KR101257194B1 - Motor - Google Patents

Abstract

The motor of the present invention is fixed to a shaft, a rotor holder fixed to an upper portion of the shaft, a bearing member which is a containing sintered bearing supporting the shaft, a bearing holding member into which the bearing member is inserted, and a bearing holding member. Mounted plate. The bearing holding member includes a bearing holding cylinder portion into which the bearing member is inserted, and a flange portion extending radially outward from a lower end of the bearing holding cylinder portion. The outer circumferential surface of the flange portion includes a positioning surface that determines the position of the central axis with respect to the mounting object by being fitted to the hole of the mounting object. The mounting plate includes an opening through which the bearing holding cylindrical portion is press-fit and a mounting portion fixed to the mounting target. The lower surface of the mounting plate is in contact with the upper surface of the flange portion, and an indentation range in which the mounting plate is press-fitted into the bearing holding cylindrical portion overlaps with the bearing member in the axial direction. In the press-fitting range, a gap is provided between the bearing member and the bearing holding cylindrical portion.

Description

Motor {MOTOR}

The present invention relates to an electric motor.

Background Art Conventionally, motors are mounted on office automation (OA) devices and the like. Such a motor is provided with a mounting plate, and the mounting plate and other members in the apparatus are fixed. The motor disclosed in Japanese Patent Laid-Open No. 2003-32987 includes a sleeve bearing made of a containing metal, a substantially cylindrical housing, and a mounting plate. The sleeve bearing is press fit inside the housing. The lower end of the housing is provided with a plurality of collar portions that bend radially outward and a plurality of drooping portions that fall down between the collar portions. The mounting plate is attached to a copying machine on which a motor is mounted. The mounting plate has a large mounting hole in the center and a hole having a small diameter around the mounting hole. In the motor, the drooping portion contacts the mounting hole in the radial direction to execute positioning in the radial direction of the housing relative to the mounting hole. The housing is fixed to the mounting plate by screwing the screw hole provided in the collar portion and the small diameter hole provided in the mounting plate.

The housing of the motor disclosed in Japanese Patent Laid-Open No. 2008-289323 includes a holding cylindrical portion, a ring-shaped flange portion, and a fitting portion. Two ball bearings are disposed inside the holding cylinder portion. The flange portion extends radially outward from the lower side of the holding cylindrical portion and is fixed to the mounting plate of the motor. The fitting portion extends in the axial direction below the flange portion and fits into the hole of another member of the apparatus on which the motor is mounted.

The motor disclosed in Japanese Unexamined Patent Publication No. 1998-127006 is for a disk drive device. The motor includes a cylindrical bearing, which is a rotating shaft, a bearing bearing, and a thick bearing retaining body into which the cylindrical bearing is press-fitted. Upper and lower shaft support portions formed on the upper and lower ends of the inner circumferential surface of the cylindrical bearing are formed convexly toward the inner side in the radial direction. On the outer circumferential surface of the cylindrical bearing, the upper part and the lower part are spaced apart from the inner circumferential surface of the bearing retaining body. Thereby, the influence on the inner diameter of the up-and-down shaft support part by press-fitting into the bearing holding body of a cylindrical bearing can be prevented.

Japanese Patent Publication No. 2003-32987 Japanese Patent Laid-Open No. 2008-289323 Japanese Patent Laid-Open No. 1998-127006

By the way, in recent years, with the economic growth of emerging countries, the demand for OA equipment is expected to increase, and the low price of OA equipment is required. For this reason, development of an inexpensive motor is required. In Japanese Patent Laid-Open No. 2003-32987, since the housing and the mounting plate are fixed by screwing, there are many processes, and the manufacturing price cannot be suppressed.

Further, in Japanese Unexamined Patent Publication No. 2003-32987, when the sleeve bearing is placed on the lower side, that is, on the output side of the motor, so that the lower end of the sleeve bearing is in the same position as the lower part, lubricating oil leaks from between the adjacent lower parts. There is a concern. For this reason, the sleeve bearing is not provided on the output side of the motor, and in order to support the shaft stably, it is necessary to lengthen the containing bearing. As a result, manufacturing cost increases.

By the way, in order to prevent the motor from moving up and down with respect to the bearing member of a shaft, an annular fall prevention part is provided in the circumference | surroundings of a shaft in the upper side and the lower side of a bearing member. In the manufacture of the motor, it is required to easily attach the fall prevention portion to the shaft. If it is going to form a fall prevention part by the metal washer inserted into the shaft, and the metal retaining ring which prevents the washer from falling off from the shaft, the washer and the shaft will rotate relative to the motor, and the washer will wear. .

