JP6744194B2 - Bearing holding structure and motor - Google Patents

Description

The present invention relates to a rolling bearing holding structure that rotatably supports a shaft, and a motor to which the bearing holding structure is applied.

The shaft of the motor is press-fitted and fixed to the inner ring of the rolling bearing, and this bearing is rotatably supported by being attached to a housing or end bell (hereinafter referred to as "housing or the like"). Examples of the structure for attaching the bearing to the housing or the like include a structure in which the bearing is housed in a recess formed in the housing and attached by an adhesive. Further, a structure has also been proposed in which a bearing is housed in a recess, a plate is fixed to a housing or the like, and the bearing is axially sandwiched by the bottom of the recess and the plate (see Patent Document 1).

JP, 2010-183709, A

The tip portion of the shaft supported by the bearing is projecting from the recess to the outside of the housing as in the above-mentioned Patent Document 1, and for example, via a gear or the like, a load (for example, office equipment or in-vehicle electrical equipment, such as "Body"). When the motor is attached to the driven body, the method of using the end bell (end case) as in Patent Document 1 described above may cause a complicated structure and shape of the end bell.

On the other hand, if the mounting plate, which is separate from the motor, is fixed to the housing and the mounting plate is fixed to the driven body so that the motor is mounted on the driven body, the above-mentioned concern is eliminated. sell. However, in this case, since a new component called a mounting plate is interposed between the motor and the driven body, it is important to improve the positional accuracy of the mounting plate with respect to the housing. That is, unless the mounting plate is mounted at an accurate position with respect to the motor, it becomes difficult to accurately fix the motor to the driven body, and it becomes impossible to achieve coaxiality.

The present invention has been devised in view of such a problem, and an object thereof is to make it easy to obtain coaxiality with a driven body to which a motor is attached in a bearing holding structure using an attachment plate. Another object is to provide a motor in which coaxiality with the driven body can be easily obtained. It is to be noted that the present invention is not limited to these objectives, and it is also possible to obtain operational effects that are obtained by the respective configurations shown in the modes for carrying out the invention described later, and which cannot be obtained by conventional techniques. Is.

(1) The bearing holding structure disclosed herein is a bearing holding structure that holds a rolling bearing that rotatably supports a shaft of a motor, and is formed into a cylindrical shape with a bottom, and the rolling bearing is provided at a bottom portion having a through hole. And a mounting plate fixed to the bottom of the housing for mounting the motor to a driven body, the housing having a cylindrical surface facing the outer peripheral surface of the rolling bearing. The bottom surface has a support surface that abuts on one end surface of the rolling bearing, the mounting plate has an opening located coaxially with the through hole in a state of being fixed to the housing, and the rolling bearing. of the abutting portion abutting on the outer circumferential surface of the other end surface the roller bearing pressing portion for pressing the possess around the opening, a gap between the outer peripheral surface and the cylindrical surface of the rolling bearing It is characterized in that to Yes.

(2) The mounting plate preferably has a plurality of pressing portions and a plurality of contact portions.
(3) The mounting plate preferably has at least three contact portions.
(4) It is preferable that the pressing portion and the contact portion are alternately arranged around the opening.

(5) It is preferable that both of the cylindrical surface and the support surface are provided as an inner surface of a recess in which the central portion of the bottom portion is recessed inward of the housing.
(6) The motor disclosed herein is a motor including a stator and a rotor that are built in a housing, and the rolling bearing that rotatably supports a shaft that rotates integrally with the rotor has the above (1) to It is characterized in that any one of the bearing holding structures of (5) is applied.

According to the disclosed bearing holding structure, the mounting plate can be fixed to the motor on the basis of the rolling bearing. That is, it is possible to fix the rotation center of the motor with a minimum error. Therefore, when the motor is mounted on the driven body via the mounting plate, the mounting position of the motor on the driven body can be accurately determined with respect to the rotation center of the motor. As a result, the coaxiality between the motor and the driven body can be easily obtained.
Further, according to the disclosed motor, since the mounting position with respect to the driven body can be determined based on the bearing, the coaxiality with the driven body can be easily obtained.

It is a disassembled perspective view of the motor which concerns on embodiment. It is an axial sectional view of the bearing holding structure concerning an embodiment. It is the perspective view seen from the mounting plate side except a bearing from FIG.

