JP7180190B2 - MOTOR MANUFACTURING METHOD, MOTOR, AND ELECTRIC POWER STEERING DEVICE - Google Patents

Description

The present invention relates to a motor manufacturing method, a motor, and an electric power steering device.

A motor mounting member having a flange portion is known as a structure for mounting a motor to another member. The motor mounting member is fixed to one axial end of the motor. As a method of fixing the motor mounting member to the motor, a method is known in which a recess is formed in the outer peripheral portion of one axial end of the motor, and the recess and a protrusion formed on the outer peripheral portion of the motor mounting member are crimped to fix. (See Patent Document 1, for example). Also, there is known a method of crimping and fixing the outer peripheral portion of one axial end of the housing and the tapered portion of the outer peripheral portion of the motor mounting member (see Patent Document 2).

Japanese Patent Application Laid-Open No. 2015-6089 Japanese Utility Model Laid-Open No. 64-006757

In the motors of Patent Documents 1 and 2, since the size of the motor mounting member corresponds to the inner diameter of the housing, the mounting position of the motor to other members is also determined by the inner diameter of the housing. Therefore, it is difficult and inconvenient to adjust the mounting position of the motor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a motor and a motor that can easily adjust the mounting position to other members.

A method of manufacturing a motor according to an exemplary embodiment of the present application comprises: a shaft extending along a central axis and having bearings at both ends in the axial direction; a rotor fixed to the shaft; and a stator disposed radially outside the rotor. , a motor comprising a housing arranged radially outwardly of the stator and a motor mounting member. The motor mounting member is a motor mounting member for mounting the motor to another member, and has a main body facing one axial end of the housing and a flange protruding radially outward from the main body. A motor manufacturing method selects one motor mounting member from a plurality of motor mounting members having different radial dimensions, and has a housing having one axial end having a first end face and a second end face facing the first end face. A step of axially joining the body portion of the one motor mounting member and the body portion at two or more joining positions provided on the first end face and the second end face. The method also includes securing the stator within the housing and mounting the rotor within the housing.

According to a method of manufacturing a motor according to an exemplary embodiment of the present application, one motor mounting member is selected from a plurality of motor mounting members having different radial dimensions, and is attached to one axial end of a housing having a first end face. and a main body portion of the motor mounting member having a second end face opposite to the first end face at two or more joint positions provided on the first end face and the second end face, thereby fixing the motor mounting member to the housing. do. Therefore, it is possible to select an optimum motor mounting member from motor mounting members having different radial dimensions without depending on the housing, and mount the motor on another member. Therefore, it is possible to realize a motor manufacturing method and a motor that can easily adjust the mounting position to other members.

FIG. 1 is a cross-sectional view showing the motor of the first embodiment. FIG. 2 is a perspective view of the housing of the first embodiment viewed from the bottom side. 3 is a bottom view of the housing to which the motor mounting member of the first embodiment is attached; FIG. FIG. 4 is a cross-sectional view of the joint of the first embodiment. FIG. 5 is a diagram showing the bonding process of the first embodiment. FIG. 6 is a sectional view of the housing to which the motor mounting member of the second embodiment is joined. FIG. 7 is a bottom view of the housing to which the motor mounting member of the second embodiment is attached. FIG. 8 is a cross-sectional view of the joint of the second embodiment. FIG. 9 is a schematic diagram of an electric power steering device according to another embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 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, let C be the central axis of the motor. The direction in which the central axis C extends is defined as the axial direction. Also, one side along the axial direction is the upper side, and the other side 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 and positional relationship. The direction of gravity is not necessarily downward. Also, in this specification, the direction perpendicular to the rotation axis of the motor is referred to as the "radial direction". A direction along an arc around the rotation axis of the motor is called a "circumferential direction."

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

(First embodiment)
<Motor>
As shown in FIG. 1 , motor 1 includes shaft 31 , rotor 30 , stator 40 , busbar support 50 , housing 20 and motor mounting member 10 .

The shaft 31 extends along the central axis C and is rotatably supported around the central axis C by an upper bearing 71 and a lower bearing 72 . The rotor 30 is fixed to the shaft 31 and rotates around the central axis C together with the shaft 31 . The upper bearing 71 is held by a bearing holder 28 located above the stator 40 .

The stator 40 is arranged radially outside the rotor 30 so as to face the rotor 30 . The stator 40 has a stator core 41 , insulators 42 and coil wires 43 . The insulators 42 are attached to teeth (not shown) of the stator core 41 . The coil wire 43 is an example of a conductive portion, is composed of a conductive wire, and is wound around teeth with an insulator 42 interposed. A conductor drawn out from coil wire 43 wound around stator 40 is connected to bus bar 61 .

