JPH083153Y2 - Rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a rotary electric machine such as an electric motor or a generator.

(Prior Art) Conventionally, for example, a rotary electric machine such as an electric motor has been commercialized as a single unit. Therefore, even when rotating a cross flow fan or the like in an indoor unit of an air conditioner, a rotary electric machine of a separate body such as an AC induction motor is used. An electric motor is arranged in the apparatus adjacent to the cross flow fan, and its drive shaft and the rotation shaft of the fan roller are connected by a coupling. Therefore, a space for accommodating the above-mentioned electric motor is required inside the device, and there is a drawback that the device becomes large. Therefore, in recent years, attempts have been made to reduce the size of the device by directly connecting the rotor of the DC brushless motor to the side plate of the fan roller. A specific example of such an apparatus is described in, for example, Japanese Utility Model Laid-Open No. 61-178095. The apparatus is schematically shown in FIG. 6. As shown in FIG. 6, the casing 83 of the rotor 82 of the DC brushless motor is provided on the outer end surface of one side plate 81 of the fan rotor 80 of the cross flow fan. The casing 83 has a ring-shaped permanent magnet 84 on the inner peripheral surface of the cylindrical portion.
Are fixed by adhesion. The fan rotor 80 directly connected to the rotor 82 in this manner is rotatably supported on the support frame by rotating shafts extending outward from both ends. On the other hand, to the support frame 86 supporting the rotary shaft 85 on the side of the rotor 82, the rotary shaft 85 is inserted and the cylindrical body 87 extending to the central through hole position of the permanent magnet 84 is fixed. The stator 89, around which the coil 88 is wound, is disposed at the tip of the stator. By controlling the energization of the coil 88 to form a rotating magnetic field, a rotating force is induced on the rotor 82, and the fan rotor 80 is driven to rotate. By directly connecting the rotor 82 to the fan rotor 80 as described above, the structure is simplified, the axial length is shortened, and the device can be downsized.

(Problems to be solved by the invention) By the way, since permanent magnets are generally made of a hard and fragile material, it is not easy to make holes for mounting on them, and therefore, it is usually necessary to use adhesive as described above. Installation is done. However, the above-mentioned conventional device configured by adopting this attachment by adhesion has the following problems. For example, a casing that covers the outer peripheral side of the permanent magnet 84
The cylindrical portion of 83 also functions as a magnetic path on the outer peripheral side of the permanent magnet 84, but since an adhesive agent, that is, a non-magnetic layer is interposed between this cylindrical portion and the permanent magnet 84, The magnetic path resistance is increased and therefore the permanent magnet 84 to the stator 89
The magnetic force acting on is reduced. Further, in the indoor unit of the air conditioner, since the cool air flows during the cooling operation and the warm air flows during the heating operation, the temperature change width is relatively large, and the thermal expansion due to such temperature change causes the casing 83 Since the permanent magnet 84 and the adhesive are different from each other, there is also a problem that the fixing strength gradually decreases, and therefore the reliability of the fixing is lacking. In addition, during assembly work, additional work such as mixing and storing the adhesive, holding the mounting state until it solidifies, and removing the adhesive protruding from the adhesive surface after solidification are required. There is also a problem that the production cost becomes high due to the increase in the number of assembly steps as well as the complexity.

Therefore, in the configuration of FIG. 6, a cup-shaped casing
83, that is, the casing 83 including the cylindrical portion and a mounting portion that serves as a mounting surface for the side plate 81, is further provided with a lid on the opening end side, and between the lid and the mounting portion of the casing 83. With the configuration of sandwiching in the axial direction, assembly without adhesive is possible, the above-mentioned problems do not occur, and the manufacturing cost can be reduced, for example. By the way, as described above, since the cylindrical portion of the casing 83 needs to function as a magnetic path on the outer peripheral surface side of the permanent magnet 84,
The casing 83 is made of a magnetic material. That is, it can be configured by using a steel plate having a low material cost such as a cold rolled steel plate. However, when the cover that covers the axial end surface of the permanent magnet 84 together with the mounting portion of the casing 83 is made of a steel plate that is low in material cost as in the case of the casing 83, this cover has a radius of Direction or multi-pole magnetized in the circumferential direction, as a magnetic path between different magnetic poles on the inner peripheral surface and the outer peripheral surface of the permanent magnet 84, or on the inner peripheral surface side between different magnetic poles in the circumferential direction. Since it becomes a path, the magnetic flux on the inner peripheral surface side of the permanent magnet 84, which should originally act on the stator 89 side, leaks also through the lid body, so that the magnetic force acting on the stator 89 is As a result, the required rotational driving force cannot be obtained. For this reason, it becomes impossible to use a steel plate having a low material cost as described above, and it is necessary to use a non-magnetic material such as an aluminum plate or stainless steel, which increases the manufacturing cost. Occurs.

