JP2008278638A - Rotor yoke, manufacturing method for rotor yoke and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent magnetic field flux from being short-circuited and reduce leakage flux. <P>SOLUTION: A rotor core 7 of an outer-periphery-side rotor includes an inner-periphery-side yoke member containing a soft magnetic material 7a on either one side and an outer-periphery-side yoke member containing a non-magnetic substance 7b on the other side. The inner-periphery-side yoke member has an annular shape and a protrusion portion at the outer-periphery portion and the outer-periphery-side yoke member has an annular shape and a fitting recessed portion for fitting onto the protrusion portion at the inner-periphery portion. While the protrusion portion is fitted into the fitting recessed portion, a joint body is formed by sinter diffusion connection. Further, by removing the inner-periphery portion and the outer-periphery so as to alternately arrange the soft magnetic material 7a and the non-magnetic substance 7b in the peripheral direction, the rotor core 7 of the outer-periphery-side rotor is formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotor yoke, a method for manufacturing the rotor yoke, and an electric motor.

Conventionally, for example, first and second rotors provided concentrically around a rotating shaft of an electric motor are provided, and the first and second rotors are provided in accordance with the rotational speed of the electric motor or the rotational magnetic field generated in the stator. An electric motor that controls the relative position of the second rotor in the circumferential direction, that is, the phase difference is known (see, for example, Patent Document 1).
In this electric motor, for example, when the phase difference between the first and second rotors is controlled according to the rotational speed of the electric motor, the first and second elements are displaced via a member that is displaced along the radial direction by the action of centrifugal force. The relative position in the circumferential direction of the rotor is changed. For example, when the phase difference between the first and second rotors is controlled in accordance with the speed of the rotating magnetic field generated in the stator, the stator windings are kept in a state where each rotor maintains the rotation speed due to inertia. The relative position in the circumferential direction of the first and second rotors is changed by passing a control current and changing the rotating magnetic field velocity.
JP 2002-204541 A

  By the way, in the electric motor according to an example of the above prior art, the field magnetic flux generated by the permanent magnet of the second rotor on the inner peripheral side does not interlink the permanent magnet of the first rotor on the outer peripheral side, and the first rotation. There is a risk of short circuit through the yoke of the child. In this case, of the field magnetic flux generated by the permanent magnet of the second rotor on the inner circumference, the permanent magnet of the first rotor on the outer circumference is linked. The amount of magnetic flux to be reduced (linkage magnetic flux amount) decreases, the leakage magnetic flux increases, and the variable width of the induced voltage constant accompanying the change in the relative position in the circumferential direction of the first and second rotors decreases. Problem arises.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotor yoke, a method of manufacturing the rotor yoke, and an electric motor that can suppress a short circuit of field magnetic flux and reduce leakage magnetic flux.

  In order to solve the above problems and achieve the object, either one of the rotor yokes according to the first aspect of the present invention is made of a soft magnetic material (for example, the soft magnetic material 7a in the embodiment). The other is an inner circumferential yoke member (for example, inner circumferential yoke member 41 in the embodiment) and an outer circumferential yoke member (for example, implementation) made of a nonmagnetic material (for example, the nonmagnetic material 7b in the embodiment). And the inner periphery side yoke member which is annular and has an uneven portion (for example, the convex portion 41a in the embodiment) on the outer periphery, and the annular and inner periphery The outer periphery side yoke member having a fitting uneven portion (for example, the fitting concave portion 42a in the embodiment) fitted to the uneven portion is fitted to the uneven portion and the fitting uneven portion. In this state, the bonded body (for example, actual Formed by cutting the inner periphery and the outer periphery of the joined body so that the soft magnetic material and the nonmagnetic material are alternately arranged in the circumferential direction. Yes.

  In addition, in the rotor yoke manufacturing method according to the second aspect of the present invention, either one is made of a soft magnetic material (for example, the soft magnetic material 7a in the embodiment), and either one is made of a non-magnetic material (for example, An inner circumference side yoke member (for example, inner circumference side yoke member 41 in the embodiment) and an outer circumference side yoke member (for example, outer circumference side yoke member 42 in the embodiment) made of the nonmagnetic material 7b in the embodiment. ) And the inner peripheral side yoke member having an irregular portion (for example, the convex portion 41a in the embodiment) on the outer peripheral portion, and the annular inner portion and fitting on the concave and convex portion on the inner peripheral portion. A fitting step (for example, embodiment) in which the outer circumferential side yoke member having a fitting uneven portion (for example, the fitting concave portion 42a in the embodiment) is fitted to the uneven portion and the fitting uneven portion. Step S02), and the concave and convex portions and the fitting concave and convex portions A joining step (for example, a joined body (for example, joined body 43 in the embodiment)) in which the inner circumferential yoke member and the outer circumferential yoke member are joined by sintered diffusion bonding in a fitted state. , Step S03 in the embodiment, and an excision step of excising the inner periphery and the outer periphery of the joined body so that the soft magnetic material and the nonmagnetic material are alternately arranged in the circumferential direction (for example, Step S04) in the embodiment.

