JP2018068000A - Bearing retention structure and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain concentricity of a driven body to which a motor is attached.SOLUTION: A motor comprises: a cylindrical housing 1 having a bottom, that has a bearing retention structure holding a rolling bearing 2 which rotatably supports a shaft of the motor; and an attachment plate 3 for attaching the motor to a driven body. In the housing 1, the rolling bearing 2 is fitted to a bottom part 1b having a penetration hole 1c. The attachment plate 3 is fixed to the bottom part 1b of the housing 1. The housing 1 includes a cylindrical surface 10a opposite to an external peripheral surface 2a of the rolling bearing 2 and a supporting surface 10b contacted to one end surface 2b of the rolling bearing 2 in the bottom part 1b. The attachment plate 3 includes an open part 30 coaxially positioned with the penetration hole 1c in a state of being fixed to the housing 1, and a contact surface 31 contacted to the external peripheral surface 2a of a pressure surface 32 pressing the other end surface 2c of the rolling bearing 2 and the rolling bearing 2 in the circumference of the open part 30.SELECTED DRAWING: Figure 2

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 an inner ring of a rolling bearing, and this bearing is rotatably supported by being attached to a housing or an end bell (hereinafter referred to as “housing or the like”). As a structure for attaching the bearing to the housing or the like, for example, a structure in which the bearing is accommodated in a recess formed in the housing or the like and attached by an adhesive can be mentioned. In addition, a structure has been proposed in which a bearing is accommodated in a recess, a plate is fixed to a housing or the like, and the bearing is clamped from the axial direction by the bottom surface of the recess and the plate (see Patent Document 1).

JP 2010-183709 A

  The front end of the shaft supported by the bearing is projected from the recess to the outside of the housing, as described in Patent Document 1 described above. For example, a load (for example, office equipment or in-vehicle electrical equipment, etc.) Body)). When the motor is attached to the driven body, the method using the end bell (end case) as in Patent Document 1 has a concern that the structure and shape of the end bell become complicated.

  On the other hand, the above-mentioned concern is solved if the motor is attached to the driven body by fixing the mounting plate separate from the motor to the housing and fixing the mounting plate to the driven body. 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, if the mounting plate is not mounted at an accurate position with respect to the motor, it is difficult to accurately fix the motor to the driven body, and the coaxiality cannot be obtained.

  The present case has been devised in view of such problems, and one of its purposes is to make it easy to achieve a coaxial degree with a driven body to which a motor is attached in a bearing holding structure using a mounting plate. Another object of the present invention is to provide a motor that can easily achieve coaxiality with a driven body. It should be noted that the present invention is not limited to these purposes, and is an operational effect derived from each configuration shown in the embodiment for carrying out the invention described later, and also has an operational effect that cannot be obtained by conventional techniques. It is.

  (1) A bearing holding structure disclosed herein is a bearing holding structure for holding a rolling bearing that rotatably supports a shaft of a motor, and is formed in a bottomed cylindrical shape, and the rolling bearing is formed at a bottom portion having a through hole. Is fitted to the bottom portion of the housing, and a mounting plate for attaching the motor to the driven body. The housing has a cylindrical surface facing the outer peripheral surface of the rolling bearing. The rolling bearing has a support surface in contact with one end face of the rolling bearing at the bottom, and the mounting plate has an opening positioned coaxially with the through hole in a state of being fixed to the housing. A pressing portion that presses the other end surface of the roller bearing and a contact portion that contacts the outer peripheral surface of the rolling bearing are provided around the opening.

(2) It is preferable that the mounting plate includes a plurality of the pressing portions and a plurality of the contact portions.
(3) It is preferable that the mounting plate has at least three contact portions.
(4) It is preferable that the said press part and the said contact part are alternately arrange | positioned around the said opening part.

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

According to the disclosed bearing holding structure, the mounting plate can be fixed to the motor based on the rolling bearing. In other words, it can be fixed with a minimum error with respect to the rotation center of the motor. For this reason, when the motor is attached to the driven body via the mounting plate, the mounting position of the motor with respect to 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, the mounting position with respect to the driven body can be determined on the basis of the bearing, so that 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 according to the embodiment. It is the perspective view seen from the attachment 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 embodiment described below is merely an example, and there is no intention of excluding various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit thereof. Further, they can be selected as necessary, or can be appropriately combined.