The present invention has been made in view of the above, and an object thereof is to provide a rotary electric machine that can reduce leakage magnetic flux and can be manufactured at low cost.

(Means for Solving Problems) Therefore, the rotary electric machine of the present invention includes a casing 15 having a mounting portion 17 that is substantially orthogonal to the rotation axis and a cylindrical portion 18 that extends from the outer peripheral edge of the mounting portion 17 in the axial direction. 20. A plurality of permanent magnets 20 are provided that are divided into arcs and are arranged at intervals along the inner circumference of the cylindrical portion 18, and the casing is also provided.
A lid body attached to the outer peripheral portion of the cylindrical portion 18 of 15 and having a fixing surface 37 extending in a direction covering the opening portion of the cylindrical portion 18.
25, and by mounting the lid 25 on the cylindrical portion 18 of the casing 15, the permanent magnets 20 are sandwiched between the mounting portion 17 and the fixing surface 37 of the lid 25 to fix the rotor 4 or the rotor 4. Each of the above-mentioned permanent magnets 20 ...
The inner circular arc surface Si of the stator 5 or the rotor 4 facing the other peripheral side surface of the stator 5 or the rotor 4
20 is magnetized in the radial direction so that there are different poles in the radial direction, and the magnetic poles of adjacent permanent magnets 20 are different from each other on the inner arc surface Si facing the peripheral side surface of the stator 5 or the rotor 4. A rotary electric machine arranged so as to form a pole, wherein the casing 15 and the lid 25 are made of a magnetic material, and the lid is further provided.
In 25, the inner peripheral edge of the fixed surface 37 is
The casing 20 is configured to come into contact with the end face of each of the permanent magnets 20 on the outer peripheral side with respect to the midpoint between the inner and outer peripheral faces on the casing opening side end face.

(Operation) In the rotary electric machine described above, the lid 25 that covers the end surface of the permanent magnet 20 for holding the permanent magnet 20 is a permanent magnet.
The inner points of the inner and outer peripheral surfaces of 20 are in contact with each other outside the magnetic neutral point between the magnetic poles of the inner and outer peripheral surfaces. Therefore, even if the lid 25 is made of a magnetic material, it is possible to suppress the generation of leakage magnetic flux through the lid 25 on the inner arc surface Si side between the permanent magnets 20, and thus to reduce the magnetic force of the permanent magnets. There is no leakage flux that causes it. As a result, for example, a cold-rolled steel plate can be used, so that the manufacturing cost can be reduced.

(Example) Next, a specific example of the rotary electric machine of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an assembly sectional view of an apparatus according to an embodiment configured by applying the present invention to a fan driving electric motor of a cross flow fan used in an indoor unit of an air conditioner. In the figure, reference numeral 1 denotes a fan rotor of a cross flow fan. A rotor 4 is attached to one side plate 2 of the fan rotor 1 via a connecting member 3 made of an elastic material such as synthetic rubber. A fixed shaft 6 to which a stator 5 is fixed is inserted inside the rotor 4. An end bracket 7 is further fixed to the right end of the fixed shaft 6. An end face of the end bracket 7 is provided with a fixing screw hole at an appropriate position. The end face of the end bracket 7 is connected to first and second side plates of a fan housing which is a mounting surface inside the indoor unit of the air conditioner. A screw is fixed to the right side plate 8 shown by a two-dot chain line in the figure. The indoor heat exchanger is arranged in the fan housing on the upstream side of the fan rotor 1 and is supported between the left and right side plates.