  An electric motor according to a third aspect of the present invention includes a rotor yoke according to the first aspect, and a plurality of permanent magnet pieces (for example, implementations) arranged in the circumferential direction on the inner peripheral side or outer peripheral side of the rotor yoke. A rotor with a permanent magnet 9a) in the form.

  Furthermore, the electric motor according to the fourth aspect of the present invention is an outer peripheral rotor (for example, in the embodiment) provided with the permanent magnet piece at a position facing the soft magnetic material in the radial direction on the outer peripheral side of the rotor yoke. And a plurality of permanent magnet pieces (for example, permanent magnets 9b in the embodiment) arranged in the circumferential direction so as to be coaxial and relatively rotatable with respect to the outer rotor. An inner circumferential rotor (for example, an inner circumferential rotor 6 in the embodiment), and phase changing means for changing a relative phase between the outer circumferential rotor and the inner circumferential rotor (for example, implementation) Phase change means 12) in the form of

  Furthermore, in the electric motor according to the fifth aspect of the present invention, a circumferential width a on the outer peripheral side of the soft magnetic material of the outer rotor and a circumferential width b on the inner peripheral side of the soft magnetic material, A predetermined relationship (a> b ≧ c) is set with respect to the circumferential width c of the magnet mounting protrusion of the inner circumferential rotor, and the outer circumferential side of the soft magnetic material of the outer circumferential rotor An angle θ1 formed by both ends in the circumferential direction with respect to the central axis, a straight line including one end in the circumferential direction on the outer peripheral side and the inner peripheral side of the soft magnetic material of the outer peripheral rotor, and a straight line including the other end A predetermined relationship (θ1 <θ2) is set with respect to the angle θ2 formed by

  According to the rotor yoke according to the first aspect of the present invention, desired soft magnetic material and non-magnetic material that are alternately arranged in the circumferential direction can be obtained while preventing troublesome labor and excessive costs. The joining strength can be ensured, and the magnetic flux can be converged in a desired direction in the rotor yoke, so that the leakage magnetic flux can be reduced.

  Further, according to the method of manufacturing the rotor yoke according to the second aspect of the present invention, the soft magnetic material and the non-magnetic material, which are alternately arranged in the circumferential direction, are prevented while taking troublesome labor and excessive costs. On the other hand, a desired bonding strength can be ensured, and the magnetic flux can be converged in a desired direction in the rotor yoke, so that the leakage magnetic flux can be reduced.

  Further, according to the electric motor according to the third aspect of the present invention, the field magnetic flux of the permanent magnet can be converged in a desired direction in the rotor yoke, the leakage magnetic flux can be reduced, and the torque and rotational speed of the electric motor can be reduced. It is possible to prevent the drivable range from decreasing.

  Further, according to the electric motor of the fourth aspect of the present invention, the field magnetic flux caused by the permanent magnet piece of the inner peripheral side rotor is short-circuited via the rotor yoke without interlinking the permanent magnet piece of the outer peripheral side rotor. And the leakage flux can be reduced, and the variable range of the induced voltage constant of the motor accompanying the change of the relative phase between the outer rotor and the inner rotor is reduced. Can be prevented.

Furthermore, according to the electric motor which concerns on the 5th aspect of this invention, the field magnetic flux by the permanent magnet piece of an inner peripheral side rotor can be efficiently linked with the permanent magnet piece of an outer peripheral side rotor.
On the other hand, for example, when the predetermined relationship (a> b ≧ c) or the predetermined relationship (θ1 <θ2) does not hold, the leakage magnetic flux increases or the field magnetic flux due to the permanent magnet piece of the inner circumferential rotor is appropriately set. The amount of field magnetic flux (linkage magnetic flux) that links the permanent magnet pieces of the outer rotor cannot be reduced, and the relative phase between the outer rotor and the inner rotor is reduced. There is a risk that the variable width of the induced voltage constant of the motor accompanying the change of the motor will be reduced.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a rotor yoke, a rotor yoke manufacturing method, and an electric motor according to the present invention will be described below with reference to the accompanying drawings.
An electric motor 1 according to this embodiment is mounted as a traveling drive source of a vehicle such as a hybrid vehicle or an electric vehicle. For example, as shown in FIGS. 1 to 3, a rotor is disposed on the inner peripheral side of an annular stator 2. It is an inner rotor type brushless motor in which the unit 3 is disposed.
The stator 2 has a multi-phase stator winding 2a, and the rotor unit 3 has a rotating shaft 4 at the shaft core.