[1. Constitution]
1 is a perspective view of a motor 9 according to this embodiment, FIG. 2 is an axial sectional view showing a bearing holding structure according to this embodiment, and FIG. 3 is a mounting plate excluding the rolling bearing 2 from FIG. It is the perspective view seen from 3 side. The motor 9 of the present embodiment is a small motor used for, for example, office equipment and household electrical equipment (hereinafter referred to as “driven body”). The type and application 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) built in the housing 1, and a shaft 4 that rotates integrally with the rotor. The housing 1 is formed in a bottomed cylindrical shape, and an end bell 5 is coupled to an opening (not shown). Note that a sliding 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 protrudes from the bottom 1b (see FIG. 2) of the housing 1, and is connected to a driven body (both not shown) via a gear or the like, for example. 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 1 b of the housing 1 is provided with a through hole 1 c through 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, an attachment plate 3 for attaching the motor 9 to the driven body is fixed to the bottom 1b of the housing 1. The bearing holding structure of the present embodiment holds the bearing 2 and includes a housing 1 and a 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 which the bearing 2 is fitted in the bottom 1b. The concave portion 10 is a portion in which the central portion of the bottom portion 1b is recessed inward of the housing 1, and includes a cylindrical surface 10a extending in the axial direction and a support surface 10b orthogonal to the cylindrical surface 10a. The cylindrical surface 10 a is a surface having the same central axis as the peripheral wall 1 a of the housing 1 among the inner surface of the recess 10 (the surface facing the outside of the housing 1). The inner diameter of the cylindrical surface 10 a is larger than the diameter of the through hole 1 c and is equal to or slightly larger than the outer diameter of the bearing 2. The support surface 10 b is an annular flat surface (a surface other than the cylindrical surface 10 a) surrounding the through hole 1 c among the inner surface of the recess 10.

  Both the cylindrical surface 10a and the support surface 10b are located inside the housing 1 from the portion of the bottom portion 1b to which the mounting plate 3 is fixed (hereinafter referred to as “fixed portion 1d”). The cylindrical surface 10a is a surface on which the outer peripheral surface 2a of the bearing 2 (that is, the outer peripheral surface of the outer ring) faces, and the support surface 10b is a surface on which one end surface 2b of the bearing 2 (one end surface of the outer ring) abuts. The cylindrical surface 10a and the outer peripheral surface 2a of the bearing 2 abut 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) with rounded corners, and a circular portion 3a that overlaps the bottom portion 1b in the axial direction, and protrudes outward from the edge of the circular portion 3a. And 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 at the tip portion thereof. An opening 30 is formed at the center of the circular portion 3 a of the mounting plate 3. The opening 30 is located coaxially with the through hole 1 c in a state where the mounting plate 3 is fixed to the bottom 1 b 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.

  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). ) Around the opening 30. The contact surface 31 of the present embodiment is provided on each of the inner wall portions 33a (described later) of the plurality of holding walls 33 arranged at equal intervals around the opening 30. In addition, the pressing surface 32 of the present embodiment is provided on each of the plurality of holding claws 34 that are 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. Note that the mounting plate 3 of the present embodiment has three contact surfaces 31 and three pressing surfaces 32.

  The holding wall 33 is a portion that is bent so that the periphery of the opening 30 in the circular portion 3a bulges in a direction away from the bottom 1b. The holding wall 33 has a U-shaped cross-sectional shape along the axial direction with the bottom 1b opened, and is configured by an inner wall 33a, an outer wall 33b, and a top 33c. The outer wall portion 33b is a substantially cylindrical wall portion erected in a substantially orthogonal direction with respect to the circular portion 3a superimposed 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 provided continuously. The top portion 33c is a portion that connects the inner wall portion 33a and the outer wall portion 33b located on the radially inner side of the outer wall portion 33b. The inner wall portion 33a is positioned between the holding claws 34 adjacent in the circumferential direction, and the end portion on the opposite side to the top portion 33c is curved toward the radially inner side, so that the end surface is provided facing the radially inner side. . An end surface facing the radially inner side of the inner wall portion 33a functions as the contact surface 31 described above.

