JP2007221977A - Brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brushless motor where damage can be prevented and there is little vibration and noise by being able to constitute a rotor firmly. <P>SOLUTION: The brushless motor has a stator 1 and a rotor 5 which is fixed to a rotating shaft 10. The stator 1 is provided with a plurality of salient magnetic poles 2a which are arranged at equal intervals on the internal perimetric side of the core 2 of an armature, and also equipped with a stator coil 3 wound on each salient magnetic pole 2a. For the rotor 5, a permanent magnet 37 for a cylindrical field provided with two or more magnetic poles is engaged with a flanged permanent magnet field yoke 36, and the periphery of the permanent magnet 37 for the cylindrical field is covered with a magnetic pole cover, and constituted integrally with an adhesive layer 8 which is applied to the engaging face between the permanent magnet field yoke 36 and the permanent magnet 37 for cylindrical field. To partially thicken the adhesive layer 8, the peripheral face of the flanged permanent magnet field yoke 36 has with a plurality of rectilinear grooves 40 and at least one circumferential groove 41. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brushless motor, and more particularly, to a permanent magnet field-type brushless motor suitable for use in vehicle auxiliary equipment.

  In recent years, in order to reduce the fuel consumption of vehicles, vehicle auxiliary machines such as oil pumps that have been driven by an engine tend to be electrified. As a motor for driving these auxiliary machines, a permanent magnet field type brushless motor having a long life and a low failure rate has been used.

  As shown in FIG. 5, a conventional permanent magnet field brushless motor has a stator 1 and a rotor 5 fixed to a rotary shaft 10 in a housing 11 made of steel or the like, and a housing 11 on the output shaft side. A flange 12 that also serves as a cover made of aluminum alloy or the like is attached and fixed to the opening end side of the plate.

  The stator 1 is provided with a plurality of salient poles 2a for three phases arranged at equal intervals on the inner peripheral surface side of the armature core 2, and an insulator-made reel 4 disposed on each of the salient poles 2a. In addition, armature windings 3 that are connected in three phases are wound. A cable 13 is connected to the end of the armature winding 3 of each phase and pulled out of the housing 11, and a terminal 14 at the tip of the cable 13 is held by a connector housing 15 made of an insulator.

  Further, the rotor 5 includes a plurality of magnetic pole permanent magnets 7 arranged on the outer peripheral surface of a cylindrical permanent magnet field yoke 6 fixed to the rotating shaft 10 by mechanical means or the like, and an adhesive layer 8 of a heat resistant adhesive. The magnet cover 9 is provided so as to be fixed and to cover the magnetic pole permanent magnet 7 portion.

  Normally, in a permanent magnet field-type brushless motor, the current flowing through the armature winding 3 is determined by magnetic pole position information which is rotation angle information of the N pole and S pole of the magnetic pole permanent magnet 7 detected by the magnetic detection element 20. I have control. For this reason, a yoke and plate 18 that rotates in synchronization with the magnetic pole permanent magnet 7 is fixed to the rotary shaft 10, and a magnetic pole position detection permanent magnet 19 is held on the rotary shaft 10 to use the magnetic pole position information for acquisition. Indirect detection is performed by a magnetic detection element 20 such as a Hall element used as a position sensor.

  The magnetic detection element 20 is usually mounted on a printed circuit board 21 that is fixed to the flange 12 side, and is disposed opposite the magnetic pole position detection permanent magnet 19 with a predetermined interval. Further, the terminals of the magnetic detection element 20 are connected to the detection cable 22 through a conductor pattern formed in the printed circuit board 21, and are pulled out to the connector housing 15 outside the housing 11 like the cable 13. Yes. As is well known, the power of the magnetic detection element 20 is supplied from the outside of the motor through the detection cable 22 in the same manner as the current of the armature winding 3. The magnetic pole position signal detected by the magnetic detection element 20 is sent to the controller from the detection cable 22 drawn out of the motor.

