JP2007244062A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enlarge the operatable revolution range and torque range thereby improving the operation efficiency by making the constant of induced voltage easily and properly variable while suppressing the complication of the motor and also to enlarge the operatable revolution range with high efficiency. <P>SOLUTION: For the motor, its outer rotor 12 is composed of a peripheral rotor core 31 roughly in the shape of a bottomed cylinder which is equipped with a roughly plate-shaped bottom 31a having an axis coaxial with a rotating shaft O and a plurality of circumferential wall pieces 31b and 31b extending in its roughly axial direction from a position at a specified interval in its circumferential direction, at the peripheral end of the bottom 31a, a peripheral permanent magnet 12a roughly in the shape of a rectangular plate which is arranged on the peripheral face 31B of each peripheral wall piece 31b of the peripheral rotor core 31, a peripheral retaining member 32 roughly in the shape of a cylinder which has an internal peripheral face abutting on the peripheral face of each peripheral permanent magnet 12a, and a peripheral axial member 33. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to 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 the above prior art, for example, when controlling the phase difference between the first and second rotors according to the rotational speed of the electric motor, the centrifugal force according to the operating state of the electric motor, that is, the rotational speed is There is a problem in that the phase difference between the first and second rotors can be controlled only in the operating state, and the phase difference cannot be controlled at an appropriate timing including the stop state of the electric motor. In addition, when the electric motor is mounted on a vehicle as a drive source, etc., when the external vibration is likely to act on the electric motor, the phase difference between the first and second rotors is determined only by the centrifugal force. The problem is that it is difficult to control properly. In addition, in this case, since the phase difference is controlled regardless of the fluctuation of the power supply voltage at the power supply to the motor, for example, the magnitude relationship between the power supply voltage and the counter electromotive voltage of the motor is reversed. May occur.
For example, when the phase difference between the first and second rotors is controlled according to the speed of the rotating magnetic field generated in the stator, the rotating magnetic field speed is changed, which complicates the motor control process. Problem arises.
Further, when changing the induced voltage constant of the electric motor by controlling the phase difference between the first and second rotors, the permanent magnet provided in the first rotor and the permanent magnet provided in the second rotor It is desired to diversify the contents of field control by increasing the variable width of the induced voltage constant according to the relative distance between the two.

  The present invention has been made in view of the above circumstances, and by making the induced voltage constant variable easily and appropriately while suppressing the complexity of the electric motor, the operable rotation speed range and torque range are expanded. An object of the present invention is to provide an electric motor capable of improving the operation efficiency and expanding the operable range with high efficiency.

  In order to solve the above-described problems and achieve the object, an electric motor according to a first aspect of the present invention includes an inner peripheral side permanent magnet (for example, an inner peripheral side permanent magnet in the embodiment) arranged along the circumferential direction. An inner circumferential rotor (for example, inner circumferential rotor 11 in the embodiment) having a magnet 11a) and an outer peripheral permanent magnet (for example, outer circumferential permanent in the embodiment) arranged along the circumferential direction. The rotating shafts of the outer circumferential rotor (for example, the outer circumferential rotor 12 in the embodiment) having the magnet 12a) are arranged coaxially, and at least any of the inner circumferential rotor and the outer circumferential rotor Rotating means that can change the relative phase between the inner circumferential rotor and the outer circumferential rotor by rotating one of them around the rotation axis (for example, phase control in the embodiment) Device 15), wherein the outer peripheral rotor A bottom portion having a central axis coaxial with the rotation axis (for example, the bottom portion 31a in the embodiment), and a peripheral wall portion extending from the outer peripheral end of the bottom portion in a direction substantially parallel to the rotation axis (for example, the embodiment) , 31b), and the outer peripheral side permanent magnet is supported by the peripheral wall portion.

According to the electric motor having the above-described configuration, the outer circumferential rotor includes, for example, a bottom portion having a central axis that is coaxial with the rotating shaft by bending molding on a single member, and a direction substantially parallel to the rotating shaft from the outer peripheral end of the bottom portion. The outer peripheral side permanent magnet is supported on the peripheral wall portion (for example, fixed on the surface of the peripheral wall portion or accommodated in the inner portion of the peripheral wall portion). Thus, for example, the bottom and the peripheral wall are secured to each other while ensuring the desired rigidity as compared with the case where the bottom and the peripheral wall are separate and independent members that are connected by a fastening member or the like to form a substantially bottomed cylindrical shape. It is possible to prevent an increase in the thickness, particularly the radial thickness of the peripheral wall portion.
Thereby, it is suppressed that the distance between the outer peripheral side permanent magnet supported by the peripheral wall portion and the inner peripheral side permanent magnet of the inner peripheral side rotor is increased, and the variable width of the induced voltage constant is increased. be able to.

And, for example, in the field strengthening state by the field magnetic flux of the inner peripheral side permanent magnet with respect to the field magnetic flux of the outer peripheral side permanent magnet, the torque constant (that is, torque / phase current) of the motor is set to a relatively high value. The maximum torque value output by the motor can be reduced without reducing the current loss during motor operation or without changing the maximum output current of the inverter that controls the energization of the stator windings. The maximum value of the operating efficiency of the electric motor can be increased, and the high efficiency region where the operating efficiency is equal to or higher than the predetermined efficiency can be expanded.
In addition, the state change between the field strengthening state and the field weakening state can be set continuously, and the induced voltage constant of the motor can be continuously changed to an appropriate value. As a result, it is possible to continuously change the values of the rotational speed and torque at which the electric motor can be operated, and it is possible to expand the range of the rotational speed and torque at which the electric motor can be operated.

