JPH11341716A - Split-pole type electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce slot gaps between poles on the stator side of an inner rotor type electric motor, and moreover improve the space factor of the armature coil of the motor. SOLUTION: A stator 4 which faced an inner rotor 3 held rotatably by a housing 2 and having permanent magnets 8 is composed of split poles PM1 -PM36 split into respective pole units. Each split pole consists of a base part 13 on an outer circumferential edge side, a pole part 14 is extended inward from the base part 13 in the radial direction and a tooth 15 formed on the tip of the pole part 14. A retaining protrusion 17 is formed on one end in the circumferential direction of the base part 13 and a retaining recess 18 retained with the retaining protrusion 17 is formed on the other end. By retaining the retaining protrusion of the split pole with the retaining recess of the adjacent split pole, the split poles are linked with each other to constitute a stator. An armature coil 16 is wound on the pole part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor having an inner rotor supported by a bearing and a stator having a predetermined number of magnetic poles wound with an armature coil.

[0002]

2. Description of the Related Art A conventional electric motor is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-149616.

In this conventional example, an inner rotor composed of a permanent magnet rotatably supported by a housing by a bearing, a cylindrical magnetic yoke disposed around the inner rotor and an inner peripheral surface thereof are provided. There is described a brushless motor having a stator including a plurality of magnetic poles around which an armature coil integrally formed so as to extend in a radial direction is wound.

[0004]

However, in the above conventional example, the stator is composed of a magnetic yoke and a number of magnetic poles formed integrally therewith, and an armature coil is wound around each magnetic pole. Since the armature coil can be mounted on each magnetic pole only from the rotor side (inside), the space factor of the winding in the winding space around each magnetic pole is reduced. The amount of heat generated increases, and the circumferential slot gap between the ends of the magnetic poles on the rotor side must be widened, generating cogging torque and the flow of magnetic flux as viewed from the permanent magnet side as the rotor. Since the difficult slot gap is large, there is an unsolved problem that the magnetic flux cannot be used effectively.

Accordingly, the present invention has been made in view of the above-mentioned unresolved problems of the prior art, and enables the armature coil to be easily wound around the magnetic poles of the stator, and the space factor to be reduced. It is an object of the present invention to provide a magnetic pole split type electric motor that can improve the slot gap and further reduce the slot gap.

[0006]

According to a first aspect of the present invention, there is provided a magnetic pole split type electric motor comprising: an inner rotor rotatably supported by a housing and having a permanent magnet; and an outer peripheral surface of the inner rotor. And an electric motor having a stator having a predetermined number of magnetic poles wound with an armature coil in opposition to the stator, the stator is configured to be divided for each magnetic pole unit, and each of the divided magnetic poles is located at a base on the outer peripheral side thereof. It is characterized in that it is engaged with each other at circumferential ends.

According to the first aspect of the present invention, since the stator is constituted by the divided magnetic poles divided for each magnetic pole unit, the armature coil is wound around each divided magnetic pole, and then the divided magnetic poles are connected to the outer peripheral side. By engaging with each other at the circumferential ends of the base portions, the stator can be formed, and the armature coil can be wound even if the slot gap is reduced. At this time, since the engagement between the divided magnetic poles is performed at the base portion on the outer peripheral side, a margin of dimensional tolerance can be increased, and the assembly between the divided magnetic poles can be easily performed to facilitate the assembly work of the stator. It is possible to do.

It is preferable that the divided magnetic poles are fitted to the cylindrical housing in a state where they are engaged with each other and integrated to form a stator. Further, the engagement between the divided magnetic poles may be performed by forming an engaging concave portion at one end of the divided magnetic pole and forming an engaging convex portion at the other end, or engaging one of the divided magnetic poles with both circumferential ends. It is preferable that a concave portion is formed, an engaging protrusion is formed on both ends in the circumferential direction of the other divided magnetic pole, and the engaging concave portion and the engaging convex portion are engaged.

Further, as the shape of the engaging concave portion and the engaging convex portion, a square shape, a wedge shape, an arc shape, and the like can be applied.
At this time, it is preferable to provide a slit on the side of the engaging concave portion for ensuring reliable engagement with the engaging convex portion.

Further, the base of each of the divided magnetic poles is configured to contact the cylindrical housing at two points on both ends in the circumferential direction to prevent the magnetic pole from being twisted, and to reduce the magnetic pole generated by the motor. This is preferable for preventing tilting.

