JPH0746043Y2 - 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 such as an AC induction electric motor is separately provided. 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 rotor 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 apparatus by directly connecting the rotor of the DC brushless motor to the side plate of the fan rotor. 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. 9. As shown in FIG.
A casing 83 of a rotor 82 of the DC brushless motor is fixed to the outer end surface of one side plate 81 of 80, and a ring-shaped permanent magnet 84 is fixed to the inner peripheral surface of the cylindrical portion of the casing 83 by adhesion or the like. Has been done. In this way, the fan rotor 80 directly connected to the rotor 82 is rotatably supported by the support frame by the rotating shafts extending outward from both ends thereof. 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 rotational force is induced on the rotor 82, whereby the fan rotor 80 is rotationally driven. 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) In the apparatus having the above-mentioned structure, the ring-shaped permanent magnet 84 is attached such that different magnetic poles of the N pole and the S pole appear alternately on the inner peripheral surface in the circumferential direction. The permanent magnet 84 is magnetized and is housed in the cup-shaped casing 83 of the rotor 82. That is, the casing 83 has a permanent magnet 84.
And a side surface fixed to the side plate 81 of the fan rotor 80. The cylindrical portion serves as a mounting surface for the permanent magnet 84, and the permanent magnet 84
It is necessary to have a function as a magnetic path on the outer peripheral side with respect to, so that the cylindrical portion is made of a magnetic material such as a steel plate. However, on the side surface integrally formed with the cylindrical portion, the axial end surface of the permanent magnet 84 is in contact with the inner peripheral surface of the permanent magnet 84. , The magnetic flux that should originally act on the side of the stator 89 leaks through the side surface of the casing 83, especially between adjacent magnetic poles, which reduces the magnetic force acting on the stator 89 and obtains the necessary rotational drive force. I will not be able to. Therefore, in practical use, the cylindrical portion surrounding the outer circumference of the permanent magnet 82 is made of a magnetic material, and the side surface that is located at the end surface of the permanent magnet 82 and is a mounting surface to the fan rotor 80 is made of a non-magnetic material. There is a problem that a casing becomes necessary and the structure becomes complicated.

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 of magnetic flux of a permanent magnet with a simple configuration.

(Means for Solving Problems) Therefore, the rotary electric machine according to the present invention includes the rotor 4 or the stator 5.
A cylindrical portion 18 is provided on one casing 15 and a plurality of permanent magnets 20 ... 20 divided into arcs are arranged along the cylindrical portion 18 at intervals, and one of the circular arc surfaces is formed.
Si is made to face the peripheral side surface of the stator 5 or the rotor 4,
Further, each of the permanent magnets 20 is magnetized in the radial direction so that there are different poles in the radial direction, and in the arc surface Si facing the peripheral side surface of the stator 5 or the rotor 4, the permanent magnets adjacent to each other.
A rotary electric machine in which the magnetic poles of 20 are arranged to be different from each other, the casing 15 is made of a magnetic material, and the casing 15 is connected to the cylindrical surface 18 and covers the axial end surface of the permanent magnet 20. On the side surface 17 of the
A through hole 38 for increasing the magnetic path resistance between the magnetic poles adjacent to each other in the circumferential direction is provided.

(Operation) In the above rotary electric machine, since the casing 15 is made of a magnetic material, the cylindrical surface 18 of the casing 15 opposes the side of the permanent magnet 20 facing the stator 5 or the rotor 4. A magnetic path is provided for the side surface. The side surface 17 of the casing 15 is provided with a through hole 38 between the magnetic poles adjacent to each other in the circumferential direction, whereby the magnetic path resistance through the side surface 17 is increased. , The side surface 17 between the adjacent magnetic poles of the permanent magnet 20.
Leakage of magnetic flux through the is reduced. Therefore, leakage of magnetic flux can be reduced with a simple structure in which the cylindrical surface 18 and the side surface 17 are integrally formed of a magnetic material.