Furthermore, the electric motor of the invention described in claim 2 includes an output shaft member (for example, the outer peripheral side shaft member 33 in the embodiment) fixed integrally with the bottom portion, and the output shaft member is connected to the outer peripheral side. It is connected to an output shaft that outputs the driving force of the rotor to the outside.
According to the electric motor having the above configuration, by connecting the bottom portion to the output shaft via the output shaft member, the driving force of the outer peripheral rotor can be appropriately applied to the output shaft without the need to increase the thickness of the bottom portion itself. Desired rigidity required for transmission can be ensured.

Furthermore, the electric motor of the invention according to claim 3 is characterized in that the outer peripheral side permanent magnet is disposed on the surface of the peripheral wall portion (for example, the outer peripheral surface 31B in the embodiment).
According to the electric motor having the above-described configuration, the increase in the distance between the outer peripheral side permanent magnet and the inner peripheral side permanent magnet can be suppressed and induced while preventing the configuration of the outer peripheral side rotor from becoming complicated. The variable width of the voltage constant can be increased.

Furthermore, in the electric motor of the invention according to claim 4, the outer peripheral side permanent magnet arranged on the surface of the peripheral wall portion is sandwiched and held from both sides in the radial direction by the surface of the peripheral wall portion. The holding member (for example, the outer peripheral side holding member 32 in the embodiment) is provided.
According to the electric motor having the above configuration, it is possible to appropriately hold the outer peripheral side permanent magnet while preventing the configuration of the outer peripheral side rotor from becoming complicated.

Furthermore, in the electric motor of the invention according to claim 5, the peripheral wall portion includes a peripheral wall piece corresponding to each of the plurality of outer peripheral side permanent magnets (for example, the peripheral wall piece 31b in the embodiment), and a plurality of the The peripheral wall pieces are arranged at predetermined intervals in the circumferential direction.
According to the electric motor having the above configuration, a single outer peripheral permanent magnet is supported for each peripheral wall piece arranged at a predetermined interval in the circumferential direction. That is, since the slit is provided between the peripheral wall pieces adjacent in the circumferential direction, the peripheral wall portion can be easily formed by, for example, bending with respect to a single member.

Furthermore, in the electric motor of the invention described in claim 6, the peripheral wall piece is provided with a positioning portion (for example, the positioning protrusion 31c in the embodiment) with respect to the circumferential position of the outer peripheral permanent magnet. .
According to the electric motor having the above configuration, the outer peripheral side permanent magnet can be easily arranged at a predetermined position of the peripheral wall piece.

Furthermore, in the electric motor according to the seventh aspect of the invention, the peripheral wall portion has an axial distal end portion (for example, an axial distal end portion β in the embodiment) in a state where an external force is not acting, and an axial proximal end portion. (For example, axial base end portion α in the embodiment)
According to the electric motor having the above configuration, the displacement amount and stress in the radial direction of the holding member according to the centrifugal force acting on the peripheral wall portion and the outer peripheral permanent magnet when the outer peripheral rotor rotates are close to the outer peripheral end of the bottom portion. As it moves from the axially proximal end portion having a relatively high rigidity toward the axially distal end portion having a relatively low rigidity, it changes in an increasing tendency.
On the other hand, the peripheral wall portion is formed so as to incline radially inward as it extends from the axial base end portion toward the axial distal end portion, so that the peripheral wall portion is substantially press-fitted. The press-fit margin that the inner peripheral portion of the annular holding member has with respect to the peripheral wall portion changes in a decreasing tendency as it goes from the axial base end portion of the peripheral wall portion toward the axial distal end portion. As a result, the stress generated in the holding member when the peripheral wall portion is press-fitted is, for example, the state where the external wall is not pressed into the inner peripheral portion of the holding member and the peripheral wall portion is applied to the rotating shaft. Compared to the case where the peripheral wall portions are formed in parallel, they are larger on the axial base end side of the peripheral wall portion, and are smaller on the axial front end portion side of the peripheral wall portion.

In other words, the increase in the stress of the holding member, which changes in an increasing tendency due to the centrifugal force as it goes from the axial base end portion of the peripheral wall portion to the axial tip end portion, is caused by press-fitting. Can be set so that the axial distribution of the stress generated in the holding member becomes uniform when the outer circumferential rotor rotates. .
In this way, the axial distribution of the allowable stress on the holding member is set to be uniform by setting the axial distribution of the stress generated in the holding member to be in a uniform state, particularly at the maximum rotation of the outer rotor. Can be set so that the outer peripheral side permanent magnet supported by the peripheral wall at the time of maximum rotation of the outer peripheral side rotor is parallel to the rotation axis, and the outer peripheral side rotor ensuring desired rotational performance can be easily performed. Can be produced.

  Furthermore, in the electric motor according to an eighth aspect of the present invention, the holding member has an axial tip portion (for example, from the axial base end portion (for example, the axial base end portion α in the embodiment) side of the peripheral wall portion). In the embodiment, it is characterized in that the radial thickness changes so as to increase as it extends toward the axial front end β).

According to the electric motor having the above-described configuration, the axial distribution of the rigidity of the peripheral wall portion is close to the outer peripheral end of the bottom portion, so that the axial distal end has a relatively low rigidity from the axial base end portion that has a relatively high rigidity. The thickness in the radial direction of the substantially annular holding member changes to an increasing tendency, that is, the axial distribution of the rigidity of the holding member changes to an increasing tendency with respect to the change toward the portion. By setting in this way, it is possible to set so that the axial distribution of the stress generated in the holding member during rotation of the outer circumferential rotor is uniform.
In this way, the axial distribution of the allowable stress on the holding member is set to be uniform by setting the axial distribution of the stress generated in the holding member to be in a uniform state, particularly at the maximum rotation of the outer rotor. Can be set so that the outer peripheral side permanent magnet supported by the peripheral wall at the time of maximum rotation of the outer peripheral side rotor is parallel to the rotation axis, and the outer peripheral side rotor ensuring desired rotational performance can be easily performed. Can be produced.