The connecting member 3 is provided for the purpose of preventing vibration of the entire indoor unit from vibrating due to rotational runout generated in the fan rotor 1, and has a central portion penetrating therethrough in the axial direction. It is a ring-shaped part having a hole 11, and its cross section is formed in a substantially U shape. That is, it is composed of the cylindrical portion 12 surrounding the through hole 11, and the side plate-side fixing surface 13 and the rotor-side fixing surface 14 which respectively spread in the radial direction from both axial end positions of the cylindrical portion 12. The side plate side fixing surface 13 is fitted into a recess formed in the end surface of the side plate 2 to be provided with a concentric position with the side plate 2, and is fixed by adhesion or the like in this state. On the other hand, an attachment portion (a surface shown as a vertical surface in the drawing) 17 of a casing 15 that constitutes the rotor 4 is fixed to the rotor-side fixing surface 14. A central bulge portion 16 that projects toward the fan rotor 1 is formed at the axial center of the mounting portion 17. Although the function of the central bulging portion 16 will be described later, the central bulging portion 16 is inserted into the through hole 11 to maintain the concentric position of both the rotor side fixing surface 14 and the central bulging portion 16. casing
Sticking and attachment of 15 to the attaching portion 17 is performed.

Next, the structure of the rotor 4 will be described with reference to the exploded perspective view of FIG. The rotor 4 is provided with the casing 15
It is composed of four permanent magnets 20 and a substantially cylindrical lid 25. The casing 15 has the mounting portion 17 fixed to the side plate 2 of the fan rotor 1 via the connecting member 3 as described above, and extends from the outer peripheral edge of the mounting portion 17 to the right side in the drawing and on the right end face. It is formed in a cup shape including a cylindrical portion 18 that opens. Then, in order to fix each of the permanent magnets 20 along the cylindrical portion 18, the mounting end 17 has the opening end at a position that divides a concentric circle inward from the cylindrical portion 18 into four equal parts. Four substantially arcuate locking pieces 26 ··· 26 that are cut and raised on the side and these locking pieces 26 · · 26
Short claw-shaped projections 27, 27 cut and raised at two positions on the circumference are formed. On the other hand, as shown in FIG. 2, each of the permanent magnets 20 is formed in a shape having an arc length that divides the inner circumference of the cylindrical portion 18 of the casing 15 into four equal parts. The shape will be described in detail later,
Sloping surfaces 52 that are inclined with respect to the radial direction at both ends in the circumferential direction,
52 are formed respectively, and a tapered gap gradually narrowing outward in the radial direction is formed between the inclined surfaces 52 of the adjacent permanent magnets 20. The arcuate locking pieces 26 are fitted into the tapered gaps from the axial center side and come into contact with the inclined surface 52 of the permanent magnet 20. Further, the cut-and-raised point of each locking piece 26 is formed on the outer peripheral surface side from the contact position. As a result, in the contact state, each locking piece 26 bends radially inward. Then, the elastic reaction force acts as a force for pressing each of the permanent magnets 20 toward the outer peripheral surface. Then, as a result of this pressing force acting on the inclined surfaces 52, 52 as described above, each permanent magnet 20
Acts as a force that pushes outwardly in the radial direction to bring it into close contact with the inner circumferential surface of the cylindrical portion 18 of the casing 15, and also acts as a force that pushes in the circumferential direction. As a result of such a pressing force being applied to both ends of each permanent magnet 20, the radial position fixing and the circumferential position fixing of each permanent magnet 20 are simultaneously and accurately applied.

