JP2019170071A - Motor and electrically-driven power steering device - Google Patents

Abstract

To provide a motor capable of achieving a reliable stop of rotation of a rotator while keeping a manufacturing cost low.SOLUTION: A motor 1 comprises: a shaft 31; a rotor 30; a stator 40; a bus bar holder 50; and a housing 20. The shaft 31 extends along a center axis C. The rotor 30 is fixed to the shaft 31. The stator 40 is positioned on a radially outer side of the rotor 30 and includes a coil wire 43. The bus bar holder 50 is positioned on one end side of the stator 40 in an axis direction, and includes a projection part 55 projecting to a radially outer side relative to the stator 40. The housing 20 is positioned on a radially outer side of the stator 40, and includes a concave part 25 to fit with one or more projection parts 55.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor and an electric power steering apparatus.

  As a method for fixing the stator to the motor housing, shrink fitting (see Patent Document 1) and caulking are known.

Japanese Patent Laying-Open No. 2015-42015

  In the shrink-fitting or caulking fixing method, there is a problem that the stator rotates relative to the housing because it is easier to rotate in the circumferential direction than in the axial direction. In recent years, an increasing number of motors use bus bars including connection terminals with the outside. If the stator rotates after the motor having such a configuration is incorporated into the host system, it is difficult to maintain the electrical contact with the host system. On the other hand, using new parts and adhesives to prevent rotation of the stator is accompanied by changes and increases in the parts and increases the manufacturing cost.

  An object of this invention is to provide the motor which can implement | achieve the rotation stop of a stator more reliably, suppressing manufacturing cost.

  The motor of an exemplary embodiment of the present application includes a shaft, a rotor, a stator, a support member, and a housing. The shaft extends along the central axis. The rotor is fixed to the shaft. The stator is disposed on the radially outer side of the rotor and has a conductive portion. The support member is disposed on one end side in the axial direction of the stator, and has a protrusion that protrudes radially outward from the stator. The housing is disposed on the outer side in the radial direction of the stator and has a recess that fits with one or more protrusions.

  According to the motor according to the embodiment of the present application, the rotation of the stator can be more reliably realized while suppressing the manufacturing cost.

FIG. 1 is a cross-sectional view showing a motor according to an embodiment. FIG. 2 is a perspective view of the stator to which the bus bar holder is fixed. FIG. 3 is a partial plan view showing the positional relationship between the protrusion of the bus bar holder and the recess of the housing. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a partial perspective view of a leg portion of a bus bar holder according to a modification. FIG. 6 is a plan view showing the positional relationship between the bus bar holder including the connection terminals and the control board. FIG. 7 is a schematic diagram of an electric power steering apparatus according to another embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention.

  In the following description, the central axis of the motor is C. The direction in which the central axis C extends is the axial direction. One along the axial direction is the upper side and the other is the lower side. However, the vertical direction in this specification is used to specify the positional relationship, and does not limit the actual direction or positional relationship. The direction of gravity is not necessarily downward. In this specification, a direction perpendicular to the rotation axis of the motor is referred to as a “radial direction”. The direction along the arc centered on the rotation axis of the motor is called “circumferential direction”. “Fitting” is sufficient if it is in a state in which the protrusions are fitted into the recesses to restrict movement of each other, and includes a loosely fitting state.

  In the drawings used in the following description, for the purpose of emphasizing the characteristic part, the characteristic part may be shown in an enlarged manner for convenience. Therefore, the dimensions and ratios of each component are not necessarily the same as actual ones.

(Embodiment)
As shown in FIGS. 1 and 2, the motor 1 includes a shaft 31, a rotor 30, a stator 40, a bus bar holder 50, and a housing 20.
The shaft 31 extends along the central axis C and is supported by the upper bearing 71 and the lower bearing 72 so as to be rotatable around the central axis C. The rotor 30 is fixed to the shaft 31 and rotates around the central axis C together with the shaft 31. Although not shown, the upper bearing 71 is held by a bearing holder located above the stator 40.

  The stator 40 is disposed on the radially outer side of the rotor 30 so as to face the rotor 30. The stator 40 includes a stator core 41, an insulator 42, and a coil wire 43. The insulator 42 is attached to the teeth (not shown) of the stator core 41. The coil wire 43 is an example of a conductive portion, is constituted by a conductive wire, and is wound around a tooth with an insulator 42 interposed.