A bearing holding structure and a motor as an embodiment will be described with reference to the drawings. The embodiments described below are merely examples, and are not intended to exclude various modifications and application of techniques that are not explicitly shown in the following embodiments. Each configuration of the present embodiment can be variously modified and implemented without departing from the spirit thereof. Further, they can be selected or combined as needed.

[1. Constitution]
1 is a perspective view of a motor 9 according to the present embodiment, FIG. 2 is an axial cross-sectional view showing a bearing holding structure according to the present embodiment, and FIG. 3 is a mounting plate excluding the rolling bearing 2 from FIG. It is the perspective view seen from the 3 side. The motor 9 of the present embodiment is a small motor used in, for example, office equipment and household electric equipment (hereinafter referred to as “driven body”). The type and use of the motor 9 are not particularly limited.

As shown in FIG. 1, the motor 9 includes a stator and a rotor (both not shown) that are both housed in the housing 1, and a shaft 4 that rotates integrally with the rotor. The housing 1 is formed in a cylindrical shape with a bottom, and an end bell 5 is connected to an opening (not shown) of the housing. A slide bearing (not shown) that rotatably supports one end of the shaft 4 is fixed to the end bell 5. The other end 4a of the shaft 4 is provided so as to project from the bottom 1b (see FIG. 2) of the housing 1, and is connected to a driven body (none of which is shown) via, for example, a gear. The motor 9 drives the driven body by the power output from the shaft 4 and transmitted to the driven body.

As shown in FIGS. 1 to 3, the bottom portion 1b of the housing 1 is provided with a through hole 1c into which the other end side of the shaft 4 is inserted, and a rolling bearing 2 that rotatably supports the other end side of the shaft 4. (Hereinafter referred to as "bearing 2") is held. Further, a mounting plate 3 for mounting the motor 9 on the driven body is fixed to the bottom portion 1b of the housing 1. The bearing holding structure of the present embodiment holds the bearing 2, and is composed of the housing 1 and the mounting plate 3. The shaft 4 is press-fitted and fixed to the inner ring of the bearing 2.

The housing 1 of this embodiment has a recess 10 in the bottom 1b into which the bearing 2 is fitted. The concave portion 10 is a portion where the central portion of the bottom portion 1b is recessed inward of the housing 1, and has a cylindrical surface 10a extending in the axial direction and a support surface 10b orthogonal to the cylindrical surface 10a. The cylindrical surface 10a is a surface having the same central axis as the peripheral wall 1a of the housing 1 in the inner surface of the recess 10 (the surface facing the outside of the housing 1). The inner diameter of the cylindrical surface 10a is larger than the diameter of the through hole 1c and is equal to or slightly larger than the outer diameter of the bearing 2. The support surface 10b is an annular plane (a surface other than the cylindrical surface 10a) that surrounds the through hole 1c of the inner surface of the recess 10.

Both the cylindrical surface 10a and the support surface 10b are located inside the housing 1 than a portion of the bottom portion 1b to which the mounting plate 3 is fixed (hereinafter referred to as "fixing portion 1d"). The cylindrical surface 10a is a surface facing the outer peripheral surface 2a of the bearing 2 (that is, the outer peripheral surface of the outer ring), and the support surface 10b is a surface contacting one end surface 2b of the bearing 2 (one end surface of the outer ring). The cylindrical surface 10a and the outer peripheral surface 2a of the bearing 2 are in contact with each other or form a slight gap (not shown).

The mounting plate 3 of the present embodiment is a substantially rhombus-shaped flat plate (made of sheet metal) having rounded corners, and has a circular portion 3a that axially overlaps the bottom portion 1b, and is protruded outward from the edge of the circular portion 3a. It has a pair of flange portions 3b. The pair of flange portions 3b are arranged 180 degrees apart. The flange portion 3b is formed in a tapered shape, and a round hole is formed in the tip portion thereof. An opening 30 is formed at the center of the circular portion 3a of the mounting plate 3. The opening 30 is positioned coaxially with the through hole 1c in a state where the mounting plate 3 is fixed to the bottom portion 1b of the housing 1 (hereinafter referred to as "fixed state"). The mounting plate 3 is fixed to the housing 1 by, for example, screwing or caulking in a state where the circular portion 3a and the bottom portion 1b are overlapped with each other.