As shown in FIG. 1, the arcuate locking piece 26 is formed in a substantially arcuate shape such that the opening end (right end in the drawing) side of the casing 15 is curved in the axial direction. Each of the permanent magnets 20 is pushed axially leftward along the cylindrical portion 18 of the casing 15 from the opening end side of the casing 15, so that the locking piece 26 gradually moves in the axial direction. It is bent into the above-mentioned assembled state. On the other hand, as shown in the sectional view below the fixed shaft 6 in the same figure, the left end surface of each permanent magnet 20 contacts the tip portion of the claw-shaped projection 27 as described above. By contacting, the positioning on the left end side is first performed. In this state, the locking piece 26 has its axial center portion abutting on the axial center portion of each permanent magnet 20. As shown in FIG. 2, the claw-shaped projection 27 is adapted to abut on each of the permanent magnets 20 at two points on both ends thereof. At this time, as shown in FIG. 1, each permanent magnet is
The right end surface of 20 is located at substantially the same position as the open end of the casing 15. After assembling the permanent magnets 20 as described above, the casing 25 is covered with the lid 25 having an inner peripheral surface having substantially the same diameter as the outer periphery of the cylindrical portion 18 of the casing 15. This lid 25
A fitting hole 35 is bored at an appropriate position on the peripheral side surface of the cylindrical portion 18, while a circle formed by projecting outward in the radial direction on the cylindrical portion 18 at a position corresponding to the fitting hole 35. An arcuate locking piece 36 is formed. By pushing the lid body 25 in the axial direction and fitting the locking piece 36 into the fitting hole 35, the lid body 25 is fixedly attached to the casing 15, and the assembly of the rotor 4 is completed. . That is, the lid
25 has a fixing surface 37 that is bent radially inward at its right end surface portion and slightly covers the outer peripheral side of each permanent magnet 20 over the entire circumference. The permanent magnets 20 are sandwiched between the claw-shaped projections 27 and the claw-shaped projections 27, so that the permanent magnets 20 are fixed in the axial direction.
As described above, the attachment of the permanent magnet, which has been conventionally performed by adhesion, can be performed more reliably and accurately by an extremely simple assembly work.

Each of the permanent magnets 20 is magnetized in the radial direction. Further, the rotor 4 is configured such that the adjacent surfaces on the inner peripheral surface facing the stator 4 have different poles from each other, that is, the four-pole NSNS field state. Each of the permanent magnets 20 described above is formed of, for example, an anisotropic magnet made of ferrite. As described above, the magnetic poles are composed of the divided magnets uniformly magnetized for each magnetic pole, and the respective magnetic poles are composed of the anisotropic magnets. As a result, the magnetic force can be greatly increased as compared with the related art. The gap between the inner peripheral surface of the magnet 20 and the outer peripheral surface of the stator 5, which will be described later, that is, the air gap can be given as relatively large as 1.5 to 2 mm.

Each of the permanent magnets 20 is configured to have the same shape, and at both ends in the circumferential direction,
A symmetrical end surface shape is provided as shown in FIG. This end face shape will be described with reference to FIG. In the figure, the permanent magnets 20 are symmetrically positioned, and a center line 1 which is the axis of symmetry at that time, and radial lines m, m extending at a center angle of 90 ° about the center line l, A horizontal plane p perpendicular to the line 1 and in contact with the outer peripheral surface So of the permanent magnet 20 is additionally shown. At both ends of the permanent magnet 20, parallel surfaces 50 parallel to the center line 1 are provided from the outer peripheral surface So to the inner peripheral surface Si, and the radial line is slightly on the side closer to the center line 1 than the radial line m. The minimum gap providing space 51 parallel to m, the inclined surface 52 extending in parallel to the horizontal plane p toward the center line 1 are sequentially formed, and are parallel to the radial line m and have a radius larger than that of the minimum clearance providing face 51. Fitting surface separated from the direction line m
53 is formed and continues to the inner peripheral surface Si. By providing such an end surface shape, when the permanent magnets 20 are arranged along the inner peripheral surface of the casing 15, the minimum gap imparting surface 51 is provided between the adjacent permanent magnets 20 and 20. , 51, a minimum gap a (1 mm) is given. By providing this minimum gap, it is possible to assemble the permanent magnets 20 and the like in which a shape processing error can be tolerated. The inclined surface 52 is formed near a radially intermediate point (hereinafter, referred to as a neutral point) between the inner peripheral surface Si and the outer peripheral surface So, and the arcuate locking piece 26 abuts as described above. Surface. The fitting surface 53 provides a gap into which the bow-shaped locking piece 26 fits in the direction of the inclined surface 52 from a radially inward direction, and the interval b is a gap (3 mm) exceeding the air gap. Therefore, the leakage magnetic flux through the gap b on the inner peripheral surface side between the adjacent permanent magnets 20 and 20 is reduced, and the magnetic force acts more effectively on the stator 5 side.

