JP5384144B2 - Axial gap type motor - Google Patents

Description

  The present invention relates to an axial gap type motor in which a disk-shaped rotor and a stator are opposed to each other in the rotation center axis direction, and more particularly to a technique for making the gap of the motor variable.

  A so-called axial gap type motor in which a stator is opposed to a disk-type rotor with a gap interposed between end faces in the direction of the rotation center axis of the rotor is conventionally known. This motor obtains a rotational driving force by a magnetic force acting between the rotor and the stator facing each other in the axial direction of the rotation center. The axial gap type motor has an advantage that the thickness in the axial direction of the rotation center can be reduced as compared with a so-called radial type motor composed of a conventional cylindrical rotor and an annular stator surrounding the peripheral surface thereof.

In the permanent magnet synchronous motor, a counter electromotive force is generated in proportion to an increase in the motor rotation speed. When the counter electromotive force becomes higher than a voltage for rotationally driving the motor, the motor cannot be rotated at a higher speed.
Therefore, in order to suppress the counter electromotive force, a voltage is applied to the stator coil so as to generate a magnetic field for canceling the magnetic field that generates the counter electromotive force in addition to the magnetic field for driving the motor. This method is usually called field weakening control. This field weakening control makes it possible to rotate the motor at a higher speed.

  For example, it is used as a motor for driving a vehicle, and in a constant speed running state, the motor is required to rotate at a high speed and have a low output torque. In such a case, in order to be able to weaken the current for the field-weakening control described above, an axial that can suppress the field-weakening current by increasing the gap distance and weakening the magnetic field between the stator and the rotor. The technique of the gap type motor is disclosed in Patent Document 1.

Japanese Patent Laying-Open No. 2005-318718 (see FIG. 1)

However, in the technique described in Patent Document 1, a coil spring as an elastic member (corresponding to the position setting member in the present invention) that urges the rotor in a direction in which the gap in the rotation central axis direction between the stator and the rotor is enlarged, The structure arrange | positioned along the rotor shaft is shown by the inner peripheral part of a stator (refer patent document 1, FIG. 1), the internal diameter of the area | region where the core of a stator is arrange | positioned is made small, and a magnetic path effective in a torque When it is going to secure an area, the coil spring arrange | positioned at the inner peripheral part of the stator was the structure which restrains it.
In addition, the biasing force (elastic force) of the elastic member needs to be set according to the magnetic attractive force between the rotor and the stator. In the case of an axial gap type motor that generates a large torque, the magnetic attractive force also increases. Accordingly, an elastic member having a large biasing force (repulsive force) is required. In this case, when a coil spring is considered as the elastic member, it is necessary to increase the wire diameter of the coil spring and increase the outer diameter. If it does so, reducing the internal diameter of the area | region of the core arrange | positioned periodically in the circumferential direction of a stator will be restrict | limited more strongly.

  The present invention solves the above-described problems, and in an axial gap type motor capable of adjusting the gap between the axial gaps formed between the stator and the rotor, the diameter of the axial gap motor is increased while increasing the output torque. An object of the present invention is to provide an axial gap type motor capable of reducing the size in the direction.

In order to solve the above-mentioned problem, an axial gap type motor according to the first aspect of the present invention is a rotor arranged to be slidable on the outer periphery of a shaft that can rotate around the rotation center axis in the direction of the rotation center axis. And a stator that is disposed opposite to the rotor with a gap from one side in the direction of the rotation center axis, and is used as a core for winding a coil. Are arranged in the circumferential direction on the opposite surface of the magnet, are magnetized in the direction of the central axis of rotation, and have a plurality of permanent magnet portions arranged so that the magnetic poles adjacent to each other in the circumferential direction are reversed with each other, thereby widening the gap interval the position setting member for urging the rotor is disposed on the inner peripheral portion of the rotor along the rotation center axis direction, the position setting member comprises a pair of permanent magnets which is disposed to face the surfaces of the same pole And wherein the door.

Usually, the inner diameter of the region where the permanent magnet portion radially fixed to the rotor is arranged is larger than the inner diameter of the region including the stator core and the coil by the amount of the coil end of the stator. A space can be secured in the inner peripheral portion on the radially inner side.
According to the first aspect of the present invention, since the position setting member is disposed on the inner peripheral portion of the rotor, the core of the stator is expanded radially inward, and the diameter of the magnetic path is secured while ensuring a wider magnetic path area than in the past. It is possible to construct a variable gap axial gap type motor that is compact in direction and can expand and contract the gap in the direction of the rotation center axis.
Moreover, since the position setting member includes a pair of permanent magnets arranged so that the surfaces of the same magnetic pole face each other, for example, magnetic repulsion is generated by arranging the south poles or the north poles facing each other, The relationship between the gap interval and the urging force can be made nonlinear.
In particular, by combining a coil spring as a position setting member and a pair of permanent magnets with the same magnetic pole face facing each other, the relationship between the gap spacing and the urging force can be made nonlinear, especially the distance between the permanent magnets and the magnetic force. From the repulsive force characteristic, the biasing force of the position setting member can be abruptly increased as the gap interval approaches the minimum. Thus, even when the attractive force due to the current applied to the permanent magnet portion of the rotor and the coil of the stator is strong, the gap interval can be maintained larger than the minimum value.
In particular, as a position setting member, by combining a stack of piezoelectric elements and a pair of permanent magnets with the same magnetic pole face facing each other, the relationship between the gap spacing and the urging force is made nonlinear, especially between the permanent magnets. From the characteristics of the distance and the magnetic repulsive force, the biasing force of the position setting member can be abruptly increased as the gap interval approaches the minimum. Further, by using a combination of piezoelectric elements, the gap between the rotor and the stator can be arbitrarily controlled by the voltage applied to the piezoelectric elements.

