JP2016184994A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor capable of being fixed to a yoke with an energization member having a sufficiently large elastic force even for a magnet in which a gentle corner part is formed on an inner circumferential surface side of a terminal part.SOLUTION: An electric motor 10 includes: a yoke 12 of a bottomed cylindrical shape; a plurality of magnets 14a, 14b, 14c disposed along an inner wall of the yoke 12; and a tabular energization member 44 disposed between facing terminal parts of neighboring magnets. The energization member 44 includes: a pair of pressing parts 50 being in contact with the magnets 14a, 14b, 14c to energize; and a coupling part 48 for coupling the pair of pressing parts 50. The coupling part 48 is formed with a width wider than a width of the pressing part 50.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electric motor structure that fixes a plurality of magnets to an inner wall surface of a yoke.

  Conventionally, the wall surface of the yoke formed in a cup shape is bulged inward to form a ridge, and one end of a pair of magnets is brought into contact with both sides of the ridge, and the pair of magnets are opposed to each other. There is a type in which an elastic member is attached between the other end portions and a magnet is assembled.

  For example, Patent Document 1 describes a fan motor that uses a U-shaped magnet holder that can be elastically deformed to position and fix a pair of magnets on the inner surface of a housing. This fan motor has a U-shape made of a plate material in the space between the opposing upper end edges of the two magnets, with the lower edges of the pair of magnets being in contact with the rising wall surface of the recessed portion provided at the lowest position of the housing. The magnet holder is press-fitted.

JP 2008-131791 A

  In the fan motor of Patent Document 1, the distance between the upper end edges facing each other of the magnets decreases toward the inner diameter side (the center side of the housing), and the plate width of the magnet holder increases within the range of the magnet thickness. Even so, the magnet holder is structured not to easily come off from the space between the upper edge portions toward the inner diameter side.

  In order to prevent the plate-like elastic member from moving toward the inner diameter side, the arrangement of the elastic member is restricted depending on the shape of the end of the magnet. For this reason, the width | variety of an elastic member must be made small. However, if the width of the elastic member is reduced, the stress generated when the elastic member is deformed increases, and it becomes difficult to obtain a sufficiently large elastic force for fixing the magnet.

  The present invention has been made in consideration of such problems, and an object thereof is to provide an electric motor capable of fixing a magnet to a yoke by a biasing member having a sufficiently large elastic force.

  An electric motor according to the present invention includes a bottomed cylindrical yoke, a plurality of magnets disposed along the inner wall of the yoke, and a plate-like biasing disposed between opposing ends of adjacent magnets. The biasing member includes a pair of pressing portions that press against the magnet and a connecting portion that connects the pair of pressing portions, and the connecting portion is more than the pressing portion. Is also formed wide.

  According to the above electric motor, the pair of belt-like portions of the urging member are connected by the connecting portion wider than the pressing portion, so that the stress generated in the urging member can be relieved and sufficiently large. The magnet can be fixed to the yoke by an urging member having elasticity.

  In the above-described electric motor, it is preferable that the side closer to the center of the yoke of the connecting portion is formed to protrude from the pressing portion in the width direction of the urging member. According to this, the urging member can be held at a stable position.

  Further, in the width direction of the urging member, both end sides of the connecting portion may be formed so as to protrude from the pressing portion, and the urging member may be formed in a symmetrical shape with the center line in the width direction as a symmetric line. According to this, when inserting the urging member into the gap formed between the end portions of adjacent magnets, it is not necessary to distinguish one end side and the other end side in the width direction, and the assembling property is improved.

  Furthermore, the distance between the opposite end portions of the adjacent magnets may be smaller toward the center of the yoke, except at least a portion near the inner peripheral surface of the magnet. For example, in the case of a magnet in which a gentle corner is formed on the inner peripheral surface side of the end, the space for placing the elastic member is particularly limited. If it is an urging member provided with this press part and a wide connection part, while being able to arrange | position in the limited space, a magnet can be fixed to a yoke with sufficient big elastic force.