The busbar 61 is held by a busbar support 50 made of an insulating material such as resin and arranged above the stator 40 in the axial direction. The busbar 61 is electrically connected to the control board 80 via an electric wire (not shown). The control board 80 is arranged above the stator 40 and includes a drive circuit (not shown) composed of electronic components of the motor 1 . In addition, the bus bar 61 may have an external connection terminal (not shown) connected to an external power supply.

The housing 20 is arranged radially outward of the stator 40, and the stator 40 is fixed to the inner peripheral surface of the housing 20 by shrink fitting, crimping, press fitting, adhesion, or the like. The housing 20 is made of a metal material, has a bottomed cylindrical shape centered on the central axis C, and has a bottom portion 23 at the lower end in the axial direction. Note that the shape of the housing 20 is not limited to a cylindrical shape. Also, the radial cross-section of the housing 20 may be polygonal, for example.

As shown in FIG. 2, the housing 20 has a first end face 23a, a first center hole 27a and a first annular wall portion 27b at the bottom portion 23. As shown in FIG. The first center hole 27a is formed in the radial center of the first end surface 23a, and allows the shaft 31 shown in FIG. 1 to pass therethrough. A first annular wall portion 27b surrounds the first central hole 27a and forms the lower bearing holder 27 . The first annular wall portion 27b extends inwardly of the housing 20 from an inner end face 23b opposite the first end face 23a, as shown in FIG. The first annular wall portion 27b accommodates the lower bearing 72 . By providing the lower bearing holder 27 inside the housing 20 in this manner, the axial size of the motor 1 can be reduced. Note that the axial height of the first annular wall portion 27b does not have to be high enough to accommodate the entire lower bearing 72, and may be high enough to accommodate a portion of the lower bearing 72. good.

The motor mounting member 10 is, as shown in FIG. The motor mounting member 10 is fixed to another member 90 by bolts (not shown) or the like inserted into mounting holes 17 provided on both sides in the radial direction of the flange portion 11 .

The motor mounting member 10 has a body portion 12 and a flange portion 11, as shown in FIG. The body portion 12 has a second end surface 12a axially facing the first end surface 23a of the housing 20, as shown in FIG. The flange portion 11 extends from the outer periphery of the body portion 12 to the radially outer side of the housing 20 .

The body portion 12 of the motor mounting member also has a second central bore 18 and a second annular wall portion 19, as shown in FIG. The second center hole 18 is axially opposed to the first center hole 27a of the housing 20 and allows the shaft 31 to pass therethrough. A second annular wall 19 surrounds the second central bore 18 and extends axially from an outer end face 12b opposite the second end face 12a.
The bottom portion 23 of the housing 20 and the main body portion 12 of the motor mounting member 10 are axially joined via a joint portion 15 . As shown in FIGS. 2 and 3 , the joints 15 are formed at four joint positions 25 provided on the inner diameter side of the outer circumference of the body portion 12 of the motor mounting member 10 . The joining positions 25 are provided at equal intervals in the circumferential direction around the central axis C. As shown in FIG.

Each joint 15 is formed by, for example, TOX (registered trademark) caulking, which will be described later. Each joint portion 15 includes a concave portion 15a recessed inwardly of the housing 20 on one side in the axial direction, as shown in FIG. The joint portion 15 or the concave portion 15a may have a trapezoidal axial cross section as shown in the figure or a rectangular parallelepiped, depending on the shape of a jig to be described later.
As described above, in the motor 1 according to the above embodiment, the joint portion 15 that joins the housing 20 and the motor mounting member 10 can be formed without protruding outside the housing 20 . In a conventional motor (for example, Patent Document 1), since the caulking portion protrudes radially outward and axially of the housing, there is a risk that the motor may come into contact with a part of another member when the motor is attached to the other member. . Such contact may damage other members. In another conventional motor (for example, Japanese Unexamined Patent Application Publication No. 2002-100001), the crimped portion does not protrude because a step is provided on the outer peripheral edge of one axial end of the housing, but the total length of the motor is increased. On the other hand, in the motor 1 according to the above-described embodiment, since no portion protruding outside the housing 20 is formed, other members 90 are less likely to be damaged when the motor 1 is mounted. In addition, the influence of the motor mounting member 10 on the size of the motor 1 in the axial direction can be minimized.