An axial gap type motor according to a second aspect of the present invention includes a rotor disposed on an outer periphery of a shaft that is rotatable around a rotation center axis so as to be slidable in the direction of the rotation center axis; An axial gap type motor including a stator and a stator that is used as a core for winding a coil, and is opposed to the rotor with a gap from one side, and the rotor is disposed in a circumferential direction on a surface facing the stator. Arranged and magnetized in the direction of the rotation center axis, and has a plurality of permanent magnet portions arranged so that the magnetic poles adjacent to each other in the circumferential direction are reversed to each other, and along the rotation center axis in the direction of expanding the gap interval A position setting member that biases the rotor is disposed on the inner peripheral portion of the rotor, and the shaft has a position setting support portion that is radially outwardly expanded to support the setting member on the outer peripheral surface thereof. Shi The rotor has an annular and bottomed position setting member arrangement chamber that opens in a surface facing the stator and extends in the direction of the rotation center axis on the inner circumferential side of the region where the permanent magnet portions are arranged in the circumferential direction, The position setting member is a pair of permanent magnets, one of the permanent magnets is fixed to the position setting member arrangement chamber, and the other magnetic pole is opposed to the surface of the position setting support portion facing the rotor. The urging force is applied to the rotor by fixing to the rotor.

According to the second aspect of the present invention, the position setting member disposition chamber is disposed on the inner peripheral side of the region where the permanent magnet portions are arranged in the circumferential direction, and one of the pair of permanent magnets is Fixed to the position setting member placement chamber, and the other permanent magnet is fixed to the surface facing the rotor of the position setting support portion so that the same magnetic pole faces, so the stator core is expanded radially inward, It is possible to configure a variable gap axial gap type motor that is compact in the radial direction and can expand and contract the gap in the direction of the rotation center axis while securing a wider magnetic path area.

In addition to the configuration of the invention described in claim 2 , the axial gap type motor according to the invention described in claim 3 includes a surface where the edge of the opening of the position setting member arrangement chamber faces the rotor of the position setting support part. It arrange | positions so that contact | abutting is possible, and the space | interval of a rotor and a stator is prescribed | regulated to the minimum space | interval, when the edge part of opening and the surface which opposes the rotor of a position setting support part contact | abut.

According to the third aspect of the present invention, the edge of the opening of the position setting member disposition chamber is disposed so as to be able to contact the surface of the position setting support portion facing the rotor, and the edge of the opening and the position setting support portion Since the gap between the rotor and the surface facing the rotor is in contact with the rotor, the gap between the rotor and the stator is defined as a minimum distance, so that contact between the rotor and the stator can be prevented.

According to a fourth aspect of the present invention, in addition to the configuration of the second aspect of the invention, the first gap magnet is press-fitted into the position setting member disposition chamber in the first permanent magnet. The other permanent magnet is inserted into an annular position setting member disposition groove formed so as to open on the surface facing the rotor of the position setting support portion, and then the second collar is positioned. It is characterized by being press-fitted into the member arrangement groove and fixed.

According to the invention described in claim 4 , since the pair of permanent magnets can be fixed by the first and second collars, the permanent magnets can be fixed securely.

The axial gap type motor according to a fifth aspect of the present invention is the axial gap motor according to any one of the first to fourth aspects, in addition to the configuration according to any one of the first to fourth aspects. As described above, a stopper is provided so as not to leave the stator.

According to the fifth aspect of the present invention, it can be prevented that the magnetic attractive force is not generated between the rotor and the stator due to the biasing force of the position setting member causing the rotor and the stator to be separated from each other in the direction of the rotation center axis. Strong field control becomes possible.

  According to the present invention, while further increasing the biasing force of the position setting member that can adjust the space between the gaps in the rotation center axis direction formed between the opposing surfaces of the stator and the rotor, the stator core and the rotor It is possible to provide an axial gap type motor with a large output torque that can reduce the size in the radial direction while securing the magnetic path area.

It is a schematic cross section of the axial gap type motor which concerns on the 1st Embodiment of this invention. It is explanatory drawing of control of the space | gap space | interval in 1st Embodiment. FIG. 2 schematically shows the upper half of the rotation center axis L of the rotor and stator in FIG. 1, and (a) controls the energization of the field current so that the magnetic attractive force between the rotor and the stator is increased. FIG. 6B is an explanatory diagram when the field current is energized and controlled so that the magnetic attractive force between the rotor and the stator is reduced. It is the A section enlarged view in FIG. 1 of the axial gap type motor which concerns on 2nd Embodiment. And curves X1 _B of the load characteristics of the elastic member in the second embodiment, during non-energization of the coil is the illustration of the characteristic curve of the magnetic attraction force F _M acting between the permanent magnet and the core of the stator of the rotor . 1. It is an A section enlarged view in FIG. 1 of the axial gap type motor in 3rd Embodiment, (a) is explanatory drawing at the time of using the cylindrical coil spring from which an axial pitch differs as an elastic member, (b) is elastic. It is explanatory drawing at the time of using a conical coil spring as a member. And curves X1 _C load characteristics of the elastic member in the third embodiment, during non-energization of the coil is an explanatory view of a curve of the magnetic attraction force F _M acting between the permanent magnet and the core of the stator of the rotor. The upper half of the rotation center axis L of the rotor and the stator in the axial gap type motors according to the second and third embodiments is schematically shown, and (a) is a gap interval when the coil is not energized. An explanatory view of the maximum state, (b) is an explanatory view of a state in which the magnetic attraction force between the rotor and the stator is increased to reduce the gap interval, and (c) is a magnetic force between the rotor and the stator according to torque control. It is explanatory drawing of the state balanced with the repulsive force of an elastic member with the attraction | suction force. It is explanatory drawing of the control method of the space | interval of the space | gap in the axial gap type motor which concerns on 2nd and 3rd embodiment. It is a schematic cross section of the axial gap type motor which concerns on the 4th Embodiment of this invention. It is the B section enlarged view in FIG. It is the B section enlarged view in Drawing 10 of an axial gap type motor concerning a modification of a 4th embodiment. It is a schematic cross section of the axial gap type motor which concerns on the 5th Embodiment of this invention. It is a schematic cross section of the axial gap type motor which concerns on the 6th Embodiment of this invention. (A), (b) is the C section enlarged view in FIG. 14 of the axial gap type motor which concerns on the modification of 6th Embodiment. It is a schematic cross section of the comparative example of the axial gap type motor which concerns on the 4th Embodiment of this invention. It is a schematic cross section of the comparative example of the axial gap type motor which concerns on the 1st Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<< First Embodiment >>
First, an axial gap type motor according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic cross-sectional view of an axial gap type motor according to the first embodiment of the present invention, and FIG. 2 is an explanatory diagram of the control of the gap interval in the axial gap type motor according to the first embodiment. .
The motor 100A in the present embodiment is an axial gap type motor, and is opposed to the stator 2 in which the core 2b and the coil 22 are arranged to constitute an electromagnet, and the stator 2 across the gap in the axial direction of the rotor shaft (shaft) 10. The rotor 1 has a permanent magnet (permanent magnet portion) 11 and is supported by the rotor shaft 10 so as to be slidable in the direction of the rotation center axis L (hereinafter referred to as “axial direction”), and the gap is axial. And an elastic member (position setting member) 3A for urging the rotor 1 in the direction of expanding to the center. Here, the elastic member 3A is constituted by a cylindrical coil spring having an equal pitch in the axial direction.
In Figure 1, shows the state of the minimum interval LG _min of air gap between the respective facing surfaces 101 and 103 of the rotor 1 and stator 2, showing a state position of maximum spacing of the gap by the phantom line in two-dot chain line.

