby, it can adapt to the rotor 12 from which the heat dissipation differs in the circumferential direction of the rotor core 41, and can prevent the fall of the magnetic characteristic of the permanent magnet 50 efficiently.

  Further, the path of eddy current generated in the permanent magnet 50 is in a plane perpendicular to the magnetization direction of the permanent magnet 50. Therefore, a portion near the outer peripheral surface where the current density is high among the respective portions in the radial direction of the permanent magnet 50 is likely to generate heat due to the eddy current. Further, the rotor 12 in the IPM motor 2 has a risk that the temperature of the permanent magnet 50 rises due to heat generated by the coil 32 and the stator core 31 constituting the IPM motor 2. Thus, since the heat dissipation of the rotor 12 differs in the radial direction, the permanent magnet 50 may be configured by a plurality of divided magnets divided in the radial direction of the rotor 12. For example, as shown in FIG. 7, it is assumed that there are four types of four divided magnets 51o to 51r. At this time, the coercive force of the divided magnets 51o to 51r is set so as to gradually decrease from the radially outer side of the rotor 12 toward the radially inner side. Thereby, it can adapt to the rotor 12 with which heat dissipation differs in the radial direction of the rotor core 41, and can prevent the fall of the magnetic characteristic of the permanent magnet 50 efficiently.

  As described above, the permanent magnet 50 is configured by a plurality of divided magnets divided in any one of the axial direction, the circumferential direction, and the radial direction of the rotor 12. On the other hand, when the heat dissipation of the rotor 12 is different in each direction from the configuration or operation of the front module 1 or the IPM motor 2, the division direction and the coercive force are set so as to adapt to this. Also good. Even in such a configuration, the same effect can be obtained.

  In addition, in order to reduce the eddy current flowing across the adjacent divided magnets, the permanent magnet 50 is formed by connecting the divided magnets 51a to 51f with a non-conductive adhesive 52 interposed therebetween. However, as described above, by forming the permanent magnet with a plurality of divided magnets, the generation of eddy currents can be reduced compared to a single permanent magnet. Therefore, the rotating electrical machine of the present invention does not necessarily require that a plurality of divided magnets are connected by the non-conductive adhesive 52, and other connecting means for connecting the respective divided magnets can be applied. .

1: Front module 2: IPM motor (rotary electric machine) 3: Clutch device 11: Stator 12: Rotor 13: Motor housing 14: Motor cover 14a: Bearing 15: Reservoir 21: Input shaft 21a: Clutch Inner, 22: Friction plate 23: Clutch outer, 24: Separate plate, 25: Turbine shaft 26: Bearing, 27: Cylindrical member, 28: Piston member, 28a: Piston upper surface 28b: Piston lower surface, 29: Piston spring 31: Stator core, 31a: Teeth, 32: Coil 41: Rotor core, 41a: Magnet insertion hole, 42: Adhesive sheet 43: End plate, 44: Fixing pin 50: Permanent magnet, 51a to 51f: Split magnet, 52: Adhesive Cyl: Cylinder part, P : The pressure chamber, Cr: axis of rotation

Claims (5)

A rotating electrical machine comprising a stator and a rotor supported rotatably with respect to the stator,
The rotor is
A plurality of insertion holes formed at equal intervals in the circumferential direction of the rotor;
A permanent magnet that is inserted into each of the plurality of insertion holes and is composed of a plurality of types of divided magnets having different coercive forces;
Have
A rotating electrical machine in which the coercive force of the divided magnet disposed in a portion having low heat dissipation in the rotor is higher than the coercive force of the divided magnet disposed in a portion having high heat dissipation in the rotor. In claim 1,
Each said divided magnet is a rotary electric machine arrange | positioned along the axial direction of the said rotor. In claim 1 or 2,
The rotor is annular,
Each said split magnet is a rotary electric machine arrange | positioned along at least one direction among the circumferential direction and radial direction of the said rotor. In any one of Claims 1-3,
The said permanent magnet is a rotary electric machine comprised by interposing a nonconductor between each said division magnet. In any one of Claims 1-4,
Each of the divided magnets is a rotating electrical machine formed of different magnetic materials.

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