Furthermore, it is preferable that the engaging projections at the bases of the respective divided magnetic poles engage with each other so as to push the engaging recesses apart.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, in which 1 denotes an electric motor as a whole, and this electric motor 1 has an inner rotor 3 and a stator 4 in a housing 2. It has a disposed configuration.

As shown in FIG. 1, the housing 2 has two housing halves 2A and 2B opposed to each other at a predetermined interval.
And the housing halves 2A and 2B in a state where a stator 4 described later is fitted between the housing halves 2A and 2B.
And a through bolt 2C for tightening.

Each of the housing halves 2A and 2B is
As shown in FIG. 1, a storage fitting recess 2a for fitting and holding the stator 4 is formed on the inner surface side, and a through hole 2b having an inner diameter smaller than the outer shape of the stator 4 is formed at the center.

The inner rotor 3 is, as shown in FIG.
A cylindrical rotor body 7 rotatably supported by bearings 6 disposed in the through holes 2b of the housing halves 2A and 2B constituting the housing 2,
For example, 24 permanent magnets 8 are stuck on the outer peripheral surface at equal intervals. Each of these permanent magnets 8 is magnetized in the front and back directions, and is adhered to the outer peripheral surface of the rotor main body 7 so as to alternately repeat the N pole and the S pole in the circumferential direction.

On the other hand, as shown in FIG.
The magnetic yoke 11 includes a cylindrical magnetic yoke 11 and 36 magnetic poles 12 disposed at equal intervals in the circumferential direction on the inner peripheral surface of the magnetic yoke 11 and protruding inward. 3
It is configured by combining ₃₆ divided magnetic poles PM _{1 to} PM ₃₆ in the circumferential direction.

Each of these divided magnetic poles PM _{1 to} PM ₃₆ is
As shown in an enlarged view in FIG. 3, an arc-shaped base portion 13 constituting a magnetic yoke 11 and a magnetic pole portion protruding in a radial direction from a central portion on the inner peripheral surface side of the magnetic yoke 11 are formed by laminating a plurality of steel plates. And a tooth portion 15 formed at the tip of the magnetic pole portion 14 and opposed to the permanent magnet 8 of the inner rotor 3 with a predetermined gap therebetween. , An armature coil 16 is wound therearound.

At the left end of the base 13 in the circumferential direction, an engagement projection 17 having a rectangular cross section extending in the axial direction of the housing 2 is formed at the center in the thickness direction of the housing 13 so as to protrude. An engagement recess 18 having a rectangular cross section with which the engagement protrusion 17 engages is formed, and the length L of the base 13 of the engagement protrusion 17 protruding from the circumferential end face is equal to the length of the base 13 of the engagement recess 18. It is selected to be shorter than the depth H from the circumferential end face.

The divided magnetic poles PM _{1 to} PM ₃₆ are shown in FIG.
By engaging the engaging projections 17 of the divided magnetic poles adjacent in the clockwise direction in the engaging recesses 18 and connecting the end faces in the circumferential direction with each other as shown in FIG. Thus, the stator 4 forming the cylindrical magnetic yoke 11 is formed, and in this state, the armature coils 16 are sequentially connected, for example, every third armature and are connected in, for example, a three-phase star connection.

The stator 4 is fitted and held in housing halves 2A and 2B constituting the housing 2 as shown in FIG. That is, one end of the stator 4 is inserted into the housing fitting recess 2a of the housing half 2A.
a, and the other end is fitted into the housing fitting recess 2a of the housing half 2B such that its end face contacts the bottom surface 2e of the fitting recess 2a. Through bolt 2C between housing halves 2A and 2B
Into each of the divided magnetic poles PM _1-
PM ₃₆ is integrated.

At the same time as the split magnetic poles PM _{1 to} PM ₃₆ are fitted, the bearing 6 is inserted into the through hole 2b of the housing halves 2A and 2B.
Is inserted into the inner rotor 3, the bearing 6 is fitted into the through hole 2 b of the housing halves 2 </ b> A and 2 </ b> B, and then the nut 21 is screwed into the inner rotor 3 so that the inner rotor 3 is rotatable with the housing 2. Hold.

