JP2009291015A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor improved in reliability and reduced in size. <P>SOLUTION: The motor 1 is provided with: a first cover member 5 to cover an upper end part 211 of an armature 21; a second cover member 6 by which the armature 21 is fixed in a press-fit state; and an elastic member 7 which is pinched between the armature 21 and the first cover member 5. In the motor 1, a recess 71 of a lower part of the elastic member 7 and the upper part thereof are engaged with a protruding part 215 of an insulator 213 and a recess 5111 of the lower end of the first cover member 5, respectively, in the circumferential direction with a center axis J1 as a center. As a result, the elastic member 7, the protruding part 215 and the recess 5111 prevent the armature 21 from rotation against the second cover member 5, and even if the fixing of the armature 21 to the second cover member 6 becomes loose, the rotation of the armature 21 is prevented and reliability of the motor 1 is improved. The motor 1 is also reduced in size in the direction perpendicular to the center axis J1 because the elastic member 7 is positioned at the upper end of the armature 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric motor.

  Conventionally, in an electric motor, the armature is prevented from rotating with respect to a cover member that covers the armature. For example, in the motor disclosed in Patent Document 1, the stator mold is disposed inside the stator (armature). An anti-vibration rubber is arranged between the concave portion provided at the time of molding and the cover, and the concave portion and the convex portion provided on the anti-vibration rubber are fitted together, that is, relative rotation between the stator and the anti-vibration rubber, that is, The relative rotation between the stator and the cover is prevented.

In the submersible motor disclosed in Patent Document 2, a key groove extending in parallel to the central axis is formed on the outer peripheral surface of the stator core, and a notch-shaped groove facing the key groove is formed on the inner peripheral surface of the motor frame covering the outer periphery of the stator core. Provided. A key is inserted between the key groove of the stator core and the motor frame, and a locking claw extending radially outward at one end of the key fits into the groove of the motor frame, thereby preventing the stator core from rotating relative to the motor frame. Is done. Patent Document 2 also discloses a technique in which a through hole toward the stator core is provided in a motor frame covering the outer periphery of the stator core, and a pin is driven into the through hole to prevent rotation of the stator core.
JP 2000-188841 A JP 2002-345185 A

  By the way, in the motor shown by patent document 1, since the anti-vibration rubber | gum is arrange | positioned inside a stator, rotation prevention of the stator with respect to a cover is not fully performed, but the reliability of a motor is not ensured. Moreover, as shown in Patent Document 2, in a motor in which a stator core is prevented from rotating with respect to a motor frame using a key, the motor becomes large in a direction perpendicular to the central axis. Furthermore, when the stator core is prevented from being rotated using pins, if the cover is thinned, the length of the through hole for the pin is not ensured, so that the strength of the stator core against the cover is reduced.

  Moreover, since the motor mounted in vehicles, such as a motor vehicle, is used in the environment which receives a vibration, high reliability is requested | required and it is necessary to perform rotation prevention of the armature with respect to a cover member reliably.

  The present invention has been made in view of the above problems, and improves the reliability of the motor by reliably preventing the armature from rotating against the cover member covering the outer periphery of the armature, and in a direction perpendicular to the central axis. The purpose is to reduce the size of the motor.

  The invention according to claim 1 is an electric motor, which is a stator portion having a substantially cylindrical armature, a rotor portion inserted into the armature, and the rotor portion with respect to the stator portion. A bearing mechanism that rotatably supports the central axis of the armature, a first cover member that covers one end of the armature in the central axis direction, an outer periphery of the armature, and the first cover member. A second cover member having an opening that is closed by one cover member; and sandwiched between the one end portion of the armature and the first cover member, and in the circumferential direction around the central axis An armature and a resin-made elastic member that engages with the first cover member are provided.

  The invention according to claim 2 is the motor according to claim 1, wherein the armature has a stator core having a plurality of teeth protruding toward the central axis, and an insulator covering the plurality of teeth; A coil formed by winding a conductive wire around the plurality of teeth, and the insulator has a protruding portion extending radially outward on an outer edge portion of the stator core at the one end portion, The elastic member contacts the projecting portion in a direction parallel to the central axis and engages in the circumferential direction.