(Example) Next, a specific example of the rotary electric machine of the present invention will be described.
A detailed description will be given with reference to the drawings.

First, FIG. 2 is an assembly sectional view of an apparatus in one 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. Fixing screw holes are bored at appropriate positions on the end surface of the end bracket 7, and the end surface of the end bracket 7 is attached to the second side plate of the fan housing, which is a mounting surface inside the indoor unit of the air conditioner. The right side plate 8 shown by a chain double-dashed line in the figure is fixed by screws. 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 a cylindrical portion 12 surrounding the through hole 11, and a side plate side fixing surface 13 and a rotor side fixing surface 14 which respectively spread radially 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, a side surface (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 position of the side surface 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. Fixed attachment is performed by adhesion to the side surface 17 of the casing 15.

Next, the structure of the rotor 4 will be described with reference to the exploded perspective view of FIG. The rotor 4 includes the casing 15 and
It is composed of four permanent magnets 20 and a substantially cylindrical lid 25. The casing 15 extends to the right side in the drawing from the side surface 17 fixed to the side plate 2 of the fan rotor 1 via the connecting member 3 and the outer peripheral edge of the side surface 17 and opens at the right end surface as described above. It is formed in a cup shape including the cylindrical surface 18. Then, in order to fix the permanent magnets 20 along the cylindrical surface 18, the side surface 17 is divided into four concentric circles inward from the cylindrical surface 18 at the opening end side. The four substantially arcuate locking pieces 26 ··· 26 that have been cut and raised, and the short lengths cut and raised at two positions each on the circumference between these locking pieces 26 · · 26 The claw-shaped protrusions 27 ... 27 are formed. On the other hand, as shown in FIG. 3, each of the permanent magnets 20 has a cylindrical surface 18 of the casing 15.
Is formed into a shape having an arc length that divides the inner circumference of the above into approximately four equal parts. Although its shape will be described in detail later, inclined surfaces 52 and 52 that are inclined with respect to the radial direction are formed at both ends in the circumferential direction, respectively, and between the inclined surfaces 52 of the adjacent permanent magnets 20. , A tapered gap is formed that gradually narrows outward in the radial direction. 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 points of the respective locking pieces 26 are formed on the outer peripheral surface side from the abutting position, and as a result, in the abutting state, the respective locking pieces 26 are bent and deformed radially inward. In the generated state, the elastic reaction force acts as a force for pressing the permanent magnets 20 to the outer peripheral surface side. This pressing force acts on the inclined surfaces 52, 52 as described above, and as a result, acts as a force that presses each permanent magnet 20 outward in the radial direction to bring it into close contact with the cylindrical surface 18 of the casing 15, and It also acts as a pressing force 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. 2, the arcuate locking piece 26 is formed in a substantially arcuate shape such that the open end (right end in the figure) side of the casing 15 is curved in the axial direction, and therefore Each of the permanent magnets 20 is pushed axially leftward along the cylindrical surface 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 axial fixing in this assembled state is performed by each permanent magnet.
The left end surface of 20 comes into contact with the tip portion of the above-mentioned claw-shaped projection 27, so that positioning is first performed on the left end side. In this state, the axial center portion of the locking piece 26 abuts the axial center portion of each permanent magnet 20. The claw-shaped protrusion
As shown in FIG. 3, the reference numerals 27 are adapted to abut on the permanent magnets 20 at two points on both ends thereof. Then, at this time, as shown in FIG.
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 magnet 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 peripheral surface of the cylindrical surface 18 of the casing 15. The lid 25 has a fitting hole 35 formed at an appropriate position on its peripheral side surface.
On the other hand, on the cylindrical surface 18, arcuate locking pieces 36 are formed at positions corresponding to the fitting holes 35 so as to project outward in the radial direction. 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. . At this time, the lid 25
The right end surface of the is provided with a fixing surface 37 that is bent inward in the radial direction and slightly covers the outer peripheral side of each end surface of each permanent magnet 20 over the entire circumference. Each permanent magnet 20 is sandwiched between the projection 27 and
Axial fixation is performed. 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 5 have mutually different poles, that is, the four-pole field state of NSNS. Each of the permanent magnets 20 as described above is composed of an anisotropic magnet made of ferrite, for example. As described above, as a result of being composed of split magnets that are uniformly magnetized for each magnetic pole, and each of which is composed of an anisotropic magnet, the magnetic force can be made significantly stronger than before, and therefore, these permanent magnets can be used. The inner peripheral surface of the magnet 20,
It is possible to provide a relatively large gap between the outer peripheral surface of the stator 5 described later, that is, an air gap of 1.5 to 2 mm.