A slit circle whose outer peripheral edge has a slit corresponding to the position of the permanent magnet 8 of the inner rotor 3 attached to a shaft portion whose rotational position of the inner rotor 3 protrudes outward from the bearing 6 of the inner rotor 3. Plate 23 and a photo-interrupter 24 disposed on the outer surface of the housing half 2A so as to sandwich the outer peripheral edge of the slit disk 23. The armature coil 16 of the stator 4 is responsive to the detection signal. Is controlled.

As described above, according to the first embodiment.
And a predetermined number of divided magnetic poles PM in units of magnetic poles.₁~
PM₃₆, So that these divided magnetic poles PM₁~
PM₃₆After the armature coil 16 is wound around
Magnetic pole PM₁~ PM₃₆Was formed on the base 13 on the outer peripheral side.
By engaging the engaging convex portion 17 and the engaging concave portion 18,
And can be integrated. Therefore, adjacent to each other
Divided magnetic pole PM₁~ PM ₃₆Can shift in the radial direction
No, the teeth 15 and the permanent magnet of the inner rotor 3
8 can be maintained at a predetermined value.
And the divided magnetic pole PM₁~ PM₃₆The circumferential dimension of
Even if the difference is set to be relatively large, the gap between the teeth 15 on the inner peripheral surface side
The effect on the lot gap can be reduced,
Divided magnetic pole PM₁~ PM₃₆With the housing connected
Just fits into the storage fitting recesses 21 of the halves 2A and 2B
Thus, the stator 4 can be easily formed,
Since no joining means is required, assembly is easy.
Can be.

Further, the armature coils 16 are wound around the divided magnetic poles PM _{1 to} PM ₃₆ and then connected to each other to form the stator 4.
Is formed, the interval between the adjacent tooth portions 15 in each of the divided magnetic poles PM _{1 to} PM ₃₆ , that is, the slot gap where the magnetic flux hardly flows when viewed from the permanent magnet side on the rotor side can be narrowed,
The magnetic flux can be used effectively, and a sudden change in reluctance can be suppressed, so that the occurrence of cogging torque can be suppressed and rotation unevenness can be suppressed.

Further, since the armature coil 16 is directly wound around each of the divided magnetic poles PM _{1 to} PM ₃₆ , the space factor of the armature coil 16 can be improved and the amount of heat generated can be suppressed. .

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, when the width of the engaging concave portion 18 is narrower than the thickness of the engaging convex portion 17 in the first embodiment, an engagement relationship between them is not obtained, and the divided magnetic poles are connected. This is intended to eliminate the possibility that the state cannot be performed.

In the second embodiment, as shown in FIG. 4, the engaging projections 17 formed on the circumferential end surfaces of the base portions 13 of the divided magnetic poles PM _{1 to} PM ₃₆ are replaced by convex sections having a rectangular cross section. The engagement concave portion 18A is changed to an approximately isosceles triangular wedge-shaped engagement concave portion 17A whose thickness becomes thinner toward the tip. Except for this point, it has the same configuration as that of FIG. 3 in the first embodiment, and the same reference numerals are given to the portions corresponding to FIG.

According to the second embodiment, the engaging projection 1
Since 7A and the engagement recess 18A are both formed in a wedge shape, in the case of connecting the divided pole PM ₁ Pm _36, is possible to reliably insert a wedge engaging protrusion 17A on the wedge-shaped engaging recess 18A is possible, it is possible to permit some deformation in the wedge-shaped engaging recess 18A side, split pole PM ₁ ~
Even when the engagement convex portion 17A of the PM ₃₆ is larger than the engagement concave portion 18A, the engagement relationship between them can be maintained, and the stator 4 can be easily assembled.

Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the positioning performance when fitting the stator 4 to the housing halves 2A and 2B is improved, and a change in posture is prevented.

That is, in the third embodiment, for example,
As shown in FIG. 5, the seven divided magnetic poles PM _{1 to} PM ₂₇
In the configuration of FIG. 4 in the second embodiment described above,
A concave portion 31 extending in the thickness direction is formed at the center of the outer peripheral edge of the base portion 13, thereby connecting the divided magnetic poles PM _{1 to} PM ₂₇ to form the stator 4 as described above. And two contact surfaces F1 that come into contact with the inner peripheral surface of the storage fitting concave portion 2a when fitting to the fitting recess 2a.
And F2 are formed, and each divided magnetic pole PM
_{1 to} PM ₂₇ except that a welded portion 32 for integrating the laminated steel plates constituting PM ₂₇ is provided, and portions corresponding to FIG. 4 are denoted by the same reference numerals. A detailed description thereof will be omitted.

