JP4352766B2 - Method for manufacturing brushless motor for electric power steering apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a brushless motor for an electric power steering apparatus including a rotor in which a plurality of cylindrical permanent magnets are fixed to the outer periphery.
[0002]
[Prior art]
As a conventional rotor, in a rotor of a prime mover constructed by adhering a cylindrical permanent magnet to a shaft, a fluid type silicone rubber adhesive having a longitudinal elastic modulus after heat curing in a predetermined value range is used as an adhesive. Some were characterized by use. Adhesive is an adhesive in the gap between the shaft and the cylindrical permanent magnet when a fluid type fluid silicone rubber system having a viscosity in a predetermined value range is applied to the outer periphery of the shaft and a cylindrical permanent magnet is inserted into the shaft. The adhesive of other parts flows to the part where the unevenness is applied, and the whole is averaged. Further, there is a neodymium sintered magnet (Nd-Fe-B) cylindrical permanent magnet that is divided into two in the longitudinal direction. In addition, as a conventional method for manufacturing a rotor, in a rotor of a prime mover configured by adhering a cylindrical permanent magnet to a shaft, an adhesive having a fluid viscosity is applied to a portion of the shaft surface where the cylindrical permanent magnet is bonded. After applying and inserting a cylindrical permanent magnet into the portion, there is one characterized in that the adhesive is cured by heating at a predetermined temperature for a predetermined time (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-8-223838 (“Claim 1”, “Claim 2”, paragraphs [0009], “0013”, FIG. 2)
[0004]
[Problems to be solved by the invention]
In the conventional rotor and its manufacturing method, there is no description about the protrusion of the adhesive from the bonding surface, but the necessary adhesive strength is ensured in consideration of the dimensional variation of the shaft diameter and the magnet inner diameter and the variation of the coating amount. For this reason, there is a case where excess adhesive inevitably protrudes from the bonding surface. When the adhesive protrudes, it is necessary to remove the adhesive. When the adhesive is interfered with the stator core, there is a problem that noise is increased. When the gap size is increased in order to avoid the interference of the protruding adhesive, the performance is reduced and the rotating electrical machine is enlarged. In particular, when a plurality of cylindrical magnets are bonded in a state where the axial end surfaces of the magnets are in contact with each other on the bonding surface, the adhesive surface further protrudes from the contact surface, and the bonding surface is in the axial direction. Therefore, the adhesive filling is difficult to stabilize in the axial direction and the adhesive strength varies. In particular, a brushless motor for an electric power steering apparatus is required to have a small, high-performance motor with excellent safety, low noise and inertia.
[0005]
The present invention has been made to solve the above-described problems, and is an electric power steering system in which the protrusion of adhesive from the bonding surfaces of a plurality of cylindrical magnets is suppressed and the magnet fixing strength is excellent. It aims at providing the manufacturing method of the brushless motor for apparatuses .