The permanent magnets 20 have the same shape, and both end portions in the circumferential direction are provided with symmetrical end face shapes 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 5 parallel to the center line 1 are provided from the outer peripheral surface So toward the inner peripheral surface Si.
0, a minimum gap imparting surface 51 parallel to the radial line m slightly on the center line 1 side of the radial line m, and an inclined surface 52 extending to the center line 1 side parallel to the horizontal plane p are sequentially formed, and A fitting surface 53, which is parallel to the radial line m and is spaced apart from the radial line m from the minimum gap providing surface 51, is formed and is continuous with 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 that can tolerate shape processing errors. The inclined surface 52 has an inner peripheral surface Si and an outer peripheral surface.
It is formed in the vicinity of the midpoint in the radial direction with So (hereinafter referred to as the neutral point), and is the surface with which the arcuate locking piece 26 abuts, as described above. The fitting surface 53 provides a clearance into which the arcuate locking piece 26 is fitted from the radially inner side toward the inclined surface 52, and the clearance b is a clearance (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, 20 is reduced, and the magnetic force acts more effectively on the stator 5 side. Further, on the side surface 17 of the casing 15 of the rotor 4, the through hole 38 obtained as a cut and raised mark of each of the arcuate locking pieces 26 has a shaft center from the position between the adjacent permanent magnets 20 of different polarities. It is formed in a slit shape extending in the direction, and this also reduces the leakage magnetic flux through the side plate 17, as described later.

Next, the assembling of the stator 5 to the rotor 4 will be described. As described above, the central bulging portion 16 on the axial center side of the side surface 17 of the casing 15 serves as a bearing storage chamber 39 in its inner space. That is, the bearing 41 is inserted into the bearing storage chamber 39 by press fitting or the like. In this bearing 41,
By inserting the tip side of the fixed shaft 6 into the inner space of the rotor 4, as shown in FIG. 3, the stator 5 having 6-pole magnetic poles formed in a star shape is concentrically formed. As a result, the fan driving electric motor is configured.
Reference numeral 40 in the figure denotes a coil wound around each magnetic pole of the stator 5. As shown in FIG. 2, the stator 5 is fixed to the fixed shaft 6 at a substantially central position. This fixed shaft 6
In FIG. 2, the tip on the left end side is formed in a taper shape, and the tapered portion to the base end side is a small diameter portion,
Further, it is formed as a shaft portion having a step portion to which the stator 5 is fixed. Then, by inserting the fixed shaft 6 through the central opening of the fixed surface 37 of the lid 25 described above on the axis, the bearing 41 of the bearing 41 attached to the inner surface of the central bulging portion 16 of the casing 15 is inserted. The small diameter part of the fixed shaft 6 is inserted into the center hole. 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 formed on the outer periphery of the end bracket 7, and a space surrounded by the cylindrical portion 42 is a control circuit component storage chamber 43. A disk-shaped printed circuit board 44 is disposed in the storage chamber 43, and control circuit components necessary for controlling the rotation of the fan driving motor are attached to the printed circuit 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, with respect to an element such as a capacitor having a size higher than the axial height of the storage chamber 43, the lead portion is bent and stored along the surface of the printed circuit board 44. Further, as shown in the figure, in the high heat generating elements such as the power transistor 45 and the control IC 46, those cooling fins are provided on the inner surface of the end bracket 7,
It is attached closely via an insulating sheet 47. That is, for the high heat generating element as described above, the end bracket 7
The whole is designed to act as their heat radiation fins. 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 pulling it out. We are trying to reduce the number of wires. It should be noted that three Hall elements H (only one is shown in the drawing) from the printed circuit board 44 extend to the side of the stator 5 so that a change in the magnetic field depending on the rotational position of the rotor 4 can be detected. ing.