Next, the assembling of the stator 5 to the rotor 4 will be described. As shown in FIG. 1, the central bulging portion 16 on the axial center side of the mounting portion 17 of the casing 15 has a bearing storage chamber 39 in its internal space. In other words, this bearing storage room 39
The bearing 41 is inserted therein by press fitting or the like. This bearing
By inserting the tip side of the fixed shaft 6 into the stator 41, a stator 5 having 6-pole magnetic poles formed in a star shape is provided in the internal space of the rotor 4 as shown in FIG. Since they are arranged concentrically, a fan driving electric motor is configured. Reference numeral 40 in the figure denotes a coil wound around each magnetic pole of the stator 5. The stator 5 is fixed to a substantially central portion of a fixed shaft 6 as shown in FIG. The fixed shaft 6 has a tapered tip on the left end side in FIG. 1, a small diameter portion from the tapered portion to the base end side, and further has a step portion to which the stator 5 is fixed. Formed as a shaft. Then, by inserting the fixed shaft 6 through the central opening of the fixed surface 37 of the lid 25 described above on the axial center, the central bulging portion 16 of the casing 15 described above.
The small diameter portion of the fixed shaft 6 is inserted into the center hole of the bearing 41 attached to the inner surface. At this time, the small diameter portion is easily inserted by being guided by the taper portion at the tip of the fixed shaft 6.

A dish-shaped end bracket 7 is concentrically fixed to the right end portion of the fixed shaft 6. A short cylindrical portion 42 extending toward the stator 5 is provided on the outer periphery of the end bracket 7.
Is formed, the space surrounded by the cylindrical portion 42,
A control circuit component storage chamber 43 is provided. A disc-shaped printed board 44 is provided in the storage chamber 43, and control circuit components necessary for controlling the rotation of the fan driving motor are mounted on the printed board 44. That is, control circuit components such as a resistance element, a capacitor, and a diode are mounted on the printed board 44 so as to be located on the end bracket 7 side. At this time, for an element such as a capacitor having a dimension higher than the height of the storage chamber 43 in the axial direction, the lead portion is bent and formed, and
It is stored along the surface of. Also, as shown in the figure, in a high heating element such as the power transistor 45 and the control IC 46,
The cooling fins are closely attached to the inner surface of the end bracket 7 via an insulating sheet 47. That is, with respect to the high heat generating elements as described above, the entire end bracket 7 acts as a radiation fin for them. By arranging each element on the printed circuit board 44 and the heat dissipation structure as described above,
A control circuit required for rotation control is configured in a space with a small axial dimension, thereby making the device compact and reducing the number of external lead wires. The above-mentioned printed circuit board 44
The three Hall elements H (only one is shown in the figure) extend to the side of the stator 5 and can detect a change in the magnetic field depending on the rotational position of the rotor 4.

After assembling the rotor 4 and the stator 5 with the fan rotor 1 as described above, this assembly is assembled into an indoor unit of an air conditioner. FIG. 5 shows a mounting structure of a side plate (hereinafter referred to as a left side plate) 60 of the fan rotor 1 opposite to the side plate 2 to an indoor unit. As shown in the figure, a rotary shaft 61 is fixed to the axial center position of the left side plate 60, and the rotary shaft 61 is inserted into a bearing 63 attached to a main body frame 62 of the indoor unit. The left side plate 60 side is attached. The bearing 63 is mounted in a bearing outer body 64 press-fitted into a mounting hole of the main body frame 62. The bearing outer body 64 is made of an elastic material such as synthetic rubber and has Is provided with a spherical seat, and the bearing 63 having a spherical outer peripheral surface is mounted slidably along the spherical seat. Therefore, as will be described later, the rotation of the rotation shaft
When a force is generated to cause the bearing 61 to incline from the horizontal mounting state, a rotating operation corresponding to the direction of the inclination occurs in the bearing 63. As described above, the assembly structure that does not mechanically restrain the rotational runout of the fan rotor 1 and allows the rotational runout does not generate a reaction force when the restraint is attached to the main body frame 62. Of the fan rotor 1 is prevented from propagating. Further, in the above, since the outer bearing body 64 surrounding the bearing 63 is made of an elastic material, the propagation of vibration can be prevented more reliably. After mounting on the left side plate 60 side, the end bracket 7 fixed to the end portion of the fixed shaft 6 is screwed to the mounting surface of the main body frame. As a result, the fixed shaft 6 and the stator 5 fixed to the fixed shaft 6 are fixed in position, and the rotating body of the fan roller 1 and the rotor 4 is also rotatable by the fixed shaft 6. Will be supported.