  Furthermore, the electric motor of the invention according to claim 9 includes an annular outer peripheral iron core (for example, an axial base end α in the embodiment) in which the outer peripheral permanent magnet is embedded, and the peripheral wall portion. Is press-fitted into the inner peripheral portion of the outer peripheral side iron core having an inner diameter having a predetermined tightening allowance with respect to the outer diameter of the outer peripheral portion of the peripheral wall portion, and is fixed in an interference-fitted state. It is said.

  According to the electric motor having the above configuration, the peripheral wall portion is press-fitted into the inner peripheral portion of the outer peripheral side iron core in which the outer peripheral side permanent magnet is embedded, thereby preventing the configuration of the outer peripheral side rotor from becoming complicated. On the other hand, the bottom part and the peripheral wall part formed in the substantially bottomed cylindrical shape and the outer peripheral rotor iron core can be integrally fixed in a state in which a desired rigidity is ensured.

  According to the electric motor of the invention described in claim 1, for example, compared with a case where the bottom and the peripheral wall are separate and independent members and are connected by a fastening member or the like to be formed into a substantially bottomed cylindrical shape. It is possible to prevent the thickness of the bottom portion and the peripheral wall portion, particularly the radial thickness of the peripheral wall portion, from increasing. Thereby, between the outer peripheral side permanent magnet supported on the peripheral wall part (for example, fixed on the surface of the peripheral wall part or accommodated in the peripheral wall part) and the inner peripheral side permanent magnet of the inner peripheral side rotor. Can be suppressed, and the variable width of the induced voltage constant can be increased.

Further, according to the electric motor of the invention described in claim 2, by connecting the bottom portion to the output shaft through the output shaft member, it is possible to drive the outer peripheral rotor without having to increase the thickness dimension of the bottom portion itself. The desired rigidity required for properly transmitting the force to the output shaft can be ensured.
Furthermore, according to the electric motor of the invention described in claim 3, the distance between the outer peripheral side permanent magnet and the inner peripheral side permanent magnet is increased while preventing the configuration of the outer peripheral side rotor from becoming complicated. And the variable width of the induced voltage constant can be increased.

Furthermore, according to the electric motor of the invention described in claim 4, the outer peripheral side permanent magnet can be appropriately held while preventing the configuration of the outer peripheral side rotor from becoming complicated.
Furthermore, according to the electric motor of the invention described in claim 5, since the so-called slit is provided between the peripheral wall pieces adjacent in the circumferential direction, the peripheral wall portion can be easily formed by, for example, bending a single member. can do.

Furthermore, according to the electric motor of the invention described in claim 6, the outer peripheral side permanent magnet can be easily arranged at a predetermined position of the peripheral wall piece.
Furthermore, according to the electric motor of the invention described in claim 7, an external force is applied to the peripheral wall portion so that the axial distribution of the stress acting on the holding member during the maximum rotation of the outer peripheral rotor becomes uniform. In such a state, the allowable stress on the holding member at the time of the maximum rotation of the outer circumferential rotor is formed by forming the tip end in the axial direction at a position shifted radially inward from the base end in the axial direction. Can be set in a uniform state, the outer peripheral side permanent magnet supported by the peripheral wall portion can be set to be parallel to the rotation axis, and the outer peripheral side rotor ensuring desired rotational performance Can be easily manufactured.

Furthermore, according to the electric motor of the invention described in claim 8, the axial distribution of the stress acting on the holding member at the time of the maximum rotation of the outer peripheral side rotor is uniform, and the holding member is fixed to the shaft of the peripheral wall portion. The axial distribution of the allowable stress on the holding member is set to a uniform state by forming the radial thickness to increase with the extension from the direction base end to the axial front end. The outer peripheral side permanent magnet supported by the peripheral wall portion can be set to be parallel to the rotation axis, and an outer peripheral side rotor that secures desired rotational performance can be easily manufactured.
Furthermore, according to the electric motor of the invention described in claim 9, the bottom portion formed in a substantially bottomed cylindrical shape while preventing the complication of the configuration of the outer peripheral rotor and ensuring the desired rigidity. And a surrounding wall part and an outer peripheral side rotor iron core can be fixed integrally.

Hereinafter, an embodiment of an electric motor of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 to 5, for example, the electric motor 10 according to the present embodiment includes substantially inner annular rotors 11 and outer circumferences each having permanent magnets 11 a and 12 a arranged along the circumferential direction. A side rotor 12, a stator (not shown) having a multi-phase stator winding (not shown) for generating a rotating magnetic field for rotating the inner circumference rotor 11 and the outer circumference rotor 12, and the inner circumference side A brushless DC motor including a phase control device 15 connected to the rotor 11 and the outer rotor 12 and controlling a relative phase between the inner rotor 11 and the outer rotor 12. For example, it is mounted on a vehicle such as a hybrid vehicle or an electric vehicle as a drive source, the output shaft of the electric motor 10 is connected to the input shaft of a transmission (not shown), and the driving force of the electric motor 10 is driven through the transmission. (Figure It is adapted to be transmitted substantially).

  When the driving force is transmitted from the driving wheel side to the electric motor 10 during deceleration of the vehicle, the electric motor 10 functions as a generator to generate a so-called regenerative braking force, and the kinetic energy of the vehicle body is converted into electric energy (regenerative energy). to recover. Further, for example, in a hybrid vehicle, the output shaft of the electric motor 10 is connected to a crankshaft of an internal combustion engine (not shown), and the electric motor 10 is used as a generator even when the output of the internal combustion engine is transmitted to the electric motor 10. Functions to generate power generation energy.