  A third aspect of the present invention is the motor according to the second aspect, wherein the insulator is arranged in the circumferential direction on the outer edge portion of the stator core and extends in a radially outward direction. The elastic member has an annular shape centered on the central axis, and is in contact with the plurality of protrusions in a direction parallel to the central axis and engaged in the circumferential direction.

  Invention of Claim 4 is a motor of Claim 2, Comprising: The length of the said circumferential direction of the said elastic member is between the teeth of the said armature in the radial position in which the said elastic member is arrange | positioned The distance corresponding to the pitch is 0.5 times or more and 1.5 times or less.

  A fifth aspect of the present invention is the motor according to any one of the first to fourth aspects, wherein the first cover member protrudes toward the one end of the armature and the second A concave portion that has a cylindrical portion fitted into the opening of the cover member and engages with the elastic member in the circumferential direction is provided at an end portion of the cylindrical portion on the armature side.

  A sixth aspect of the present invention is the motor according to any one of the first to fifth aspects, wherein the first cover member is fixed to the second cover member with a screw.

  A seventh aspect of the present invention is the motor according to any one of the first to sixth aspects, and is mounted on a vehicle.

  According to the present invention, the reliability of the motor is improved by reliably preventing the armature from rotating with respect to the cover member covering the outer periphery of the armature, and the motor can be downsized in the direction perpendicular to the central axis. Become.

  Further, in the inventions of claims 2 and 3, the strength of the armature detent can be easily secured, and in the invention of claim 4, the size of the elastic member is ensured while ensuring the detent function by the elastic member. Can be kept small. In the invention of claim 5, the recess that engages with the elastic member can be easily provided. In the invention of claim 6, the first cover member is reliably prevented from rotating with respect to the second cover member.

  FIG. 1 is a diagram showing a power steering device 9 equipped with an electric motor 1 according to an embodiment of the present invention. The power steering device 9 is used for assisting driving operation of a vehicle such as an automobile, and includes a shaft portion 91 connected to a steering mechanism such as a steering wheel and an axle, a torque sensor 92 that detects torque applied to the steering wheel, and a torque sensor 92. A control unit 93 such as an ECU (Electronic Control Unit) that calculates a necessary assist force based on the output of the motor, a motor 1 that generates a rotational force based on the output from the control unit 93, and a motor while reducing the rotational speed A speed reduction mechanism 94 that transmits the rotational force of 1 to the steering mechanism is provided.

  In a vehicle equipped with the power steering device 9, the motor 1 of the power steering device 9 is driven based on the rotational force applied to the steering wheel by the operator, and the rotation of the steering wheel is assisted by the rotational force of the motor 1. Thus, the operator can operate the steering wheel with a relatively small force without directly using the engine output.

  FIG. 2 is a partial cross-sectional view of the motor 1. The motor 1 is provided above and below the armature 21 along the central axis J1 as a stator mechanism 2 having a substantially cylindrical armature 21, a substantially cylindrical rotor section 3 inserted into the armature 21, and a bearing mechanism. Ball bearing 4 (the lower ball bearing is not shown), the first cover member 5 covering the upper end portion 211 of the armature 21, and the bottomed cylindrical second member covering the outer periphery and the lower end portion of the armature 21. The cover member 6 and the elastic member 7 made of resin are provided between the upper end portion 211 of the armature 21 and the first cover member 5. The armature 21 is fixed in a press-fitted state in the side portion 61 of the second cover member 6 by shrink fitting. In the following description, the first cover member 5 side is described as the upper side and the second cover member 6 side is the lower side along the central axis J1 of the armature 21, but the central axis J1 is not necessarily required to coincide with the direction of gravity. Absent.

  The rotor unit 3 includes a shaft 31, a substantially cylindrical rotor core 32 attached around the shaft 31, a field magnet 33 attached to the outer periphery of the rotor core 32, and an end plate 34 (lower) attached to the upper and lower surfaces of the rotor core 32. The end plate on the side is not shown). The shaft 31 is inserted into the hole 51 of the first cover member 5, and the field magnet 33 faces the armature 21 in a direction perpendicular to the central axis J1.