With reference to FIG. 2, load characteristics indicating changes in the repulsive force (biasing force) F _S of the elastic member 3 </ b> A with respect to the gap LG of the elastic member 3 </ b> A, and when the coil 22 is not energized, the magnetic attraction force F _M will be described acting between the core 2b. In FIG. 2, the horizontal axis shows the distance LG (mm) of the gap, the vertical axis represents the repulsive force F _S of the elastic member 3A, the magnetic attractive force F _M.
Load characteristic showing a change in repulsive force F _S of the elastic member 3A for distance LG of voids in the motor 100A is linear as indicated by the straight line X1 _A in FIG. Then, at the time of non-energization of the coil 22, the magnetic attraction force F _M acting between the permanent magnet 11 and the core 2b of the stator 2, as shown by the curve X2 in Fig. 2, rapidly when the distance of the gap LG increases Attenuating non-linear. Here, intervals LG voids between the minimum distance LG _min and a maximum distance LG _max, i.e., is regulated as described later in a section DerutaLG.
Then, the spring constant (load characteristic) determined by the material, etc. of inner and wire of the wire diameter and coil spring of the coil spring constituting the elastic member 3A If distance LG of voids close to the minimum distance LG _min is the repulsive force F _S magnetic below than the suction force F _M, the interval of the gap LG increases, contrary to the repulsive force F _S is to exceed the magnetic attraction force F _M, i.e., the straight line X1 _a and curve X2 is set to cross.

Returning to FIG. 1, the detailed configuration of each part will be described.
The rotor 1 is mainly composed of a hub part 1a and a disk part 1b that is provided on the radially outer side of the hub part 1a and holds a plurality of permanent magnets 11 fixedly arranged in the circumferential direction according to the number of poles. ing. The hub portion 1 a has a substantially annular shape, and the inner peripheral side is engaged with the rotor shaft 10 by a detent means such as a spline engagement structure 51, whereby the hub portion 1 a is axial with respect to the rotor shaft 10. It is slidable in the direction and supported so as not to be relatively rotatable in the circumferential direction.

A number of permanent magnets 11 corresponding to the number of poles are fixedly arranged at equal intervals in the circumferential direction on the rotor core 42 of the disk portion 1b. At this time, specifically, the magnetic poles of the permanent magnet 11 facing the stator 2 are S poles, N poles, S poles, N poles,... And are arranged so as to be alternately reversed in the circumferential direction.
The permanent magnet 11 is embedded in, for example, a rotor core 42 made of a material with high magnetic permeability whose inner periphery is a void, and is fixed with the surface of the magnetic pole exposed to the stator 2 side. Then, a fixing member 40 having a screw hole is inserted into the fixing hole on the outer peripheral side of the hub portion 1 a communicating with the fixing member hole radially formed in the rotor core 42, and then the fixing ring 43 is inserted into the outer periphery of the rotor core 42. And the rotor core 42 is fixed to the hub portion 1a by being fastened and fixed to the screw hole with a screw 41.

  The stator 2 is provided with electromagnet segments each having a coil 22 wound around a fan-shaped core 2b when viewed from the axial end direction of the rotor shaft 10 in the circumferential direction so as to face the rotor 1 side. The back yoke portion 2a as a whole has a substantially annular shape. The stator 2 is supported by a motor case (not shown).

A bottomed annular position setting member arrangement chamber 35A opened to the stator 2 side is provided at a predetermined distance radially outward from the spline engagement structure 51 portion on the inner peripheral side of the hub portion 1a. . Further, a flange-shaped support portion (position setting support portion) 53A having a radially increased diameter for supporting one end of the elastic member 3A is provided on the outer peripheral surface of the rotor shaft 10 close to the stator 2 side. Is provided. The elastic member 3A is arranged with one end abutting on the bottom of the position setting member arrangement chamber 35A and the other end abutting on the support 53A.
The rotor shaft 10, the moving amount in the axial direction away from the stator 2 of the hub portion 1a, i.e., stopper 13 for regulating the maximum distance LG _max voids is fixedly disposed. The stopper 13 is arranged so as to abut on a stopper seat 33 provided on the spline engaging structure 51 on the opposite side of the stator 2 of the hub portion 1a.
The range in which the hub portion 1a can move in the axial direction is restricted by the stopper 13 and the support portion 53A.

Incidentally, the edges of the radially inner side of the opening of the position setting member disposing chamber 35A of the hub portion 1a, is brought into contact with the rotor 1 side surface of the support portion 53A described above, restricting the minimum interval LG _min void The abutting portion 31 is configured so that the rotor 1 and the stator 2 do not come into contact with each other. The abutting portion 31 is retracted in the axial direction opposite to the stator 2 side with respect to the opposing surface 101, and the surface on the rotor 1 side of the support portion 53A and the surface on the stator 2 side of the abutting portion 31 are in contact with each other. When contacting, the support portion 53A is configured to be included in the axial length of the hub portion 1a, and the axial length of the outer shape of the motor 100A can be shortened.

(Control method of gap interval)
Next, referring to FIG. 2 and FIG. 3, during the motor operation, the gap between the rotor 1 and the stator 2 is divided into two stages, that is, according to the minimum gap LG _min and the current flowing through the coil 22 of the stator 2. A method of controlling in two steps, the gap between the generated magnetic attraction force between the rotor 1 and the stator 2 and the biasing force of the elastic member 3A, will be described.