According to the third embodiment, the split magnetic pole P
When the stator 4 is formed by connecting M _{1 to} PM ₂₇ and fitted to the housing halves 2A and 2B, the two contact surfaces F1 and F2 of the base 13 of each of the divided magnetic poles PM _{1 to} PM ₂₇ are formed.
6 comes into contact with the inner peripheral surface of the housing fitting recess 2a as shown in FIG.

For this reason, even if the finishing accuracy of the outer peripheral surface of the base 13 in each of the divided magnetic poles PM _{1 to} PM ₂₇ is somewhat inferior, the divided magnetic poles PM _{1 to} PM ₂₇ are connected to form the stator 4, and this is assembled with the housing half. when is fitted to the body 2A and 2B, will be the base 13 of the split pole PM ₁ Pm ₂₇ is brought into contact reliably accommodating fitting recesses 2a, the armature coils 1
When the drive torque is generated by controlling the energization of the inner rotor 3 to generate the driving torque, it is possible to reliably prevent the tooth portion 15 from wobbling and causing a vibration or noise.

Even when the magnetic pole portion 14 of each of the divided magnetic poles PM _{1 to} PM ₂₇ is deformed when a driving torque is generated, the base 1
The contact point on the housing half 2A and 2B does not change on the 3 side, and the contact surfaces F1 and F2 of the base 13 and the housing fitting recess 2a of the housing half 2A and 2B are brought into close contact to form a magnetic path. As a result, it is possible to reliably prevent the magnetic flux density from changing.

Further, welding of the laminated steel plate can be performed on the bottom surface of the concave portion 31, and the welded portion 32 is formed between the contact surfaces F1 and F1.
It is possible to reliably avoid projecting outward from 2 and affecting the fitting with the housing halves 2A and 2B.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, the third embodiment
In the embodiment of the present invention, the stator 4 is formed by connecting the divided magnetic poles PM _{1 to} PM ₂₇ , and when the stator 4 is fitted to the housing halves 2 </ b> A and ₂ </ b> B, the engagement convex portion 17 </ b> A and the engagement concave portion 1 are formed.
A step is prevented from being formed at the engagement position 8A.

In the fourth embodiment, as shown in FIG. 7, in the third embodiment shown in FIG. 5, the engagement recess 18 is located at the connecting position between the engagement projection 17A and the contact surface F1.
A has the same configuration as that of FIG. 5 except that a non-engaging portion 35 which is a notch that does not engage with the distal end portion of A is formed,
Parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0037] According to the fourth embodiment, the outermost of the outer inclined surfaces of the divided pole PM ₁ Pm ₂₇ by connecting when constituting the stator 4, one divided pole PM _i engaging recess 18A The upper portion is opposed to the non-engaging portion 35 formed on the engaging convex portion 17A of the divided magnetic pole PM _{i + 1} engaging with the upper portion, and the uppermost portion of the outer inclined surface of the engaging concave portion 18A is radially oriented. Since it is possible to bend inward, the engaging concave portion 18A and the engaging convex portion 17A engage with each other when the stator 4 is formed and fitted to the housing halves 2A, 2B.
It is possible to avoid the formation of a step at the engagement position of, and a good connection relationship can be obtained.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In the fifth embodiment, each divided magnetic pole P
When M _{1 to} PM ₂₇ are connected to form the stator 4,
With the engaging convex portion 17A and the engaging concave portion 18A that engage with each other,
Even when the apex angle of the engagement projection 17A is larger than the apex angle of the engagement recess 18A, they are connected to each other and the stator 4
In this configuration, the circumferential length is prevented from increasing.

That is, in the fifth embodiment, FIG.
As shown in FIG.
It has the same configuration as that of the above-described second embodiment except that a slot 37 toward the A side is formed, and the same reference numerals are given to portions corresponding to FIG. Omit this.