  FIG. 3 is a plan view of the armature 21 and the second cover member 6, and the elastic member 7 is indicated by a two-dot chain line. As shown in FIGS. 2 and 3, the armature 21 of the stator unit 2 includes a stator core 212 having twelve teeth 2121 protruding toward the central axis J1, an insulator 213 covering the teeth 2121, and twelve coils. 214 (not shown in FIG. 3). The stator core 212 is formed by laminating a plurality of silicon steel plates. On the outer periphery of the stator core 212, the outer sides of two adjacent teeth 2121 are connected to each other to form an annular core back 2122.

  The insulator 213 has twelve protrusions 215 extending outward in the radial direction around the central axis J1 at the upper end 211, and each of the twelve protrusions 215 is an outer edge portion of the stator core 212 as shown in FIG. (Ie, on the core back 2122). Also, a coil 214 shown in FIG. 2 is formed by winding a conducting wire on the teeth 2121 with the insulator 213 interposed. In addition to the armature 21, the stator unit 2 includes a substrate that holds the wiring of the armature 21, a sensor that detects the rotation of the rotor unit 3, and the like.

  As shown in FIG. 2, the ball bearing 4 is disposed inside the hole 51 of the first cover member 5, and the other ball bearing positioned below the ball bearing 4 is the center of the bottom 62 of the second cover member 6. The upper and lower portions of the shaft 31 are supported by two ball bearings. In the motor 1, torque is generated between the armature 21 of the stator portion 2 and the field magnet 33 of the rotor portion 3, and the rotor portion 3 can rotate about the central axis J <b> 1 with respect to the stator portion 2. The

  FIG. 4 is an exploded perspective view of the motor 1, showing the armature 21 protruding above the second cover member 6, and the elastic member 7 between the armature 21 and the first cover member 5. Show. Further, illustration of the boundary between the steel plates forming the stator core 212 is omitted. The first cover member 5 has a cylindrical portion 511 that protrudes toward the upper end portion 211 of the armature 21, and four holes 53 that extend in parallel to the central axis J <b> 1 on the outer periphery. The end on the child 21 side is long in the circumferential direction centered on the central axis J1 (hereinafter simply referred to as “circumferential direction”) and is radial in the direction centered on the central axis J1 (hereinafter simply referred to as “radial direction”). Is provided with a notch-shaped recess 5111 across the cylindrical portion 511. The second cover member 6 has flange-like portions at four locations in the circumferential direction of the upper portion, and female screw portions 63 are formed at the portions.

  As shown in FIG. 2, the opening 611 at the upper end of the second cover member 6 is closed by the first cover member 5 to form a space in which the armature 21 is accommodated, and the screw 8 shown in FIG. The first cover member 5 is fixed to the second cover member 6 by being inserted into the hole portion 53 of the member 5 and screwed into the female screw portion 63 of the second cover member 6. In the motor 1, the elastic member 7 is sandwiched between the upper end portion 211 of the armature 21 and the cylindrical portion 511 of the first cover member 5 as shown in FIG. 2.

  FIG. 5 is a front view of the elastic member 7, and FIG. 6 is a plan view of the elastic member 7. The elastic member 7 is formed of rubber, for example, and has a substantially rod shape extending in a direction perpendicular to the radial direction around the central axis J1 (see FIG. 2) as shown in FIGS. 5 and 6, as shown in FIG. Thus, a notch-shaped recess 71 is formed at the lower end of the elastic member 7 so as to cross the elastic member 7 in a direction perpendicular to the direction in which the elastic member 7 extends (that is, in the radial direction).

  As shown in FIG. 4, the elastic member 7 is arranged so as to be aligned in a direction parallel to the central axis J1 with respect to the concave portion 5111 of the cylindrical portion 511 of the first cover member 5 and one protrusion 215 of the insulator 213. As described above, the elastic member 7 is sandwiched between the cylindrical portion 511 and the protruding portion 215. As shown in FIGS. 3 and 4, the length of the elastic member 7 in the circumferential direction is between the teeth 2121 (see FIG. 3) at the outer edge of the stator core 212 (that is, the radial position where the elastic member 7 is disposed). The distance in the circumferential direction of the recess 71 of the elastic member 7 shown in FIG. 4 is made substantially equal to the width in the circumferential direction of the protrusion 215. Further, the circumferential width of the recess 5111 of the first cover member 5 is slightly larger than the circumferential length of the elastic member 7.