  The rotor unit 3 includes, for example, an annular outer circumferential rotor 5 and an annular inner circumferential rotor 6 disposed coaxially inside the outer circumferential rotor 5. The circumferential rotor 6 is relatively rotatable within a predetermined set angle range.

The outer peripheral rotor 5 includes a plurality of permanent magnets 9a fixed on the outer peripheral surface of an annular rotor core 7 (rotor yoke) which is a rotor body, and each permanent magnet 9a is a flat plate magnetized in the thickness direction. It is made into a shape.
The inner peripheral rotor 6 includes a plurality of magnet mounting slots 8a formed at equal intervals in the circumferential direction at positions offset toward the outer peripheral side of the annular rotor core 8 serving as the rotor body. A flat permanent magnet 9b magnetized in the thickness direction is attached to 8a.

  The same number of permanent magnets 9a and 9b of the outer circumferential rotor 5 and inner circumferential rotor 6 are provided, and correspond one-on-one. Thereby, the permanent magnets 9a and 9b of the outer circumferential rotor 5 and the inner circumferential rotor 6 are opposed to each other with different polarities (the same pole arrangement), so that the field of the entire rotor unit 3 is the most. A strengthened field state (for example, see FIGS. 2 and 4 (a)) can be obtained, and the permanent magnets 9a and 9b of the outer rotor 5 and the inner rotor 6 have the same polarity. By facing each other (with different polarity arrangement), it is possible to obtain a field-weakening state (see, for example, FIGS. 3 and 4B) in which the field of the entire rotor unit 3 is most weakened.

  The rotor core 7 of the outer rotor 5 is formed by a fitting process, a joining process, and a cutting process, which will be described later. For example, as shown in FIGS. 2 and 3, a soft magnetic material 7a joined by sintered diffusion bonding and The nonmagnetic material 7b is alternately arranged in the circumferential direction. Each permanent magnet 9a of the outer rotor 5 is disposed on the outer peripheral surface of each soft magnetic material 7a and is held by a magnet holding layer 7c formed on the outer peripheral surface of the nonmagnetic material 7b by, for example, filament winding. .

  Further, the rotor core 8 of the inner rotor 6 includes protrusions 8b protruding outward in the radial direction corresponding to the respective permanent magnets 9b, and magnet mounting slots 8a are formed in the protrusions 8b. Yes.

  For example, as shown in FIG. 5, a circumferential width a on the outer peripheral side of the soft magnetic material 7a of the rotor core 7 of the outer rotor 5 and a circumferential width b on the inner peripheral side of the soft magnetic material 7a. A predetermined relationship (a> b ≧ c) is set with respect to the circumferential width c of the protrusion 8b of the rotor core 8 of the inner rotor 6 and the rotor core 7 of the outer rotor 5 is set. Of the outer peripheral side of the soft magnetic material 7a, the angle θ1 formed with respect to the central axis O and the circumferential direction on the outer peripheral side and inner peripheral side of the soft magnetic material 7a of the rotor core 7 of the outer rotor 5 A predetermined relationship (θ1 <θ2) is set with respect to an angle θ2 formed by a straight line including one end and a straight line including the other end.

  In the electric motor 1, when the predetermined relationship (a> b ≧ c) or the predetermined relationship (θ1 <θ2) does not hold, the leakage magnetic flux increases or the permanent magnet 9b of the inner circumferential rotor 6 The amount of field magnetic flux (interlinkage magnetic flux) interlinking the permanent magnet 9a of the outer rotor 5 is reduced without properly converging the field magnetic flux, and the outer rotor 5 and inner periphery are reduced. There is a possibility that the variable width of the induced voltage constant of the electric motor 1 accompanying the change of the relative phase with the side rotor 6 may be reduced.

Further, for example, as shown in FIGS. 1 to 3, 6, and 7, the rotor unit 3 includes a rotating mechanism 11 for relatively rotating the outer peripheral rotor 5 and the inner peripheral rotor 6. ing. The rotating mechanism 11 constitutes a part of phase changing means 12 for arbitrarily changing the relative phase of the rotors 5 and 6, and is a working fluid (for example, an incompressible working fluid) It may be operated by the pressure of transmission T / M lubricating oil, engine oil or the like.
For example, as shown in FIG. 7, the phase changing unit 12 includes a rotation mechanism 11 and a hydraulic control device 13 that controls the pressure of the hydraulic fluid supplied to the rotation mechanism 11 as main elements. Yes.