FIG. 3 schematically shows the upper half of the rotation center axis L of the rotor 1 and the stator 2 in FIG. 1, and (a) shows the field current so that the magnetic attractive force between the rotor and the stator is increased. FIG. 4B is an explanatory diagram when the field current is energized and controlled so that the magnetic attractive force between the rotor and the stator is reduced.
The field magnetic flux Φa generated in the core 2 b of the stator 2 is determined by the field current Ia flowing through the coil 22. The field current Ia is expressed as a vector Ia = [Id, Iq] ^T. Here, Id represents a d-axis current component, and Iq represents a q-axis current component. The current phase difference β is a phase difference between the field current Ia and the rotating magnetic field Φa that generate the rotating magnetic field Φa, and the q axis.

It is assumed that the field current Ia has a d-axis current component with a current phase difference β of 90 °, that is, a strong field current component. In other words, in addition to the magnetic flux B _M to form the permanent magnet 11, In addition, the stator flux B _S which is formed by the d-axis current component of the field current Ia flowing through the coil 22, so that increases further the magnetic attraction force F _M to controlling the field current Ia, the rotor 1 and the magnetically attracting force F _M increases between the stator 2, if the interval of the gap LG is on the right side of the cross point of the straight line X1 _a and curve X2 in Fig. 2 even had, when a straight line X1 magnetic attraction force resultant force due to the rotor 1 of the electromagnet of the permanent magnet 11 and the stator 2 that exceeds the repulsive force F _S on the upper side of the _a F _M, points on the minimum distance LG _min void Move to P _Hi .

For example, even if the coil 22 of the motor 100A is in a non-energized state and the gap interval is at the position F _M2 of LG _max in FIG. 2, the stator 2 that exceeds the repulsive force F _S of the straight line X1 _A upwards. moving the suction force or by the electromagnet, when the suction force [Delta] F _C2 by the electromagnet of the stator 2 that exceeds the repulsive force F _S2 of the elastic member 3A applied, along a path Y1, the point P _Hi on minimum distance LG _min void To do. Here, when the above-described strong field current flowing through the coil 22 is stopped, the point moves to the point F _M1 . Here, the value of the magnetic attraction force F _M of the permanent magnet 11 even in a non-energized state to the coil 22 (F _M1), is greater than the value of the repulsive force F _S of the elastic member 3A (F _S1), then, The gap space LG maintains LG _min .

It is assumed that the field current Ia has a d-axis current component whose current phase difference β is an advance angle of 90 °, that is, a large field weakening current component. In other words, when the field current Ia is controlled so that the stator magnetic flux B _{S in the} direction opposite to the magnetic flux B _M formed by the permanent magnet 11 is formed by the d-axis current component of the field current Ia, the magnetic flux B _M is canceled out. , and the magnetic attraction force F _M is reduced between the rotor 1 and the stator 2, the void spacing LG is even had a position of minimum distance LG _min voids 2, the magnetic attraction force F _M of the curve X2 reducing by the electromagnet of the permanent magnet 11 and the stator 2 of the rotor 1 which exceeds the lower side to the magnetic attractive force F _M of the resultant force, along the path Y2 moves to the point P _LOW on maximum spacing LG _max voids.

2, the position of the cross point of the straight line X1 _A and curve X2 in any position beyond the right, if stopping the the weak field current flowing through the coil 22, the distance LG subsequent gap, the elastic member The repulsive force F _{S of} 3A and the magnetic attractive force F _M resulting from the synthesis of the stator magnetic flux B _S by the field current Ia flowing through the coil 22 and the magnetic flux B _M of the permanent magnet 11 are settled.

  According to the present embodiment, the permanent magnet 11 of the rotor 1 is disposed on the hub portion 1a radially inward from the disk portion 1b (region where the permanent magnet portions are arranged in the circumferential direction) arranged in the circumferential direction. Since the position setting member arrangement chamber 35A is arranged, and the elastic member 3A is arranged so as to contact the bottom of the position setting member arrangement chamber 35A and the surface of the support portion 53A facing the rotor 1, the core 2b of the stator 2 has a diameter. Axial gap type motor with variable gap that expands and reduces the axial gap in the radial direction while increasing the output torque and regenerative torque by widening inward in the direction and securing a larger magnetic path area than before. The motor 100A can be configured.

When the motor 100A of the present embodiment shown in FIG. 1 is compared with the axial gap type motor 150 of the comparative example shown in FIG. 17, the motor 150 of the comparative example has an annular region including the core 2b of the stator 2 and the coil 22. since the peripheral portion are disposed a spring 153 which is an elastic member, the inner circumference of the region the inner circumference of the area for arranging the core 2b in the circumferential direction to place D _2, and the core 2b in Figure 1 in the circumferential direction D ₁ has a smaller value. That is, according to the present embodiment, the motor can be made smaller in the radial direction than the comparative example.
Further, in the motor 150 of the comparative example, the winding diameter of the spring 153 is smaller than that of the coil spring of the elastic member 3A of the present embodiment because it is arranged on the inner peripheral portion of the stator 2, and the spring in the direction of expanding the gap interval. This is also a disadvantageous configuration for increasing the repulsive force (biasing force). In other words, the present embodiment is advantageous in increasing the spring repulsive force (biasing force) as compared with the comparative example of FIG.

Also, if the spring constant (load characteristic) gap spacing LG of the elastic member 3A close to the minimum distance LG _min is the repulsive force F _S is below than the magnetic attraction force F _M, the interval of the gap LG is increased, the reverse Since the repulsive force F _S exceeds the magnetic attractive force F _M , that is, the line X1 _A and the curve X2 are crossed, the motor operation is performed by the field weakening control or field strengthening control of the field current Ia. 2 stage distance LG of voids suitable condition, and the minimum distance LG _min, arbitrarily select one of the positions to be balanced and the magnetic attraction force F _M by synthesis of a magnetic flux B _M and the stator flux B _S of the permanent magnet 11 Can be set. As a result, when the required output torque or regenerative torque value is small, or when the rotational speed of the motor 100A is large and the field weakening current is reduced, the gap interval is positively made larger than the minimum gap. This makes it possible to operate the motor efficiently.