The present invention aims to reduce the manufacturing cost of the motor as one of its main objectives, and also aims to easily attach the fall prevention portion to the shaft.

A motor according to an exemplary first aspect of the present invention includes a shaft disposed about a central axis in a vertical direction, a substantially cylindrical rotor holder having a lid fixed to an upper portion of the shaft, and a cylindrical portion of the rotor holder. A rotor magnet fixed to an inner circumferential surface, a bearing member that is a containing sintered bearing for rotatably supporting the shaft about the central axis, a bearing holding member into which the bearing member is inserted, and a radially inner side of the rotor magnet A stator, a mounting plate fixed to the bearing holding member, the bearing holding member having a bearing holding cylinder portion into which the bearing member is inserted, and a flange portion extending radially outward from a lower end of the bearing holding cylinder portion. The stator is fixed to the outer peripheral surface of the bearing holding cylinder portion, A lower end of the shaft protrudes below the flange portion, and includes a positioning surface for determining the position of the central axis with respect to the mounting target member by fitting an outer peripheral surface of the flange portion into a hole of the mounting target member; The mounting plate includes an opening through which the bearing holding cylinder portion is press-fit and a mounting portion fixed to the mounting target member, and a lower surface of the mounting plate contacts the upper surface of the flange portion so that the bearing holding cylinder portion is in the axial direction. The press-in range in which the mounting plate is press-fitted and the existence range of the bearing member overlap, and a gap is provided between the bearing-member and the bearing holding cylindrical portion in the press-in range.

A motor according to an exemplary second aspect of the present invention includes a shaft disposed about a central axis facing in the vertical direction, a substantially cylindrical rotor holder having a lid fixed to an upper portion of the shaft, and an inner circumferential surface of the cylindrical portion of the rotor holder. A rotor magnet fixed to the bearing, a bearing member which is a containing sintered bearing for rotatably supporting the shaft about the central axis, a bearing holding member into which the bearing member is inserted, and a stator disposed inside the rotor in the radial direction. And a mounting plate fixed to the bearing holding member, wherein the bearing holding member has a bearing holding cylinder portion into which the bearing member is inserted, and a flange portion extending radially outward from a lower end of the bearing holding cylinder portion. And the stator is fixed to an outer circumferential surface of the bearing holding cylindrical portion, The lower end protrudes below the said flange part, The outer peripheral surface of the said flange part includes the positioning surface which determines the position of the said central axis with respect to the said mounting object member by fitting in the hole of a mounting object member, A spacer having an opening through which the bearing holding cylindrical portion is press-fit and a mounting portion fixed to the mounting target member, and determining a distance between the mounting plate and the flange portion in the axial direction between the mounting plate and the flange portion; Wealth is prepared.

A motor according to an exemplary third aspect of the present invention includes a shaft disposed about a central axis in a vertical direction, a substantially cylindrical rotor holder having a lid fixed to an upper portion of the shaft, and an inner circumferential surface of a cylindrical portion of the rotor holder. A rotor magnet fixed to the bearing, a bearing member which is a containing sintered bearing for rotatably supporting the shaft about the central axis, a bearing holding member into which the bearing member is inserted, and a stator disposed inside the rotor in the radial direction. And a mounting plate fixed to the bearing holding member, a drop preventing portion mounted to the shaft at a lower side of the bearing member, wherein the bearing holding member has a bearing holding cylinder portion into which the bearing member is inserted, and the bearing holding portion. And a flange portion that extends radially outward from the lower end of the cylindrical portion. Data is fixed to an outer circumferential surface of the bearing holding cylindrical portion so that a lower end of the shaft protrudes below the flange portion, and an outer circumferential surface of the flange portion is fitted to a hole of the mounting target member, And a positioning surface for determining a position, wherein the mounting plate includes an opening through which the bearing holding cylindrical portion is press-fitted, and a mounting portion fixed to the mounting target member, wherein the release preventing portion is formed in a circumferential direction on an outer circumferential surface of the shaft. A fixed ring of metal sandwiched therein, a washer of metal inserted into the shaft and disposed above the fixed ring, and an annular resin plate disposed between the washer and the bearing member, wherein the washer protrudes downward; The projection portion and a portion of the fixing ring is the central axis It is fixed to each other in the circumferential direction as the center.