  The inner circumferential rotor 11 has a substantially cylindrical inner circumferential rotor core 21 formed by laminating electromagnetic steel sheets such as silicon steel plates, and an outer circumferential portion of the inner circumferential rotor core 21 with a predetermined interval in the circumferential direction. 11a, an inner peripheral side end face plates 22 and 22 having an annular plate shape, and an inner peripheral side shaft member 23. The inner peripheral side permanent magnets 11a,.

A plurality of inner peripheral magnet mounting portions 21a,..., 21a are provided at predetermined intervals in the circumferential direction on the outer peripheral portion of the inner peripheral rotor core 21, and the inner peripheral magnet mounting portions 21a adjacent to each other in the circumferential direction are provided. On the outer peripheral surface 21A of the inner rotor core 21 between 21a, a concave groove 21b extending in parallel with the rotation axis O of the electric motor 10 is formed.
The inner peripheral side magnet mounting portion 21a includes, for example, an inner peripheral side magnet mounting hole 24 penetrating in parallel to the rotation axis O. The inner peripheral side magnet mounting hole 24 is a cross section with respect to a direction (axial direction) parallel to the rotation axis O. However, the inner circumferential side permanent magnet is formed in a substantially rectangular shape having a substantially circumferential direction in the longitudinal direction and a substantially radial direction in the short direction. A magnet 11a is attached.

  The inner peripheral permanent magnet 11a mounted in the inner peripheral magnet mounting hole 24 is magnetized in the thickness direction (that is, the radial direction of the inner peripheral rotor 11), and is adjacent to each inner peripheral magnet mounting hole in the circumferential direction. The inner peripheral side permanent magnets 11a, 11a attached to the 24, 24 are set so that their magnetization directions are different from each other. That is, the inner peripheral side magnet mounting portion 21a to which the inner peripheral side permanent magnet 11a having the N pole on the outer peripheral side is mounted is attached to the inner peripheral side magnet mounting portion 21a to which the inner peripheral side permanent magnet 11a having the S pole on the outer peripheral side is mounted. The part 21a is adjacent in the circumferential direction via the concave groove 21b.

  The annular plate-like inner peripheral side end face plate 22 is, for example, slightly smaller than the outer diameter of the inner peripheral side rotor core 21 and from the inner peripheral surface of the inner peripheral side magnet mounting hole 24 of the inner peripheral side rotor core 21. The inner diameter of the inner peripheral side rotor core 21 is smaller than the inner peripheral surface of the inner peripheral side magnet mounting hole 24 and slightly larger than the inner diameter of the inner peripheral side rotor core 21. Then, it abuts on the axial end of the inner peripheral permanent magnet 11 a mounted in the inner peripheral magnet mounting hole 24 of the inner rotor core 21. That is, the inner peripheral side permanent magnet 11a is formed by the two inner peripheral end face plates 22 and 22 arranged so as to sandwich the inner peripheral side permanent magnet 11a mounted in the inner peripheral side magnet mounting hole 24 from both sides in the axial direction. Displacement along the axial direction is restricted.

  The inner peripheral side shaft member 23 is formed in, for example, a substantially bottomed cylindrical shape having an outer diameter slightly larger than the inner diameter of the inner peripheral portion of the inner peripheral side rotor core 21, and is formed on the inner peripheral portion of the inner peripheral side rotor core 21. It is press-fitted and fixed in an interference-fitted state. This inner peripheral side shaft member 23 is phase-controlled by inserting inner peripheral side fastening members 25 such as rivets and bolts into a plurality of inner peripheral side fastening holes 23a,..., 23a penetrating the bottom along the axial direction. By being fastened to the device 15, it is connected to the phase control device 15.

  The outer circumferential rotor 12 has a substantially plate-shaped bottom 31a having a central axis coaxial with the rotation axis O, and a plurality of axially extending axially ends from a circumferentially spaced position at the outer circumferential end of the bottom 31a. A substantially bottomed cylindrical outer rotor core 31 having peripheral wall pieces 31b, ..., 31b, and a substantially rectangular plate-shaped outer peripheral side disposed on the outer peripheral surface 31B of each peripheral wall piece 31b of the outer peripheral rotor core 31. A permanent magnet 12a, a substantially cylindrical outer peripheral holding member 32 having an inner peripheral surface in contact with the outer peripheral surface of each outer peripheral permanent magnet 12a, and an outer peripheral shaft member 33 are provided.

The outer rotor core 31 is formed in a substantially bottomed cylindrical shape by, for example, bending with respect to a single member.
In addition, positioning protrusions 31c and 31c are provided at both circumferential ends of each peripheral wall piece 31b so as to protrude radially outward from the outer peripheral surface 31B of the peripheral wall piece 31b. And the outer peripheral side permanent magnet 12a arrange | positioned on the outer peripheral surface 31B of the surrounding wall piece 31b is positioned so that it may be pinched | interposed from the both sides of the circumferential direction by the two positioning protrusions 31c and 31c of the surrounding wall piece 31b, and the circumferential direction Displacement along is restricted.

  The outer peripheral side permanent magnets 12a supported by the peripheral wall pieces 31b are magnetized in the thickness direction (that is, the radial direction of the outer peripheral rotor 12) and are supported by the peripheral wall pieces 31b and 31b adjacent in the circumferential direction. The permanent magnets 12a and 12a are set so that their magnetization directions are different from each other. That is, the peripheral wall piece 31b supporting the outer peripheral side permanent magnet 12a having the N pole on the outer peripheral side is provided with the slit 31d having a predetermined circumferential width on the peripheral wall piece 31b supporting the outer permanent magnet 12a having the S pole on the outer peripheral side. And are adjacent to each other in the circumferential direction.