  The holding claw 34 is a portion where a part of the holding wall 33 is cut and raised, and has flexibility. Specifically, a plurality of cuts are formed in a part of the holding wall 33 along the radial direction, and the holding claws 34 are formed by raising between two adjacent cuts. The holding claw 34 is raised by the bearing 2 and elastically deformed in a state where the bearing 2 is held (hereinafter referred to as “holding state”), and an elastic force is generated 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 into the recess 10 and the mounting plate 3 is fixed to the housing 1 (fixed state). The mounting plate 3 is formed by pressing a single metal plate, and a circular portion 3a, a flange portion 3b, a holding wall 33, and a holding claw 34 are integrally provided.

  Here, the assembly procedure of 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 1 b of the housing 1. At this time, the radial position of the mounting plate 3 is determined by bringing the contact surface 31 of the mounting plate 3 into contact with the outer peripheral surface 2 a of the bearing 2. In this state, the mounting plate 3 is fixed to the bottom 1b of the housing 1 by screwing or caulking. Thereby, since the pressing surface 32 of the holding claw 34 presses the other end surface 2c of the bearing 2, the bearing 2 is sandwiched between the support surface 10b and the pressing surface 32 from the axial direction.

[2. effect]
(1) According to the bearing holding structure described above, since the bearing 2 can be sandwiched between the support surface 10b of the housing 1 and the pressing surface 32 of the mounting plate 3 in the axial direction, the movement of the bearing 2 can be suppressed. . Furthermore, since the mounting plate 3 is provided with a contact surface 31 that contacts the outer peripheral surface 2 a 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 rotation center of the motor 9 substantially coincide with each other, the mounting plate 3 can be fixed to the motor 9 with a minimum error with respect to the rotation center of the motor 9 with the above-described bearing holding structure. . For this reason, when the motor 9 is attached to the driven body via the mounting plate 3, the mounting position of the motor 9 with respect to 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, when the bearing holding structure described above and 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 effective between the motor 9 and the driven body than the latter. The coaxiality can be easily obtained.

  (2) In the bearing holding structure described above, a plurality of contact surfaces 31 and pressing surfaces 32 are provided, so that the contact surfaces 31 and the pressing surfaces 32 can be divided and arranged around the opening 30. The configuration of the mounting plate 3 can be simplified. Accordingly, for example, the mounting plate 3 can be formed by cutting and pressing a single metal plate, so that the manufacturing cost of the mounting plate 3 can be reduced. In the present embodiment, the pressing surface 32 is provided on each of the plurality of holding claws 34 arranged at equal intervals around the opening 30, so that it is pressed against the bearing 2 with a uniform force in the circumferential direction. Can do. 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 determined with high accuracy. In other words, the positioning accuracy of the mounting plate 3 can be improved.
(4) Since the contact surface 31 and the pressing surface 32 are alternately arranged around the opening 30, the mounting plate 3 presses the bearing 2 (suppresses movement) and the mounting plate 3. The function of positioning can be exhibited in a well-balanced manner. In other words, according to the bearing holding structure described above, the positioning accuracy of the mounting plate 3 can be enhanced while ensuring the holding performance of the bearing 2.

(5) In the bearing holding structure described above, the cylindrical surface 10a and the support surface 10b are both provided as the inner surface of the recess 10 that is recessed in the bottom 1b. That is, since both the cylindrical surface 10a and the support surface 10b are located inward of the housing 1 relative to the fixing portion 1d of the bottom portion 1b, the amount of protrusion of the bearing 2 from the bottom portion 1b can be reduced. Thereby, since the position of the pressing surface 32 which presses the other end surface 1c of the bearing 2 can be brought close to the bottom portion 1b, 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 on the basis of the bearing 2 (with a minimum error with respect to the rotation center of the motor 9). The degree can be easily obtained.

[3. Others]
The bearing holding structure described in the above embodiment is an example, and the configuration is not limited to that described above. For example, in the mounting plate 3 described above, three contact surfaces 31 and three pressing surfaces 32 are alternately provided around the opening 30. The number of the contact surfaces 31 and the pressing surfaces 32 is particularly large. It is not restricted and the number of each other does not need to 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 may not be alternately arranged, and the arrangement intervals of the contact surfaces 31 and the arrangement intervals of the pressing surfaces 32 may not be equal. In addition, since the contact surface 31 prescribes | regulates the position of the attachment plate 3 with respect to the housing 1, when providing two or more, it is preferable that the number is three or more.