  For example, as shown in FIG. 1 to FIG. 3 and FIG. 6, the rotation mechanism 11 can be relatively rotated to the outer peripheral side of the vane rotor 14 and the vane rotor 14 that is spline fitted to the outer periphery of the rotary shaft 4. And the annular housing 15 is integrally fitted and fixed to the inner peripheral surface of the inner peripheral rotor 6, and the vane rotor 14 is provided between the annular housing 15 and the inner peripheral rotor 6. It is integrally coupled to the outer peripheral rotor 5 via a pair of disc-shaped drive plates 16, 16 straddling the side end portions on both sides. Therefore, the vane rotor 14 is integrated with the rotary shaft 4 and the outer peripheral rotor 5, and the annular housing 15 is integrated with the inner peripheral rotor 6.

  In the vane rotor 14, a plurality of blade portions 18 projecting radially outward are provided at equal intervals in the circumferential direction on the outer periphery of a cylindrical boss portion 17 that is spline-fitted to the rotary shaft 4. On the other hand, the annular housing 15 is provided with a plurality of concave portions 19 on the inner peripheral surface at equal intervals in the circumferential direction, and the corresponding blade portions 18 of the vane rotor 14 are accommodated in the concave portions 19. Each recess 19 is configured by a bottom wall 20 having an arc surface that substantially matches the rotational trajectory of the tip of the blade 18 and a substantially triangular protrusion 21 that separates the adjacent recesses 19, 19. When the relative rotation of 14 and the annular housing 15 is performed, the blade portion 18 can be displaced between the one projecting portion 21 and the other projecting portion 21.

  In this embodiment, the projecting portion 21 also functions as a regulating member that regulates the relative rotation of the vane rotor 14 and the annular housing 15 by contacting the blade portion 18. A seal member 22 is provided along the axial direction at the tip of each blade 18 and the tip of the protrusion 21, and the blade 18 and the bottom wall 20 of the recess 19 protrude from these seal members 22. The space between the outer peripheral surface of the portion 21 and the boss portion 17 is liquid-tightly sealed.

  Further, the base portion 15a of the annular housing 15 fixed to the inner peripheral rotor 6 is formed in a cylindrical shape having a constant thickness, and for example, as shown in FIG. On the other hand, it protrudes outward in the axial direction. Each end projecting outward of the base portion 15a is slidably held in an annular guide groove 16a formed in the drive plate 16, and the annular housing 15 and the inner peripheral rotor 6 are connected to the outer peripheral rotor. 5 and the rotating shaft 4 are supported in a floating state.

  The drive plates 16 and 16 on both sides connecting the outer rotor 5 and the vane rotor 14 are slidably in close contact with both side surfaces (both end surfaces in the axial direction) of the annular housing 15, and the side of each recess 19 of the annular housing 15. Respectively. Therefore, each recessed part 19 forms the independent space part by the boss | hub part 17 of the vane rotor 14, and the drive plates 16 and 16 of both sides, and this space part is the introduction space 23 into which a hydraulic fluid is introduce | transduced. Each introduction space 23 is divided into two chambers by corresponding vane portions 18 of the vane rotor 14, one chamber being an advance side working chamber 24 and the other chamber being a retard side working chamber 25. .

  The advance side working chamber 24 rotates the inner circumferential side rotor 6 relative to the outer circumferential side rotor 5 in the advance direction by the pressure of the working fluid introduced inside, and the retard side working chamber 25 is The inner rotor 6 is rotated relative to the outer rotor 5 in the retard direction by the pressure of the working fluid introduced therein. In this case, “advance angle” means that the inner rotor 6 is advanced in the rotation direction of the electric motor 1 indicated by the arrow R in FIGS. 2 and 3 with respect to the outer rotor 5. “Angle” means that the inner rotor 6 is advanced to the opposite side of the rotation direction R of the electric motor 1 with respect to the outer rotor 5.

  Further, the supply and discharge of the hydraulic fluid to and from each of the advance side working chambers 24 and the retard side working chambers 25 is performed through the rotating shaft 4. Specifically, the advance side working chamber 24 is connected to, for example, the advance side supply / discharge passage 26 of the hydraulic control device 13 shown in FIG. 7, and the retard side working chamber 25 is connected to the retard side of the hydraulic control device 13. It is connected to the supply / discharge passage 27. Further, a part of the advance side supply / exhaust passage 26 and the retard side supply / exhaust passage 27 are constituted by passage holes 26a, 27a formed along the axial direction of the rotary shaft 4 as shown in FIG. 1, for example. Has been.