And the outer peripheral side rotor core 31 which supports the outer peripheral side permanent magnet 12a by each peripheral wall piece 31b is the inner periphery of an internal diameter provided with a predetermined interference with respect to the outer diameter set by the outer peripheral surface of each outer peripheral side permanent magnet 12a. It is press-fitted into the inner peripheral portion of the outer peripheral side holding member 32 having a surface and is fixed in an interference-fitted state. Thereby, each outer peripheral side permanent magnet 12a is fixed by being sandwiched from both sides in the radial direction by the inner peripheral surface of the outer peripheral side holding member 32 and the outer peripheral surface 31B of each peripheral wall piece 31b.
In addition, the outer peripheral side holding member 32 is formed in a substantially cylindrical shape in which, for example, the radial thickness at an appropriate position in the axial direction has a predetermined uniform thickness.

  For example, as shown in the embodiment shown in FIG. 6, the outer circumferential rotor core 31 is held on the outer circumferential side in a state before being press-fitted into the inner circumferential portion of the outer circumferential holding member 32 (before press fitting), that is, in a natural state. While the inner diameter of the member 32 is formed to be uniform along the axial direction, each peripheral wall piece 31b extends from the axial base end portion α toward the axial front end portion β. The piece 31b is formed so as to incline inward in the radial direction, and the axial distal end β of each peripheral wall piece 31b is disposed at a position shifted radially inward from the axial base end α.

That is, before press-fitting, the outer diameter set by the outer peripheral surface of each peripheral wall piece 31b of the outer peripheral rotor core 31 is directed from the axial base end portion α of each peripheral wall piece 31b toward the axial front end portion β. It is set in a tapered shape that changes in a decreasing trend.
Thereby, the tightening margin which the internal diameter of the inner peripheral part of the outer peripheral side holding member 32 has with respect to the outer diameter set by the outer peripheral surface of the outer peripheral side permanent magnet 12a supported by each peripheral wall piece 31b of the outer peripheral side rotor iron core 31. Is changed to a decreasing tendency as it goes from the axial base end α to the axial tip β of each peripheral wall piece 31b.

  In the state after the outer peripheral rotor core 31 is press-fitted into the inner peripheral portion of the outer peripheral holding member 32 (after press-fitting), for example, each peripheral wall piece 31b is in the axial direction as in the comparative example shown in FIG. The stress generated in the outer peripheral holding member 32 due to the press-fitting is larger at the axial base end portion α of each peripheral wall piece 31b than in the case where the peripheral wall pieces are set to be parallel to each other. It becomes smaller at the axial front end β of 31b.

  When the outer peripheral rotor 12 rotates, the radial displacement amount and stress of the outer peripheral holding member 32 according to the centrifugal force acting on each peripheral wall piece 31 b are the outer periphery of the bottom 31 a of the outer rotor core 31. Increasing tendency with increasing proximity to the end from the axial base end α of each peripheral wall piece 31b having relatively high rigidity toward the axial front end β of each peripheral wall piece 31b having relatively low rigidity To change.

At this time, with respect to the maximum rotation of the outer rotor 12, the peripheral wall pieces 31b are set so as to be parallel to the axial direction as in the comparative example shown in FIG. Even if the distribution along the axial direction of the stress of the outer peripheral holding member 32 obtained by adding the stress according to the pressure and the stress according to the press-fitting is not uniform, each peripheral wall as in the embodiment Press-fitting is performed so as to cancel out the increase in stress of the outer peripheral holding member 32 that changes in an increasing tendency due to centrifugal force as it goes from the axial base end α to the axial tip β of the piece 31b. It is possible to set a decrease in the stress of the outer peripheral side holding member 32 that changes in a decreasing tendency due to the rotation of the outer peripheral side holding member 32 during rotation of the outer peripheral side rotor 12, particularly at the maximum rotation. The axial distribution can be set to be uniform it can.
Thereby, at the time of the maximum rotation of the outer peripheral side rotor 12, the outer peripheral side holding member 32, each peripheral wall piece 31b, and the outer peripheral side permanent magnet 12a can be set to be parallel to the axial direction. The axial distribution of the allowable stress with respect to the outer peripheral holding member 32 at the time of the maximum rotation can be set to a uniform state.

  For example, as shown in FIG. 7, the centrifugal force acting on each peripheral wall piece 31b changes according to the rotational speed ω, the mass m, and the radius r, so that, for example, as in the comparative example shown in FIG. In the case where each peripheral wall piece 31b is set to be parallel to the axial direction, for example, as shown in FIG. 8, the axial direction of the centrifugal force acting on each peripheral wall piece 31b and the outer peripheral side permanent magnet 12a The distribution is uniform. However, as the rigidity of each peripheral wall piece 31b moves from the axial base end portion α to the axial front end portion β, the rigidity tends to decrease, the radial displacement of the outer peripheral holding member 32 due to centrifugal force. The axial distribution of the amount and stress changes in an increasing tendency as it goes from the axial base end α to the axial front end β of each peripheral wall piece 31b, resulting in a non-uniform state.

  The outer peripheral side shaft member 33 is formed, for example, in a substantially annular plate shape that is fixed integrally with the bottom 31a of the outer peripheral side rotor core 31, and an output shaft (not shown) that outputs the driving force of the outer peripheral side rotor 12 to the outside. It is connected to the. In addition, the outer peripheral side shaft member 33 is disposed, for example, inside a substantially bottomed cylindrical outer peripheral side rotor iron core 31, and has a plurality of outer peripheral side fastening holes 33a that penetrate the outer peripheral side shaft member 33 along the axial direction. , 33a and a plurality of outer peripheral side through holes 31e,..., 31e penetrating through the bottom 31a of the outer peripheral rotor core 31 so as to communicate with the outer peripheral side fastening holes 33a,. The outer peripheral side fastening member 34 such as a bolt is fastened to be connected to the phase control device 15.