[0040] According to the fifth embodiment, the other split pole PM for one split poles PM _i engaging recess 18A
_{When the i + 1} engagement convex portion 17A is engaged, when the vertex angle θ ₁ of the engaging convex portion 17A is larger than the vertex angle θ ₂ of the engaging concave portion 18A, the engaging convex portion 17A Part 17A
The insertion depth of the engaging recess 1 is small in this embodiment.
When the engaging projection 17A is engaged and pushed into the 8A, the engaging recess 18A is slightly opened by the slit 37 due to the wedge effect, and the regular insertion depth can be secured. Accordingly, the circumferential length when each of the divided magnetic poles PM _{1 to} PM ₂₇ is connected can be made to substantially match the design length, and the fitting to the housing halves 2A and 2B can be easily performed.

Next, a sixth embodiment of the present invention will be described with reference to FIG. The sixth embodiment is different from the fifth embodiment in that, when the engaging projection 17A is engaged with the engaging recess 18A having a smaller apex angle, the outside of the engaging recess 18A in the radial direction is outside. , And each of the divided magnetic poles PM _{1 to} PM
_This prevents the outer diameter of the stator 13 to which the connecting member ₂₇ is connected from increasing.

In the sixth embodiment, FIG.
As shown, each divided magnetic pole PM₁~ PM ₂₇Engaging projection 17A
And the shape of the engaging recesses 18A are each from an isosceles triangular shape.
The apex angle is set to the inner diameter side, and the inclined surface E1 on the outer diameter side is set to the inner diameter side.
Side is set to be longer than the inclined surface E2, and
At the connecting position of the slopes G1 and G2 of 18A, a slot 37 is provided.
The fifth embodiment described above, except that
8 has the same configuration as that of FIG.
And its detailed description is omitted.

According to the sixth embodiment, similarly to the fifth embodiment, the engaging concave portion 18A of one divided magnetic pole PMi is _{engaged with} the engaging convex portion of the other divided magnetic pole PMi _{+ 1} . 17
A, when the vertex angle θ ₁ of the engaging convex portion 17A is larger than the vertex angle θ ₂ of the engaging concave portion 18A, the engaging convex portion 17A
A will spread out the inclined surface of A.
The slope G2 on the inner diameter side is shorter than the slope G1 on the outer diameter side, and the thickness between the inner diameter side end face is thin, so that the slope G2 side is expanded and the outer diameter side expands outward. Can be reliably prevented from being emitted from each of the divided magnetic poles PM ₁ to PM ₁ .
The outer peripheral edge of the PM ₂₇ can be fitted in a state where the outer peripheral edge of the housing half 2A, 2B is in accurate contact with the inner peripheral edge of the housing fitting concave portion 2a, and the assembling accuracy of the stator 4 can be improved.

Next, a seventh embodiment of the present invention will be described with reference to FIG. In the seventh embodiment, each divided magnetic pole P
The engagement state when the stator 4 is configured by connecting the M _{1 to} PM ₂₇ is more reliably performed.

That is, in the seventh embodiment, as shown in FIG. 10, the apex angle θ1 of the engaging projection 17A is
A has the same configuration as that of the above-described second embodiment except that it is set to be slightly larger than the vertex angle θ2 of A, and the same reference numerals are given to portions corresponding to FIG. Detailed description is omitted.

According to the seventh embodiment, when the divided magnetic poles PM _{1 to} PM ₂₇ are connected to form the stator 4,
When the engaging protrusion 17A is inserted into the engaging recess 18A, the engaging recess 18A is necessarily expanded by the engaging protrusion 17A, and a reliable engagement relationship is obtained.
M _{1 to} PM ₂₇ can be assembled accurately without shaking.

[0047] Note that in the above-described seventh embodiment of has been attached explained to set larger than the apex angle θ2 of the engaging recess 18A apex angle θ1 of the engaging portion 17A of the divided pole PM ₁ Pm ₂₇ , But is not limited to this.
As shown in the figure, the apex angles θ1 and θ2 of the engaging convex portion 17A and the engaging concave portion 18A are the same, but arc-shaped chamfered portions 40 and 41 are provided at the tips of the engaging convex portion 17A and the engaging concave portion 18A, respectively. Is formed, and the radius R1 of the chamfered portion 40 is
By setting the radius to be larger than the radius R2, it is possible to obtain an effect that a reliable engagement relationship between the divided magnetic poles can be obtained as in the sixth embodiment.

