JP2005080339A - Bearing structure of motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing structure of a motor which can lengthen a life of a preload imparting member by preventing the member from being fully compressed and damaged even if a thrust force to fully compress the member is operated at a rotary shaft. <P>SOLUTION: The bearing structure of the motor includes a bearing holding part 6c of a yoke 6 having a contact recess part 6e provided to be possible to be brought into contact with a lower end face 10a of the rotary shaft 10 when the rotary shaft 10 is rotated in a direction that a plate spring 15 is compressed and set so that an interval L1 between the contact recess part 6e and the lower end face 10a of the rotary shaft 10 in an axial direction becomes larger by a predetermined length than the length (plate thickness L2 of the plate spring 15) of the axial direction when the plate spring 15 is fully compressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bearing structure for a motor including a radial ball bearing and a preload applying member such as a wave washer that applies a preload to the bearing.

A radial ball bearing has a structure in which a plurality of balls are interposed between an inner ring and an outer ring fixed to a rotating shaft, and as is well known, the structure allows the ball to roll between the inner ring and the outer ring. In addition, the inner ring and the outer ring have a relative backlash in the axial direction, which causes the rotating shaft to rattle in the axial direction. Therefore, for example, in the bearing structure of Patent Document 1, the outer ring of the bearing is accommodated in a bearing holding portion provided in the motor housing so as to be movable in the axial direction, and a metal preload applying member (such as a wave ring) is placed in the bearing holding portion. The preload is applied to the outer ring on one side in the axial direction by the preload applying member, and the axial rotation of the rotating shaft supported by the bearing is prevented.
JP 2001-304254 A

  By the way, if an excessive thrust force is applied due to excessive vibration or a large impact applied to the rotating shaft, the preload application member may be fully compressed and exceed the allowable stress of the member, which may be repeated. If this state is maintained for a long time even once, the member is damaged. However, in the above-mentioned Patent Document 1, no countermeasure is particularly taken against such a problem.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a motor bearing capable of preventing the precompression-applying member from being completely compressed to prevent its damage and extending the life of the member. To provide a structure.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a motor configured by housing a motor component in a bottomed cylindrical yoke, and in an axial direction in a bearing holding portion provided at the bottom of the yoke. A radial ball bearing configured such that a ball is interposed between an outer ring that is movably inserted into an inner ring and an inner ring that is fixed to a rotation shaft of the motor, and a preload applying member that is disposed in the bearing holding portion. A bearing structure of a motor that applies a preload to the outer ring in one axial direction and prevents the axial rotation of the rotary shaft, wherein the preload-applying member is compressed in the bearing holding portion of the yoke. And a contact portion that can come into contact with one end surface of the rotation shaft or one end surface of the inner ring when the rotation shaft moves in a direction to move, the contact portion and one end surface of the rotation shaft or the inner ring The axial distance from one end face is Serial are set to be larger than the axial length of the time of full compression of the preload applying member.

  The invention according to claim 2 is a motor holder in which a mounting portion for mounting to another member is formed on the outer surface of the motor housing portion, and the motor component is housed in a bottomed cylindrical yoke. In a motor comprising a motor main body configured and held in the motor storage portion, an outer ring fitted in a bearing holding portion provided at the bottom of the yoke so as to be movable in the axial direction and a rotation shaft of the motor A radial ball bearing having a ball interposed between the inner ring and the inner ring to be fixed is provided, and a preload is applied to the outer ring in one axial direction with respect to the outer ring by a preload applying member disposed in the bearing holding portion. A bearing structure for a motor that prevents backlash in the axial direction of the rotating shaft, wherein the rotating shaft moves when the rotating shaft moves in a direction in which the preload-applying member compresses in a motor housing portion of the motor holder. A pre-load applying member having a contact portion capable of contacting with one end surface of the shaft or one end surface of the inner ring, wherein an axial interval between the contact portion and one end surface of the rotating shaft or one end surface of the inner ring; Is set to be larger than the axial length at the time of full compression.

  According to a third aspect of the present invention, in the motor bearing structure according to the first or second aspect, a driven member is attached to one end of the rotating shaft, and the preload applying member is The rotary shaft is installed with respect to the radial ball bearing that supports an end opposite to an end on which the driven member is mounted.