  The magnetic pole of the magnetic pole position detecting permanent magnet 19 is magnetized so that the surface facing the magnetic detecting element 20 has the same relationship as the outer peripheral pole of the magnetic pole permanent magnet 7, that is, the angular position of the N and S poles. In addition, the permanent magnet 19 for detecting the magnetic pole position is fixed so that the current flowing in the armature winding 3 needs to be controlled with high accuracy, so that the deviation of the magnetic pole permanent magnet 7 from the magnetic pole position of the N-pole and S-pole angles. It is assembled to be as small as possible.

  On the other hand, the rotary shaft 6 provided with the stator 5 has bearings 16 and 17 fixed to the left and right by press-fitting or the like, respectively. , 12a are fitted and supported. Since the bearings 16 and 17 are fitted into a gap due to a difference in linear expansion from the bearing housings 11a and 12a due to a temperature rise during operation of the motor, for example, a C-shaped stopper that holds the side surface of the bearing 17 on the bearing housing 12a side in FIG. Wheels 22 are provided to restrict movement in the thrust direction due to vibration during operation.

  The structure of the brushless motor and the mounting structure of the magnetic detection element as described above are described in, for example, Patent Documents 1 to 3, and the like, and fixing the rotor to the rotating shaft with an adhesive is described in, for example, Patent Document 4 Etc. are described.

Japanese Patent Laid-Open No. 2-87959 JP-A-6-113520 JP 2002-10777 A Japanese Utility Model Publication No. 7-16558

  In the conventional brushless motor configuration described above, the small gap in the adhesive layer 8 between the permanent magnet field yoke 6 and the field permanent magnet 7 of the rotor 5 is misaligned with respect to the rotating shaft 10 of the field permanent magnet 7. There is a problem that the adhesive layer 8 must be formed by curing the adhesive while maintaining a certain small gap in order to suppress and secure the adhesive force, and to consider the magnetic characteristics. If the small gaps in the adhesive layer 8 are not uniform, the magnetic flux in the gap between the armature core 1 and the field permanent magnet 7 becomes unbalanced, the torque fluctuates significantly, and motor vibration and noise are generated. It becomes an increase factor.

  In addition to the shear stress due to the rotational torque generated in the field permanent magnet 7, the adhesive layer 8 generates tensile stress due to the centrifugal force generated by the rotation, so that the strength is insufficient when the thickness of the adhesive layer 8 varies. The field permanent magnet 7 may be peeled off.

  In general, the outer diameter of the field permanent magnet 7 is covered with a magnet cover 9 to prevent a part of the field permanent magnet 7 from being scattered even if it is peeled off, and the rotor 5 as a whole is not affected. However, if the field permanent magnet is peeled off, there is a risk that vibration and noise increase due to the movement.

  It is an object of the present invention to provide a brushless motor that has a rotor that is firmly configured to prevent damage and that is less susceptible to vibration and noise.

  The brushless motor of the present invention has a stator and a rotor that is fixed to a rotating shaft, and the stator includes a plurality of salient poles arranged at equal intervals on the inner peripheral surface side of the armature core, and An armature winding wound around each salient pole, and the rotor includes a permanent magnet field yoke fixed to a rotating shaft and a permanent magnet for the magnetic pole. A cylindrical permanent magnet for magnetic poles provided with a plurality of magnetic poles is fitted to a brazed permanent magnet field yoke having a portion formed thereon, and fixed integrally with an adhesive layer formed on the fitting surface. And

  Preferably, a plurality of linear grooves substantially parallel to the axial direction are provided on the outer peripheral surface of the permanent magnet field yoke.

  Preferably, at least one circumferential groove is provided on the outer peripheral surface of the permanent magnet field yoke.

  More preferably, a plurality of linear grooves and at least one circumferential groove substantially parallel to the axial direction are provided on the outer peripheral surface of the permanent magnet field yoke.

  Further, the brushless motor of the present invention has a stator and a rotor fixed to the rotating shaft, and the stator is provided with a plurality of salient poles arranged at equal intervals on the inner peripheral surface side of the armature core, Armature windings wound around the salient pole magnetic poles, and the rotor includes a permanent magnet field yoke and a permanent magnet for magnetic poles fixed to a rotating shaft, and the rotor is disposed on an outer peripheral surface. A cylindrical field permanent magnet provided with a plurality of magnetic poles on a brazed permanent magnet field yoke having a plurality of linear grooves and at least one circumferential groove substantially parallel to the axial direction and having a flange on one end side. The magnet is fitted so that the flange and the end face are in contact with each other, and the permanent magnet field yoke and the cylindrical field permanent magnet are fixed by an adhesive layer formed on the fitting surface, and the cylindrical field magnet is used. The outer surface of the permanent magnet is covered with a magnetic pole cover, and is configured integrally.