Next, an eighth embodiment of the present invention will be described with reference to FIG. The eighth embodiment is similar to the third embodiment described above.
As in the embodiment, the stator 4 is connected to the housing half 2A.
2B and 2B.

That is, in the eighth embodiment, as shown in FIG. 12, the base 1 in each of the divided magnetic poles PM _{1 to} PM ₂₇ is changed.
3 is perpendicular to the center line LC passing through the center of the magnetic pole portion 14, and the starting point a of the engaging convex portion 17A and the engaging concave portion 18A.
And b, except that it is formed on a flat surface 45 connecting the same to the above-described second embodiment. The same reference numerals are given to the portions corresponding to those in FIG. Omitted.

According to the eighth embodiment, the split magnetic pole P
When the stator 4 is formed by connecting M _{1 to} PM ₂₇ and is fitted to the housing halves 2A and 2B, the outer peripheral surface of the base 13 of each of the divided magnetic poles PM _{1 to} PM ₂₇ is formed as a flat surface. Therefore, they do not come into contact with the inner peripheral surfaces of the housing fitting recesses 2a of the housing halves 2A and 2B, and the starting points a and b of the engagement projections 17A and the engagement recesses 18A are not changed.
Only the points fit into the storage fitting recess 2a.

For this reason, even when the finishing accuracy of the outer peripheral surface of the base 13 in each of the divided magnetic poles PM _{1 to} PM ₂₇ is somewhat inferior, the divided magnetic poles PM _{1 to} PM ₂₇ are connected to form the stator 4, and this is assembled with the housing half. when is fitted to the body 2A and 2B, split pole PM ₁ Pm base 13 of ₂₇ will be in contact with the housing fitting recess 2a stable, the inner rotor 3 and the armature coil 16 energization control to When the drive torque is generated by rotating the tooth, it is possible to surely prevent the tooth portion 15 from wobbling and causing vibration and noise.

Even if the magnetic pole portion 14 of each of the divided magnetic poles PM _{1 to} PM ₂₇ is deformed when a driving torque is generated, the base 1
It is possible to reliably prevent a change in the contact point with the housing halves 2A and 2B on the third side.

Further, the laminated steel plate can be welded at the center of the flat surface 45. This welded portion projects outward from the arcuate surface of the housing fitting recess 2a passing through the starting points a and b, and the housing half is welded. It is possible to reliably avoid affecting the fitting with the bodies 2A and 2B.

Next, a ninth embodiment of the present invention will be described with reference to FIG. In the ninth embodiment, the shapes of the engaging projection 17A and the engaging recess 18A in each of the divided magnetic poles are simplified.

In the ninth embodiment, as shown in FIG. 13, the engaging projections 17A on the base 13 of each of the divided magnetic poles PM _{1 to} PM ₂₇ are replaced by isosceles triangular shapes from the outer circumferential surface to the inner circumferential surface. It is cut off diagonally straight down to the left to form a right-angled triangular shape having one inclined engagement surface 50. In response to this, the engagement recess 18A is also inclined to the base 13 diagonally left down from the outer peripheral surface side. It has the same configuration as that of the second embodiment except that it is cut off linearly toward the continuous contact point c with the magnetic pole portion 14 and is formed in a shape having one inclined engagement surface 51. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0056] According to the ninth embodiment, one split pole PM _i other split pole P adjacent the engaging portion 17A of the
The engagement is performed by engaging with the engagement recess 18A of Mi _-1 . At this time, since the engagement convex portion 17A and the engagement concave portion 18A only engage the one inclined engagement surfaces 50 and 51 with each other, Since the inner surface of the inclined engaging surface 51 of the engaging concave portion 18A extends to the continuous contact point c between the base 13 and the magnetic pole portion 14, the engaging convex portion 17A is moved inward. , The inner end of the inclined engagement surface 50 abuts the magnetic pole portion 14 at the connection point c to restrict the movement,
The stator 4 is configured by maintaining the engaged state of each of the divided magnetic poles PM _{1 to} PM ₂₇ .

The stator 4 is integrated by fitting the stator 4 into the housing recess 2a of the housing halves 2A and 2B. As described above, according to the ninth embodiment, the coupling of the divided magnetic poles PM _{1 to} PM ₂₇ is simple in that both the engagement projection 17A and the engagement recess 18A have the single inclined engagement surfaces 50 and 51. The state can be maintained, the divided magnetic poles PM _{1 to} PM ₂₇ can be easily formed, and the manufacturing cost can be reduced.