  FIG. 7 is a view showing a cross section perpendicular to the radial direction of the cylindrical portion 511 of the first cover member 5, the elastic member 7, the protruding portion 215 of the insulator 213, and the stator core 212. The upper portion 72 of the elastic member 7 fits into the concave portion 5111 of the cylindrical portion 511, and the concave portion 71 of the elastic member 7 fits into the protruding portion 215. Accordingly, the elastic member 7 has the upper portion 72 engaged with both sides in the circumferential direction of the concave portion 5111 of the cylindrical portion 511 (that is, in contact with the circumferential direction), and the surface facing the lower side of the concave portion 71 with respect to the protruding portion 215. While contacting in the direction parallel to the central axis J1 (see FIG. 2), the portions on both sides in the circumferential direction of the recess 71 engage with the protruding portion 215 in the circumferential direction (that is, contact in the circumferential direction).

  In the motor 1, the elastic member 7, the concave portion 5111 of the first cover member 5, and the protruding portion 215 prevent the armature 21 (see FIG. 4) from rotating with respect to the second cover member 6. Since the circumferential length of the elastic member 7 is slightly smaller than the distance corresponding to the pitch between the teeth 2121, the elastic member 7 can be kept small in size while ensuring the function of preventing the armature 21 from rotating. Designed.

  Since the armature 21 shown in FIG. 2 is firmly fixed to the second cover member 6 by shrink fitting, the armature 21 does not normally move with respect to the second cover member 6. However, when the motor 1 is placed in a harsh environment where a large force acts on the motor 1, and further, the motor 1 changes over time, so that the armature 21 is fixed to the second cover member 6 temporarily. Even if loosening occurs, the elastic member 7 is engaged with the armature 21 and the first cover member 5 in the circumferential direction, so that the armature 21 is reliably prevented from rotating with respect to the second cover member 6. . The armature 21 is also prevented from rotating by friction between the upper surface of the upper portion 72 of the elastic member 7 shown in FIG. 7 and the surface of the cylindrical portion 511 facing the lower side of the concave portion 5111. Further, upward movement of the armature 21 with respect to the second cover member 6 through the elastic member 7 is also prevented.

  When the first cover member 5 is fixed to the second cover member 6, first, as shown in FIG. 4, the elastic member 7 is placed on the armature 21, and the recess 71 is one protrusion of the insulator 213. It is fitted to the part 215. Next, the first cover member 5 faces the second cover member 6 in the direction of the central axis J1 so that the elastic member 7 and the recess 5111 of the first cover member 5 are aligned in a direction parallel to the central axis J1. Be placed. Then, as shown in FIG. 2, the cylindrical portion 511 of the first cover member 5 is fitted into the opening 611 of the second cover member 6.

  Accordingly, the elastic member 7 is sandwiched between the upper end portion 211 of the armature 21 and the first cover member 5 in a compressed state. Thereafter, as shown in FIG. 4, the screw 8 is inserted into the hole 53 of the first cover member 5 and screwed into the female screw portion 63 of the second cover member 6, so that the first cover member 5 and the second cover The member 6 is fixed.

  As described above, in the motor 1, the elastic member 7 is engaged with the concave portion 5111 of the first cover member 5 and the protruding portion 215 of the insulator 213 in the circumferential direction, whereby the first cover member 5 and the second cover member 6 are engaged. Accordingly, the armature 21 is reliably prevented from rotating, and the reliability of the motor 1 is improved. Further, since the elastic member 7 is engaged with the protruding portion 215 of the insulator 213 located on the outer edge of the stator core 212 in the circumferential direction, the strength of the armature 21 can be easily secured. Thus, since the motor 1 has high reliability, it is particularly suitable as a vehicle motor.