(Function)
According to the first aspect of the present invention, the inner ring of the radial ball bearing fixed to the one end surface of the rotating shaft or the rotating shaft when the rotating shaft moves in the direction in which the preload applying member compresses in the bearing holding portion of the yoke. A contact portion capable of contacting with one end surface is provided, and an axial distance between the corresponding contact portion and one end surface of the rotation shaft or one end surface of the inner ring is larger than an axial length of the preload applying member when fully compressed. Set to be larger. As a result, even if an excessive thrust force that fully compresses the preload application member due to excessive vibration or a large impact applied to the rotating shaft acts before the preload application member fully compresses. In addition, one end surface of the rotating shaft or one end surface of the inner ring abuts on a contact portion provided on the bearing holding portion of the yoke, and further movement of the rotating shaft is prevented. Therefore, the preload application member is prevented from being fully compressed, and the member is prevented from being damaged.

  According to the second aspect of the present invention, the inner ring of the radial ball bearing is fixed to one end face of the rotating shaft or the rotating shaft when the rotating shaft moves in the direction in which the preload applying member compresses in the motor housing portion of the motor holder. An abutting portion capable of abutting on one end surface of the shaft is provided, and an axial interval between the corresponding contacting portion and one end surface of the rotating shaft or one end surface of the inner ring is based on an axial length when the preload applying member is fully compressed. Is set to be larger. As a result, even if an excessive thrust force that fully compresses the preload application member due to excessive vibration or a large impact applied to the rotating shaft acts before the preload application member fully compresses. Further, one end surface of the rotating shaft or one end surface of the inner ring abuts on a contact portion provided in the motor housing portion of the motor holder, and further movement of the rotating shaft is prevented. Therefore, the preload application member is prevented from being fully compressed, and the member is prevented from being damaged.

  According to the invention described in claim 3, the preload applying member is installed with respect to the radial ball bearing that supports the end of the rotating shaft opposite to the end on which the driven member is mounted. In other words, in such a configuration, an excessive thrust force that fully compresses the preload applying member may be applied even when the driven member is mounted on the rotating shaft, and this also damages the preload applying member. This is particularly effective in such a configuration.

  According to the present invention, even if a thrust force that fully compresses the preload applying member acts on the rotating shaft, the member is prevented from being fully compressed and damaged, and the life of the member can be extended. A motor bearing structure can be provided.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a blower motor 1 of a vehicle air conditioner. The blower motor 1 is configured by attaching a motor body 3 to a synthetic resin motor holder 2 for fixing to the vehicle side. The motor holder 2 is provided at the center of a flange portion 5 that is an attachment portion for attaching a bottomed cylindrical motor accommodation portion 4 that accommodates the motor body 3 to other members. The motor body 3 is housed in the motor housing portion 4, and the bottom portion 4 a of the housing portion 4 and the bottom portion 6 a of the yoke 6 constituting the motor body 3 are fixed with screws 7.

  The motor body 3 includes a yoke 6 formed of a magnetic metal and having a bottomed cylindrical shape. A magnet 8 as a motor component is fixed to the inner peripheral surface of the yoke 6, and an armature (armature) 9 as a motor component is rotatably accommodated inside the magnet 8. The armature 9 includes a rotating shaft 10, a core 11 fixed to the rotating shaft 10, a winding 12 wound around the core 11, and a commutator 13 fixed to the rotating shaft 10. . The armature 9 is disposed such that the side on which the commutator 13 is disposed with respect to the core 11 is located on the side opposite to the bottom 6 a of the yoke 6, that is, on the opening 6 b side of the yoke 6.