  If constituted as in the present invention, the rotor can be made into a strong integrated structure, so that a brushless motor with high mechanical strength and excellent reliability, low torque fluctuation, low vibration and low noise can be obtained.

  In addition, a plurality of linear grooves and at least one circumferential groove substantially parallel to the axial direction are provided on the outer peripheral surface, and a plurality of magnetic poles are provided on a brazed permanent magnet field yoke having a flange on one end side. The cylindrical field permanent magnet to be provided is fitted so that the flange portion is in contact with the end face, and the outer surface of the cylindrical field permanent magnet is covered with a magnetic pole cover from the flange side of the flanged permanent magnet field yoke. If the brazed permanent magnet field yoke and the cylindrical field permanent magnet are configured integrally with an adhesive layer applied to the fitting surface, a part of the adhesive layer can be thickened at the groove portion, so that the mechanical strength is further increased. It can be a strong and reliable brushless motor.

  The brushless motor of the present invention has a stator and a rotor fixed to a rotating shaft, and the stator is provided with a plurality of salient poles arranged at equal intervals on the inner peripheral surface side of the armature core. Armature windings wound around the salient pole magnetic poles, and a permanent magnet field magnet is provided by fixing a cylindrical field permanent magnet to the permanent magnet field yoke. In addition, the rotor includes an adhesive layer formed on the mating surface while fitting a cylindrical field permanent magnet having a plurality of magnetic poles to a brazed permanent magnet field yoke having a flange on one end side. Adhering to one piece.

  An embodiment of the brushless motor of the present invention will be described below with reference to the drawings in which the same parts as those in the prior art are denoted by the same reference numerals. As shown in FIG. 1, the rotor 5 of the present invention has a cylindrical field that forms a plurality of magnetic poles for each phase on a brazed permanent magnet field yoke 36 that is fitted and fixed to a rotating shaft 10 as will be described in detail later. A permanent magnet field 37 is fixed to constitute a permanent magnet field.

  Then, the magnetic detection element 20 is arranged on one end face of the cylindrical field permanent magnet 37 through a small gap so as to detect the magnetic pole position information of each phase. The magnetic detection element 20 detects the rotation angle information of the N and S poles of each phase of the cylindrical field permanent magnet 37 and controls the current flowing through the armature winding 3.

  The magnetic detection element 20 is connected to internal wiring by fixing each phase component at a predetermined position on the printed circuit board 21. In this example, the printed circuit board 21 is formed in a disc shape through which the rotary shaft 10 can pass, The magnetic detecting elements 20 for three phases can be easily arranged to face each other at one end face position of the permanent magnet 37 for the state field. In this structure, not only can the axial dimension of the motor be shortened but also the number of parts can be reduced, so that the motor can be lightweight and easy to assemble.

  As shown in FIG. 1, the printed circuit board 21 is mechanically supported by an insulator holder 22 disposed and held between the housing 11 and the flange 12, and is predetermined to face one end surface of the cylindrical field permanent magnet 37. Further, the magnetic detection elements 20 for three phases are arranged at predetermined positions.

  The insulator holder 22 is made of a heat-resistant resin in a circular shape that can be placed and fixed between the housing 11 and the flange 12, for example, and is provided with a projection 23 for mechanically supporting the printed board 21 at a predetermined position. ing. The insulator holder 22 is electrically connected with a bus bar 33 for three phases from a plurality of terminals 32 connected to the lead wire 3 a of the armature winding 3 and a plurality of detection bus bars 34 connected to the magnetic detection element 20. It is built in an insulated state. The externally exposed portion of the detection bus bar 34 is penetrated at the connection position of the printed circuit board 21 and is electrically connected to the internal wiring pattern with solder or the like so that the connection wiring is not routed.