The mounting plate 3 includes a plurality of contact surfaces 31 (contact portions) that contact the outer peripheral surface 2a of the bearing 2 and a plurality of pressing surfaces 32 (pressing portions) that press the other end surface 1c of the bearing 2 (the other end surface of the outer ring). ) And around the opening 30. The contact surface 31 of the present embodiment is provided on each of inner wall portions 33a (described later) of the plurality of holding walls 33 arranged at equal intervals around the opening portion 30. Further, the pressing surface 32 of the present embodiment is provided on each of the plurality of holding claws 34 arranged at equal intervals around the opening 30. That is, the contact surface 31 and the pressing surface 32 of this embodiment are alternately arranged around the opening 30. The mounting plate 3 of this embodiment has three contact surfaces 31 and three pressing surfaces 32.

The holding wall 33 is a portion that is bent and formed so that the periphery of the opening 30 in the circular portion 3a bulges in a direction away from the bottom portion 1b. The holding wall 33 has a U-shaped cross section along the axial direction with the bottom portion 1b side open, and includes an inner wall portion 33a, an outer wall portion 33b, and a top portion 33c. The outer wall portion 33b is a substantially cylindrical wall portion that is erected in a direction substantially orthogonal to the circular portion 3a that is overlaid on the bottom portion 1b. The tip of the outer wall portion 33b is curved inward in the radial direction, and the top portion 33c is continuously provided. The top portion 33c is a portion that connects the inner wall portion 33a and the outer wall portion 33b, which are located radially inside the outer wall portion 33b. The inner wall portion 33a is located between the holding claws 34 that are adjacent to each other in the circumferential direction, and the end portion on the side opposite to the top portion 33c is formed so as to be curved inward in the radial direction, so that the end surface is provided facing inward in the radial direction. .. The end surface of the inner wall portion 33a facing inward in the radial direction functions as the contact surface 31.

The holding claw 34 is a portion obtained by cutting and raising a part of the holding wall 33 and has flexibility. Specifically, a plurality of cuts are formed in a part of the holding wall 33 along the radial direction, and a holding claw 34 is formed by causing a gap between two adjacent cuts. When the holding claw 34 holds the bearing 2 (hereinafter referred to as “holding state”), the holding claw 34 is raised by the bearing 2 and elastically deforms, and an elastic force is generated in an attempt to return to the original state. This force becomes a force (pressing force) for pressing the bearing 2 against the support surface 10b. That is, the surface of the holding claw 34 that contacts the bearing 2 functions as the pressing surface 32. The holding state here is a state in which the bearing 2 is fitted in the recess 10 and the mounting plate 3 is fixed (fixed) to the housing 1. The mounting plate 3 is formed by pressing a single metal plate, and is integrally provided with a circular portion 3a, a flange portion 3b, a holding wall 33, and a holding claw 34.

Here, the procedure for assembling the bearing holding structure will be described. First, the bearing 2 is fitted into the recess 10 of the housing 1. That is, the one end surface 2b of the bearing 2 is brought into contact with the support surface 10b, and the outer peripheral surface 2a and the cylindrical surface 10a are opposed to each other. Next, the mounting plate 3 is fixed to the bottom portion 1b of the housing 1. At this time, the abutting surface 31 of the mounting plate 3 is brought into contact with the outer peripheral surface 2a of the bearing 2 to determine the radial position of the mounting plate 3. In this state, the mounting plate 3 is fixed to the bottom portion 1b of the housing 1 by screwing or caulking. As a result, the pressing surface 32 of the holding claw 34 presses the other end surface 2c of the bearing 2, so that the bearing 2 is sandwiched between the support surface 10b and the pressing surface 32 in the axial direction.

[2. effect]
(1) According to the bearing holding structure described above, the bearing 2 can be sandwiched in the axial direction by the support surface 10b of the housing 1 and the pressing surface 32 of the mounting plate 3, so that the movement of the bearing 2 can be suppressed. .. Further, since the mounting plate 3 is provided with the contact surface 31 that contacts the outer peripheral surface 2a of the bearing 2, the position (radial position) of the mounting plate 3 with respect to the housing 1 can be determined with reference to the bearing 2. it can.