[0006]
[Means for Solving the Problems]
[0007]
In the method for manufacturing a brushless motor for an electric power steering apparatus according to the present invention, a cylindrical stator core, and a yoke portion integrally formed on a rotor shaft disposed on the inner peripheral side of the stator core, A step portion formed integrally with the shaft and contacting one end of the magnet in the axial direction; a blank portion formed between the step portion and the yoke portion; and a plurality of portions bonded to the outer peripheral surface of the yoke portion. The cylindrical magnet, and an adhesive reservoir provided in at least one of a contact portion where the magnets contact each other in the axial direction and a facing portion where the contact portion of the yoke portion faces. A brushless motor for an electric power steering apparatus, comprising: a protruding portion in which the magnet protrudes axially from the yoke portion on the side opposite to the stepped portion; and a heat shrinkable tube covering the outer peripheral surface and both end surfaces of the magnet. A granulation method, between the yoke portion, the stepped portion, is formed during machining of both shafts grinding undercut portion, the outer peripheral surface and a plurality of cylindrical inner circumferential surface of the magnet of the yoke portion integrally formed on the sheet Yafuto A step of applying an adhesive to at least the yoke portion side, disposing the plurality of magnets on an outer peripheral surface of the yoke portion, a step of covering the outer peripheral surface of the plurality of magnets with a heat shrinkable tube, and the bonding A heating step of simultaneously curing the agent and shrinking of the heat shrinkable tube, and a step of magnetizing the magnet after shrinking the heat shrinkable tube.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. Figure 1 is the invention by that vehicles of the electric power steering apparatus for a brushless motor (hereinafter referred to as "motor".) In a cross-sectional view showing a motor portion of Figure 2 is the axial direction of the rotor 3 is a front view of the shaft, FIG. 4 is a sectional view of the magnet, and FIG. 5 is a sectional view showing a state in which the magnet is assembled to the shaft. In the following description, the same or corresponding parts in the drawings are denoted by the same reference numerals. In FIG. 1, reference numeral 1 denotes a motor. A stator 3 is fixed to the inner periphery of a frame 2 made of a steel plate by press-fitting or the like, and the rotor 4 is connected to the inner periphery of the stator 3 via a predetermined gap. It is arranged. The rotor 4 is rotatably supported by a bearing 6 provided on the housing 5 side made of aluminum and a bearing 7 provided on the frame 2 side.
[0009]
In the stator 3, a coiled bobbin 9 formed of nylon or the like is attached to a cylindrical stator core 8 in which electromagnetic steel plates are laminated, and the stator coil 11 is wound around 12 teeth 10 by concentrated winding. Has been. The wire diameter of the stator coil 11 is, for example, an enamel-coated copper wire of about φ1 to φ2, and the coil terminal 12 such as the start and end of winding of the stator coil 11 is a coil disposed on the side of the stator 3. A predetermined connection (for example, a three-phase Y connection) is made by the connection body 13. A power supply for supplying power to the motor 1 is connected to the connection terminal 14 provided in the coil connection body 13. In addition, the engaging claw 15 provided in the coil connecting body 13 is configured to be integrated with the stator 3 by engaging the coil bobbin 9.
[0010]
1 to 4, the shaft 16 of the rotor 4 includes a yoke portion 17 that is integrally formed with the shaft 16 and forms an iron core, and is a step portion that is integrally formed with the shaft 16 and has a diameter larger than that of the yoke portion 17. 18 is provided. The two neodymium iron-based magnets 19 having a cylindrical cross section are in contact with each other in the axial direction, and one end in the axial direction is in contact with the step portion 18 so that the position in the axial direction is regulated. Between the step portion 18 and the yoke portion 17 that are integrally formed with the shaft 16, there is a waste portion 20 that forms a liquid pool of adhesive. One magnet 19 has an axial length of about 30 mm and an outer diameter of about 45 mm.
[0011]
Further, in the yoke portion 17 to which the magnet 19 is bonded, a groove portion 23 that forms an adhesive reservoir portion 22 is provided in a facing portion 21a that faces the contact portion 21 with which the magnet 19 abuts. The groove 23 is installed at a position where the accumulated adhesive enters the groove 23 when the magnet 19 is placed at the bonding position and abuts each other when the magnet 19 is inserted into the yoke 17. ing. The corners of the groove 23, and a face-up 23a ing from the tapered surface or the like. The outer diameters of the yoke part 17, the step part 18, the Nusumi part 20 and the groove part 23 are all formed when the shaft 16 is machined. In particular, the yoke part 19 is formed with good coaxiality. The adhesive is applied at least on the yoke portion 17 side.
[0012]
Further, the outer peripheral surface of the magnet 19 is covered with a heat shrinkable tube 24 and is firmly covered with the heat shrinkable tube 24 which is shrunk by heating. Further, both end surfaces of the magnet 19 are also covered integrally with the outer peripheral surface by the contracted heat shrinkable tube 24. The heat shrinkable tube 24 is made of an electron beam cross-linked soft polyolefin resin or the like and is a tube having a thickness of about 0.05 to 0.1 mm.