<Motor manufacturing method>
In manufacturing the motor 1, first, a plurality of motor mounting members having different radial dimensions are prepared, and one motor mounting member is selected. The axial lower end of the housing 20 and the body portion 12 of the selected motor mounting member 10 are axially joined at four predetermined joining positions 25 . Joining is performed, for example, by TOX (registered trademark) caulking as follows.

As shown in FIG. 5, a jig 100 including a punch 101 and a die 102 is used to form the joint 15 . A laminate of the housing 20 and the body portion 12 of the motor mounting member 10 at the joint location 25 is placed on the die 102 . The punch 101 has a tip portion 101 a having an outer surface shape corresponding to the inner surface shape of the recess 15 a of the joint portion 15 . First, as shown in FIG. 5A, the tip 101a of the punch 101 is arranged so as to face the joining position 25. Then, as shown in FIG. Subsequently, as shown in FIG. 5B, the tip portion 101a is pushed into the laminate and pressed. At this time, the body portion 12 of the motor mounting member 10 and the housing 20 are plastically deformed, and the tip portion 101a of the punch 101 bites into the hole 102a of the die 102 . As a result, the layers of the housing 20 and the layers of the body portion 12 of the motor mounting member 10 are deformed along the shape of the hole 102 a of the die 102 . As a result, as shown in FIG. 5(c), a joint portion 15 having a concave portion 15a recessed axially and inwardly of the housing 20 is formed.

After the joint portion 15 is formed, the stator 40 is shrink-fitted in the housing 20, crimped, press-fitted, adhered, or otherwise fixed. The rotor 30 is arranged radially inside the stator 40 .
In the method of manufacturing the motor 1 described above, one motor mounting member is selected from a plurality of motor mounting members having different radial dimensions, and the motor mounting member 10 is fixed to the housing 20 . That is, the motor mounting member 10 can be selected according to the motor mounting position of the other member 90 . Therefore, the motor 1 can be attached to another member 90 without relying on the radial dimension φ of the housing 20 shown in FIG. Therefore, it is possible to realize a motor manufacturing method and a motor that can easily adjust the mounting position to the other member 90 .

(Second embodiment)
A motor according to the second embodiment will be described with reference to FIGS. 6 to 8. FIG. Since the motor according to the present embodiment is the same as the motor 1 according to the first embodiment except for the housing 20 and the motor mounting member 10, part of the illustration and description will be omitted. Also, the same components as those of the motor 1 according to the first embodiment will be described with the same reference numerals, and detailed description thereof will be omitted.

As shown in FIGS. 6 and 7 , the bottom portion 23 of the housing 20 according to this embodiment and the main body portion 12 of the motor mounting member 210 are axially joined via a joint portion 215 . The joint portions 215 are formed at four joint positions 25 provided on the inner diameter side of the outer circumference of the main body portion 12 of the motor mounting member 210 . The joining positions 25 are provided at equal intervals in the circumferential direction around the central axis C, as in the first embodiment.

Each joint 215 has a through hole 215c and a curved portion 215a, as shown in FIG. The through hole 215c axially penetrates the bottom portion 23 of the housing 20 . The curved portion 215a has a U-shaped cross section in the axial direction. Each joint 215 is formed using a predetermined jig (not shown). First, three sides of the portion of the motor mounting member 210 corresponding to the joining position 25 are cut, and the cut portions are inserted into the through holes 215c so as to protrude axially inward of the housing 20. As shown in FIG. Next, the protruding slit portion is bent and fixed by sandwiching the outer edge 215e of the through hole 215c. As a result, the housing 20 and the motor mounting member 210 are joined together.

In the motor 1 having the joint portion 215 according to the present embodiment, as in the first embodiment, the joint portion 215 does not form a portion protruding outside the housing 20, so that other members 90 are not damaged during mounting of the motor. This makes it possible to minimize the influence of the motor mounting member 210 on the size of the motor 1 in the axial direction. Also, in the method of manufacturing the motor, as in the first embodiment, the motor mounting member 210 can be selected according to the motor mounting position of the other member 90. Therefore, the motor mounting member 210 can be selected without depending on the radial dimension of the housing. A motor can be attached to another member 90 .

The through hole 215c may be provided on the motor mounting member 210 side, and the curved portion 215a may be provided on the housing 20 side. In this case, the curved portion 215a slightly protrudes from the outer end surface 12b of the motor mounting member 210 shown in FIG. 7, but the effect is small.