  In the embodiment described above, 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 in a direction away from the bottom portion 1b, and is provided as a substantially cylindrical wall portion standing in a substantially orthogonal direction with respect to the circular portion 3a stacked on the bottom portion 1b. It may be. In this case, by bringing the surface facing the radially inner side of the holding wall into contact with the outer peripheral surface 2a of the bearing 2, this portion can be made to function as a contact surface. Even in such a configuration, since the position of the mounting plate 3 with respect to the housing 1 can be determined with reference to the bearing 2, the same effect as 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 the edge (end surface) functions as a contact surface. In this case, the holding wall can be omitted. In addition, the mounting plate should just have the part (structure) contact | abutted to the outer peripheral surface 2a of the bearing 2, and the part does not need to be a surface (for example, a line and a point may be sufficient). The abutting portion may be provided as a portion that abuts on the outer peripheral surface 2 a of the bearing 2 at least around the opening 30.

  In the above-described embodiment, the configuration in which the pressing surface 32 is provided on the holding claw 34 formed by cutting and raising a part of the holding wall 33 is illustrated. However, the holding claw 34 is constituted by a part of the holding wall 33. It does not have to be. For example, with respect to the flat circular portion 3a, a portion to be a holding claw and a portion to be a holding wall are formed to be separated in the circumferential direction, and each portion is bent (curved) to form an adjacent holding claw. A space may be provided between the holding wall and the holding wall. Even if it is such a structure, the effect similar to embodiment mentioned above can be acquired. In addition, the mounting plate should just have the part (structure) which presses the other end surface 2c of the bearing 2, and the part does not need to be a surface (for example, a line and a point may be sufficient). The pressing portion only needs to be provided as a portion that abuts against the other end surface 2c of the bearing 2 at least around the opening 30 and may not be provided on the holding claw.

  In the above-described 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 support surface 10b are provided as the inner surface of the concave portion 10. 10 a and the support surface 10 b may not be the inner surface of the recess 10. For example, the concave portion 10 is omitted, a support surface is provided on the same surface as the outer surface of the bottom portion 1b, and a cylindrical wall portion protruding outward of the housing 1 is provided outside the support surface in the radial direction. The radially inner surface may be a cylindrical surface. In addition, the support surface 10b may be comprised from several planes spaced apart in the circumferential direction instead of an annular shape. The housing 1 only needs to have a cylindrical surface facing the outer peripheral surface 2a of the bearing 2 and a support surface in contact with the one end surface 2b of the bearing 2 at the bottom 1b.

  The outer 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, or the shape may be other than the above-described shape. The material of the mounting plate 3 is not limited to sheet metal, and the mounting plate may be made of resin, for example. In addition, the shape of the housing 1 should just be a bottomed cylinder shape, and an axial orthogonal cross section may be a rectangular shape, an ellipse shape, etc.

DESCRIPTION OF SYMBOLS 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 Holding wall 34 Holding claw

Claims (6)

A bearing holding structure for holding a rolling bearing that rotatably supports a shaft of a motor,
A housing that is formed in a bottomed cylindrical shape, and in which the rolling bearing is fitted to a bottom portion having a through hole;
An attachment plate fixed to the bottom of the housing and for attaching the motor to a driven body;
The housing has a cylindrical surface facing the outer peripheral surface of the rolling bearing and a support surface in contact with one end surface of the rolling bearing at the bottom.
The mounting plate has an opening positioned 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. A bearing holding structure having a contact portion around the opening. The bearing holding structure according to claim 1, wherein the mounting plate includes a plurality of the pressing portions and a plurality of the abutting portions. The bearing holding structure according to claim 2, wherein the mounting plate has at least three of the contact portions. The bearing holding structure according to claim 2, wherein the pressing portion and the abutting portion are alternately arranged around the opening. The cylindrical surface and the support surface are both provided as an inner surface of a concave portion in which a central portion of the bottom portion is recessed inward of the housing. The bearing holding structure described. In a motor having a stator and a rotor built in a housing,
A motor in which the 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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