The inner circumferential rotor 11 is disposed, for example, inside a substantially bottomed cylindrical outer rotor core 31, and the inner circumferential rotor 11 and the outer circumferential rotor 12 have a rotating shaft whose electric axis is the electric motor 10. It arrange | positions so that it may become coaxial with the rotating shaft O. And each inner peripheral side magnet mounting hole 24, ..., 24 of the inner peripheral side rotor 11 and each peripheral wall piece 31b, ..., 31b of the outer peripheral side rotor 12 are radial direction of each rotor 11,12. They are formed so that they can be arranged to face each other.
Thereby, the state of the electric motor 10 is changed between the inner peripheral side permanent magnet 11a of the inner peripheral side rotor 11 and the outer peripheral side according to the relative positions of the inner peripheral side rotor 11 and the outer peripheral side rotor 12 around the rotation axis O. From the field-weakening state in which the magnetic poles of the same polarity with the outer peripheral side permanent magnet 12a of the rotor 12 are arranged to face each other (that is, the inner peripheral side permanent magnet 11a and the outer peripheral side permanent magnet 12a are arranged as a counter electrode), The magnetic poles of different polarities of the inner peripheral permanent magnet 11a of the rotor 11 and the outer peripheral permanent magnet 12a of the outer rotor 12 are opposed to each other (that is, the inner peripheral permanent magnet 11a and the outer peripheral permanent magnet 12a are the same). It is possible to set an appropriate state over the strong field state that is pole-arranged.
In particular, in the weak field state and the strong field state, the long side of the inner peripheral permanent magnet 11a and the long side of the outer peripheral permanent magnet 12a are set to face each other in the cross section with respect to the axial direction.

  The phase control device 15 is disposed inside, for example, a substantially bottomed cylindrical inner peripheral shaft member 23, and at least one of the inner peripheral rotor 11 and the outer peripheral rotor 12 is electrically or hydraulically driven. An actuator that changes the relative phase between the inner circumferential rotor 11 and the outer circumferential rotor 12 by rotating around the rotation axis O is provided.

  The stator (not shown) is formed in, for example, a substantially cylindrical shape facing the outer periphery of the outer rotor 12 and is fixed to, for example, a vehicle transmission housing (not shown).

As described above, according to the electric motor 10 according to the present embodiment, the outer peripheral rotor 12 includes, for example, a bottom portion 31a having a central axis coaxial with the rotation axis O by bending molding of a single member, and the bottom portion. 31b is formed in a substantially bottomed cylindrical shape including a plurality of peripheral wall pieces 31b,..., 31b extending in a direction substantially parallel to the rotation axis O from the outer peripheral end of 31a, and the outer peripheral side permanent magnet 12a is supported by each peripheral wall piece 31b. Therefore, for example, the bottom 31a and each peripheral wall piece 31b are separate and independent members that are connected to each other by a fastening member or the like, and are formed into a substantially bottomed cylindrical shape, while ensuring a desired rigidity. The thickness of the bottom 31a and the peripheral wall piece 31b, particularly the radial thickness of the peripheral wall piece 31b, can be easily prevented from increasing.
Moreover, since the bottom 31a of the outer rotor core 31 is connected to the output shaft O via the outer shaft member 33, the driving force of the outer rotor 12 is not required without increasing the thickness of the bottom 31a itself. Can be ensured to have a desired rigidity required for properly transmitting to the output shaft O.
Thereby, it is suppressed that the distance between the outer peripheral side permanent magnet 12a supported by the peripheral wall piece 31b and the inner peripheral side permanent magnet 11a of the inner peripheral side rotor 11 is increased, and the induced voltage constant is variable. The width can be increased.

  Further, in the outer circumferential rotor 12, by providing a slit 31d having a predetermined circumferential width between the circumferential wall pieces 31b, 31b adjacent in the circumferential direction, the inner circumferential rotor 11 which is not in a mutually opposed relationship is provided. It is possible to suppress the occurrence of a short circuit between the magnetic poles of the peripheral permanent magnet 11a and the outer peripheral permanent magnet 12a of the outer rotor 12.

  Further, by providing the concave groove 21b having a relatively small magnetic permeability between the inner peripheral side permanent magnets 11a, 11a adjacent in the circumferential direction in the inner peripheral side rotor core 21, the inner peripheral side permanent magnets that are not in a mutually opposed relationship. Magnetic path short circuit between the magnetic poles of the magnet 11a and the outer peripheral permanent magnet 12a (for example, between the magnetic poles of the inner peripheral permanent magnet 11a and the outer peripheral permanent magnet 12a arranged so as to straddle the concave groove 21b). Can be prevented from occurring.

  Further, the axial distribution of the stress acting on the outer circumferential holding member 32 during the maximum rotation of the outer circumferential rotor 12 is made uniform, so that each circumferential wall piece 31b is axially distal with no external force acting. By forming the portion β to be disposed at a position shifted radially inward from the axial base end portion α, the allowable stress on the outer peripheral holding member 32 at the time of maximum rotation of the outer peripheral rotor 12 is increased. The axial distribution can be set to a uniform state, the outer peripheral permanent magnet 12a supported by each peripheral wall piece 31b can be set to be parallel to the rotation axis O, and the outer periphery ensuring desired rotational performance. The side rotor 12 can be easily manufactured.

  The inner rotor 11 and the outer rotor 12 are provided with substantially rectangular plate-like permanent magnets 11a, 12a along the circumferential direction, and the permanent magnets 11a, 12a are parallel to the rotation axis O. By setting so that the rotors 11 and 12 can be arranged so as to face each other along the radial direction of the rotors 11 and 12 in a cross section with respect to the direction, the magnetic fluxes of the permanent magnets 11a and 12a 21 and 31) can be suppressed. Thereby, generation | occurrence | production of an iron loss is suppressed, for example, the amount of interlinkage magnetic flux in which the field magnetic flux by the outer peripheral side permanent magnet 12a of the outer peripheral side rotor 12 is linked with the stator winding of a stator is changed to the inner peripheral side rotor. 11 can be efficiently increased or decreased by the field magnetic flux generated by the inner peripheral permanent magnet 11a. In the field-enhanced state, the torque constant (that is, torque / phase current) of the electric motor 10 can be set to a relatively high value without reducing the current loss during operation of the electric motor 10, or The maximum torque value output from the electric motor 10 can be increased without changing the maximum value of the output current of an inverter (not shown) that controls energization of the stator windings.