[0013]
A silicon-based adhesive is applied to the outer peripheral surface of the yoke portion 17 and the inner peripheral surface of the magnet 19, and the magnet 19 is inserted from the opposite step side to dispose the magnet as shown in FIG. A heat-shrinkable tube 24 is placed on the outer peripheral surface and heated to cure the adhesive and shrink the heat-shrinkable tube 24 simultaneously to obtain the rotor 4 as shown in FIG. The heat-shrinkable tube 24 is covered in a state longer than the axial length of the magnet 19 and covers both end faces of the magnet 19 by contraction. Thereafter, the magnet 19 of the rotor 4 is magnetized to 8 poles.
[0014]
Next, the operation of the first embodiment configured as described above will be described. When electric power PWM (pulse width modulation) is supplied to the connection terminal 14 from a control device (not shown), the stator coil 11 that is three-phase Y-connected by the coil connection body 13 is energized to prepare for the rotor 4. The shaft 16 is rotated by electromagnetic action with the magnet 19, and the steering force of the steering can be assisted by the rotational force. The brushless motor for an electric power steering apparatus is a motor used at about 12V and about 50 to 100A. In particular, a small, high performance and inexpensive motor is required which is excellent in safety, responsiveness and quietness.
[0015]
The first embodiment is configured as described above, and since the reservoir portion 22 is provided in the facing portion 21a of the yoke portion 17 where the abutting portion 21 of the magnet 19 faces, the magnet 19 is bonded to the yoke portion 17 when it is disposed. The adhesive overflowing from the surface is accommodated in the pool portion 22, and the sticking out of the adhesive can be suppressed. In addition, the adhesive is replenished to the adhesive surface from the reservoir 22, so that the adhesive strength can be improved and stabilized. Since the pool portion 22 is provided at least in the facing portion 21a that the abutting portion 21 faces, the protrusion of the adhesive from the abutting portion 21 can be effectively suppressed, and the abutting portion 21, that is, the vicinity of the end of the magnet 19 By adhering with the adhesive accumulated in the accumulation portion 22, the adhesive strength can be improved and stabilized. In addition, the removal of the protruding adhesive can be reduced and the motor can be made inexpensive, and the adhesive can be prevented from protruding, so there is no interference with the stator core 8 and low noise can be achieved. A motor with good performance can be obtained.
[0016]
Further, since the yoke portion 17 is formed integrally with the shaft 16, it can be processed simultaneously with the shaft 16, the productivity is good, and the coaxiality is excellent, so that a motor with good rotation balance and low noise can be obtained. In addition, the number of parts is reduced as compared with the case where the separate yoke portion 17 is fixed to the shaft 16, and the coaxiality of the yoke portion 17 is also improved. Compared to the case where a separate yoke portion 17 made of a laminated core is fixed to the shaft 16, the adhesive does not penetrate into the laminated core, the rotational balance is not deteriorated, the adhesive does not protrude, and the adhesive strength is stabilized.
[0017]
Since the reservoir portion 22 is constituted by the groove portion 23 provided in the yoke portion 17, it can be easily formed at the time of processing the shaft 16, and the workability and the rotation balance are good, and if necessary, the size and number of the groove portions 23 are easy. There is an effect that can be changed. Further, the groove 23 is provided with a chamfer 23a, and it is difficult to remove the adhesive on the inner surface of the magnet 19, and the adhesive accumulated in the chamfer 23a and the groove 23 is easily supplied to the inner surface of the magnet 19, so that the adhesive strength is stable. To do.
[0018]
Since the step portion 18 is formed integrally with the shaft 16 and contacts one end in the axial direction of the magnet 19, the adhesive adheres to the step portion 18, and the protrusion of the adhesive is suppressed by that amount. Adhesive strength is improved by bonding the ends. The step portion 18 can be processed at the same time as the shaft 16 and can be easily formed. The step portion 18 easily positions the magnet 19 in the axial direction, and the assemblability is good and the rotation balance is improved. Further, since the nose portion 20 is provided between the step portion 18 and the yoke portion 17, the adhesive protruding from the adhesive surface accumulates in the nose portion 20, so that the sticking out of the adhesive is suppressed, and the end of the magnet 19 However, the adhesive strength is also improved by being bonded at the Nusumi portion 20.