  A conducting wire drawn from the coil wire 43 wound around the stator 40 to the upper side of the stator 40 is connected to the bus bar 61.

  The bus bar 61 is a plate-like conduction member. The bus bar 61 electrically connects the coil wire 43 to the connection terminal 63 and the control board 80 shown in FIG. The connection terminal 63 extends upward in the axial direction and is electrically connected to the control board 80 and an external power source (not shown).

  The bus bar holder 50 is an example of a support member, and supports the bus bar 61 and the connection terminal 63. The bus bar holder 50 is made of an insulating material such as resin. The bus bar holder 50 is disposed on one end side in the axial direction of the stator 40. The bus bar holder 50 includes an annular main body 51 disposed above the stator 40, and a leg 53 that extends from the main body 51 toward the stator 40 and is connected to one end of the stator 40. A plurality of, for example, three leg portions 53 are provided along the periphery of the main body portion 51. The leg portion 53 has a protruding portion 55 that protrudes radially outward from the stator 40. The protruding portions 55 may be provided on all the leg portions 53, but are provided only on a part of the leg portions, for example, one leg portion 53 or the two leg portions 53 at positions facing each other in the radial direction. May be. The numbers of the leg portions 53 and the protruding portions 55 are not limited to the above, and may be small or large.

  The housing 20 is disposed on the radially outer side of the stator 40, and the stator 40 is fixed to the inner peripheral surface of the housing 20 by shrink fitting or caulking. The housing 20 has a bottomed cylindrical shape with the central axis C as the center. The housing 20 includes a cylindrical portion 21 that extends in the axial direction, a bottom portion 23 that is positioned at the lower end of the cylindrical portion 21, and an opening portion 24 that opens upward.

  The shape of the housing 20 is not limited to a cylindrical shape. Further, the cross section of the housing 20 may be, for example, a polygon. Further, the housing 20 may be cylindrical instead of bottomed.

  The housing 20 has a concave portion 25 fitted to the protruding portion 55 on the inner peripheral surface. As shown in FIG. 3, the width of the protrusion 55, that is, the length in the circumferential direction is smaller than the width of the recess 25. Since the protrusion 55 has a margin in the circumferential direction in the recess 25, it is easier to adjust the position of the stator 40 in the circumferential direction than when there is no margin. Further, as shown in FIG. 4, the height of the protrusion 55 in the axial direction may be smaller than the height of the recess 25. Thereby, it becomes easy to adjust the position of the bus bar holder 50 in the axial direction.

  In manufacturing the motor 1, the protrusion 55 of the bus bar holder 50 and the recess 25 of the housing 20 are formed at predetermined positions so that the positions in the circumferential direction and the axial direction coincide with each other. A bus bar holder 50 is attached to one axial end side of the stator 40. At this time, the protrusion 55 of the bus bar holder 50 is fitted into the recess 25 of the housing 20.

  As described above, in the motor 1 according to the above-described embodiment, the bus bar holder 50 is disposed on one end side in the axial direction of the stator 40 and has one or more projecting portions 55 projecting radially outward from the stator 40. The housing 20 has a recess 25 that fits with one or more protrusions 55. Thereby, the rotation of the stator 40, which is not sufficient only by fixing such as shrink fitting or caulking, can be stopped more reliably. In addition, positioning of the conductive members such as the connection terminal 63 and the bus bar 61 in the circumferential direction is facilitated. Furthermore, since the structure is simple, it is possible to prevent rotation of the stator 40 while suppressing manufacturing costs.

(Modification)
(1)
As shown in FIG. 5, the leg portion 53 of the main body 51 of the bus bar holder 50 may have an extending portion 57 protruding in the axial direction at the tip. The extension portion 57 is fitted in the groove portion 45 formed on the outer surface of the stator 40 in the axial direction. Thereby, the bus bar holder 50 is fixed in the circumferential direction.
The fixing of the bus bar holder 50 in the circumferential direction is not limited to the fitting of the extending portion 57 and the stator 40, and may be fixed by other methods such as adhesion, welding, and caulking. The bus bar holder 50 may be fixed to other members fixed in the circumferential direction other than the stator 40.
Moreover, the extension part 57 has the following effect. As shown in FIG. 6, when the motor 1 has a control board 80 on one end side in the axial direction of the bus bar holder 50, the control board 80 is connected to a connection terminal 63 fixed to the bus bar holder 50. By fitting the extending portion 57 of the leg portion 53 of the bus bar holder 50 into the groove portion 45 of the stator 40, the connection terminal 63 and the control board 80 can be easily positioned.