In the first to ninth embodiments, the case where the shapes of the engaging projections 17 and 17A and the engaging recesses 18 and 18A are square or triangular has been described. Instead, as shown in FIG. 14, as shown in FIG. 14, even if the engagement convex portion 17A is a semi-cylindrical engagement convex surface 60 and the engagement concave portion 18A is a semi-cylindrical engagement concave surface 61, both are good. In this case, the same embodiment as the third to eighth embodiments can be applied, and further, a polygonal cylindrical engagement surface such as a hexagon, an octagon, or the like is formed. You can also.

Further, in the first to ninth embodiments, the case where the number of divided magnetic poles is set to 36 or 27 has been described. However, the present invention is not limited to this. Also, the connection method of the armature coil 16 is not limited to the star connection, and any connection method such as the delta connection can be applied. Further, the number of phases is not limited to three, but may be four, six, or the like. Any number of phases can be set.

Further, in the first to ninth embodiments, the case where the housing 2 is constituted by the housing halves 2A and 2B and the through bolt 2C has been described.
However, the present invention is not limited to this, and may be constituted by a cylindrical case body having a bottom and an open end, and an end plate for closing the open end thereof, and may have an arbitrary structure.

[0061]

As described above, according to the divided magnetic pole type electric motor according to the first aspect, since the stator is constituted by the divided magnetic poles divided for each magnetic pole unit, the armature coil is provided for each divided magnetic pole. , And the divided magnetic poles are engaged with each other at the circumferential ends of the base on the outer peripheral side, so that a stator can be formed. The child coil can be securely wound, the space factor can be improved, the heat generation can be reduced, and the slot gap can be reduced, so that the magnetic flux of the permanent magnet of the inner rotor is effectively used. In addition, the cogging torque is reduced, and the engagement between the divided magnetic poles is performed at the base on the outer peripheral side. Effect is obtained that it becomes possible to easily perform the assembling work of the stator carried out to facilitate the engagement of the magnetic poles.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of FIG.

FIG. 3 is an enlarged view of a divided magnetic pole of FIG. 2;

FIG. 4 is an enlarged view of a divided magnetic pole according to a second embodiment of the present invention.

FIG. 5 is an enlarged view of a divided magnetic pole according to a third embodiment of the present invention.

FIG. 6 is a diagram illustrating a connection state of divided magnetic poles according to a third embodiment.

FIG. 7 is an enlarged view of a divided magnetic pole according to a fourth embodiment of the present invention.

FIG. 8 is an enlarged view of a divided magnetic pole according to a fifth embodiment of the present invention.

FIG. 9 is an enlarged view of a divided magnetic pole according to a sixth embodiment of the present invention.

FIG. 10 is an enlarged view of a divided magnetic pole according to a seventh embodiment of the present invention.

FIG. 11 is an enlarged view of a divided magnetic pole showing a modification of the seventh embodiment of the present invention.

FIG. 12 is an enlarged view of a divided magnetic pole according to an eighth embodiment of the present invention.

FIG. 13 is an enlarged view of a divided magnetic pole according to a ninth embodiment of the present invention.

FIG. 14 is an enlarged view of a divided magnetic pole showing another embodiment of the present invention.

[Description of Signs] 1 Electric motor 2 Housing 2A, 2B Half housing 2a Fitting recess for housing 3 Inner rotor 4 Stator 8 Permanent magnet PM _{1 to} PM ₃₆ Split magnetic pole 13 Base 14 Magnetic pole 15 Tooth 16 Armature coil 17 , 17A engaging convex portion 18, 18A engaging concave portion 31 concave portion 35 non-engaging portion 37 slit 40, 41 chamfered portion 45 flat surface 50, 51 inclined engaging surface 60, 61 cylindrical engaging surface

Claims (1)

[Claims] An electric motor comprising: an inner rotor rotatably supported by a housing and having a permanent magnet; and a stator having a predetermined number of magnetic poles wound with an armature coil facing an outer peripheral surface of the inner rotor. The split-pole electric motor is characterized in that the stator is divided in units of magnetic poles, and the divided magnetic poles are engaged with each other at circumferential ends of a base portion on an outer peripheral side thereof.