  As shown in FIGS. 1 and 2, a bottomed cylindrical bearing holding portion 6 c is formed at the central portion of the bottom portion 6 a of the yoke 6 so as to extend downward in the axial direction. A radial ball bearing 14 in which a plurality of balls 14c are interposed between an inner ring 14a and an outer ring 14b is fitted into the bearing holding portion 6c so as to be movable in the axial direction. The inner ring 14a is press-fitted and fixed to the lower end portion of the rotary shaft 10. The outer diameter of the outer ring 14b is set slightly smaller than the inner diameter of the bearing holding portion 6c so that the outer ring 14b can move along the axial direction in the bearing holding portion 6c. Incidentally, the radial ball bearing 14 and the radial ball bearing 17 to be described later have a structure in which the ball 14c can roll between the inner ring 14a and the outer ring 14b, so that the inner ring 14a and the outer ring 14b are relatively axially arranged. This is a factor that causes the rotating shaft 10 to rattle in the axial direction.

  A disc spring 15 as a preload application member is accommodated in the bearing holding portion 6c so that the lower end portion of the rotary shaft 10 is inserted between the bottom portion 6d and the radial ball bearing 14. The disc spring 15 is formed in an annular shape having a C-shaped cross section. The disc spring 15 is formed by pressing a metal plate material. The disc spring 15 has a small-diameter portion 15a and a large-diameter portion 15b. The small-diameter portion 15a abuts on the bottom 6d of the bearing holding portion 6c, and the large-diameter portion 15b abuts on the lower end surface 14d of the outer ring 14b of the bearing 14. Are arranged as follows. In addition, a contact recess 6e is formed in the center portion of the bottom 6d of the bearing holding portion 6c as a contact portion that is further recessed downward in the axial direction inside the small diameter portion 15a of the disc spring 15. Yes. The contact recess 6e comes into contact with the lower end surface 10a of the rotating shaft 10 when the upper surface 6f of the rotating shaft 10 moves downward by a predetermined amount. Incidentally, the position of the rotating shaft 10 shown in FIG. 2 is the upper end position where the upward movement is restricted further, and the position of the rotating shaft 10 shown in FIG. This is the lower end position that is in contact with 6f and is further restricted from moving downward.

  The axial length of the disc spring 15 is desired between the lower end surface 14d of the outer ring 14b of the bearing 14 and the bottom portion 6d of the bearing holding portion 6c when the rotary shaft 10 is disposed at the upper end position shown in FIG. It is set to compress the amount. That is, in this state, the disc spring 15 urges the outer ring 14b of the bearing 14 upward in the axial direction, and applies a preload to the outer ring 14b. Further, when a preload is applied to the outer ring 14b, a preload is applied to the rotating shaft 10 (armature 9) via the ball 14c and the inner ring 14a, and the rotating shaft 10 generated due to the structure of the radial ball bearings 14 and 17 is applied. Shaking in the axial direction is prevented. The rotating shaft 10 is usually disposed at the upper end position shown in FIG. 2 where the upward movement is restricted by the biasing force of the disc spring 15.

  When the rotary shaft 10 is disposed at the upper end position shown in FIG. 2, the disc space 15 is fully compressed by the axial distance L1 between the lower end surface 10a of the rotary shaft 10 and the upper surface 6f of the contact recess 6e. The length in the axial direction at the time, that is, the plate thickness L2 of the disc spring 15 is set to be larger by a predetermined length. That is, in FIG. 3, excessive vibration or large impact is applied to the rotating shaft 10 to apply excessive thrust force, and the lower end surface 10a of the rotating shaft 10 contacts the upper surface 6f of the contact recess 6e. Even if the rotating shaft 10 is arranged at the lower end position shown, the disc spring 15 is configured not to be fully compressed. Therefore, an excessive thrust force acts on the rotary shaft 10 to prevent the disc spring 15 from being fully compressed and exceeding the allowable stress of the disc spring 15, thereby preventing the disc spring 15 from being damaged.

  As shown in FIG. 1, an end cover 16 made of synthetic resin is attached to the opening 6 b of the yoke 6. A bearing holding portion 16 a extending in a substantially cylindrical shape toward the upper side in the axial direction is formed at the center portion of the end cover 16. A radial ball bearing 17 in which a plurality of balls 17c are interposed between an inner ring 17a and an outer ring 17b is mounted on the bearing holding portion 16a. That is, the inner ring 17a is press-fitted into a predetermined portion on the upper side of the rotary shaft 10, and the outer ring 17b is press-fitted into the bearing holding portion 16a. Further, a brush holder (not shown) is formed inside the end cover 16, and a brush (not shown) that slides on the commutator 13 of the armature 9 is accommodated in the brush holder. Is supplied to the winding 12 through the commutator 13. The armature 9 rotates based on power supply, and the rotating shaft 10 rotates. A fan 18 as a driven member is press-fitted and attached to the upper end portion 10 b protruding from the end cover 16 of the rotating shaft 10. The fan 18 is rotated by the rotation of the rotating shaft 10, and the blowing operation of the blowing motor 1 is performed.