  In addition, the magnitude of the field magnetic flux interlinking the stator winding 13a can be continuously changed, and the induced voltage constant of the electric motor 10 can be continuously changed to an appropriate value. As a result, it is possible to continuously change the values of the rotational speed and torque at which the electric motor 10 can be operated, and it is possible to expand the range of the rotational speed and torque that can be operated. Furthermore, the maximum value of the operation efficiency of the electric motor 10 can be increased, and the high efficiency region where the operation efficiency is equal to or higher than the predetermined efficiency can be expanded.

  In the above-described embodiment, the outer peripheral side permanent magnet 12a is arranged on the outer peripheral surface 31B of the peripheral wall piece 31b. However, the present invention is not limited to this, for example, a magnet mounting that extends in the axial direction inside the peripheral wall piece 31b. It may be attached to the hole.

Further, in the above-described embodiment, the substantially cylindrical outer peripheral holding member 32 is formed so that the axial distribution of the radial thickness is uniform, but is not limited thereto, for example, As the thickness of each circumferential wall piece 31b extends from the axial base end α side toward the axial front end β side along the axial direction, the radial thickness changes in an increasing trend, that is, the rigidity increases. You may form so that it may change to a tendency.
In this modification, for example, as in the embodiment shown in FIG. 9, each peripheral wall piece 31b is pivoted in a state before being press-fitted into the inner peripheral portion of the outer peripheral holding member 32 (before press-fitting), that is, in a natural state. It is formed so as to be parallel to the direction.

  Then, in a state after the outer peripheral rotor core 31 is press-fitted into the inner peripheral portion of the outer peripheral holding member 32 (after press-fitting), for example, the radial thickness of the outer peripheral holding member 32 as in the comparative example shown in FIG. The stress generated in the outer peripheral holding member 32 due to the press-fitting as compared with the case where the thickness is formed to be a predetermined uniform thickness at an appropriate position along the direction parallel to the axial direction It becomes larger at the axial base end portion α of the piece 31b, and becomes smaller at the axial tip portion β of each peripheral wall piece 31b.

When the outer peripheral rotor 12 rotates, the radial displacement amount and stress of the outer peripheral holding member 32 according to the centrifugal force acting on each peripheral wall piece 31 b are the outer periphery of the bottom 31 a of the outer rotor core 31. Increasing tendency with increasing proximity to the end from the axial base end α of each peripheral wall piece 31b having relatively high rigidity toward the axial front end β of each peripheral wall piece 31b having relatively low rigidity To change.
At this time, with respect to the maximum rotation of the outer circumferential rotor 12, for example, as in the comparative example shown in FIG. 9, the radial thickness of the outer circumferential holding member 32 is a predetermined uniform at an appropriate position along the axial direction. When the axial distribution of the stress of the outer peripheral holding member 32 obtained by adding the stress according to the centrifugal force and the stress according to the press-fitting is set to be a thickness, the axial distribution is in a non-uniform state. However, as in the embodiment, the outer peripheral holding member 32 changes in an increasing tendency due to centrifugal force as it goes from the axial base end α to the axial front end β of each peripheral wall piece 31b. The amount of stress increase of the outer peripheral side holding member 32 that changes in a decreasing tendency due to press-fitting can be set so as to cancel out the increase in stress of the outer peripheral side. Axial amount of stress generated in the outer peripheral holding member 32 during rotation The cloth can be set to be in a uniform state.
Thereby, at the time of the maximum rotation of the outer peripheral side rotor 12, each peripheral wall piece 31b and the outer peripheral side permanent magnet 12a can be set to be parallel to the axial direction. The axial distribution of the allowable stress with respect to the outer peripheral holding member 32 can be set to a uniform state.

  In the above-described embodiment, each peripheral wall piece 31b is formed so as to be inclined inward in the radial direction as each peripheral wall piece 31b extends from the axial base end portion α toward the axial front end portion β. In addition, as the radial thickness of the outer peripheral holding member 32 changes in an increasing trend from the axial base end α side of each peripheral wall piece 31b toward the axial front end β side, that is, The rigidity is changed so as to increase, and the axial distribution of the stress generated in the outer peripheral holding member 32 is set to be uniform when the outer rotor 12 rotates, particularly at the maximum rotation. Also good.

In the above-described embodiment, the slit 31d is provided between the circumferential wall pieces 31b and 31b adjacent in the circumferential direction. However, the present invention is not limited to this. For example, the axial direction of the circumferential wall pieces 31b and 31b adjacent in the circumferential direction is provided. The tip portions β and β may be connected. That is, in this modified example, the outer peripheral rotor 12 includes a substantially plate-shaped bottom portion 31a having a central axis coaxial with the rotation axis O, and a cylindrical peripheral wall portion extending in a substantially axial direction from the outer peripheral end of the bottom portion 31a. And an elongated hole penetrating in the radial direction at a predetermined interval in the circumferential direction on the circumferential surface of the circumferential wall portion and extending from the axial proximal end portion toward the axial distal end portion, and adjacent in the circumferential direction The outer peripheral permanent magnet 12a is supported on the peripheral wall portion between the long holes.
Thereby, the rigidity in the axial direction front-end | tip part (beta) side of each surrounding wall piece 31b can be increased.