<< Second Embodiment >>
Next, an axial gap type motor according to a second embodiment of the present invention will be described with reference to FIG. 1, FIG. 4, and FIG.
The motor 100B in this embodiment is basically the same as the first embodiment except that the elastic member 3A in the first embodiment is replaced with an elastic member (position setting member) 3B, and the load characteristic curve of the elastic member 3B is changed. It is the same structure as embodiment. About the same structure as 1st Embodiment, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

FIG. 4 is an enlarged view of a portion A in FIG. 1 of the axial gap motor according to the second embodiment, and FIG. 5 shows a curve X1 _B of the load characteristic of the elastic member in the second embodiment, when not energized is an explanatory diagram of the characteristic curve of the magnetic attraction force F _M acting between the permanent magnet and the core of the stator of the rotor.
As shown in FIG. 4, the elastic member 3B in the present embodiment is configured by a multi-stage spring in which a plurality of coil springs 3B ₁ , 3B ₂ , 3B ₃ are stacked in series via annular plate members 46A, 46B. Then, assuming that the wire diameters of the coil springs 3B ₁ , 3B ₂ , 3B ₃ are d _B1 , d _B2 , d _B3 , the arrangement is d _B2 > d _B3 > d _B1 . This can be achieved by arranging those largest of the wire diameter in the axial direction center, in order to prevent buckling of the coil spring 3B _2.

Thus, by connecting a plurality of coil springs 3B ₁ , 3B ₂ , 3B ₃ having different spring constants in series, a broken line-shaped load characteristic as shown by a curve X1 _B in FIG. 5 is obtained. In the present embodiment, between a minimum distance LG _min and a maximum distance LG _max of gap spacing LG (ΔLG), curve linear X1 _A and the magnetic attraction force of the load characteristic as in the first embodiment X2 The spring constant is set so that the curve X1 _{B of the} load characteristic always exceeds the curve X2 of the magnetic attractive force without crossing.

<< Third Embodiment >>
Next, an axial gap type motor according to a third embodiment of the present invention will be described with reference to FIG. 1, FIG. 6, and FIG.
In the motor 100C in this embodiment, the elastic member 3A in the first embodiment is basically replaced with the elastic member (position setting member) 3C or the elastic member 3D, and the load characteristic curve of the elastic member 3B or the elastic member 3D is changed. Except for this point, the configuration is the same as that of the first embodiment. About the same structure as 1st Embodiment, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

FIG. 6 is an enlarged view of a portion A in FIG. 1 of the axial gap motor according to the third embodiment. FIG. 6A is an explanatory diagram when cylindrical coil springs having different axial pitches are used as elastic members. ) Is an explanatory diagram when a conical coil spring is used as an elastic member. Figure 7 is a curve X1 _C load characteristics of the elastic member in the third embodiment, during non-energization of the coil, the description of the curve of the magnetic attraction force F _M acting between the permanent magnet and the core of the stator of the rotor FIG.

The elastic member 3C according to the first example of the present embodiment is configured by a cylindrical coil spring having an unequal pitch in the axial direction as shown in FIG. Further, the elastic member 3D of the second example of the present embodiment is configured by a conical coil spring as shown in FIG. 6B.
In this way, by using a non-equal pitch cylindrical coil spring or a conical coil spring, a non-linear load characteristic as shown by a curve X1 _C in FIG. 7 can be obtained. In the present embodiment, between a minimum distance LG _min and a maximum distance LG _max of gap spacing LG (ΔLG), curve linear X1 _A and the magnetic attraction force of the load characteristic as in the first embodiment X2 The spring constant is set so that the curve X1 _{C of the} load characteristic always exceeds the curve X2 of the magnetic attractive force without crossing.

(Control method of gap space LG in the second and third embodiments)
Next, a method for controlling the gap gap LG in the second and third embodiments will be described with reference to FIGS. In this description, the elastic member 3D, that is, the motor 100C of the third embodiment using a conical coil spring is taken as an example, and the load characteristic curve X1 _C of the elastic member 3C will be described as an example.
FIG. 8 schematically shows the upper half of the rotation center axis L of the rotor and the stator in the axial gap type motors according to the second and third embodiments, and (a) shows when the coil is not energized. FIG. 6B is an explanatory diagram of a state in which the gap interval is maximum, FIG. 5B is an explanatory view of a state in which the magnetic attraction force between the rotor and the stator is increased to reduce the gap interval, and FIG. It is explanatory drawing of the state balanced with the repulsive force of an elastic member by the magnetic attraction force of a stator and a stator.
FIG. 9 is an explanatory diagram of a method for controlling the gap interval in the axial gap type motors according to the second and third embodiments.

In the motor 100C, the elastic repulsive force F _S of the member 3D load characteristics, within a tolerance ΔLG void spacing LG, than the value of the curve X2 of the magnetic attraction force F _M of the rotor 1 and the stator 2 in the non-energized since it exceeds, if you are driving the motor 100C is, and a repulsive force F _S and the magnetic attraction force F _M of the load characteristics of the elastic member 3D the distance LG of voids balance.
For example, when the rotor 1 is at the maximum gap LG _max , the point P ₁ in FIG. 9, and the gap LG is further reduced, the current phase difference β is retarded in the field current Ia as the moving current. The d-axis current component of 90 ° is increased (the state of moving current conduction in FIG. 8). That is, the strong field control is performed as the field current Ia having a strong field current component and close to the 90 ° delay angle, and the state is shifted to the point P ₂ (Step 1).
Then, since the magnetic attractive force F _M exceeds the repulsive force F _S, moves while increasing the magnetic attraction force in the upper left direction in FIG. 9 (Step2).
Incidentally, the left side of FIGS. 8A and 8B shows an initial state in which the rotor 1 has the maximum gap LG _max . And the state of above-mentioned Step1, Step2 is a figure of the left-right center in (a), (b) of FIG.

When the target gap interval LG (point P ₃ ) is reached, the current phase difference β added as the moving current decreases the d-axis current component with a delay of 90 ° to the original level, and the field current Ia is torqued. performing control to a suitable control (state of the torque current in FIG. 8) and (Step3), the magnetic attractive force F _M is balanced in the state of the repulsive force F _S and the torque current of the elastic member 3C, restless to the point P ₅ The gap LG is maintained at a value with good motor efficiency. When the coil 22 is de-energized, it returns to the point P ₁ .

If, in Step 2, the current phase difference β added as the moving current decreases the d-axis current component with the delay angle of 90 ° to the original level, the timing of the step 2 ′ is too long to reach the minimum interval LG _min of the point P _4. However, if the current phase difference β added as the moving current decreases the d-axis current component with the retard angle of 90 ° to the original level, the point P ₄ is settled along the path of Step 3 ′.
Incidentally, in the torque energized state, if you want the distance LG of voids of the rotor 1 and the stator 2 and the maximum distance LG _max, d-axis current component of the field current Ia 90 ° lead angle, that is, weakening of the current component by the field-weakening control more easily move to the lower right direction along the curve X1 _C, it can drive motor 100C to a maximum distance LG _max voids.