That is, according to the bearing holding structure described above, the mounting plate 3 can be fixed to the motor 9 with the bearing 2 as a reference. Since the center of the bearing 2 and the center of rotation of the motor 9 are substantially coincident with each other, the bearing holding structure described above can fix the mounting plate 3 to the motor 9 with a minimum error with respect to the center of rotation of the motor 9. .. Therefore, when the motor 9 is mounted on the driven body via the mounting plate 3, the mounting position of the motor 9 on the driven body can be accurately determined with respect to the rotation center of the motor 9. Therefore, the coaxiality between the motor 9 and the driven body can be easily obtained. For example, comparing the bearing holding structure described above with the structure in which the position (radial position) of the mounting plate 3 with respect to the housing 1 is determined with the peripheral wall 1a as a reference, the former is more likely to have a motor 9 and a driven body than the latter. The coaxiality can be easily obtained.

(2) In the above-described bearing holding structure, since the contact surface 31 and the pressing surface 32 are each provided in plural, the contact surface 31 and the pressing surface 32 can be divided and arranged around the opening 30. The configuration of the mounting plate 3 can be simplified. Thereby, since the mounting plate 3 can be formed by cutting and pressing one metal plate, for example, the manufacturing cost of the mounting plate 3 can be reduced. In the present embodiment, since the pressing surface 32 is provided on each of the plurality of holding claws 34 that are arranged at equal intervals around the opening 30, the pressing surface 32 is pressed against the bearing 2 with a uniform force in the circumferential direction. You can Thereby, the movement of the bearing 2 can be suppressed and the holding performance can be improved.

(3) According to the bearing holding structure described above, since the mounting plate 3 has the three contact surfaces 31, the position of the mounting plate 3 with respect to the housing 1 can be accurately determined. In other words, the positioning accuracy of the mounting plate 3 can be improved.
(4) Further, since the contact surface 31 and the pressing surface 32 are alternately arranged around the opening 30, the mounting plate 3 has a function of pressing the bearing 2 (suppressing movement) and the mounting plate 3. It is possible to exert a good balance with the function of performing positioning. In other words, according to the bearing holding structure described above, it is possible to improve the positioning accuracy of the mounting plate 3 while ensuring the holding performance of the bearing 2.

(5) In the bearing holding structure described above, both the cylindrical surface 10a and the support surface 10b are provided as the inner surface of the recess 10 formed in the bottom portion 1b. That is, since both the cylindrical surface 10a and the support surface 10b are located inside the housing 1 than the fixed portion 1d of the bottom portion 1b, the amount of protrusion of the bearing 2 from the bottom portion 1b can be reduced. As a result, the position of the pressing surface 32 that presses the other end surface 1c of the bearing 2 can be brought closer to the bottom portion 1b, so that the axial length of the mounting plate 3 can be shortened.
(6) According to the motor 9 described above, the mounting position with respect to the driven body can be determined with the bearing 2 as a reference (with a minimum error with respect to the rotation center of the motor 9). You can easily give a degree.

[3. Other]
The bearing holding structure described in the above embodiment is an example, and the configuration is not limited to the above. For example, the mounting plate 3 described above is provided with three contact surfaces 31 and three pressing surfaces 32 alternately around the opening 30, but the number of contact surfaces 31 and pressing surfaces 32 is particularly large. There is no limitation, and the numbers may not be the same. For example, a cylindrical contact surface 31 and an annular pressing surface 32 may be provided. Further, the contact surfaces 31 and the pressing surfaces 32 do not have to be alternately arranged, and the arrangement intervals of the contact surfaces 31 and the pressing surfaces 32 do not have to be equal intervals. Since the contact surface 31 defines the position of the mounting plate 3 with respect to the housing 1, when a plurality of contact surfaces 31 are provided, the number thereof is preferably three or more.

In the above-described embodiment, the configuration in which the contact surface 31 is provided on the inner wall portion 33a of the holding wall 33 having a U-shaped cross section is illustrated, but the shape of the holding wall is not limited to the above. For example, the periphery of the opening 30 in the circular portion 3a is bent and formed in a direction away from the bottom portion 1b, and is provided as a substantially cylindrical wall portion that is erected in a direction substantially orthogonal to the circular portion 3a that is overlapped with the bottom portion 1b. May be. In this case, by bringing the surface of the holding wall facing inward in the radial direction into contact with the outer peripheral surface 2a of the bearing 2, this portion can function as the contact surface. Even with such a configuration, the position of the mounting plate 3 with respect to the housing 1 can be determined on the basis of the bearing 2, so that the same effect as that of the above-described embodiment can be obtained.