  In the above-described embodiment, the outer peripheral side permanent magnet 12a is disposed on the outer peripheral surface 31B of the peripheral wall piece 31b of the outer peripheral side rotor iron core 31. However, the present invention is not limited to this. , And a substantially cylindrical rotor core having an inner peripheral surface having an inner diameter with a predetermined allowance with respect to the outer diameter set by the outer peripheral surface 31B of each peripheral wall piece 31b, ..., 31b of the outer peripheral rotor core 31. , 12a are mounted at predetermined intervals in the circumferential direction on the inner peripheral portion of the rotor core, and the peripheral wall pieces 31b,..., 31b of the outer rotor core 31 are attached to the inner peripheral portion of the rotor core. May be press-fitted.

It is a principal part perspective view which decomposes | disassembles and shows the principal part of the inner peripheral side rotor of an electric motor which concerns on one Embodiment of this invention, and an outer peripheral side rotor. It is a principal part perspective view which decomposes | disassembles and shows the principal part of the inner peripheral side rotor of an electric motor which concerns on one Embodiment of this invention, and an outer peripheral side rotor. It is a principal part perspective view of the inner peripheral side rotor and outer peripheral side rotor of the electric motor which concerns on one Embodiment of this invention. It is a principal part perspective view of the inner peripheral side rotor and outer peripheral side rotor of the electric motor which concerns on one Embodiment of this invention. It is sectional drawing of the inner peripheral side rotor and outer peripheral side rotor of the electric motor which concerns on one Embodiment of this invention. An example of the axial direction distribution of the shape and displacement state of the outer peripheral side holding member and the peripheral wall piece and the stress of the outer peripheral side holding member in the example of the electric motor according to one embodiment of the present invention, and the outer peripheral side holding member in the comparative example, and It is a figure which shows an example of the axial direction distribution of the shape of a surrounding wall piece, a displacement state, and the stress of an outer peripheral side holding member. It is a graph which shows an example of the change according to the rotation speed (omega) of the electric motor of the centrifugal force which acts on the surrounding wall piece and outer peripheral side permanent magnet in the comparative example with respect to the electric motor which concerns on one Embodiment of this invention. The axial distribution of the rigidity of the peripheral wall piece in the comparative example for the electric motor according to the embodiment of the present invention, the axial distribution of the centrifugal force acting on the peripheral wall piece and the outer permanent magnet when the electric motor rotates, the peripheral wall piece and the outer peripheral It is a graph which shows each example of axial direction distribution of the radial direction displacement of the outer peripheral side holding member according to the centrifugal force which acts on a side permanent magnet, and axial direction distribution of the stress of an outer peripheral side holding member. An example of the axial direction distribution of the shape and displacement state of the outer peripheral holding member and the peripheral wall piece and the stress of the outer peripheral holding member in the example of the electric motor according to the modification of the embodiment of the present invention, and the outer peripheral side in the comparative example It is a figure which shows an example of the axial direction distribution of the shape of a holding member and a surrounding wall piece, a displacement state, and the stress of an outer peripheral side holding member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric motor 11 Inner peripheral side rotor 11a Inner peripheral side permanent magnet 12 Outer peripheral side rotor 12a Outer peripheral side permanent magnet 15 Phase control apparatus (rotating means)
31a Bottom part 31b Perimeter wall piece (peripheral wall part)
31B Outer peripheral surface (surface)
32 Outer peripheral side holding member (holding member)
33 Outer shaft member (Output shaft member)

Claims (9)

The rotation axes of the inner peripheral rotor having the inner peripheral permanent magnet arranged along the circumferential direction and the outer rotor having the outer permanent magnet arranged along the circumferential direction are coaxially arranged. The relative phase between the inner peripheral rotor and the outer peripheral rotor by rotating at least one of the inner peripheral rotor and the outer peripheral rotor about the rotation axis. An electric motor provided with rotating means capable of changing
The outer peripheral rotor is formed in a substantially bottomed cylindrical shape including a bottom portion having a central axis coaxial with the rotation shaft, and a peripheral wall portion extending in a direction substantially parallel to the rotation shaft from an outer peripheral end of the bottom portion. ,
The electric motor according to claim 1, wherein the outer peripheral permanent magnet is supported by the peripheral wall portion. An output shaft member fixed integrally with the bottom,
The electric motor according to claim 1, wherein the output shaft member is connected to an output shaft that outputs the driving force of the outer peripheral rotor to the outside. The electric motor according to claim 1, wherein the outer peripheral side permanent magnet is disposed on a surface of the peripheral wall portion. 4. A substantially annular holding member that holds the outer peripheral side permanent magnet disposed on the surface of the peripheral wall portion from both sides in the radial direction with the surface of the peripheral wall portion. The electric motor described in 1. The said surrounding wall part is provided with the surrounding wall piece corresponding to each said some said outer periphery side permanent magnet, The said some surrounding wall piece is arrange | positioned at predetermined intervals in the circumferential direction, The Claim 1 characterized by the above-mentioned. Item 5. The electric motor according to any one of Items 4. The electric motor according to claim 5, wherein the peripheral wall piece includes a positioning portion with respect to a circumferential position of the outer peripheral side permanent magnet. 5. The electric motor according to claim 4, wherein the peripheral wall portion is disposed at a position where an axial distal end portion is displaced radially inward from an axial proximal end portion when no external force is applied. . The holding member is formed such that the radial thickness changes in an increasing tendency as it extends from the axial base end side to the axial tip end side of the peripheral wall portion. The electric motor according to claim 4. The outer peripheral iron core includes an annular outer peripheral core embedded in the outer peripheral permanent magnet, and the peripheral wall portion has an inner diameter with a predetermined tightening margin with respect to an outer diameter of the outer peripheral portion of the peripheral wall portion. The electric motor according to claim 1, wherein the electric motor is fixed in a state of being press-fitted into an inner peripheral portion and being tightly fitted.

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