  Further, since the first cover member 5 and the second cover member 6 are fixed by the screws 8, the first cover member 6 is reliably prevented from rotating with respect to the second cover member 5, and as a result, the second The armature 21 is prevented from rotating with respect to the cover member 5 more reliably. In the 1st cover member 5, the recessed part 5111 engaged with the elastic member 7 using the cylindrical part 511 can be provided easily.

  In the motor 1, the elastic member 7, the protruding portion 215 of the insulator 213, and the concave portion 5111 of the first cover member 5 are arranged side by side in a direction parallel to the central axis J <b> 1 to prevent the armature 21 from rotating. The motor 1 can be downsized in the direction perpendicular to J1. Moreover, even if the height of the armature 21 has an error due to the elastic member 7 being sandwiched between the first cover member 5 and the armature 21, the height of the motor 1 does not change.

  8 and 9 are a bottom view and a plan view according to another example of the elastic member. As shown in FIG. 8, the elastic member 7a according to another example has a substantially annular shape, and the lower part of the elastic member 7a is provided with recesses 73 at equal intervals at 12 locations. As shown in FIG. Is provided with a convex portion 74 protruding upward at a position overlapping with the concave portion 73. When the elastic member 7a is employed, the cylindrical portion 511 of the first cover member 5 shown in FIG. 4 is formed with concave portions 5111 at 12 locations corresponding to the convex portions 74 of the elastic member 7a.

  FIG. 10 is a view showing a cross section perpendicular to the radial direction of the cylindrical portion 511 of the first cover member 5, the elastic member 7a, the protruding portion 215 of the insulator 213, and the stator core 212, and corresponds to FIG. In the elastic member 7a, each concave portion 73 engages with the corresponding protruding portion 215 in the circumferential direction around the central axis J1 (see FIG. 2), and each convex portion 74 circumferentially engages with the corresponding concave portion 5111 of the cylindrical portion 511. Engage in. Thereby, it is realized that the strength of the rotation prevention of the armature 21 (see FIG. 3) with respect to the second cover member 6 is easily secured by the elastic member 7a, the protruding portion 215, and the concave portion 5111 of the cylindrical portion 511. Moreover, workability | operativity can be improved compared with the case where the intensity | strength of a detent | locking is improved using the elastic member 7 shown in FIG.

  FIG. 11 is a perspective view according to still another example of the elastic member. The elastic member 7b shown in FIG. 11 is substantially annular like the elastic member 7a shown in FIG. 8 and FIG. 9, and the lower part of the elastic member 7b is provided with recesses 75 at equal intervals in 12 locations, Are provided with smooth (and gentle) convex portions 76 at equal intervals. When the elastic member 7b is employed, the cylindrical portion 511 of the first cover member 5 shown in FIG. 4 is formed with smooth (and gentle) concave portions 5111 at four locations corresponding to the convex portions 76 of the elastic member 7b. Is done.

  Also in the elastic member 7b shown in FIG. 11, each concave portion 75 is in contact with a corresponding protrusion 215 (see FIG. 4) in a direction parallel to the central axis J1 and engaged in a circumferential direction around the central axis J1, The convex portion 76 also contacts the corresponding concave portion 5111 of the cylindrical portion 511 in the direction parallel to the central axis J1 and engages in the circumferential direction. Accordingly, it is possible to easily secure the strength of the rotation prevention of the armature 21 with respect to the second cover member 6 by the elastic member 7b, the protruding portion 215, and the recessed portion 5111. In particular, in the elastic member 7b, the convex portion 76 is formed into a gentle shape to reduce the number (preferably 6 or less), whereby the pressing force applied to the cylindrical portion 511 is dispersed, and the rotor portion with respect to the stator portion 2 due to distortion is dispersed. 3 is prevented from being displaced. In order to firmly engage the four recesses 5111 with the elastic member 7b, the recesses 5111 are provided on the center axis J1 side of the hole 53 of the first cover member 5 shown in FIG.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, the length of the elastic member 7 in the circumferential direction is not limited to that shown in the above embodiment, and preferably, the teeth at the radial position of the elastic member 7 in order to sufficiently prevent the armature 21 from rotating. The distance corresponding to the pitch between 2121 is 0.5 times or more, and 1.5 times or less of the distance in order to prevent the elastic member 7 from interfering with the protrusions 215 located on both sides of the elastic member 7. The In the motor 1, an arc-shaped elastic member that is a part of the elastic member 7a shown in FIGS. 8 and 9 may be mounted.