Next, an operation state of the electric motor for driving a fan having the above configuration will be described.

As shown in FIG. 2, the three Hall elements H1 to H3 described above are arranged on the tip end sides of three adjacent poles of the stator 5, respectively.
Each permanent magnet according to the rotation position of the rotor 4 by H3
A change in the magnetic field due to 20 is detected. Upon receiving the detection signal, a drive signal is generated by the control IC 46 at a predetermined timing, whereby the energization of each coil 40 is periodically controlled, and a rotating magnetic field is generated on the stator 5 side.
In this way, the rotor 4 is rotationally driven by the rotating magnetic field on the side of the stator 5, and the rotation of the rotor 4 is transmitted to the fan rotor 1 to rotationally drive the fan rotor 1.

By the way, the fan rotor 1 has a long axial length and is made of a synthetic resin material having a rigidity lower than that of a metal material. More specifically, as described in Japanese Utility Model Publication No. 57-30471, for example, a large number of blades are installed in a cylindrical shape between circular blade support plates to form a short blade unit, and this blade unit is bonded. Etc. to form a long assembly having a predetermined axial length, and then the rotary shaft is fixed to the blade supporting plates located on both end faces of the assembly, or a connecting member is formed. The fan rotor 1 is constructed by performing the end surface processing required for the attachment of No. 3. Therefore, it is not easy to configure the assembly so that the center of gravity of the assembly coincides with the rotation axis. Therefore, the rotational runout accompanied by the warp such that the central portion side is eccentric to the outside causes the rotor 4, the bearing 41, and the fixed portion to rotate. When propagating along the shaft 6 to the mounting surface of the device, vibration and abnormal noise of the entire device occur, but in the above embodiment, the side plate 2 of the fan rotor 1 and the casing of the rotor 4 are generated. 15 and the fan rotor 1 through the connecting member 3 made of an elastic body.
The left side plate 60 also has the antivibration mounting structure as described above, and therefore, the operation of the entire device while suppressing the generation of vibration and noise can be performed.