Next, characteristic effects of the present embodiment will be described.
(1) When the rotary shaft 10 moves in the direction in which the disc spring 15 compresses in the bearing holding portion 6c of the yoke 6, a contact recess 6e that can contact the lower end surface 10a of the rotary shaft 10 is provided. The axial distance L1 between 6e and the lower end surface 10a of the rotary shaft 10 is larger by a predetermined length than the axial length (plate thickness L2 of the disc spring 15) when the disc spring 15 is fully compressed. Is set. As a result, even if an excessive thrust force that fully compresses the disc spring 15 due to an excessive vibration or a large impact applied to the rotating shaft 10, the disc spring 15 is more than compressed. Before, the lower end surface 10a of the rotating shaft 10 and the contact recessed part 6e provided in the bearing holding part 6c of the yoke 6 contact | abut, and the further movement of the rotating shaft 10 is prevented. Therefore, it is possible to prevent the disc spring 15 from being fully compressed. As a result, damage to the disc spring 15 can be prevented, and the life of the disc spring 15 can be extended.

  (2) The disc spring 15 is installed with respect to the radial ball bearing 14 that supports the lower end portion of the rotating shaft 10 opposite to the fan 18. That is, in such a configuration, there is a case where an excessive thrust force that fully compresses the disc spring 15 acts even when the fan 18 is press-fitted into the rotating shaft 10 and is mounted. Since 15 may be damaged, it is particularly effective in such a configuration.

  (3) Since it is not necessary to contact the jig to the lower end surface 10a of the rotating shaft 10 in order to receive the thrust force when the fan 18 is press-fitted, the through hole for inserting the jig into the bearing holding portion 6c is held. There is no need to provide the portion 6c. That is, as in the present embodiment, the bottom portion 6d of the bearing holding portion 6c can be closed. For this reason, it is possible to prevent foreign matters from entering the motor body 3 from the outside through the through-holes and oil used inside the motor body 3 from leaking to the outside through the through-holes. Also, it is not necessary to consider measures for preventing this.

(4) Although it is conceivable that the disc spring 15 itself is provided with a means for preventing total compression, the present embodiment can be performed more easily than this.
(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the present embodiment, since only the structure for preventing the total compression of the disc spring 15 is different from that in the first embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and described. Omitted.

  In the blower motor 1a of the present embodiment shown in FIGS. 4 to 6, a through hole 6g having substantially the same diameter as the small diameter portion 15a of the disc spring 15 is formed at the center portion of the bottom portion 6d of the bearing holding portion 6c of the yoke 6. ing. The through hole 6g is inserted with a contact cylinder portion 4b as a contact portion extending in the axial direction upward from the bottom portion 4a of the motor housing portion 4 in the motor holder 2. The lower end portion of the rotating shaft 10 is inserted into the contact cylinder portion 4b. In the abutting tube portion 4b, when the rotary shaft 10 moves downward by a predetermined amount, the upper end surface 4c of the tube portion 4b contacts the lower end surface 14e of the inner ring 14a of the radial ball bearing 14. Incidentally, the position of the rotating shaft 10 shown in FIG. 5 is the upper end position where the upward movement is restricted further, and the position of the rotating shaft 10 shown in FIG. 4b is a lower end position that is in contact with the upper end surface 4c of 4b and is further restricted from moving downward.

  The axial length of the disc spring 15 is the same as that of the lower end surface 14d of the outer ring 14b of the bearing 14 and the bearing holding portion 6c when the rotary shaft 10 is disposed at the upper end position shown in FIG. It is set to compress the desired amount with the bottom 6d. That is, in this state, the disc spring 15 urges the outer ring 14b of the bearing 14 upward in the axial direction, and applies a preload to the outer ring 14b.