  The end portions of the passage holes 26a and 27a are respectively connected to an annular groove 26b and an annular groove 27b formed at two positions offset in the axial direction of the outer peripheral surface of the rotary shaft 4, and the respective annular grooves 26b and 27b. Are connected to a plurality of conduction holes 26c, ..., 26c, 27c, ..., 27c formed in the boss portion 17 of the vane rotor 14 along the substantially radial direction. Each conduction hole 26c of the advance side supply / discharge passage 26 connects the annular groove 26b and each advance side working chamber 24, and each conduction hole 27c of the retard side supply / exhaust passage 27 connects to the annular groove 27b and each retard side. The working chamber 25 is connected.

  In the electric motor 1 of this embodiment, when the inner circumferential rotor 6 is at the most retarded position with respect to the outer circumferential rotor 5, the permanent magnets 9a of the outer circumferential rotor 5 and the inner circumferential rotor 6 are provided. 9b is opposed to the different poles and is in a strong field state (see, for example, FIG. 2 and FIG. 4A), and the inner circumferential rotor 6 is at the most advanced angle position with respect to the outer circumferential rotor 5. In some cases, the permanent magnets 9a, 9b of the outer rotor 5 and the inner rotor 6 face each other with the same poles and are in a field-weakening state (see, for example, FIGS. 3 and 4B). Is set to

  The electric motor 1 can arbitrarily change the state of the strong field and the state of the weak field by controlling the supply and discharge of the hydraulic fluid to the advance side working chamber 24 and the retard side working chamber 25. When the strength of the magnetic field is changed in this way, the induced voltage constant Ke changes accordingly, and as a result, the characteristics of the electric motor 1 are changed. That is, when the induced voltage constant Ke increases due to the strong field, the allowable rotational speed at which the motor 1 can operate decreases, but the maximum torque that can be output increases, and conversely, the induced voltage constant Ke decreases due to the weak field. Then, although the maximum torque that can be output from the electric motor 1 decreases, the allowable rotational speed at which the motor 1 can operate increases.

  For example, as shown in FIG. 7, the hydraulic control device 13 includes an electric oil pump (EOP) 32 that sucks up hydraulic fluid from an oil tank (not shown) and discharges the hydraulic fluid into a passage, and the hydraulic fluid discharged from the oil pump 32. Is adjusted and introduced into the high-pressure line passage 33, and the surplus hydraulic fluid is discharged to the low-pressure passage 34 for lubricating and cooling various devices, and the hydraulic fluid introduced into the line passage 33 Is switched to the advance-angle side supply / discharge passage 26 and the retard-angle side supply / discharge passage 27, and the flow path is switched to discharge unnecessary hydraulic fluid to the drain passage 36 through the advance-angle supply / discharge passage 26 and the retard-side supply / discharge passage 27. And a valve 37.

The regulator valve 35 receives the pressure of the line passage 33 as a control pressure, and distributes the hydraulic fluid according to the balance with the reaction force spring 38.
The flow path switching valve 37 has an electromagnetic solenoid 37b for advancing and retracting the control spool 37a, and this electromagnetic solenoid 37b is controlled by a control device (not shown).

  The rotor iron core 7 (rotor yoke) and the electric motor 1 of the outer peripheral rotor 5 according to the present embodiment have the above-described configuration. Next, a method for manufacturing the rotor iron core 7 (rotor yoke) will be described.

First, in the green compact forming process of step S01 shown in FIG. 8, for example, as shown in FIGS. 9A and 9B, either the soft magnetic material or the non-magnetic material is compression-molded and compressed. An annular inner yoke member 41 made of powder is formed, and either a soft magnetic material or a nonmagnetic material is compression-molded to form an annular outer yoke member 42 made of green compact.
The inner circumferential side yoke member 41 is provided with a concavo-convex part on the outer peripheral part, for example, a plurality of convex parts 41 a projecting radially outward. A fitting concave / convex portion 42a into which a fitting concave / convex portion to be fitted, for example, a convex portion 41a of the inner circumferential side yoke member 41 is fitted, is provided.

  Here, at a predetermined temperature (for example, a temperature of 912 ° C. or more) related to sintering diffusion bonding in a bonding process described later, the linear expansion coefficient of the inner peripheral side yoke member 41 is the linear expansion coefficient of the outer peripheral side yoke member 42. For example, the inner yoke member 41 is a green compact made of nonmagnetic material such as aluminum or copper, and the outer yoke member 42 is made of a soft magnetic material, for example. It is a green compact made of some pure iron-based sintered material.

  For example, as shown in FIG. 10, the circumferential width of the convex portion 41a of the inner circumferential yoke member 41 and the circumferential width of the fitting concave portion 42a of the outer circumferential yoke member 42 are from the radially inner side to the radially outer side. It is formed to gradually decrease as it goes to. Further, the inner diameter of the outer yoke member 42 has a predetermined allowance relative to the outer diameter of the inner yoke member 41, and the fitting recess 42a of the outer yoke member 42 has a width direction (that is, a circumferential direction). Has a predetermined allowance for the convex portion 41a of the inner peripheral side yoke member 41, and in the depth direction (that is, radial direction) than the length of the convex portion 41a of the inner peripheral side yoke member 41. It is formed slightly deep.