  The insulator holder 22 has three bus bars 33 for three phases and three output signal bars for the magnetic detection element 20 and five detection bus bars 34 for positive and negative electrodes, which are pulled out of the housing 11 and external terminals 43 and 44. An integrated connector housing 35 that encloses the portion is formed at the portion to facilitate connection with the outside.

  In the brushless motor of the embodiment of the present invention, as shown in the drawing, the rotor 5 uses a cylindrical flanged permanent magnet field yoke 36 having a disk-shaped flange 38 formed on one end side, for example. A brazed permanent magnet field yoke 36 is fixed to the rotary shaft 10.

  The hollow permanent magnet field yoke 36 is fitted with a hollow cylindrical field permanent magnet 37 to be inserted from one end side to the flange portion 38 side and fixed integrally with the adhesive layer 8. For example, the adhesive layer 8 is fixed between the two by applying an adhesive to the outer peripheral surface of the brazed permanent magnet field yoke 36 and then fitting the cylindrical field permanent magnet 37 to cure the adhesive. Alternatively, it may be performed by injecting an adhesive into the gap between the two after the fitting and curing the adhesive.

  In addition, in this embodiment, the rotor 5 is integrated by covering from the flange 38 side of the permanent magnet field yoke 6 with a cup-shaped magnetic pole cover 42 used for protecting the outer surface of the cylindrical field permanent magnet 37. It has a configuration. For example, the cup-shaped magnetic pole cover 42 is fitted and fixed to the rotary shaft 10 or is fixed by fitting a cylindrical field permanent magnet 37 whose outer surface is coated with an adhesive.

  The flange portion 38 of the flanged permanent magnet field yoke 36 is formed concentrically with the rotating shaft 10 and has the same size as the outer diameter of the cylindrical field permanent magnet 37 for easy assembly. If only the opposing arrangement of the magnetic detection elements 20 is taken into consideration, a cylindrical field permanent magnet having no wrinkles can be used.

  The cup-shaped magnetic pole cover 42 has a through hole 39 through which the rotary shaft 10 is passed using a non-magnetic material such as stainless steel. The inner diameter dimension of the cup-shaped magnetic pole cover 42 is smaller than that of the cylindrical field permanent magnet 37. The smallest gap that can be assembled is formed. When this cup-shaped magnetic pole cover 42 is used, it is possible to prevent any trouble occurring in the cylindrical field permanent magnet 37 during the rotation of the rotor 5, and the cup-shaped magnetic pole cover 42 can be prevented. When the adhesive layer 8 is incorporated in an uncured state, the misalignment between the permanent magnet field yoke 36 and the cylindrical field permanent magnet 37 can be suppressed physically.

  If the cylindrical field permanent magnet 37 is used and the outer diameter and the dimension of the flange portion 38 of the flanged permanent magnet field yoke 36 and the inner diameter of the cup-shaped magnetic pole cover 42 are appropriately selected, the cylindrical field magnet is selected. The mechanical misalignment of the permanent magnet 37 and the brazed permanent magnet field yoke 36 can be mechanically suppressed, the non-uniformity of the adhesive layer 8 can be made smaller, the torque fluctuation is small, and the brushless motor can be made with low vibration and low noise.

  In this example, the size of the cylindrical field permanent magnet 37 is set such that the end facing the magnetic detection element 20 protrudes beyond the end surface of the brazed permanent magnet field yoke 36, thereby The end face of the magnetic permanent magnet 37 and the magnetic detection element 20 can be opposed to each other at a smaller interval.

  The adhesive layer 8 in the narrow gap between the permanent magnet field yoke 6 and the cylindrical field permanent magnet 37 is specially devised in order to make the fixing by this more effective. That is, as shown in FIGS. 2 to 4, a plurality of linear grooves 40 substantially parallel to the axial direction are provided on the outer peripheral surface of the brazed permanent magnet field yoke 36, and the adhesive layer 8 is partly formed by the linear grooves 40. In addition, a circumferential groove 41 is provided in the vicinity of the flange portion 38 so that the adhesive layer 8 is partially thickened.