  When the rotary shaft 10 is disposed at the upper end position shown in FIG. 5, the axial distance L3 between the lower end surface 14e of the inner ring 14a of the bearing 14 and the upper end surface 4c of the abutting cylinder portion 4b is a disc spring. The axial length when 15 is fully compressed, that is, the plate thickness L2 of the disc spring 15, is set to be larger by a predetermined length. That is, excessive vibration or large impact is applied to the rotating shaft 10 to apply excessive thrust force, and the lower end surface 14e of the inner ring 14a fixed to the rotating shaft 10 is in contact with the upper end surface 4c of the abutting cylinder portion 4b. Even if the rotating shaft 10 is arranged at the lower end position shown in FIG. Therefore, also in the present embodiment, an excessive thrust force acts on the rotary shaft 10 to prevent the disc spring 15 from being fully compressed and exceeding the allowable stress of the disc spring 15, thereby preventing the disc spring 15 from being damaged. Has been.

Next, characteristic effects of the present embodiment will be described.
(1) When the rotating shaft 10 moves in the direction in which the disc spring 15 is compressed in the motor housing portion 4 of the motor holder 2, the contact with the lower end surface 14 e of the inner ring 14 a of the bearing 14 fixed to the rotating shaft 10 is possible. A contact tube portion 4b is provided, and an axial distance L3 between the corresponding contact tube portion 4b and the lower end surface 14e of the inner ring 14a is an axial length when the disk spring 15 is fully compressed (plate thickness L2 of the disk spring 15). ) Is set to be larger than a predetermined length. As a result, even if an excessive thrust force that fully compresses the disc spring 15 due to an excessive vibration or a large impact applied to the rotating shaft 10, the disc spring 15 is more than compressed. Before, the lower end surface 14e of the inner ring 14a and the abutting cylinder portion 4b provided in the motor housing portion 4 of the motor holder 2 abut against each other, and further movement of the rotating shaft 10 is prevented. Therefore, also in the present embodiment, it is possible to prevent the disc spring 15 from being fully compressed. As a result, breakage of the disc spring 15 can be prevented, and the life of the disc spring 15 can be extended.

In addition, you may change embodiment of this invention as follows.
In the first embodiment, before the disc spring 15 is fully compressed, the contact recess 6e of the bearing holding portion 6c of the yoke 6 and the lower end surface 10a of the rotary shaft 10 come into contact with each other, and the disc spring 15 is fully compressed. However, as in the second embodiment, the bearing holding portion 6c of the yoke 6 is provided with a contact portion that can contact the lower end surface 14e of the inner ring 14a of the bearing 14, and the corresponding contact portion and the inner ring 14a May be made to prevent the disc spring 15 from being fully compressed.

  In the second embodiment, before the disc spring 15 is fully compressed, the abutting tube portion 4b of the motor housing portion 4 of the motor holder 2 and the lower end surface 14e of the inner ring 14a of the bearing 14 come into contact with each other. However, as in the first embodiment, the motor housing 4 of the motor holder 2 is provided with a contact portion that can contact the lower end surface 10a of the rotary shaft 10, and You may make it prevent that the disc spring 15 fully compresses by contact | abutting with the rotating shaft 10. FIG.

  In the contact cylinder part 4b of the motor housing part 4 of the second embodiment, the inside is a through hole, but as shown in FIG. 7, the through hole is blocked at the lower end of the contact cylinder part 4b. A closed portion 4d may be formed. By providing such a blocking portion 4d, it is possible to prevent foreign matters from entering the motor main body 3 from the outside through the through hole and oil used inside the motor main body 3 from leaking to the outside through the through hole. can do.

  In each of the above embodiments, the disc spring 15 formed into a ring shape by pressing a metal plate material is used as the preload application member, but other preload application members such as a wave washer may be used. Moreover, you may use the preload provision member which is not cyclic | annular. Moreover, you may use the preload provision member formed with materials other than metal board | plate materials.

  The configuration of the motor body 3 in each of the above embodiments is not limited to this, and may be changed as appropriate. For example, the motor body 3 using the commutator 13 and the brush is used, but a brushless motor that does not use the commutator 13 and the brush may be used.