  Next, in the fitting step of step S02, the convex portion 41a of the inner circumferential side yoke member 41 is fitted into the fitting concave portion 42a of the outer circumferential side yoke member 42 so that the inner circumferential side is located inside the outer circumferential side yoke member 42. The side yoke member 41 is press-fitted to form a joined body 43 in which the inner circumferential side yoke member 41 and the outer circumferential side yoke member 42 are joined, for example, as shown in FIG.

  Next, in the joining step of step S03, the joined body 43 is subjected to a sintering process to diffuse atoms at the interface between the inner peripheral side yoke member 41 and the outer peripheral side yoke member 42 to ensure a desired joint strength. The temperature condition in this sintering process is appropriately set according to the material of the inner peripheral side yoke member 41 and the outer peripheral side yoke member 42, for example. Further, appropriate pressurization may be performed to promote diffusion.

  Next, in the excision step of step S04, the inner peripheral portion and the outer peripheral portion of the joined body 43 are excised by cutting or the like, for example, as shown in FIG. 9D, for example, the nonmagnetic material of the inner peripheral yoke member 41 7b and the soft magnetic material 7a of the outer yoke member 42 are alternately arranged in the circumferential direction, and the rotor has a predetermined relationship (a> b ≧ c) and a predetermined relationship (θ1 <θ2). An iron core 7 is formed.

As described above, according to the rotor iron core 7 (rotor yoke) according to the present embodiment, the soft magnetic material 7a and the non-magnetic material 7a that are alternately arranged in the circumferential direction are prevented while avoiding complicated labor and excessive costs. A desired bonding strength with the magnetic material 7b can be ensured, and the magnetic flux can be converged in a desired direction in the rorotor core 7 (rotor yoke), so that the leakage magnetic flux can be reduced.
Further, according to the method for manufacturing the rotor core 7 (rotor yoke) according to the present embodiment, a desired bonding strength is ensured with respect to the soft magnetic material 7a and the nonmagnetic material 7b arranged alternately in the circumferential direction. The rotor core 7 (rotor yoke) capable of converging the magnetic flux in a desired direction and reducing the leakage magnetic flux can be easily manufactured while preventing troublesome labor and excessive costs.

  Moreover, according to the electric motor 1 according to the present embodiment, the field magnetic flux of the permanent magnet 9b of the inner rotor 6 is converged in a desired direction in the rotor core 7 (rotor yoke) of the outer rotor 5. It is possible to reduce the leakage magnetic flux, to prevent the operable range with respect to the torque and the rotational speed of the electric motor 1 from being reduced, and to prevent the outer peripheral side rotor 5 and the inner peripheral side rotor 6 from It can prevent that the variable width of the induced voltage constant of the electric motor 1 accompanying changing a relative phase falls.

Furthermore, according to the electric motor 1 according to the present embodiment, the predetermined relationship (a> b ≧ c) and the predetermined relationship (θ1 <θ2) are set, so that the permanent magnet 9b of the inner circumferential rotor 6 The field magnetic flux can be efficiently linked to the permanent magnet 9a of the outer rotor 5.
On the other hand, for example, when the predetermined relationship (a> b ≧ c) or the predetermined relationship (θ1 <θ2) does not hold, the leakage magnetic flux increases or the field magnetic flux generated by the permanent magnet 9b of the inner circumferential rotor 6 is increased. The amount of field magnetic flux (linkage magnetic flux) that links the permanent magnets 9a of the outer rotor 5 decreases without being properly converged, and the outer rotor 5 and inner rotor 6 decrease. There is a possibility that the variable width of the induced voltage constant of the electric motor 1 accompanying the change of the relative phase with the motor may decrease.

  In the above-described embodiment, the joined body 43 is formed from the inner circumference side yoke member 41 and the outer circumference side yoke member 42 made of green compact. However, the present invention is not limited to this, and the inner circumference made of green compact is used. Either one of the side yoke member 41 and the outer peripheral side yoke member 42 is sintered to form a sintered body, and the sintered body and the inner peripheral side yoke member 41 and the outer peripheral side yoke member 42 made of a green compact are formed. The joined body 43 may be formed by either one.