Thus, according to the motors 100B and 100C of the second and third embodiments, as in the first embodiment, the output torque and the regenerative torque are more compact in the radial direction than the comparative example as shown in FIG. An axial gap motor having a large gap gap LG can be configured.
Further, the load characteristics of the elastic members 3B, 3C, 3D can be made larger than that of the comparative example of FIG. 17 and can be made non-linear, and the above-described movement current control is temporarily performed for adjusting the gap interval. (D-axis current component control) is performed, and the torque can be arbitrarily moved to the gap LG having a high motor efficiency.

<< Fourth Embodiment >>
Next, an axial gap type motor 100D according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a schematic cross section of an axial gap type motor according to the fourth embodiment of the present invention, and FIG. 11 is an enlarged view of a portion B in FIG.
The motor 100D of this embodiment is different from the motor 100A of the first embodiment in the following points. (1) Instead of the elastic member 3A in the motor 100A of the first embodiment, a pair of permanent magnets (position setting members) 54 (54A, 54B) are opposed to the same magnetic pole, and the permanent magnet 54A is a position setting member. This is the point of fitting in the groove 56 provided in the arrangement chamber 35B and the support portion 53B.
The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The axial depth of the position setting member arrangement chamber 35B is shallower than the position setting member arrangement chamber 35A in the first embodiment, and the permanent magnet 54A of the pair of permanent magnets 54 is fitted, Further, a collar 55A (see FIG. 11) is press-fitted and fixed so as not to be loose in the radial direction and the axial direction. Further, on the outer peripheral surface of the rotor shaft 10, a flange-like support portion (position setting support portion) 53 </ b> B that is expanded radially outward is provided close to the stator 2 side. An annular groove 56 opened on the rotor 1 side surface is formed in the support portion 53B, the other permanent magnet 54B of the pair of permanent magnets 54 is fitted, and a collar 55B (see FIG. 11) is press-fitted, It is fixed so that there is no play in the radial and axial directions.

Incidentally, the radially inner edge of the opening of the position setting member arrangement chamber 35B of the hub portion 1a is brought into contact with the radially inner edge of the opening facing the groove 56 of the support portion 53B. The abutting portion 31 that regulates the minimum gap LG _min is set so that the rotor 1 and the stator 2 do not come into contact with each other.
In the present embodiment, the axial thickness of the flange-shaped support portion 53B is thicker than that of the flange-shaped support portion 53A of the first embodiment, and the abutment portion 31 is correspondingly larger than the opposing surface 101 in the stator 2. When the surface on the rotor 1 side of the support portion 53B and the surface on the stator 2 side of the abutment portion 31 abut on each other, the support portion 53B moves in the axial direction of the hub portion 1a. It is comprised so that it may be included in length, and it is set as the structure which can shorten the axial direction length of the external shape of motor 100D.

Also with the pair of permanent magnets 54 in the present embodiment, the nonlinear load characteristic curve X1 _C shown in FIG. 7 can be realized.

(Modification of the fourth embodiment)
Next, a modification of the fourth embodiment will be described with reference to FIG. FIG. 12 is an enlarged view of a portion B in FIG. 10 of the axial gap motor according to the modification of the fourth embodiment.
The shape of the position setting member arrangement chamber 35B of the hub portion 1a and the shape of the support portion 53B are close in dimension to those of the first embodiment. That is, the axial length of the annular position setting member arrangement chamber 35B is as long as that of the first embodiment, the support portion 53B has a bowl shape, and the groove 56 has a shallow axial depth opened to the rotor 1 side. This is an annular groove.

In this modification, for example, one end of the elastic member 3A, which is a cylindrical coil spring having an equal pitch in the axial direction, abuts the bottom of the position setting member arrangement chamber 35B, and the other end has a U-shaped cross section that holds the permanent magnet 54A. It is welded to an annular metal retaining ring 54a. Then, the other permanent magnet 54B paired with the permanent magnet 54A is fitted and fixed in the groove 56 of the support portion 53B. Here, the combination of the elastic member 3 </ b> A and the pair of permanent magnets 54 corresponds to a “position setting member” recited in the claims.
Thus, by combining the elastic member 3A of the cylindrical coil spring and the pair of permanent magnets 54, the movable gap interval ΔLG can be expanded as compared with the case of only the pair of permanent magnets 54, and as shown in FIG. Non-linear load characteristics can be realized.

As described above, according to the motor 100D of the fourth embodiment and the modification thereof, as in the first embodiment, the output torque and the regenerative torque are smaller than those of the comparative example that is compact in the radial direction and shown in FIG. A large axial gap type motor having a variable gap LG can be constructed.
Further, the load characteristics of the pair of permanent magnets 54 or the combination of the elastic member 3A and the pair of permanent magnets 54 can be made larger than that of the comparative example of FIG. In order to adjust the interval, the above-described movement current control (d-axis current component control) can be temporarily performed, and the torque can be arbitrarily moved to the gap LG having good motor efficiency. In particular, by using a pair of permanent magnets 54, it is possible to have the increasing characteristic of the more rapidly repulsive force approaches a minimum distance LG _min of air gap position setting member.

  In this modification, the elastic member combined with the pair of permanent magnets 54 in the axial direction is the elastic member 3A that is a cylindrical coil spring having an equal pitch in the axial direction, but is not limited thereto. Instead of the elastic member 3 </ b> A, the elastic member 3 </ b> C of the non-equal pitch cylindrical coil or the elastic member 3 </ b> D which is a conical coil spring may be combined with the pair of permanent magnets 54 in the axial direction.