In each of the above-described embodiments, the driven member is the fan 18 of the vehicle air conditioner. However, the motor may be applied to other motors.
The technical idea that can be grasped from each of the above embodiments will be described below.

  (B) The motor bearing structure according to any one of claims 1 to 3, wherein the preload applying member is formed in an annular shape corresponding to the outer ring. Construction. Even if it does in this way, the effect similar to invention of the said claim can be acquired.

  (B) In the motor bearing structure according to any one of claims 1 to 3 and (a) above, the preload imparting member may be formed by processing a metal plate. Motor bearing structure. Even if it does in this way, the effect similar to invention of the said claim can be acquired.

Sectional drawing of the motor for ventilation of 1st Embodiment. Sectional drawing of the principal part of the motor for ventilation when a rotating shaft is arrange | positioned in an upper end position. Sectional drawing of the principal part of the motor for ventilation when a rotating shaft is arrange | positioned in a lower end position. Sectional drawing of the motor for ventilation of 2nd Embodiment. Sectional drawing of the principal part of the motor for ventilation when a rotating shaft is arrange | positioned in an upper end position. Sectional drawing of the principal part of the motor for ventilation when a rotating shaft is arrange | positioned in a lower end position. The principal part sectional drawing of the motor for ventilation in another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Motor for ventilation as a motor, 2 ... Motor holder, 3 ... Motor main body as a motor, 4 ... Motor accommodating part, 4b ... Contact cylinder part as a contact part, 5 ... Flange part as attachment part, 6 ... Yoke, 6a ... Bottom, 6c ... Bearing holding part, 6e ... Contact recess as contact part, 8 ... Magnet as motor component, 9 ... Armor as motor component, 10 ... Rotating shaft, 10a ... One Lower end surface as end surface, 10b ... Upper end portion as one end portion, 14 ... Radial ball bearing, 14a ... Inner ring, 14b ... Outer ring, 14c ... Ball, 14e ... Lower end surface as one end surface, 15 ... As preload application member Disc spring, 18 ... fan as driven member, L1 ... interval, L3 ... interval.

Claims (3)

In a motor constructed by housing motor components in a bottomed cylindrical yoke, it is fixed to an outer ring fitted in a bearing holding portion provided at the bottom of the yoke so as to be movable in the axial direction and to the rotating shaft of the motor. A radial ball bearing configured such that a ball is interposed between the inner ring and a preload applying member disposed in the bearing holding portion, and applying a preload to the outer ring in one axial direction, A bearing structure for a motor that prevents axial rotation of the rotating shaft,
The bearing holding portion of the yoke has an abutting portion capable of abutting against one end surface of the rotating shaft or one end surface of the inner ring when the rotating shaft moves in a direction in which the preload applying member is compressed. The axial distance between the contact portion and one end surface of the rotating shaft or one end surface of the inner ring is set to be larger than the axial length of the preload applying member during full compression. Motor bearing structure. A motor holder in which an attachment portion for attachment to another member is formed on the outer surface of the motor housing portion, and a motor component part housed in a bottomed cylindrical yoke, are housed in the motor housing portion. A motor having a motor main body held by a ball, and a ball between an outer ring fitted in a bearing holding portion provided at the bottom of the yoke so as to be movable in the axial direction and an inner ring fixed to the rotating shaft of the motor. A radial ball bearing constructed by interposing, a preloading member disposed in the bearing holding portion applies a preloading load in one axial direction to the outer ring, and an axial direction of the rotating shaft is A motor bearing structure that prevents rattling,
The motor holder of the motor holder has a contact portion that can come into contact with one end surface of the rotation shaft or one end surface of the inner ring when the rotation shaft moves in a direction in which the preload applying member compresses, The axial distance between the contact portion and one end surface of the rotating shaft or one end surface of the inner ring is set to be larger than the axial length of the preload applying member when fully compressed. Motor bearing structure. In the bearing structure of the motor according to claim 1 or 2,
A driven member is attached to one end of the rotating shaft,
The preload applying member is installed on the radial ball bearing that supports an end portion of the rotating shaft opposite to an end portion on which the driven member is mounted. Bearing structure.

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