(2)
The protrusion 55 may be provided on the outer periphery of a bearing holder (not shown) instead of the bus bar holder 50. The bearing holder has a substantially disk shape when viewed from above, and is a support member that is disposed above the stator 40 and holds the upper bearing 71.

(3)
In the present embodiment, the bus bar 61 is given as an example of the conductive member, but is not limited thereto. For example, a coil lead wire or the like drawn from the coil wire 43 may be used.

(Other embodiments)
An example in which the motor 1 is mounted on the electric power steering apparatus 2 will be described with reference to FIG.

  The electric power steering device 2 is mounted on a steering mechanism of a vehicle wheel 912. The electric power steering device 2 is a column type power steering device that directly reduces the steering force by the power of the motor 1. The electric power steering device 2 includes a motor 1, a steering shaft 914, and an axle 913.

  The steering shaft 914 transmits the input from the steering 911 to the axle 913 having the wheels 912. The power of the motor 1 is transmitted to the axle 913 via a ball screw. The motor 1 employed in the column-type electric power steering device 2 is provided inside an engine room (not shown). The electric power steering device 2 shown in FIG. 7 is a column type, but may be a rack type.

  The electric power steering device 2 includes a motor 1. For this reason, the electric power steering apparatus 2 with the same effect as that of the above embodiment can be obtained.

  Here, although the electric power steering apparatus 2 has been described as an example of the usage method of the motor 1, the usage method of the motor 1 is not limited and can be used in a wide range such as a pump and a compressor.

  The above-described embodiments and modification examples are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

DESCRIPTION OF SYMBOLS 1 ... Motor, 2 ... Electric power steering device, 20 ... Housing, 21 ... Tube part, 23 ... Bottom part, 24 ... Opening part, 25 ... Recessed part, 30 ... Rotor, 31 ... Shaft, 40 ... Stator, 441 ... Stator core, 42 Insulator, 43 ... Coil wire, 45 ... Groove, 50 ... Busbar holder, 51 ... Main body, 53 ... Leg, 55 ... Projection, 57 ... Extension, 61 ... Busbar, 63 ... Connection terminal, 71 ... Upper side Bearing, 72 ... lower bearing, 80 ... control board, 911 ... steering, 912 ... wheel, 913 ... axle, 914 ... steering axis, C ... central axis

Claims (9)

A shaft extending along the central axis;
A rotor fixed to the shaft;
A stator that is disposed radially outside the rotor and has a conductive portion;
A support member that is disposed on one axial end side of the stator and has a protruding portion that protrudes radially outward from the stator; and
A housing that is disposed on a radially outer side of the stator and has a recess that fits into the one or more protrusions;
Comprising a motor. A conductive member disposed on the support member and connected to the conductive portion of the stator;
The motor according to claim 1. The support member is
The main body,
A leg portion extending from the main body portion toward the stator and connected to the one end side of the stator;
Have
The leg has the protrusion.
The motor according to claim 1 or 2. The support member has an extending part that protrudes in the axial direction from the tip of the leg part,
The stator has a groove portion provided on the outer surface in the radial direction and fitted in the extension portion and the axial direction.
The motor according to claim 3. A control board disposed on one end side in the axial direction of the support member;
A connection terminal disposed on the support member and extending in the axial direction and connected to the control board;
Comprising
The motor according to claim 1. The width of the protrusion in the circumferential direction of the motor is smaller than the width of the recess in the circumferential direction.
The motor according to any one of claims 1 to 5. The height of the protruding portion in the axial direction is smaller than the height of the concave portion in the axial direction.
The motor according to any one of claims 1 to 6. A plurality of the protrusions and the recesses are provided along the circumferential direction of the motor.
The motor according to claim 1.   An electric power steering apparatus comprising the motor according to claim 1.