After the rotor 4 and the stator 5 are assembled to the fan rotor 1 as described above, this assembly is assembled to the indoor unit of the 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 on the side opposite to the side plate 2 to the indoor unit. As shown in the figure, the left side plate
A rotary shaft 61 is fixed to the axial center position of 60, and the rotary shaft 61 is mounted on a main body frame 62 of the indoor unit.
The left side plate 60 side is attached by inserting it through the 63. The bearing 63 is mounted in a bearing outer body 64 press-fitted into a mounting hole of the main body frame 62, and the bearing outer body 64 is made of an elastic material such as synthetic rubber and has an internal structure. Is formed with a spherical seat, and the bearing 63 having a spherical outer peripheral surface is mounted slidably along the spherical seat. Therefore, as described below,
When a force that causes the rotation shaft 61 to tilt from the horizontally mounted state is generated by the rotational runout of the fan rotor 1, the bearing 63 is rotated in accordance with the tilt direction. As described above, by using the assembly structure in which the rotational runout of the fan rotor 1 is not mechanically restrained and the rotational runout is allowed, a reaction force at the time of restraint attachment is not generated in the main body frame 62, and as a result, the main body frame 62 Propagation of vibration due to rotational runout of the fan rotor 1 is prevented. 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 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 rotor 1 and the rotor 4 is also rotatable by the fixed shaft 6. Will be supported.

Next, the operating state of the fan driving electric motor having the above configuration will be described.

The three Hall elements H1 to H3 described above are, as shown in FIG. 3, on the tip side of three adjacent poles of the stator 5,
These Hall elements H1 to H3 are arranged respectively, and the change of the magnetic field by each permanent magnet 20 according to the rotational position of the rotor 4 is detected by these Hall elements H1 to H3. 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 fixed 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, and therefore, a rotational runout accompanied by a warp such that the central portion side is eccentric outward is likely to occur.
Such a rotational runout on the side of the fan rotor 1 causes the rotor 4,
When propagating through the bearing 41 and the fixed shaft 6 to the mounting surface of the device, vibration and noise of the entire device occur, but in the above-described embodiment, rotation of the side plate 2 of the fan rotor 1 and rotation of the fan rotor 1 are prevented. The casing 15 of the child 4 is connected via the connecting member 3 made of the elastic body described above, and the left side plate 60 of the fan rotor 1 also has the vibration-proof mounting structure as described above.
For this reason, it is possible to perform operation while suppressing the generation of vibration and abnormal noise of the entire device.