The motor according to the fourth exemplary aspect of the present invention includes a shaft disposed about a central axis facing in the vertical direction, a substantially cylindrical rotor holder having a lid fixed to an upper portion of the shaft, and an inner circumferential surface of the cylindrical portion of the rotor holder. A rotor magnet fixed to the bearing, a bearing member which is a containing sintered bearing for rotatably supporting the shaft about the central axis, a bearing holding member into which the bearing member is inserted, and a stator disposed inside the rotor in the radial direction. And a mounting plate fixed to the bearing holding member, a drop preventing portion mounted to the shaft at a lower side of the bearing member, wherein the bearing holding member has a bearing holding cylinder portion into which the bearing member is inserted, and the bearing holding portion. And a flange portion that extends radially outward from the lower end of the cylindrical portion. Data is fixed to an outer circumferential surface of the bearing holding cylindrical portion so that a lower end of the shaft protrudes below the flange portion, and the outer circumferential surface of the flange portion is fitted to a hole of the mounting target member so that the center of the mounting target member is centered. And a positioning surface for positioning the shaft, wherein the mounting plate includes an opening through which the bearing holding cylindrical portion is press-fitted, and a mounting portion fixed to the mounting target member, wherein the release preventing portion is formed in a circumferential direction on an outer circumferential surface of the shaft. And a fixing ring of resin sandwiched between the resin ring, a metal washer inserted into the shaft, and disposed above the fixing ring, and an annular resin plate disposed between the washer and the bearing member.

According to the invention of claims 1 to 3, the manufacturing cost of the motor can be reduced. According to the invention of claims 4 to 6, the fall prevention portion can be easily attached to the shaft.

1 is a plan view of a motor according to a first embodiment,
2 is a bottom view of the motor,
3 is a side view of the motor,
4 is a cross-sectional view of the motor,
5 is an enlarged view of a part of a motor;
6 is an enlarged view of a part of a motor;
7 is a sectional view of a motor according to a second embodiment,
8 is a plan view of a bearing holding member;
9 is a sectional view showing a lower vicinity of a bearing member;
10 is a bottom view of the lower fall prevention portion and the shaft,
11 is a sectional view showing an upper vicinity of a bearing member;
12 is a sectional view of a motor according to another example;
13 is a sectional view of a motor according to another example;
14 is a cross-sectional view showing a lower vicinity of a bearing member of a motor according to a third embodiment.

In the present specification, the upper side in the central axis direction of the motor is simply referred to as "upper side", and the lower side is simply referred to as "lower side". In addition, the up-down direction does not represent the positional relationship or direction when assembled to an actual apparatus. In addition, the direction parallel or substantially parallel to a central axis is called "axial direction", the radial direction centering on a central axis is only called "diameter direction", and the circumferential direction centering on a central axis is only called "circle direction". .

(First Embodiment)

1 is a plan view of a motor 1 according to a first embodiment of the present invention. The motor 1 is used as a drive source of OA (Office Automation) equipment, such as a copy machine, a printer, and a multifunction machine, for example. The motor 1 includes a motor main body 11, a mounting plate 12, and a circuit board 13. The motor main body 11 is provided on the mounting plate 12. 2 is a bottom view of the motor 1. 1 and 2, the mounting plate 12 is provided with a mounting portion 121 having a mounting hole 121a. The mounting plate 12 is molded by press working. In the OA apparatus, the mounting portion 121 is fixed to the hole of the member to be mounted by screwing.

3 is a left side view of the motor 1. 1 to 3, the circuit board 13 protrudes radially outward from the motor main body 11. The connector 131 is fixed to the circuit board 13. The connector 131 is connected to an external power source. In the motor 1, electric power is supplied to the motor main body 11 from an external power supply via the wiring of the connector 131 and the circuit board 13.

4 is a cross-sectional view of the motor 1 cut at the position of arrow A in FIG. 1. The motor main body 11 is an outer rotor type motor. The motor main body 11 is provided with the rotating part 2 which is a rotating assembly, the stator 3, and the bearing mechanism 4. As shown in FIG. The rotating part 2 is rotatably supported with respect to the mounting plate 12 via the bearing mechanism 4 about the center axis J1 of the motor main body 11 which faces the up-down direction.

The rotating part 2 is provided with the substantially cylindrical rotor holder 21 and rotor magnet 22 which have a cover. The rotor holder 21 includes a cylindrical portion 211 and a lid portion 212. The cylindrical portion 211 is parallel to the central axis J1. The lid part 212 closes the upper end of the cylindrical part 211. The center portion 212a of the lid portion 212 is recessed downward. The center part 212a is provided with the center cylindrical part 212b extended downward from the lower end of a dent. Thereby, it becomes easy to form the center cylindrical part 212b below an axial direction by a burring process. The rotor magnet 22 is a ferrite magnet and is fixed to the inner circumferential surface 211a of the cylindrical portion 211. The rotor magnet 22 may be cylindrical shape or may arrange | position the some magnet element in the circumferential direction.