  According to the electric motor of the present invention, the stress generated in the biasing member due to the elastic deformation of the biasing member can be relieved, and the load required to fix the magnet and the stress applied to the biasing member can be reduced. Easy to set up.

It is sectional drawing which shows the whole structure of the electric motor which concerns on 1st Embodiment of this invention. It is the figure which looked at the yoke of the electric motor which concerns on 1st Embodiment of this invention, a magnet, and the biasing member from the A direction of FIG. It is the B section enlarged view of FIG. It is a perspective view in the free state (state before mounting | wearing) of the urging | biasing member of FIG. It is the figure which looked at the energizing member of Drawing 4 from the C direction. It is a perspective view in the free state (state before mounting | wearing) of the urging | biasing member of the electric motor which concerns on 2nd Embodiment of this invention. It is the figure which looked at the energizing member of Drawing 6 from the D direction.

  Hereinafter, preferred embodiments of the electric motor according to the present invention will be described with reference to the accompanying drawings.

  As shown in FIG.1 and FIG.2, the electric motor 10 which concerns on 1st Embodiment of this invention is used for the pump action | operation of the antilock brake device for vehicles. The electric motor 10 is an inner rotor type electric motor, and includes a plurality of magnets 14 a, 14 b and 14 c assembled along the inner wall of the yoke 12, and a rotor 16 accommodated in the yoke 12. The electric motor 10 is inserted and fixed by inserting a main body side end 20 which is one end of the rotating shaft 18 into a block body (not shown), and inserting a terminal 22 for supplying power to the electric motor 10 into a connection terminal of an electronic control unit (not shown). Is done.

  The yoke 12 is formed in a bottomed cylindrical shape and constitutes a housing of the electric motor 10. As the material of the yoke 12, a metal material such as a rolled steel plate is preferably used.

  A bearing housing portion 24 that protrudes toward the rotor 16 is formed at the bottom of the yoke 12. The bearing accommodating portion 24 is formed by folding the bottom of the yoke 12 in the axial direction by press molding. A rolling bearing 26 is fitted in the bearing housing portion 24, and a rotor side end portion 28 which is the other end of the rotating shaft 18 is rotatably supported by the rolling bearing 26.

  A brush holder 30 is provided in the opening of the yoke 12. The brush holder 30 holds a brush 34 that can supply power to the commutator 32 through the terminal 22 from a block body that is a main body of the apparatus. The brush 34 is urged so as to be in sliding contact with the commutator 32 at all times by a spring 36 elastically mounted between the brush holder 30 and the inner wall. A cover body 38 is fitted from the outside of the brush holder 30 so as to cover the opening of the yoke 12.

  Three arc-shaped magnets 14a, 14b, 14c made of a magnetic material such as ferrite are assembled on the inner wall surface of the yoke 12, and are magnetized to a required number of magnetic poles. Chamfering is applied to the boundary between the inner peripheral surface and the axial end surface of each magnet 14a, 14b, 14c, and chamfering is also applied to the boundary between the outer peripheral surface and the axial end surface of each magnet 14a, 14b, 14c. ing.

  As shown in FIG. 3, the opposing circumferential ends of the magnet 14 a and the magnet 14 b include a first inclined surface 40 formed closer to the outer peripheral surface and a second inclined surface 42 formed closer to the inner peripheral surface. It has a mountain shape when viewed from the axial direction. The distance between the circumferential end portions of the magnet 14a and the magnet 14b becomes smaller toward the center of the yoke 12 at the portion where the first inclined surfaces 40 face each other, and the second inclined surfaces 42 face each other. In the part, it becomes large toward the center of the yoke 12. The circumferential end portions of the magnets 14b and 14c facing each other and the circumferential end portions of the magnets 14c and 14a facing each other have the same configuration.