However, since the rotor 4 causes an eccentricity that is allowed within the range of, for example, the assembly accuracy of the inner and outer rings of the bearing 41 due to the rotational runout on the side of the fan rotor 1, an air gap between the rotor 4 and the stator 5 is generated. Is not maintained uniformly over the entire circumference. Then, in order to allow such an operation in which the fluctuation of the air gap is allowed, the permanent magnet 20 is configured by a split type anisotropic magnet to enhance the magnetic force, and as described above, it is larger than the normal motor configuration. Giving an air gap. Furthermore, in order to make the magnetic force of the permanent magnet 20 act more effectively on the stator 5 side, it is necessary to minimize the leakage of the magnetic flux of the permanent magnet 20. Therefore, in the above embodiment, in order to fix the permanent magnet 20 in the axial direction,
In the lid 25 assembled in contact with the axial end surface of 20,
The contact area is configured to be a narrow portion on the outer peripheral surface side of the permanent magnet 20. That is, in the permanent magnet 20 that is magnetized in the radial direction, the inner peripheral surface side and the outer peripheral surface side have magnetic neutral points at the midpoints between the inner and outer peripheral surfaces and different polarities at the neutral points. The above is the lid
The fixing surface 37 of 25 is designed to contact only the pole area on the outer peripheral side of the neutral point. Therefore, even when the lid 25 is made of a magnetic material, the lid 25
Only acts as a magnetic path between the magnetic poles on the outer peripheral surface side between the adjacent permanent magnets 20 and 20, and the strength of the magnetic force acting from the inner peripheral surface side of the permanent magnet 20 to the stator 5 side is weakened. Therefore, the lid 25 can be made of a material having a low material cost, such as a cold-rolled steel sheet, which makes it possible to reduce the leakage flux and to reduce the manufacturing cost. Is there. At this time, in the above embodiment, the outer peripheral surface side of the permanent magnet 20 is doubly covered by the cylindrical portion of the lid 25 together with the cylindrical portion 18 of the casing 15. This makes it possible to reduce the thickness of the casing 15, which also reduces the leakage magnetic flux and the manufacturing cost. That is, even if the cylindrical portion 18 of the casing 15 is made thin, a magnetic path that does not saturate the magnetic flux density on the outer peripheral side of the permanent magnet 20 is provided together with the cylindrical portion of the lid 25, whereby the stator 5
The magnetic force acting on the side is not impaired, and a stable rotational driving force can be obtained. Then, as described above, the cylindrical portion 18
By making it thin, the thickness of the mounting portion 17 of the casing 15 connected to the cylindrical portion 18 is naturally thin, and as a result, even when the casing 15 is integrally formed of a magnetic material, the mounting portion 17 Since the magnetic resistance in the area becomes large, the leakage magnetic flux through the mounting portion 17 is reduced. The casing 15 as described above is formed by deep drawing using a cold-rolled steel sheet for deep drawing, for example, to form a cylindrical portion 17.
Since the mounting portion 18 and the central bulging portion 16 can be integrally manufactured, it is possible to manufacture at low material cost and processing cost.

Further, in the above embodiment, the permanent magnet 20 is attached to the mounting portion 17 of the casing 15 by the claw-shaped projection 27 in a state of being separated therefrom, and this also further prevents the leakage of the magnetic flux through the mounting portion 17. It can be suppressed. In particular, the tip portion of the claw-shaped projection 27 is formed in a semicircular shape, and therefore comes into point contact with each permanent magnet 20. In this way, the leakage magnetic flux is also reduced by minimizing the contact area of each permanent magnet 20 with the end face in the axial direction. Further, the claw-shaped projection 27 and the arcuate locking piece 26 are in contact with each other in the vicinity of the neutral point, so that the leakage magnetic flux can be reduced, and the adjacent magnetic poles of different poles can be connected to each other. In the mounting portion 17 of the casing 15 at the position between the permanent magnets 20, the slit opening of the cut-and-raised mark of the arcuate locking piece 26 extends in the radial direction, and therefore the leakage through the mounting portion 17 is caused. The magnetic flux is further reduced.

Further, in the above embodiment, by providing the lid 25 with the axial fixing function of the permanent magnet 20, and by providing the cylindrical portion having a length substantially the same as the axial length of the cylindrical portion 18 of the casing 15, Such a function as a magnetic path member is also provided, and the claw-shaped projection 27 and the arcuate locking piece 2 are also provided.
6. The central bulging portion 16 and the like can also be integrally formed by cutting and raising from the mounting portion 17 or by deep drawing, so that the structure can be further simplified and the manufacturing cost can be reduced. .

As described above, in the above embodiment, the lid 25 is configured so as to be in contact with the permanent magnet 20 on the outer peripheral side from the neutral point, so that the leakage of the magnetic flux through the lid 25 does not occur, The lid 25 can be formed of a steel plate or the like having a low material cost together with the casing 15, so that the rotor 4 with reduced leakage flux can be manufactured at a low cost.

In the fan device described above, the central bulging portion 16
A bearing 41 is provided inside, and the rotor 4 is rotatably supported by the fixed shaft 6 via the bearing 41. That is, the fan rotor 1 and the rotor 4 are connected by the connecting member 3 on the outer peripheral side away from the shaft center, and the rotor 4 is rotatably supported by the fixed shaft 6 on the shaft center side. Since the directional space is commonly used for the connection and the rotation support, the axial size of the device can be further reduced. In the above embodiment, the rotor 4 is rotatably supported on the tip side of the fixed shaft 6 to which the stator 5 is fixed, and the fixed shaft and the rotary shaft are arranged side by side as in the conventional device. Since it is not necessary to do so, the structure is further simplified, and the number of assembling steps can be reduced and the assembling workability can be improved.