In the above-described embodiment, the fitting recess 42a of the outer yoke member 42 is formed slightly deeper in the depth direction (that is, in the radial direction) than the length of the protrusion 41a of the inner yoke member 41. However, the present invention is not limited to this. For example, as shown in FIG. 11A, the depth of the fitting recess 42a may be approximately the same as the length of the protrusion 41a.
Further, in the above-described embodiment, the circumferential width of the convex portion 41a of the inner yoke member 41 is gradually decreased from the radially inner side to the radially outer side. For example, as shown in FIG. 11B, the circumferential width of the convex portion 41a may be unchanged in the radial direction.

In the above-described embodiment, for example, the inner yoke member 41 is a green compact made of nonmagnetic material such as aluminum or copper, and the outer yoke member 42 is pure iron that is a soft magnetic material, for example. However, the invention is not limited to this. For example, the inner circumferential side yoke member 41 is a green compact made of a pure iron-based sintered material that is a soft magnetic material. The side yoke member 42 may be a green compact made of austenitic stainless steel, which is a nonmagnetic material.
In this case, the linear expansion coefficient of the pure iron-based sintered material, which is a soft magnetic material, is austenite, which is a nonmagnetic material, at a predetermined temperature (for example, a temperature of 912 ° C. or higher) related to the sintering diffusion bonding in the bonding process. It has a value larger than the linear expansion coefficient of the stainless steel.

For example, as shown in FIGS. 12A and 12B, the circumferential width of the protrusion 41a of the inner yoke member 41 and the circumferential width of the fitting recess 42a of the outer yoke member 42 are radial. It is formed so as to gradually increase as it goes from the inside toward the outside in the radial direction.
Then, for example, a joined body 43 shown in FIG. 12C is formed by performing a fitting process and a joining process on the inner circumferential side yoke member 41 and the outer circumferential side yoke member 42, and this joined body. By performing the cutting process on 43, for example, the rotor core 7 in which the predetermined relationship (a> b ≧ c) and the predetermined relationship (θ1 <θ2) shown in FIG.

  In the embodiment described above, each permanent magnet 9a of the outer rotor 5 is disposed on the outer peripheral surface of each soft magnetic material 7a, and is formed on the outer peripheral surface of the nonmagnetic material 7b by, for example, filament winding. However, the present invention is not limited to this. For example, as shown in FIG. 13A, each permanent magnet 9a of the outer rotor 5 is softened by laser welding or the like. You may fix on the outer peripheral surface of the material 7a. For example, as shown in FIG. 13B, a magnet holding layer 70 made of, for example, a laminated steel plate and having a magnet mounting slot 70a is provided on the outer peripheral surface of the rotor core 7, and each magnet mounting slot 70a has a thickness. A plate-like permanent magnet 9a magnetized in the direction may be mounted.

  In the above-described embodiment, the inner rotor 6 is provided with the permanent magnet 9b mounted in the magnet mounting slot 8a. However, the present invention is not limited to this. For example, as shown in FIGS. In the inner rotor 6, the magnet mounting slot 8 a and the permanent magnet 9 b may be omitted.

  In this case, the permanent magnet 9a and the soft magnetic material 7a of the outer rotor 5 and the protrusion 8b of the inner rotor 6 are opposed to each other in the radial direction, so that the field of the entire rotor unit 3 is the strongest. The strong magnetic field state (see, for example, FIG. 14) can be obtained, and the nonmagnetic material 7b of the outer rotor 5 and the protrusion 8b of the inner rotor 6 are opposed to each other in the radial direction. Thus, it is possible to obtain a field weakening state (for example, see FIG. 15) in which the field of the entire rotor unit 3 is most weakened.

  In the above-described embodiment, the electric motor 1 is an inner rotor type. However, the electric motor 1 is not limited to this, and the electric motor 1 is an outer rotor type in which the rotor unit 3 is disposed on the outer peripheral side of the annular stator 2. Also good.

  In the above-described embodiment, the rotor unit 3 includes the outer peripheral side rotor 5 and the inner peripheral side rotor 6. However, the present invention is not limited to this, and for example, the inner peripheral side rotor 6 is omitted. Then, the induced voltage constant of the electric motor 1 may be fixed to a predetermined value.