  In the gap formed between the first inclined surfaces 40 facing each other of the magnet 14a and the magnet 14b, a plate-like bias that biases the gap between the end of the magnet 14a and the end of the magnet 14b in a widening direction. A member 44 is provided. Similarly, the gap formed between the first inclined surfaces 40 facing each other of the magnet 14b and the magnet 14c and the gap formed between the first inclined surfaces 40 facing each other of the magnet 14c and the magnet 14a are similarly energized. A member 44 is provided. The urging member 44 is made of a metal material such as piano wire or stainless steel. The configuration of the urging member 44 will be described in detail later.

  The core 56 of the rotor 16 is integrally fitted into the rotor side end portion 28 of the rotating shaft 18. The periphery of the core 56 is covered with an insulator 58 made of an insulating material, and an armature winding 60 is wound around a slot formed in the core 56.

  The commutator 32 is fitted into the rotary shaft 18 between the rotor 16 and a support ball bearing 62 described later, and rotates together with the rotary shaft 18. A brush 34 is pressed against the commutator 32 so that power is supplied through the terminal 22.

  A support ball bearing 62 is press-fitted to the main body side end 20 side of the rotating shaft 18 from the commutator 32. The support ball bearing 62 is adapted to receive a radial load applied to the rotary shaft 18 by press-fitting and supporting the cover body 38 covering the outer periphery thereof on the block body side. Further, an eccentric shaft portion 64 is formed in the vicinity of the main body side end portion 20 of the rotary shaft 18, and an operation ball bearing 66 is press-fitted into the eccentric shaft portion 64. The operation ball bearing 66 is configured to reciprocate a piston of a plunger pump (not shown) linked to a spring.

  As shown in FIG. 4, the urging member 44 includes a pair of strips 46 and an arcuate connection 48 that connects one end side of the pair of strips 46. The other end sides of the pair of belt-like portions 46 are bent in a direction away from each other in the first bent portion 47 and then bent in a direction approaching each other in the second bent portion 49 to reach the tip. Thereby, the press part 50 which presses magnet 14a, 14b, 14c is formed. Further, the pair of belt-like portions 46 includes a third bent portion 51 that is bent slightly outward at an intermediate position from one end side connected to the connecting portion 48 to the first bent portion 47.

  As shown in FIG. 5, each strip 46 has one edge 52 in the straight width direction and the other edge 54 in the width direction of the broken line. One edge 52 in the width direction and the other edge 54 in the width direction are parallel to each other from the tip to the first bent portion 47. From the first bent portion 47 to the third bent portion 51, one end connected to the connecting portion 48 from the third bent portion 51 is inclined in a direction in which the other edge portion 54 in the width direction is separated from the one edge portion 52 in the width direction. Up to the side, one edge 52 in the width direction and the other edge 54 in the width direction are parallel to each other. For this reason, the width (W2) of the connecting portion 48 is larger than the width (W1) of the pressing portion 50.

  The electric motor 10 according to the present embodiment is basically configured as described above. Hereinafter, a method for fixing the magnets 14a, 14b, and 14c to the yoke 12 and the operation and effect thereof will be described.

  First, the bottomed cylindrical yoke 12 is placed on a horizontal floor surface with the bottom portion facing downward, and the three magnets 14a, 14b, 14c are arranged circumferentially on the bottom portion of the yoke 12. Next, the pressing portion 50 is inserted into the gap formed between the opposing first inclined surfaces 40 of the magnets 14a, 14b, and 14c with the connecting portion 48 facing the back side (the bottom side of the yoke 12). The urging member 44 is inserted to the position up to this side. At this time, one edge 52 in the width direction of the belt-like portion 46 is positioned on the side opposite to the center of the yoke 12, and the other edge 54 in the width direction is positioned on the center side of the yoke 12. In the present embodiment, there are three gaps between the circumferential ends of the three magnets 14a, 14b, and 14c, and the biasing member 44 is inserted into all of them as described above.