The above embodiment is not intended to limit the present invention, and various modifications can be made within the scope of the present invention. For example, in the above embodiment, the lid 25 and the fixed surface 37 contacting the end face of the permanent magnet 20 and the above. Although the example of the configuration having a cylindrical portion located on the outer peripheral side of the permanent magnet 20 has been described, for example, a ring-shaped flat plate shape that is in contact with the end surface of the permanent magnet 20 is used, while the opening end of the cup-shaped casing has a radius. It is also possible to further provide a flange portion extending outward in the direction and to fix the flat plate-like lid body to the flange portion with a screw. Further, in the above description, the material of the casing 15 and the like has been described by taking the cold-rolled steel sheet as an example, but it may be made of another soft magnetic material such as a silicon steel sheet. Further, the above is an explanation of an example in which it is configured as a fan motor of a DC brushless motor type for rotationally driving a crossflow fan, but the present invention can be applied to other types of electric motors and even generators. .

(Effect of the Invention) As described above, in the rotary electric machine of the present invention, the lid for fixing the permanent magnet in the axial direction is provided with only the magnetic pole area outside the neutral point between the different magnetic poles of the permanent magnet. Since it is configured to contact with, it is possible to suppress the generation of leakage magnetic flux on the inner arc surface side of each permanent magnet, and therefore the lid together with the casing can be made of an inexpensive material such as cold-rolled steel plate. It is possible to manufacture a rotor or the like with reduced leakage magnetic flux at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a fan device to which the present invention is applied and which is shown in FIG.
A sectional view taken along line II-II, FIG. 3 is a front view of a permanent magnet used in the fan device, FIG. 4 is an exploded perspective view of the fan device, and FIG. 5 is a left side plate of a fan rotor in the fan device. FIG. 6 is a sectional view showing a mounting structure, and FIG. 6 is a sectional view of a conventional device. 4 ... Rotor, 15 ... Casing, 17 ... Mounting part, 18 ...
… Cylindrical part, 20 …… Permanent magnet, 25 …… Lid body.

Claims (1)

[Scope of utility model registration request] 1. A casing (15) having a mounting portion (17) substantially orthogonal to a rotation axis and a cylindrical portion (18) extending in the axial direction from the outer peripheral edge of the mounting portion (17) is provided and divided into an arc shape. A plurality of configured permanent magnets (20 · · · 20) are arranged along the inner peripheral portion of the cylindrical portion (18) at intervals, and the outer peripheral portion of the cylindrical portion (18) of the casing (15). A lid (25) which is attached to the cylindrical part (18) and has a fixing surface (37) extending in a direction covering the opening of the cylindrical part (18). The permanent magnet (20) is attached to the rotor (4) or the stator (5) by sandwiching the permanent magnet (20) between the mounting portion (17) and the fixing surface (37) of the lid (25). On the other hand, the inner circular arc surface (Si) of each of the permanent magnets (20 ... 20) is connected to either the stator (5) or the rotor (4) on the other side. The permanent magnets (20) face each other in the radial direction such that the permanent magnets (20) face each other in the radial direction so as to have different poles in the radial direction, and face the circumferential side faces of the stator (5) or the rotor (4). In the rotating electric machine in which the magnetic poles of the permanent magnets (20) adjacent to each other on the inner circular arc surface (Si) are different from each other, the casing (15) and the lid (25) are magnetized. Consists of the body,
Further, in the lid (25), the inner peripheral edge of the fixing surface (37) is located on the outer peripheral side of the permanent magnet (20) on the outer peripheral side with respect to the midpoint between the inner and outer peripheral surfaces of the end surface of the permanent magnet (20) on the casing opening side. 20) A rotary electric machine characterized in that it is configured to contact the end face of 20).