The stator 3 includes a stator core 31 and a coil 32 wound on the stator core 31. The stator 3 is disposed in the radially inner side of the rotor magnet 22. When the motor main body 11 is driven, torque is generated between the rotor magnet 22 and the stator 3. The upper surface 311 of the stator core 31 is located above the lower end of the center cylindrical part 212b of the rotor holder 21.

The circuit board 13 is arrange | positioned on the upper surface of the mounting plate 12, and is caulked by the caulking part 122 provided in the mounting plate 12. FIG. On the circuit board 13, a hall sensor 132 (a hall element, a hole IC, etc.) is mounted in the vicinity of the rotor magnet 22 and between the teeth of the stator core 31.

The bearing mechanism 4 includes a shaft 41, a bearing member 42 which is a containing sintered bearing, a substantially cylindrical bearing retaining member 43, a cylindrical spacer 44, and an annular fall prevention portion 45. It is provided. The bearing member 42 is substantially cylindrical. The shaft 41 is disposed in the bearing member 42 about the center axis J1. The upper portion of the shaft 41 is fixed to the central cylindrical portion 212b of the rotor holder 21. The bearing holding member 43 is molded by press working of a metal plate. The bearing holding member 43 includes a bearing holding cylindrical portion 431 and a flange portion 432. The flange portion 432 extends radially outward from the lower end of the bearing retaining cylindrical portion 431. The outer circumferential surface 531 of the flange portion 432 has a circular shape centering on the central axis J1. The lower end of the shaft 41 protrudes below the flange portion 432.

The bearing member 42 is press-fitted into the bearing holding cylindrical part 431. On the upper part of the outer peripheral surface 51 of the bearing holding cylindrical part 431, the lower part of the inner peripheral surface of the stator core 31 is fixed by press fit. The upper surface 311 of the stator core 31 is located above the upper end of the bearing holding cylindrical portion 431.

In the bearing mechanism 4, the bearing retaining member 43 is substantially covered with the entire outer circumferential surface 62 of the bearing member 42. Therefore, leakage of lubricating oil is prevented. In the axial direction, the position of the bottom surface 421 of the bearing member 42 is the same as the bottom surface 532 of the flange portion 432. However, it does not need to be exactly the same, and the bearing member 42 may protrude slightly from the lower surface 532 of the flange portion 432. Specifically, in the axial direction, the distance between the lower end surface 421 and the lower surface 532 of the bearing member 42 is 1 mm or less, more preferably 0.5 mm or less. Even in this case, since the entire lower part of the outer circumferential surface 62 of the bearing member 42 is entirely covered by the flange portion 432, leakage of lubricating oil is prevented.

In the center of the mounting plate 12, a cylindrical opening 123 is provided. The opening 123 is formed by burring. In the motor 1, the mounting plate 12 is fixed to the bearing holding cylindrical portion 431 by press-fitting the lower portion of the bearing holding cylindrical portion 431 into the opening 123. The site | part near the opening part 123 of the lower surface 124 of the mounting plate 12 contacts the upper surface 533 of the flange part 432. As will be described later, the axial indentation range in which the mounting plate 12 is press-fitted into the bearing holding cylindrical portion 431 overlaps with the axial direction existence range of the bearing member 42 in the radial direction.

When the motor 1 is mounted in the apparatus, the mounting plate 12 is mounted on the upper surface 91 which is the mounting surface of the mounting object member 9 shown by the dashed-dotted line in FIG. At this time, the outer circumferential surface 531 of the flange portion 432 is fitted into the hole portion 92 of the mounting target member 9. Thereby, the position of the center axis J1 with respect to the mounting object member 9 in the direction parallel to the upper surface 91 is determined. In this way, the outer circumferential surface 531 of the flange portion 432 serves as a positioning surface for the mounting target member 9 by using the fitting. In addition, only a part of the outer peripheral surface 531 may function as a positioning surface.

When the motor 1 is driven, the bearing member 42 rotatably supports the shaft 41 about the center axis J1. In the device, the pinion gear (not shown) is fixed to the lower part of the shaft 41, and the pinion gear and the other gear mesh with each other, so that the power of the motor 1 is transmitted. In the motor 1, since the stator 3 is fixed to the upper part of the bearing holding cylindrical part 431, the support center of the shaft 41 by the bearing member 42 is lower than the stator 3, ie, It exists in the output side rather than the position where the torque of the motor 1 generate | occur | produces. As a result, the shaft 41 is stably supported.