[0019]
Since the outer peripheral surface of the magnet 19 is covered with the heat-shrinkable tube 24, the fixing strength of the magnet 19 increases and the protrusion of the adhesive from the contact portion 21 is suppressed. Even when the adhesive protrudes, the adhesive that protrudes due to the shrinkage of the heat shrinkable tube 24 does not rise in a thin film state on the outer peripheral surface of the magnet and is held by the heat shrinkable tube 24, thereby preventing interference with the stator core 8. Thus, a low noise motor can be obtained. Further, since the side surface of the magnet 19 is also covered with the heat shrinkable tube 24 and the entire outer surface of the magnet 19 is covered, it is possible to more effectively prevent the magnet 19 and the fragments of the adhesive from being scattered by centrifugal force. . Further, since the heat shrinkable tube 24 is made of a resin material, there is no loss of eddy current, and the motor can be downsized.
[0020]
A brushless motor for an electric power steering device is particularly required to have a small, high performance motor with excellent safety and low noise and inertia. By using the motor of the present invention, the brushless motor for an electric power steering device is required. A suitable motor can be obtained. In particular, since the reservoir portion 22 and the waste portion 20 are provided to prevent the adhesive from sticking out, and the outer peripheral surface and both end surfaces of the magnet 19 are covered with the heat shrinkable tube 24, the adhesive is applied to the inner periphery of the stator core 8. Small electric power with low noise, low safety, low inertia, etc., because it does not interfere with the surface, etc., and the scattering of the magnet 19 and the adhesive is prevented and the heat shrinkable tube 24 is light and there is no eddy current loss. A brushless motor for a steering device can be obtained.
[0021]
Further, since the magnet 19 is magnetized after the heat shrinkable tube 24 is shrunk, there is no magnetic force before the heat shrinkable tube 24 is shrunk, and the magnet 19 can be covered with the heat shrinkable tube 24 in a state where no foreign matter is adsorbed. it is possible to obtain a suitable motor to the brushless motor for an electric power steering apparatus.
[0022]
An adhesive is applied between the outer peripheral surface of the yoke portion 17 integrally formed with the shaft 16 and the inner peripheral surfaces of the plurality of cylindrical magnets 19, and the plurality of magnets 19 are disposed on the outer peripheral surface of the yoke portion 17. The process includes a step of covering the outer peripheral surfaces of the plurality of magnets 19 with the heat-shrinkable tube 24 and a heating step of simultaneously curing the adhesive and shrinking the heat-shrinkable tube 24. Improves. Further, the shrinkage of the heat shrinkable tube 24 prevents the adhesive from protruding from the contact portion 21, and the contact portion 21 is covered by the heat shrinkable tube 24 even when the adhesive protrudes from the contact portion 21. Therefore, the protruding adhesive is pressed against the outer peripheral surface of the magnet 19 by the shrinkage of the heat shrinkable tube 24 and hardens in a thin film state, and is retained by the heat shrinkable tube 24 after being cured. A removal process can be dispensed with.
[0023]
In addition, by covering both end surfaces of the magnet 19 with the heat shrinkable tube 24, scattering of the adhesive and the magnet 19 can be more effectively prevented. Further, by providing the pool portion 22 in at least one of the contact portion 21 or the facing portion 21a of the magnet 19, an effect of further suppressing the protrusion of the adhesive from the contact portion 21 can be obtained.