Further, the contact surface may not be provided on the holding wall. For example, the edge (end surface) of the opening 30 may be brought into contact with the outer peripheral surface 2a of the bearing 2 so that this edge (end surface) functions as the contact surface. In this case, the retaining wall can be omitted. The mounting plate has only to have a portion (structure) that comes into contact with the outer peripheral surface 2a of the bearing 2, and that portion does not have to be a surface (for example, a line or a point). The abutting portion may be provided as a portion that abuts the outer peripheral surface 2a of the bearing 2 at least around the opening 30.

In the above-described embodiment, the holding claw 34 formed by cutting and raising a part of the holding wall 33 is provided with the pressing surface 32, but the holding claw 34 is a part of the holding wall 33. You don't have to. For example, by forming a holding claw portion and a holding wall portion on the flat plate-shaped circular portion 3a in the circumferential direction, and bending (curving) each portion, adjacent holding claws are formed. A space may be provided between the holding wall and the holding wall. Even with such a configuration, the same effect as that of the above-described embodiment can be obtained. The mounting plate may have a portion (structure) that presses the other end surface 2c of the bearing 2, and that portion does not have to be a surface (for example, it may be a line or a dot). The pressing portion may be provided as a portion that abuts the other end surface 2c of the bearing 2 at least around the opening 30, and may not be provided in the holding claw.

In the above-mentioned embodiment, the concave portion 10 into which the bearing 2 is fitted is provided in the bottom portion 1b of the housing 1, and the cylindrical surface 10a and the supporting surface 10b are provided as the inner surface of the concave portion 10. 10a and the supporting surface 10b do not have to be the inner surface of the recess 10. For example, the recess 10 is omitted, a supporting surface is provided on the same surface as the outer surface of the bottom portion 1b, and a cylindrical wall portion projecting outward of the housing 1 is provided radially outside the supporting surface. The inner surface in the radial direction may be a cylindrical surface. Note that the support surface 10b may be formed of a plurality of flat surfaces that are separated in the circumferential direction, instead of the annular shape. The housing 1 may have a cylindrical surface facing the outer peripheral surface 2a of the bearing 2 and a support surface that abuts on the one end surface 2b of the bearing 2 at least on the bottom portion 1b.

The external shape of the mounting plate 3 described above is an example and is not particularly limited. For example, three or more flange portions 1b may be provided, and the shape thereof may be a shape other than the above. The material of the mounting plate 3 is not limited to sheet metal, and the mounting plate may be made of resin, for example. The housing 1 may have any shape as long as it has a bottomed tubular shape, and the cross-section orthogonal to the axis may be rectangular or oval.

1 Housing 1b Bottom part 1c Through hole 1d Fixed part 2 Bearing (rolling bearing)
2a Outer peripheral surface 2b One end surface 2c Other end surface 3 Mounting plate 4 Shaft 9 Motor 10 Recess 10a Cylindrical surface 10b Support surface 30 Opening 31 Contact surface (contact portion)
32 Pressing surface (pressing part)
33 retaining wall 34 retaining claw

Claims (6)

A bearing holding structure for holding a rolling bearing that rotatably supports a motor shaft,
A housing having a bottomed tubular shape, and the rolling bearing fitted to a bottom portion having a through hole;
A mounting plate fixed to the bottom portion of the housing, for mounting the motor on a driven body,
The housing has a cylindrical surface facing the outer peripheral surface of the rolling bearing and a support surface abutting on one end surface of the rolling bearing in the bottom portion,
The mounting plate has an opening located coaxially with the through hole in a state of being fixed to the housing, and abuts against a pressing portion that presses the other end surface of the rolling bearing and the outer peripheral surface of the rolling bearing. have a contact portion around the opening,
Characterized in that it have a gap between the outer peripheral surface and the cylindrical surface of the rolling bearing, bearing retaining structure. The bearing holding structure according to claim 1, wherein the mounting plate has a plurality of the pressing portions and a plurality of the contact portions. The bearing holding structure according to claim 2, wherein the mounting plate has at least three contact portions. The bearing holding structure according to claim 2 or 3, wherein the pressing portion and the contact portion are alternately arranged around the opening. 5. The cylindrical surface and the support surface are both provided as an inner surface of a recessed portion in which the central portion of the bottom portion is recessed inward of the housing, and the cylindrical surface and the support surface are provided. The bearing holding structure described. In a motor equipped with a stator and rotor built into the housing,
A bearing holding structure according to any one of claims 1 to 5 is applied to a rolling bearing that rotatably supports a shaft that rotates integrally with the rotor.

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