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 the rotor 4 having a simplified structure, the leakage of the magnetic flux is reduced by the slit-shaped through holes 38 obtained as cut and raised marks of the arcuate locking pieces 26, for example. In other words, the cylindrical surface of the casing 15 that houses each permanent magnet 20 inside
18 forms a magnetic path on the outer peripheral surface side of the permanent magnet 20,
It is formed of a plate material made of a soft magnetic material such as a steel plate.
Then, in order to rotatably support the rotor 4 on the fixed shaft 6, the rotor 4 extends from the cylindrical surface 18 to the axial center side, and the permanent magnet 20
The through-holes 38 are formed in the side surface 17 that covers the axial end faces of the through-holes 38, and these through-holes 38 are formed from the positions where the respective end portions of the adjacent permanent magnets 20, 20 of different polarities face each other. It extends to the heart. Therefore, the magnetic path via the side surface 17 between the magnetic poles on the inner peripheral surface side of the adjacent permanent magnets 20 and the magnetic poles is
The through hole 38 is provided as a path that bypasses the axial center side. Therefore, the magnetic path resistance increases, and as a result, the leakage of magnetic flux through the side surface 17 between the adjacent permanent magnets 20, 20 is reduced, and the magnetic force acts more effectively on the stator 5 side. It will be. Further, the leakage magnetic flux is further reduced not only by the through hole 38 but also by the claw-shaped projection 27 in the embodiment. That is, the permanent magnet 20 is attached to the side surface 17 in a state of being separated from each other by the claw-shaped projections 27, and particularly the tip end portion of the claw-shaped projection 27 is formed in a semicircular shape. Therefore, the permanent magnets 20 come into contact with each other in a point contact state so as to provide a large magnetic resistance between the permanent magnets 20 and the side surfaces 17. Therefore, the above side
The leakage of magnetic flux through 17 is suppressed. Further, the fixing surface 37 of the lid body 25 for fixing the right end side of each of the permanent magnets 20 is configured to contact only the narrow portion on the outer peripheral surface side of each permanent magnet 20, and thus the lid body 25 side also has a magnetic flux. It is configured to suppress the leakage of. Further, the claw-shaped protrusion 27 and the arcuate locking piece 26 are in contact with each other in the vicinity of the neutral point to reduce the leakage magnetic flux.

Even when the side surface 17 of the casing 15 and the cylindrical portion 18 are integrally formed of a magnetic material as described above, leakage of magnetic flux is suppressed, and the lid 25 is also the same. It can be made of a low-priced material such as cold-rolled steel sheet for drawing, and thus the manufacturing cost can be reduced. Further, in the above embodiment, the through hole 38 is obtained as a cut and raised mark of the arcuate locking piece 26, and the claw-shaped projection 27
The central bulge 16 and the like can also be integrally formed by cutting and raising from the side surface 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 casing
On the side surface 17 of 15, at a position between the adjacent permanent magnets 20 and 20,
Since the through hole 38 that increases the magnetic path resistance between the two is formed, even in a simple structure in which the cylindrical surface 18 and the side surface 17 of the casing 15 are integrally formed, a configuration in which leakage of magnetic flux is reduced can be obtained. can do. Further, the casing 15 as described above can be formed of, for example, a steel plate whose material cost is low, and as a result, it can be manufactured at low cost.

Further, in the above fan device, a bearing 41 is provided in the central bulging portion 16, 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. Further, in the above embodiment, the fixed shaft 6 to which the stator 5 is fixedly attached.
Since the rotor 4 is also rotatably supported on the tip side of the device, there is no need to arrange a fixed shaft and a rotating shaft side by side as in the conventional device. Therefore, the structure is further simplified and the number of assembly steps is reduced. It is possible to reduce and improve assembly workability.

In the above-described configuration in which the through-hole 38 is provided, the shape of the through-hole 38 is appropriately changed to positively control the leakage amount of the magnetic flux of the permanent magnets, thereby changing the load torque on the fan rotor side, for example. It is also possible to allow various models to operate with high efficiency with a configuration in which changes in specifications are reduced. Examples of measurement data for explaining this are shown in FIGS. FIG. 6 shows the configuration described in the above embodiment (hereinafter,
Measurement data S of the magnetic flux density along the inner peripheral surface of one permanent magnet 20 in a steel plate casing), and a case where the casing 15 is replaced with a non-magnetic aluminum plate in the above configuration (hereinafter referred to as an aluminum casing) ) Shows the same measurement data Al as above. As shown in the figure, the magnetic flux density is slightly reduced in the steel plate casing as compared with the case of the aluminum casing in which the leakage of the magnetic flux through the side surface of the casing does not occur. 7 and 8 show measured data of the rotational speed and torque of the steel plate casing S and the aluminum casing Al, and the rotational speed and operating efficiency. Fig. 7 shows that while the rotation speed is small,
In the case of an aluminum casing with a large magnetic flux density, a larger torque can be obtained at the same rotation speed, but as the rotation speed increases, the counter electromotive force generated in the stator coil becomes
Since the magnetic flux density increases according to the magnetic flux density from the permanent magnets, it is shown that a larger torque can be obtained at the same rotation speed in the case of a steel plate casing having a small magnetic flux density. When a fan rotor having a relatively small load torque as shown by a load torque curve F in the figure is driven to rotate at a high rotation speed, as shown in FIG. 8, for example, a rotation speed of 1400 rpm When the value exceeds, the steel plate casing S has higher operating efficiency than the aluminum casing Al. This shows that when the load torque differs depending on the shape of the fan rotor side, etc., the efficiency changes by increasing or decreasing the strength of the magnetic field that acts on the stator from the permanent magnets according to the operating speed. And, in the above embodiment, by adjusting the magnetic path resistance by changing the shape such as the length and width to the axial center side of the through hole 38, thereby controlling the leakage magnetic flux amount, other Without changing the specifications
The operation can be performed with increased efficiency.