  The elastic member may be formed of various resins (including a case of having a material other than resin) as long as it has a certain degree of elasticity, and is reinforced with other materials such as rubber and fiber having various rigidity. A material formed of rubber or other polymer material having elasticity may be used.

  In the above embodiment, the cylindrical portion 511 of the first cover member 5 is provided with a convex portion instead of the concave portion 5111, and the elastic member 7 is provided with a concave portion, whereby the first cover member 5, the elastic member 7, The engagement in the circumferential direction may be realized. The armature 21 may be fixed to the second cover member 6 in a press-fitted state by a method other than shrink fitting, and the second cover member 6 is a cylindrical shape whose bottom is not blocked as long as the outer periphery of the armature 21 is covered. It may be said.

  The motor 1 may be mounted on the vehicle as a motor such as a power window.

It is a figure which shows the power steering apparatus by which the motor which concerns on 1st Embodiment is mounted. It is a fragmentary sectional view of a motor. It is a top view of an armature and the 2nd cover member. It is a disassembled perspective view of a motor. It is a front view of an elastic member. It is a top view of an elastic member. It is sectional drawing of an elastic member, a 1st cover member, a 2nd cover member, and a stator core. It is a bottom view of the elastic member which concerns on another example. It is a top view of an elastic member. It is sectional drawing of an elastic member, a 1st cover member, a 2nd cover member, and a stator core. It is a perspective view of the elastic member which concerns on another example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Stator part 3 Rotor part 4 Ball bearing 5 1st cover member 6 2nd cover member 7,7a, 7b Elastic member 8 Screw 21 Armature 211 (armature) upper end part 212 Stator core 213 Insulator 215 Protrusion part 511 Cylinder Portion 611 (second cover member opening) 2121 Teeth 5111 Recessed portion J1 Central axis

Claims (7)

An electric motor,
A stator portion having a substantially cylindrical armature;
A rotor portion inserted into the armature;
A bearing mechanism that rotatably supports the rotor portion with respect to the stator portion around a central axis of the armature;
A first cover member covering one end of the armature in the central axis direction;
A second cover member that covers an outer periphery of the armature and has an opening that is closed by the first cover member;
Resin-made elasticity that is sandwiched between the one end of the armature and the first cover member and that engages with the armature and the first cover member in a circumferential direction centered on the central axis Members,
A motor comprising: The motor according to claim 1,
The armature is
A stator core having a plurality of teeth protruding toward the central axis;
An insulator covering the plurality of teeth;
A coil formed by winding a conductive wire around the plurality of teeth;
With
The insulator has a protrusion extending radially outward on the outer edge of the stator core at the one end;
The motor, wherein the elastic member is in contact with the protruding portion in a direction parallel to the central axis and is engaged in the circumferential direction. The motor according to claim 2,
The insulator has a plurality of protrusions arranged in the circumferential direction on the outer edge of the stator core and extending radially outward;
The motor according to claim 1, wherein the elastic member has an annular shape centered on the central axis, and is in contact with the plurality of protrusions in a direction parallel to the central axis and engaged in the circumferential direction. The motor according to claim 2,
The length of the elastic member in the circumferential direction is not less than 0.5 times and not more than 1.5 times the distance corresponding to the pitch between the teeth of the armature at the radial position where the elastic member is disposed. A motor characterized by The motor according to any one of claims 1 to 4,
The first cover member has a cylindrical portion that protrudes toward the one end portion of the armature and is fitted into the opening of the second cover member, and the end of the cylindrical portion on the armature side The motor is characterized in that a concave portion that engages with the elastic member in the circumferential direction is provided in the portion. The motor according to any one of claims 1 to 5,
The motor, wherein the first cover member is fixed to the second cover member with a screw. The motor according to any one of claims 1 to 6,
A motor mounted on a vehicle.

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