(Comparative example with respect to the fourth embodiment)
As a comparative example, as shown in FIG. 16, a pair of permanent magnets 54 </ b> A and 54 </ b> B may be disposed on the inner side of the substantially annular region including the core 2 b and the coil 22 of the stator 2. In this case, the diameter of the rotor shaft 10 is increased from the outer peripheral surface, the stepped portion is in contact with the abutting portion 31 of the rotor 1, the diameter is further increased, and the other permanent magnet can be accommodated to accommodate the permanent magnets 54A and 54B. A support portion 155B for fixing 54B is provided. In this case, one permanent magnet 54 </ b> A is fixed to a surface facing the stator 2 that is radially outward from the abutting portion 31 of the rotor 1.
Thus, since the pair of permanent magnets 54 is disposed on the inner side of the substantially annular region including the core 2b and the coil 22 of the stator 2, the inner periphery of the region where the core 2b in FIG. 10 is disposed in the circumferential direction. The diameter of D ₃ is smaller. That is, according to 4th Embodiment and its modification, it can be set as a motor smaller in a radial direction than the comparative example shown in FIG.

<< Fifth Embodiment >>
Next, an axial gap motor 100E according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 13 is a schematic cross section of an axial gap type motor according to a fifth embodiment of the present invention.
The motor 100E of this embodiment is different from the motor 100D of the fourth embodiment in the following points. (1) Instead of the pair of permanent magnets 54 in the motor 100D of the fourth embodiment, the permanent magnet 54A is arranged in the position setting member arrangement chamber 35B, and the electromagnet 57 is fitted in the groove 56 provided in the support portion 53B. Is a point.
Here, the permanent magnet 54A and the electromagnet 57 correspond to the “position setting member” described in the claims.
The same components as those in the fourth embodiment are denoted by the same reference numerals, and redundant description is omitted.

  A permanent magnet 54A is fitted in the position setting member arrangement chamber 35B, and a collar is press-fitted and fixed so that there is no backlash in the radial direction and the axial direction. In the annular groove 56, a plurality of electromagnets 57 wound around a coil 57a around a core 57b are fitted in the circumferential direction, and a collar is press-fitted so that there is no play in the radial and axial directions. A wiring hole 105 that obliquely penetrates from the bottom of the groove 56 to the inner peripheral side of the stator 2 is formed in the support portion 53B, and a wiring 58 covered with an insulation coating of a coil 57a is inserted. The wiring 58 is wired along the outer peripheral surface of the rotor shaft 10 along the axial direction, and is electrically connected to the slip rings 107A and 107B of the plus terminal and the minus terminal. Then, two sliders (not shown) can slide on the slip rings 107A and 107B to supply a direct current.

The non-linear load characteristic curve X1 _C shown in FIG. 7 can also be realized by controlling energization of the electromagnet 57 so that a repulsive force is generated between the permanent magnet 54A and the electromagnet 57 in the present embodiment. Further, it is not necessary to control the d-axis current component in order to control the gap gap LG, and simply controlling the energization current to the coil 57a of the electromagnet 57 makes it possible to control the gap with good motor efficiency in terms of torque control. It can be arbitrarily moved to the interval LG.

<< Sixth Embodiment >>
Next, an axial gap motor 100F according to a sixth embodiment of the present invention will be described with reference to FIG. FIG. 14 is a schematic cross section of an axial gap type motor according to a sixth embodiment of the present invention.
The motor 100F of this embodiment differs from the motor 100D of the fourth embodiment in the following points. (1) Instead of the pair of permanent magnets 54 in the motor 100D of the fourth embodiment, approximately half the axial length of the annular piezoelectric element stack (piezoelectric element) 59 is placed in the position setting member arrangement chamber 35C. This is the point where the remaining half of the axial length of the piezo element stack 59 is fitted into the groove 56 provided in the support portion 53C.
Here, the piezo element stack 59 corresponds to a “position setting member” recited in the claims.
The same components as those in the fourth embodiment are denoted by the same reference numerals, and redundant description is omitted.

The piezo element stack 59 is molded into an annular body, and is inserted into the hub portion 1a of the rotor 1 into the position setting member arrangement chamber 35C and the groove 56 that are deeper in the axial direction than the position setting member arrangement chamber 35B in the fourth embodiment. Is done. The support portion 53C has substantially the same shape as the support portion 53B in the fourth embodiment, but has a deeper groove 56 in the axial direction. A wiring hole 105 that obliquely penetrates from the bottom of the groove 56 to the inner peripheral side of the stator 2 is formed, and a wiring 58 covered with an insulation coating of a coil 57a is inserted. The wiring 58 is wired along the outer peripheral surface of the rotor shaft 10 along the axial direction, and is electrically connected to the slip rings 107A and 107B of the plus terminal and the minus terminal. Then, two sliders (not shown) can slide with the slip rings 107A and 107B to supply a DC voltage.
The piezo element stack 59 can adjust the gap LG by applying a voltage in both expansion and contraction directions.
FIG. 14 shows a state where the axial length of the piezo element stack 59 is reduced to the minimum length.

According to the present embodiment, by using the piezo element stack 59, the space between the rotor 1 and the stator 2 can be arbitrarily controlled by the voltage applied to the piezo element stack 59. The nonlinear load characteristic curve X1 _C shown in FIG. 7 can also be realized by the elongation force generated by the piezo element stack 59 in the present embodiment.
A magnetic attraction force between the rotor 1 and the stator 2 by the permanent magnet 11 always acts between the rotor 1 and the stator 2 regardless of whether the coil 22 is energized or not. A compressive force acts on the piezoelectric element stack 59, and even if a voltage for reducing the piezoelectric element stack 59 is applied, no tensile stress is generated in the piezoelectric element stack 59.

(Modification of the sixth embodiment)
Next, a modification of the sixth embodiment will be described with reference to FIG. (A), (b) of FIG. 15 is the C section enlarged view in FIG. 14 of the axial gap type motor which concerns on the modification of 6th Embodiment.
In the modification shown in FIG. 15A, for example, one end of the elastic member 3A, which is a cylindrical coil spring having an equal pitch in the axial direction, abuts the bottom of the position setting member arrangement chamber 35C, and the other end is the piezo element stack 59. Are welded to a ring-shaped metal seat plate 59a fixed to one end thereof. Then, almost the entire piezo element stack 59 is stored in the groove 56 of the support portion 53C, and the other end is fixed to the bottom portion. Here, the combination of the elastic member 3A and the piezo element stack 59 corresponds to the “position setting member” recited in the claims.
In this way, by combining the elastic member 3A of the cylindrical coil spring and the piezo element stack 59, the movable gap interval ΔLG can be expanded as compared with the case of the piezo element stack 59 alone, and a non-linearity as shown in FIG. Load characteristics can be realized.
Incidentally, the elastic member combined with the piezo element stack 59 is not limited to a cylindrical coil spring having an equal pitch in the axial direction, and may be a cylindrical coil spring or a conical coil spring having an unequal pitch in the axial direction.