The above embodiment is not limited to this invention, and various modifications can be made within the scope of this invention. For example, in the above embodiment, the through hole 38 is formed as a cut and raised mark of the arcuate locking piece 26. However, in the configuration in which the permanent magnet is arranged in the casing by adhesion or the like, for example, the through hole as described above is uniquely formed at a position corresponding to the adjacent magnetic poles of the permanent magnet. Of course, it is possible. Further, although the above embodiment describes the configuration in which the permanent magnets 20 are arranged on the outer peripheral side of the stator 5, the present invention can be applied to a structure in which the stator and the permanent magnets are provided inside out. Further, in the above description, the material of the casing 15 is described by taking the cold-rolled steel sheet as an example, but it may be made of other soft magnetic materials such as 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, a through hole is formed on the side surface of the casing at a position between the adjacent magnetic poles of the permanent magnet to increase the magnetic path resistance therebetween. Therefore, since leakage of magnetic flux through the side surface of the permanent magnet is suppressed, it is possible to integrally form the cylindrical surface and the side surface of the casing with a magnetic material,
Therefore, it is possible to reduce the leakage of the magnetic flux of the permanent magnet with a simple configuration.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an apparatus according to an embodiment configured as a fan device to which the present invention is applied, FIG. 2 is a sectional view of a main part of the fan device, and FIG. 3 is a III-III line in FIG. 4 is a front view of a permanent magnet used in the fan device, FIG. 5 is a cross-sectional view showing a mounting structure of a left side plate of a fan rotor in the fan device, and FIG. 6 is a rotation in the fan device. Measurement data of the magnetic flux density along the inner peripheral surface of the permanent magnets respectively arranged in the child casing and the aluminum casing, FIG. 7 is measurement data of torque and rotation speed, FIG. 8 is efficiency measurement data, and FIG. FIG. 9 is a sectional view of a conventional device. 4 ... Rotor, 5 ... Stator, 15 ... Casing, 17 ... Side,
18 ... Cylindrical surface, 20 ... Permanent magnet, 38 ... Through hole.

Claims (1)

[Scope of utility model registration request] 1. A casing (15) of one of a rotor (4) and a stator (5) is provided with a cylindrical portion (18), and a plurality of arc-shaped permanent magnets (20 ... 20) are provided. Above cylindrical part (1
8) along with a space, and one of the circular arc surfaces (Si) faces the peripheral side surface of the stator (5) or the rotor (4). ) Is magnetized in the radial direction so that different poles exist in the radial direction, and in the arc surface (Si) facing the peripheral side surface of the stator (5) or the rotor (4), adjacent permanent magnets ( 20) is a rotary electric machine in which the magnetic poles are arranged so that the magnetic poles are different from each other, the casing (15) is made of a magnetic material, and is connected to the cylindrical surface (18) and the shaft of the permanent magnet (20). The side surface (17) of the casing (15) covering the end face in the direction is formed with a through hole for increasing the magnetic path resistance between the magnetic poles adjacent to each other in the circumferential direction of the permanent magnet (20). (38)
A rotary electric machine characterized by being provided with.