[0024]
Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a sectional view of the rotor in the axial direction, and FIG. 7 is a sectional view of the magnet. A thinning portion 25 is provided on the inner peripheral surface side of the end surface in the axial direction of the magnet 19, and this thinning portion 25 constitutes an adhesive reservoir 22 provided in the contact portion 21 of the magnet 19. Yes. When the magnet 19 is inserted into the yoke portion 17, the adhesive accumulated on the end surface of the magnet is disposed at the position where the accumulated adhesive is accommodated in the thickness removal portion 25 when the magnet 19 is disposed at the adhesion position and abuts each other. 25 is installed. The length in the axial direction of the two magnets 19 is slightly longer than the length in the axial direction of the yoke portion 17 (dimension A in FIG. 6), and the magnet 19 extends axially from the yoke portion 17 on the opposite step side. The dimension has a protruding portion 26 that slightly protrudes. An adhesive is applied to the outer peripheral surface of the yoke portion 17 and the inner peripheral surface of the magnet 19, and the magnet 19 is assembled as shown in FIG. 6, and the adhesive is heated and cured.
[0025]
The second embodiment is configured as described above, and since the reservoir portion 22 is provided in the contact portion 21, the adhesive overflowing from the adhesive surface is accommodated in the reservoir portion 22 so that the protrusion of the adhesive can be suppressed. Since at least the pool part 22 is provided in the contact part 21, the protrusion of the adhesive from the contact surface can be effectively suppressed. Moreover, since the pool part 22 is the thinning part 25 provided in the magnet 19, it can be easily configured such that it can be formed at the same time as the magnet 19 is pressed. In addition, since the protruding portion 26 is provided, the adhesive that protrudes from the adhesive surface is held on the inner peripheral surface side of the protruding portion 26, so that it is possible to provide an advantageous configuration against the scattering of the adhesive.
[0026]
Embodiment 3 FIG.
A third embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a sectional view in the axial direction of the rotor, and FIG. 9 is a sectional view of the magnet. On both end surfaces of the magnet 19 in the axial direction, thinning portions 25 each having a tapered surface are provided on the inner peripheral surface side. The end surfaces of the thinning portion 25 are in contact with each other to form the pool portion 22, and the groove portion 23 provided in the facing portion 21 a of the contact portion 21 also forms the pool portion 22. The side constitutes a reservoir of adhesive. The reservoir 22 is provided with an O-ring 27 made of an elastic body that acts to press the contact portion 21 in the outer peripheral direction from the inner peripheral side. An adhesive is applied to the outer peripheral surface of the yoke portion 17 and the inner peripheral surface of the magnet 19, and the magnet 19 and the O-ring 27 are assembled as shown in FIG. 8, and the adhesive is heated and cured.
[0027]
The third embodiment is configured as described above, and the O-ring 27 is provided in the pool portion 22, so that the protrusion from the contact portion 21 can be further effectively suppressed. Since the O-ring 27 acts to press the abutting portion 21 in the outer peripheral direction, it is bonded with the clearance of the bonding surface made uniform, the coaxiality of the magnet 19 with respect to the yoke portion 17 is improved, and the rotation balance is excellent and the noise is low. Thus, a motor suitable for a brushless motor for an electric power steering apparatus with small cogging torque and torque ripple can be obtained. Further, the other side of the thinning portion 25 abuts on the step portion 18 to form a liquid reservoir of adhesive, and the thinning portion 25 on the opposite end surface side also forms a liquid pool of adhesive. The protrusion can be suppressed and the adhesive strength is also improved. Further, since the thinned portion 25 is provided on both sides of the magnet 19, there is no directionality when assembled, and the thinned portion 25 can be formed easily at the same time as the magnet 19 is pressed.
[0028]
Further, since the thinned portion 25 is a tapered surface, the applied adhesive is difficult to be removed when the magnet 19 is assembled, and the accumulated adhesive is easily replenished to the adhesive surface. Stabilize.
[0029]
Moreover, since the pool part 22 is comprised by the groove part 23 provided in the yoke part 17, and the thickness removal part 25 provided in the magnet 19, the protrusion of an adhesive agent can be suppressed more effectively.
[0030]
Embodiment 4 FIG.