  After that, when each urging member 44 is pushed in one by one, each urging member 44 reduces the distance between the pair of pressing portions 50, and the first bent portion 47 and the second bent portion. 49 is stretched and elastically deformed. Each of the magnets 14 a, 14 b, 14 c is pressed against the inner peripheral surface of the yoke 12 by a reaction force accompanying elastic deformation of the urging member 44. When the pressing portion 50 is disposed in the gap between the first inclined surfaces 40, the magnets 14 a, 14 b, 14 c are fixed to the yoke 12 by a large frictional force generated between the inner peripheral surface of the yoke 12. When inserting and pushing the urging member 44 into the gap between the first inclined surfaces 40, a jig (not shown) is used.

  In a state where each urging member 44 is mounted, one edge 52 in the width direction of the belt-like portion 46 including the pressing portion 50 of each urging member 44 abuts against the inner wall of the yoke 12 over the entire length thereof. Further, the other edge portion 54 in the width direction of the pressing portion 50 abuts on the first inclined surface 40 of the magnets 14a, 14b, and 14c at the second bent portion 49 that protrudes most toward the first inclined surface 40 side ( (See FIG. 3). The portion near the center of the yoke 12 in the connecting portion 48 is located in a gap formed between the second inclined surfaces 42 facing each other of the magnets 14a, 14b, 14c. Magnetization of the magnets 14a, 14b, and 14c is performed after the magnets 14a, 14b, and 14c are fixed to the yoke 12.

  As shown in FIG. 3, in the state where the urging member 44 is mounted, the interval L1 between the strips 46 on the connecting portion 48 side is smaller than the interval L2 between the narrowest portions of the magnets. The connecting portion 48 side is assembled well without contacting the magnets 14a and 14b.

  According to the present embodiment, the pressing portion 50 of the urging member 44 is disposed in the gap formed between the first inclined surfaces 40 whose distance decreases toward the center of the yoke 12. 44 does not deviate in the central direction (inner diameter direction) of the yoke 12. Further, since the pair of belt-like portions 46 are connected by the wide connecting portion 48, the biasing member 44 can relieve stress generated in the connecting portion 48 due to elastic deformation. Furthermore, the biasing member 44 can hold the biasing member 44 in a stable position because one edge 52 in the width direction of the belt-like portion 46 including the pressing portion 50 abuts the inner wall of the yoke 12 over substantially the entire length thereof.

  Next, the urging member 70 of the electric motor according to the second embodiment will be described with reference to FIGS. 6 and 7. The electric motor according to the second embodiment is different from the first embodiment only in the configuration of the urging member 70. The yoke and the magnet are denoted by the same reference numerals as in the first embodiment, and detailed description thereof is omitted.

  As shown in FIG. 6, the urging member 70 of the present embodiment includes a pair of band-shaped parts 72 and an arc-shaped connection part 74 that connects one end side of the pair of band-shaped parts 72. The other end sides of the pair of band-shaped portions 72 are bent in a direction away from each other in the first bent portion 73 and then bent in a direction approaching each other in the second bent portion 75 to reach the tip. Thereby, the press part 76 which presses magnet 14a, 14b, 14c is formed. Further, the pair of belt-like portions 72 has a third bent portion 77 that is bent slightly outward at an intermediate position from one end side connected to the connecting portion 74 to the first bent portion 73.

  As shown in FIG. 7, each strip 72 is formed in a symmetric shape with a center line CL in the width direction as a symmetric line. One edge 78 in the width direction and the other edge 80 in the width direction of each strip 72 are inclined in a direction away from the center line CL from the tip to the third bent portion 77. From the third bent portion 77 to one end connected to the connecting portion 74, one edge 78 in the width direction and the other edge 80 in the width direction are parallel to the center line CL. For this reason, the width (W4) of the connecting portion 74 is larger than the width (W3) of the pressing portion 76.