It is principal part sectional drawing of the electric motor which concerns on embodiment of this invention. It is the side view which abbreviate | omitted some components of the rotor unit currently controlled by the most retarded angle position of the electric motor which concerns on embodiment of this invention. It is the side view which abbreviate | omitted some components of the rotor unit currently controlled by the most advanced angle position of the electric motor which concerns on embodiment of this invention. The figure (a) which shows typically the strong magnetic field state by which the permanent magnet of the inner peripheral side rotor of the electric motor which concerns on embodiment of this invention, and the permanent magnet of the outer peripheral side rotor are arrange | positioned with the same polarity, It is the figure which described collectively the figure (b) which shows typically the field-weakening state by which the permanent magnet of the side rotor and the permanent magnet of the outer peripheral side rotor were arrange | positioned differently. It is a principal part side view of the rotor unit of the electric motor which concerns on embodiment of this invention. It is a disassembled perspective view of the rotor unit of the traveling motor and electric power generation motor which concerns on embodiment of this invention. It is a block diagram of the hydraulic control apparatus which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing method of the rotor core (rotor yoke) of the outer peripheral side rotor which concerns on embodiment of this invention. Side views (a) and (b) showing the inner peripheral side yoke member and the outer peripheral side yoke member in the manufacturing process of the rotor core (rotor yoke) of the outer peripheral side rotor according to the embodiment of the present invention, and the joined body It is the figure which combined and described the side view (c) which shows, and the side view (d) which shows a rotor iron core. It is a principal part side view of the zygote concerning an embodiment of the invention. It is a principal part side view of the conjugate | zygote which concerns on the modification of embodiment of this invention. Side views (a) and (b) showing the inner peripheral side yoke member and the outer peripheral side yoke member in the manufacturing process of the rotor core (rotor yoke) of the outer peripheral side rotor according to the modification of the embodiment of the present invention; It is the figure which combined and described the side view (c) which shows a joined body, and the side view (d) which shows a rotor iron core. It is a principal part side view of the rotor unit of the electric motor which concerns on the modification of embodiment of this invention. It is the side view which abbreviate | omitted some components of the rotor unit controlled to the most retarded angle position of the electric motor which concerns on the modification of embodiment of this invention. It is the side view which abbreviate | omitted some components of the rotor unit currently controlled by the most advanced angle position of the electric motor which concerns on the modification of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric motor 5 Outer peripheral side rotor 6 Inner peripheral side rotor 7a Soft magnetic material 7b Nonmagnetic material 9a, 9b Permanent magnet 11 Rotating mechanism 12 Phase change means 41 Inner peripheral side yoke member 41a Convex part (uneven part)
42 Outer peripheral side yoke member 42a Fitting recess (fitting uneven portion)
43 joined body step S02 fitting process step S03 joining process step S04 excision process

Claims (5)

Either one is made of a soft magnetic material, and one of the other is made of a non-magnetic material.
The inner periphery side yoke member that is annular and has an uneven portion on the outer periphery, and the outer periphery side yoke member that is annular and has a fitting uneven portion that fits on the uneven portion on the inner periphery. In a state where the portion and the fitting uneven portion are fitted, a joined body is formed by sintering diffusion bonding,
A rotor yoke, wherein the soft magnetic material and the nonmagnetic material are formed by cutting away an inner peripheral portion and an outer peripheral portion of the joined body so that the soft magnetic material and the nonmagnetic material are alternately arranged in a circumferential direction. Either one is made of a soft magnetic material, and one of the other is made of a non-magnetic material.
The inner periphery side yoke member that is annular and has an uneven portion on the outer periphery, and the outer periphery side yoke member that is annular and has a fitting uneven portion that fits on the uneven portion on the inner periphery. A fitting step for fitting the part and the fitting uneven part,
A joining step of joining the inner circumferential side yoke member and the outer circumferential side yoke member by sintered diffusion bonding in a state where the concave and convex portions and the fitting concave and convex portion are fitted, and a joined body;
A method for manufacturing a rotor yoke, comprising: a cutting step of cutting an inner peripheral portion and an outer peripheral portion of the joined body so that the soft magnetic material and the nonmagnetic material are alternately arranged in a circumferential direction. The rotor yoke according to claim 1;
An electric motor comprising: a rotor including a plurality of permanent magnet pieces arranged in a circumferential direction on an inner peripheral side or an outer peripheral side of the rotor yoke. Outer peripheral side rotor provided with the permanent magnet piece at a position facing the soft magnetic material in the radial direction of the outer peripheral side of the rotor yoke;
An inner rotor having a plurality of permanent magnet pieces arranged coaxially and relative to the outer rotor and arranged in the circumferential direction;
The electric motor according to claim 3, further comprising phase changing means for changing a relative phase between the outer peripheral rotor and the inner peripheral rotor. The circumferential width a of the outer circumferential rotor on the outer circumferential side of the soft magnetic material, the circumferential width b of the inner circumference of the soft magnetic material, and the circumference of the magnet mounting protrusion of the inner circumferential rotor. A predetermined relationship (a> b ≧ c) is set with respect to the direction width c, and an angle θ1 formed by circumferential ends on the outer peripheral side of the soft magnetic material of the outer rotor on the center axis And an angle θ2 formed by a straight line including one end in the circumferential direction on the outer peripheral side and the inner peripheral side of the soft magnetic material of the outer rotor and a straight line including the other end (θ1) The motor according to claim 4, wherein <θ2) is set.

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