A fourth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a sectional view of the rotor in the axial direction. The magnet 19 is the same as that shown in FIG. The end surfaces of the thinned portion 25 are in contact with each other, and a double-sided tape 28 serving as a sealing means is provided at the contact portion 21. The double-sided tape 28 has adhesiveness on both sides thereof, and is joined in a flexible state at the contact surfaces 21 of the two magnets 19. An adhesive is applied to the outer peripheral surface of the yoke portion 17 and the inner peripheral surface of the magnet 19, and the magnet 19 is assembled as shown in FIG. 10, and the adhesive is heat-cured.
[0031]
The fourth embodiment is configured as described above, and since the abutting portion 21 includes the double-sided tape 28 serving as a sealing means, the abutting portion 21 is sealed, and the protrusion of the adhesive can be suppressed. Since the two magnets 19 are joined in a flexible state by the double-sided tape 28, even if there is a slight misalignment between the inner diameter surfaces of the two magnets, the magnets can be smoothly assembled to the yoke portion 17. It is possible to suppress the removal of the adhesive or to suppress the protrusion. Further, since the thinned portion 25 is a tapered surface, the applied adhesive is difficult to be removed when the magnet 19 is assembled, and the adhesive accumulated in the thinned portion 25 is easily supplied to the adhesive surface, so Adhesive strength is also stabilized.
[0032]
Further, even when the two magnets 19 are individually assembled, the protruding portion of the adhesive can be suppressed by the pool portion 22, and the contact portion 21 is provided with the double-sided tape 28, so that the contact portion 21 is sealed. The sticking out of the adhesive can be suppressed.
[0033]
Reference Example A reference example of the present invention will be described with reference to FIG. FIG. 11 is a sectional view of the rotor in the axial direction. The magnets 19 are the same as those in FIG. 4, and the three magnets 19 are in contact with each other in the axial direction and bonded to the outer peripheral surface of the yoke portion 17. The facing portion 21 a corresponding to the abutting portion 21 of the magnet 19 has a groove portion 23, and constitutes an adhesive reservoir 22. The yoke portion 17 and the three magnets 19 have substantially the same axial length, and both end surfaces of the yoke portion 17 are provided with chamfers 29 formed of tapered surfaces.
[0034]
The reference example is configured in this way, and since the pooling portion 22 including the groove portion 23 is provided in the facing portion 21a of the contact portion 21, the adhesive can be prevented from protruding and the adhesive strength is improved. Since both end surfaces of the yoke portion 17 are provided with chamfers 29 each having a tapered surface, the applied adhesive is difficult to be removed when the magnet 19 is assembled, and the chamfer 29 forms a reservoir portion and accumulates adhesion. The agent is easily replenished to the adhesive surface and firmly adhered, and the adhesive force is stabilized.
[0035]
Moreover, since the step part 18 is not provided in FIG. 11, a motor with little inertia and a short axial dimension can be obtained. Further, by covering the outer surface of the magnet 19 in FIG. 11 with the heat shrinkable tube 24, it is possible to obtain a small motor that is further suppressed from protruding the adhesive and that has excellent rotational strength.
[0036]
[0037]
【The invention's effect】
[0038]
A cylindrical stator core, a yoke portion integrally formed with a rotor shaft disposed on the inner peripheral side of the stator core, and an axial end of the magnet that are integrally formed with the shaft. A stepped portion, a blank portion formed between the stepped portion and the yoke portion, a plurality of cylindrical magnets bonded to the outer peripheral surface of the yoke portion, and the magnets abutting each other in the axial direction An adhesive reservoir provided in at least one of the contact portion and the facing portion of the yoke portion facing the contact portion, and the magnet protrudes axially from the yoke portion on the opposite side. A brushless motor for an electric power steering apparatus comprising a projecting portion and a heat-shrinkable tube covering an outer peripheral surface and both end surfaces of the magnet , wherein the yoke portion, the stepped portion, and the Nusumi portion are Shaft mechanical processing Sometimes form, between the inner peripheral surface of the outer peripheral surface and the plurality of cylindrical magnets of the sheet Yafuto the yoke portion integrally formed, an adhesive is applied to at least the yoke portion, the yoke portion a step of disposing the outer peripheral surface of said plurality of magnets, a step of covering the heat shrinkable tube on an outer peripheral surface of the plurality of magnets, and a heating step of performing a curing and shrinkage of the heat shrinkable tube of the adhesive at the same time And the step of magnetizing the magnet after shrinking the heat-shrinkable tube , the adhesive sticking out is suppressed, the magnet fixing strength is excellent, the number of parts is small, the heating step is reduced, It is possible to obtain a method for manufacturing a brushless motor for an electric power steering apparatus that is excellent in productivity, such as eliminating the step of removing the protruding adhesive.