(Other embodiments)
(1)
In the first and second embodiments, the number and positions of the joints 15 and 215 are not limited to the above example. Two or more joining portions 15 and 215 may be provided. For example, the joint portions 15 and 215 may be provided at two joint positions 25 with the central axis C interposed therebetween. Alternatively, the joints 15 and 215 may be provided at five or more joint positions 25 . Moreover, the plurality of joining positions 25 need not be evenly distributed in the circumferential direction, and may be arranged at irregular intervals. Also, the radial length from the central axis C to each joint position 25 need not be constant and may be different.

(2)
In the first and second embodiments, the method of forming the joints 15 and 215 is not limited to the above examples. For example, joining by spot welding may be used.

(3)
The form of the motor 1 is not limited to the first and second embodiments. For example, the motor 1 may be a type of motor that does not include a busbar support or a busbar, and the lead wires of the coil wires 43 are connected to the control board 80 .

(4)
An example in which the motor 1 is installed in the electric power steering device 2 will be described with reference to FIG.

The electric power steering device 2 is mounted on a steering mechanism for wheels 912 of an automobile. 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 .

Steering shaft 914 transmits input from steering 911 to axle 913 having wheels 912 . Power of the motor 1 is transmitted to the axle 913 via the ball screw. A motor 1 employed in a column-type electric power steering device 2 is provided inside an engine room (not shown). The electric power steering device 2 shown in FIG. 9 is of a column type, but may be of a rack type.

An electric power steering device 2 includes a motor 1 . Therefore, it is possible to obtain the electric power steering apparatus 2 that exhibits the same effects as those of the above-described embodiment.

Here, the electric power steering device 2 is given as an example of the usage of the motor 1, but the usage of the motor 1 is not limited, and can be used in a wide range of applications such as pumps and compressors.

The above-described embodiments and modifications should be considered illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above-described embodiments, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 1... Motor 2... Electric power steering apparatus 10, 210... Motor attachment member 11... Flange part 12... Body part 12a... Second end face 12b... Outer end face 15, 215... Joining part 15a... Recessed part , 17... Mounting hole 18... Second central hole 19... Second annular wall part 20... Housing 23... Bottom part 23a... First end surface 23b... Inner end surface 25... Joint position 27... Lower bearing Holder 27a First center hole 27b First annular wall 28 Bearing holder 30 Rotor 31 Shaft 40 Stator 41 Stator core 42 Insulator 43 Coil wire 50 Bus bar Support 61 Busbar 71 Upper bearing 72 Lower bearing 80 Control board 90 Other member 100 Jig 101 Punch 101a Tip 102 Die 102a Hole 210...Motor mounting member 215a...Bending portion 215c...Through hole 215e...Outer edge 911...Steering 912...Wheel 913...Axle 914...Steering shaft C...Center shaft

Claims (5)

a shaft extending along a central axis and having bearings at both ends in the axial direction; a rotor fixed to the shaft; a stator arranged radially outward of the rotor; and a housing arranged radially outward of the stator. a motor mounting member for mounting a motor to another member, the motor mounting member having a main body facing one axial end of the housing and a flange protruding radially outward from the main body; A method for manufacturing a motor comprising:
a first step of selecting one motor mounting member from the plurality of motor mounting members having different radial dimensions;
After the first step, one axial end of the housing having a first end surface and a body portion of the one motor mounting member having a second end surface facing the first end surface are separated from each other by the first end surface and the a second step of axially joining at two or more joining positions provided on the second end face;
after the second step, accommodating the bearing in the housing; fixing the stator in the housing; and mounting the rotor in the housing ;
A method of manufacturing a motor, comprising: joining the one axial end of the housing and the body portion of the one motor mounting member is at least one of welding and caulking;
A method of manufacturing a motor according to claim 1 . In the caulking joint, at the two or more joining positions, one axial end of the housing and the main body portion of the one motor mounting member are pushed in one axial direction by a jig to plastically deform to form a recess. including,
3. A method of manufacturing a motor according to claim 2. In the caulking joint, at the two or more joint positions, a through hole is formed in one of the axial ends of the housing and one of the main body portions of the one motor mounting member. In the other of the main body portions of the one motor mounting member, a portion facing the through hole is cut into a U shape, and the cut portion is curved to sandwich the outer edge of the through hole.
3. A method of manufacturing a motor according to claim 2. The joining position is
provided in plurality along the circumferential direction of the housing,
arranged on the inner diameter side of the outer circumference of the main body of the motor mounting member,
A method for manufacturing a motor according to any one of claims 1 to 4.

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