  In the same manner as in the first embodiment, the urging member 70 is inserted and pushed into a gap formed between the first inclined surfaces 40 facing each other of the magnets 14a, 14b, and 14c. Each of the magnets 14 a, 14 b, and 14 c is pressed against the inner peripheral surface of the yoke 12 by a reaction force accompanying elastic deformation of the biasing member 70, and is fixed to the yoke 12 by a frictional force generated between the inner peripheral surface of the yoke 12. Is done. When the urging member 70 is inserted, any one of the widthwise one edge 78 and the widthwise other edge 80 of the belt-like portion 72 may be positioned on the center side of the yoke 12. Below, the case where the urging | biasing member 70 is inserted so that the edge part 80 of the width direction other side of the strip | belt-shaped part 72 may be located in the center side of the yoke 12 is demonstrated.

  In a state where each urging member 70 is mounted, one edge 78 in the width direction of the belt-like portion 72 of each urging member 70 contacts the inner wall of the yoke 12 at a position from the tip to the third bent portion 77. . Further, the other edge 80 in the width direction of the pressing portion 76 is in contact with the first inclined surface 40 of the magnets 14a, 14b, and 14c at the portion of the second bent portion 75 that protrudes most toward the first inclined surface 40 side. The portion near the center of the yoke 12 in the connecting portion 74 is located in a gap formed between the second inclined surfaces 42 facing each other of the magnets 14a, 14b, 14c.

  According to the present embodiment, the urging member 70 is provided with the pressing portion 76 in the gap formed between the first inclined surfaces 40 whose intervals are smaller toward the center of the yoke 12. Does not deviate in the center direction (inner diameter direction). Further, since the pair of belt-like portions 72 are connected by the wide connecting portion 74, the biasing member 70 can relieve the stress generated in the connecting portion 74 due to elastic deformation. Furthermore, since the urging member 70 is formed in a symmetrical shape with the center line CL in the width direction as a symmetric line, the urging member is placed in the gap between the first inclined surfaces 40 facing each other of the magnets 14a, 14b, 14c. When inserting 70, it is not necessary to distinguish one side and the other side in the width direction, and the assembling property is improved.

  In each of the above-described embodiments, three magnets are used. However, the number of magnets is not limited to this, and may be two or four or more. In addition, the urging members are all disposed between the circumferential ends of the opposing magnets, but one ridge is provided inwardly projecting from the inner wall surface of the yoke. One end of the pair of magnets may be brought into contact. Further, the shape of the urging member is not limited to each embodiment, and the connecting portion only needs to be formed wider than the pressing portion.

  In the above-described embodiment, the electric motor provided in the vehicle brake hydraulic pressure control device has been described as an example, but the use of the electric motor is not limited thereto.

  Of course, the electric motor according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Electric motor 12 ... Yoke 14a, 14b, 14c ... Magnet 44, 70 ... Energizing member 48, 74 ... Connection part 50, 76 ... Pressing part

Claims (4)

Electric motor provided with a bottomed cylindrical yoke, a plurality of magnets disposed along the inner wall of the yoke, and a plate-like biasing member disposed between opposing ends of the adjacent magnets A motor,
The urging member includes a pair of pressing portions that abut against the magnet and urges, and a connecting portion that connects the pair of pressing portions, and the connecting portion is formed wider than the pressing portion. An electric motor characterized by that. The electric motor according to claim 1, wherein
In the width direction of the urging member, a side closer to the center of the yoke of the connecting portion is formed to protrude from the pressing portion. The electric motor according to claim 1, wherein
In the width direction of the urging member, both end sides of the connecting portion are formed to protrude from the pressing portion, and the urging member is formed in a symmetrical shape with a center line in the width direction as a symmetric line. Electric motor. The electric motor according to any one of claims 1 to 3,
An electric motor characterized in that a distance between opposing ends of adjacent magnets decreases toward the center of the yoke except at least a portion near the inner peripheral surface of the magnet.

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