Since the protruding portion is provided, since the adhesive protruding from the adhesive surface is held on the inner peripheral surface side of the protruding portion, it can be configured to be advantageous for scattering of the adhesive,
Since the magnet is magnetized after shrinking the heat-shrinkable tube, there is no magnetic force before shrinking the heat-shrinkable tube, and it can be covered with a heat-shrinkable tube without foreign matter adsorbed. It can be suitable for a brushless motor.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a motor portion of a brushless motor for an electric power steering apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a sectional view in the axial direction of a rotor showing Embodiment 1 of the present invention.
FIG. 3 is a front view of a shaft showing Embodiment 1 of the present invention.
FIG. 4 is a cross-sectional view of a magnet showing Embodiment 1 of the present invention.
FIG. 5 is a sectional view in which a magnet is assembled to a shaft showing Embodiment 1 of the present invention.
FIG. 6 is a sectional view in the axial direction of a rotor showing Embodiment 2 of the present invention.
FIG. 7 is a sectional view of a magnet showing a second embodiment of the present invention.
FIG. 8 is a sectional view in the axial direction of a rotor showing a third embodiment of the present invention.
FIG. 9 is a sectional view of a magnet showing Embodiment 3 of the present invention.
FIG. 10 is an axial sectional view of a rotor showing Embodiment 4 of the present invention.
FIG. 11 is a sectional view in the axial direction of a rotor showing a reference example of the present invention.
[Explanation of symbols]
1 motor, 4 rotor, 8 stator core, 16 shaft, 17 yoke portion, 18-unit, 19 a magnet, 20 grinding undercut portion 21 contact portion, 21a opposing portion, 22 reservoir, 23 groove, 24 heat-shrinkable Tube, 25 Demineralized part, 26 Protruding part, 27 O-ring, 28 Double-sided tape (sealing means), 29 Chamfering.

Claims (1)

A cylindrical stator core, a yoke portion integrally formed with a rotor shaft disposed on the inner peripheral side of the stator core, and an axial end of the magnet that are integrally formed with the shaft. a stepped portion, and a grinding undercut portion formed between said stepped portion and the yoke portion, a plurality of cylindrical the magnet to be bonded to the outer peripheral surface of the yaw-click section, together the magnet in the axial direction a reservoir portion of the abutment portion abutting with the adhesive provided on at least one of said opposing portions abutment faces in the yoke portion, the shaft from the front Symbol yoke portion and the magnet in Handan side A method of manufacturing a brushless motor for an electric power steering apparatus , comprising: a projecting portion projecting in a direction; and a heat shrinkable tube covering an outer peripheral surface and both end surfaces of the magnet , wherein the yoke portion, the stepped portion, and the Nusumi portion Together with the mechanical processing of the shaft Sometimes form, between the inner peripheral surface of the outer peripheral surface and the plurality of cylindrical magnets of the sheet Yafuto the yoke portion integrally formed, an adhesive is applied to at least the yoke portion, the yoke portion a step of disposing the outer peripheral surface of said plurality of magnets, a step of covering the heat shrinkable tube on an outer peripheral surface of the plurality of magnets, and a heating step of performing a curing and shrinkage of the heat shrinkable tube of the adhesive at the same time And a step of magnetizing the magnet after contracting the heat-shrinkable tube. A method of manufacturing a brushless motor for an electric power steering apparatus .

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