In the modified example shown in FIG. 15B, one permanent magnet 54A of the annular permanent magnet 54 (54A, 54B) in which a pair of identical magnetic poles face each other is colored at the bottom of the position setting member arrangement chamber 35C. It is fixed by press-fitting 55A. The other permanent magnet 54B is welded to an annular metal seat plate 59a fixed to one end of an annular piezo element stack 59 fixed to one end of the permanent magnet 54B via a connecting member 59b. Then, almost the entire piezo element stack 59 is stored in the groove 56 of the support portion 53C, and the other end is fixed to the bottom portion. Here, the combination of the pair of permanent magnets 54 (54A, 54B) and the piezo element stack 59 corresponds to the “position setting member” recited in the claims.
By combining the pair of permanent magnets 54 and the piezo element stack 59 in this manner, the gap ΔLG between the movable air gaps can be increased as compared with the case of the piezo element stack 59 alone, and a non-linear load as shown in FIG. The characteristics can be realized.

As described above, according to the motor 100F of the sixth embodiment and the modification thereof, as in the first embodiment, the output torque and the regenerative torque are smaller than those of the comparative example that is compact in the radial direction and shown in FIG. A large axial gap type motor having a variable gap LG can be constructed.
Furthermore, the load characteristic of the combination of the elastic member and the piezo element stack 59 or the combination of the pair of permanent magnets 54 and the piezo element stack 59 can be made non-linear, and the d-axis current component can be adjusted to adjust the gap interval. By controlling the voltage applied to the piezo element stack 59 without performing the control, it can be arbitrarily moved to the gap LG having a good motor efficiency in terms of torque control.

  In addition, 1st Embodiment (refer FIG. 1), 2nd Embodiment (refer FIG. 4), 3rd Embodiment (refer FIG. 6), the modification (refer FIG. 12) of 4th Embodiment, 1st Instead of the elastic members 3A, 3B, 3C, 3D in the modification of the sixth embodiment (see FIG. 15A), a plurality of disc springs may be used in a stacked manner. Further, a part of the elastic members 3A, 3B, 3C, and 3D may be replaced with one or a plurality of stacked disc springs.

DESCRIPTION OF SYMBOLS 1 Rotor 1a Hub part 1b Disk part 2 Stator 2a Back yoke part 2b Core 3A, 3B, 3C, 3D Elastic member (position setting member)
3B ₁ , 3B ₂ , 3B ₃ coil spring 10 Rotor shaft (shaft)
11 Permanent magnet (permanent magnet part)
13 Stopper 22 Coil (Coil)
31 Abutting portion 33 Stopper seat 35A, 35B, 35C Position setting member arrangement chamber 40 Disc member 43 for fixing 43 Fixing ring 46A Plate material 51 Spline engagement structure 53A, 53B, 53C Support portion 54 A pair of permanent magnets 54A, 54B Permanent magnet 54a Metal retaining ring 55A, 55B collar 56 groove 57 electromagnet 57a coil 57b core 58 wiring 59 piezo element stack (piezoelectric element)
59a Metal seat plate 59b Connection member 100A, 100B, 100C, 100D, 100E, 100F Motor 101 Opposing surface (opposing surface of rotor)
103 Opposing surface (facing surface of stator)
105 Wiring hole 107A, 107B Slip ring L Rotation center axis

Claims (5)

On the outer periphery of the shaft that can rotate around the rotation center axis, the rotor arranged to be slidable in the direction of the rotation center axis, and arranged to face the rotor from one side in the direction of the rotation center axis, A stator used as a core for winding a coil, and an axial gap type motor comprising:
The rotor includes a plurality of permanent magnet portions arranged in a circumferential direction on a surface facing the stator, magnetized in the rotation central axis direction, and arranged so that magnetic poles adjacent to each other in the circumferential direction are reversed to each other. Have
A position setting member for urging the rotor along the rotation center axis in a direction in which the space between the gaps is enlarged is disposed on an inner peripheral portion of the rotor ;
The position setting member includes a pair of permanent magnets arranged so that the surfaces of the same magnetic pole face each other . On the outer periphery of the shaft that can rotate around the rotation center axis, the rotor arranged to be slidable in the direction of the rotation center axis, and arranged to face the rotor from one side in the direction of the rotation center axis, A stator used as a core for winding a coil, and an axial gap type motor comprising:
The rotor includes a plurality of permanent magnet portions arranged in a circumferential direction on a surface facing the stator, magnetized in the rotation central axis direction, and arranged so that magnetic poles adjacent to each other in the circumferential direction are reversed to each other. Have
A position setting member for urging the rotor along the rotation center axis in a direction in which the space between the gaps is enlarged is disposed on an inner peripheral portion of the rotor ;
The shaft has, on its outer peripheral surface, a position setting support portion whose diameter is increased radially outward for supporting the position setting member,
The rotor has an annular and bottomed position setting member that opens in a surface facing the stator and is radially inward of a region where the permanent magnet portions are arranged in the circumferential direction, and extends in the direction of the rotation center axis. Has a placement chamber,
The position setting member is a pair of permanent magnets, one permanent magnet is fixed to the position setting member arrangement chamber, and the other permanent magnet is placed on the surface of the position setting support portion facing the rotor. An axial gap type motor characterized in that an urging force is applied to the rotor by abutting or fixing so as to face each other . An edge portion of the opening of the position setting member arrangement chamber is disposed so as to be able to contact a surface of the position setting support portion facing the rotor,
3. The gap between the rotor and the stator is defined as a minimum distance by abutting an edge of the opening and a surface of the position setting support portion facing the rotor. Axial gap type motor. One permanent magnet in the pair of permanent magnets is fixed with a first collar press-fitted into the position setting member arrangement chamber,
The other permanent magnet is inserted into an annular position setting member disposition groove formed so as to open on a surface facing the rotor of the position setting support portion, and then a second collar is disposed on the position setting member disposition. The axial gap type motor according to claim 2 , wherein the axial gap type motor is fixed by being press-fitted into the groove. On the outer circumferential surface of the shaft, the rotor according to any one of claims 1 to 4, characterized in that a stopper so as not leave the allowed maximum distance or the stator are of the gap Axial gap type motor.

Images