  These linear grooves 40 and circumferential grooves 41 are provided either or both at the same time depending on the size of the permanent magnet field yoke 36 and the cylindrical field permanent magnet 37, and the number and size thereof. Since the adhesive layer 8 can be partially thickened as a result, the permanent magnet field yoke 36 and the cylindrical field permanent magnet 37 by the adhesive layer 8 are more securely fixed. Thus, peeling of the adhesive layer 8 can be effectively prevented.

  Since the shear strength of the adhesive layer 8 is highly sensitive to the thickness, forming a partially thick portion in the adhesive layer 8 by the linear groove 40 and the circumferential groove 41 relatively reduces the sensitivity to thickness variation and shears. The stability of strength can be increased to improve reliability, and the stability of torque transmission generated by the cylindrical field permanent magnet 37 can be increased to improve reliability.

  The rotating shaft 10 having the rotor 5 is supported by bearings 16 and 17 fitted in the bearing housings 11a and 12a, and in this embodiment, a coil spring 45 is disposed on the output shaft side portion of the rotating shaft 10 to rotate. One end of the coil spring 45 is engaged with the shaft 10 and the other end is engaged with the side surface of the bearing 17. As a result, the bearings 16 and 17 are pressed outwardly toward the bearing housings 11a and 12a by the force of the coil spring 45, and the movement of the rotor 5 in the axial direction due to vibrations is prevented. It is regulated.

It is a longitudinal cross-sectional view which shows one Example of the brushless motor of this invention. It is a disassembled perspective view of the rotor in the brushless motor of this invention. It is an axial longitudinal cross-sectional view of the rotor of the present invention. It is an AA view of the rotor of FIG. It is a longitudinal cross-sectional view of the conventional brushless motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stator, 2 ... Armature core, 2a ... Salient pole magnetic pole, 3 ... Armature winding, 5 ... Rotor, 8 ... Adhesive layer, 10 ... Rotating shaft, 11 ... Housing, 12 ... Flange, 16, 17 DESCRIPTION OF SYMBOLS ... Bearing, 20 ... Magnetic detection element, 21 ... Printed circuit board, 30 ... Insulator holder, 36 ... Permanent permanent magnet field yoke, 37 ... Cylindrical field permanent magnet, 38 ... Saddle, 40 ... Linear groove 41 ... Circumferential groove, 42 ... Magnetic pole cover.

Claims (5)

  A stator and a rotor fixed to a rotating shaft, the stator having a plurality of salient poles arranged at equal intervals on the inner peripheral surface side of the armature core, and wound around each salient pole pole A brushless motor having a permanent magnet field yoke fixed to a rotating shaft and a magnetic pole permanent magnet, wherein the rotor has a flange formed on one end side. A brushless motor characterized in that a cylindrical field permanent magnet provided with a plurality of magnetic poles is fitted to an attached permanent magnet field yoke and fixed integrally with an adhesive layer formed on a fitting surface.   2. The brushless motor according to claim 1, wherein a plurality of linear grooves substantially parallel to the axial direction are provided on the outer peripheral surface of the permanent magnet field yoke.   2. The brushless motor according to claim 1, wherein at least one circumferential groove is provided on an outer peripheral surface of the permanent magnet field yoke.   2. The brushless motor according to claim 1, wherein a plurality of linear grooves and at least one circumferential groove substantially parallel to the axial direction are provided on the outer peripheral surface of the permanent magnet field yoke. A stator and a rotor fixed to a rotating shaft, the stator having a plurality of salient poles arranged at equal intervals on the inner peripheral surface side of the armature core, and wound around each salient pole pole A brushless motor having a permanent magnet field yoke fixed to a rotating shaft and a magnetic pole permanent magnet, wherein the rotor is substantially parallel to the axial direction on the outer peripheral surface. A cylindrical field permanent magnet provided with a plurality of magnetic poles on a flanged permanent magnet field yoke provided with a plurality of linear grooves and at least one circumferential groove and having a flange on one end side, and the flange The end surfaces are fitted so that they are in contact with each other, and the brazed permanent magnet field yoke and the cylindrical field permanent magnet are fixed by an adhesive layer formed on the fitting surface, and the outer surface of the cylindrical field permanent magnet Brushless motor characterized in that it is constructed integrally with a magnetic pole cover

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