FIG. 5 is an enlarged view of a part of the motor main body 11. The spacer 44 is formed of a resin such as PBT (polybutylene terephthalate), and the upper end of the bearing member 42 and the rotor holder 21. Is disposed between the lower ends of the central cylindrical portion 212b. By providing the spacer 44, the shaft 41 and the rotating part 2 are prevented from moving downward. The fall prevention part 45 is fixed to the shaft 41 below the bearing member 42. The fall prevention part 45 is provided with the annular fixing ring 451 and the annular resin plate 452 arrange | positioned on the upper surface of the fixing ring 451. The resin plate 452 is formed of PEEK (polyether ether ketone), for example. The fall prevention part 45 is provided, and the shaft 41 is prevented from moving upwards. Moreover, by providing the resin plate 452, even if the fall prevention part 45 contacts the bearing member 42, damage to the bearing member 42 is prevented.

The inner circumferential surface 61 of the bearing member 42 is provided with a recess 611 that is recessed toward the radially outer side at the center in the axial direction. On the outer circumferential surface 62 of the bearing member 42, the diameter of the upper portion 621 is smaller than the central portion 622 and the lower portion 623. The diameters of the central portion 622 and the lower portion 623 are the same. In the inner circumferential surface 52 of the bearing holding cylindrical portion 431, the diameter of the lower portion 523 is larger than the diameters of the upper portion 521 and the central portion 522. The diameters of the upper portion 521 and the central portion 522 are the same. On the inner circumferential surface 52 of the bearing holding cylindrical portion 431, an end portion 520 is formed at the boundary between the central portion 522 and the lower portion 523. In addition, on the outer circumferential surface 51 of the bearing holding cylindrical portion 431, an end portion 510 is formed at the boundary between the central portion 512 and the lower portion 513.

In the bearing mechanism 4, a first gap 721 is provided between the upper portion 621 of the outer circumferential surface 62 of the bearing member 42 and the upper portion 521 of the inner circumferential surface 52 of the bearing retaining cylindrical portion 431. do. A second gap 722 is provided between the lower portion 623 of the outer circumferential surface 62 of the bearing member 42 and the lower portion 523 of the inner circumferential surface 52 of the bearing holding cylindrical portion 431. A third gap 723 is provided between the recess 611 of the inner circumferential surface 61 of the bearing member 42 and the outer circumferential surface 411 of the shaft 41.

As shown in FIG. 6, in the radial direction, the first gap 721 almost overlaps the press-in range 711 in which the stator core 31 is press-fitted into the bearing holding cylindrical portion 431. In the radial direction, the second gap 722 overlaps the indentation range 712 into which the mounting plate 12 is press-fitted into the bearing holding cylindrical portion 431. Hereinafter, the indentation ranges 711 and 712 are referred to as "first indentation range 711" and "second indentation range 712". Thereby, even if the mounting plate 12 and the stator core 31 press the bearing holding cylinder part 431, respectively, to the inner peripheral surface 61 of the bearing member 42 inserted in the bearing holding cylinder part 431 Distortion is prevented from occurring.

In the radial direction, the third gap 723 is a press-fitting range between the central portion 522 of the inner circumferential surface 52 of the bearing holding cylindrical portion 431 and the central portion 622 of the outer circumferential surface 62 of the bearing member 42 ( 713). Thereby, even when the bearing member 42 is distorted by the pressurization from the bearing holding cylinder part 431, the influence to the rotation of the shaft 41 does not arise.

As mentioned above, although the structure of the motor 1 which concerns on 1st Embodiment was demonstrated, the mounting plate 12 and the bearing holding member 43 are press-fitted to the bearing holding member 43 by the mounting plate 12. FIG. Can be easily assembled. As a result, assembly labor can be reduced and manufacturing cost can be reduced.

In the bearing mechanism 4, a first gap 721 is provided between the bearing member 42 and the bearing holding cylindrical portion 431 in the first press-fitting range 711. Thereby, it can suppress that the upper part of the inner peripheral surface 61 of the bearing member 42 is deformed. Further, in the second press-in range 712, a second gap 722 is provided between the bearing member 42 and the bearing holding cylindrical portion 431. Thereby, it can suppress that the lower part of the inner peripheral surface 61 of the bearing member 42 deforms. As a result, the bearing member 42 can be easily arranged on the output side of the shaft 41. Since the bearing member 42 is arrange | positioned at the output side of the shaft 41, even if the length of the bearing member 42 is shortened, the shaft 41 can be supported suitably. Thereby, manufacturing price can be reduced more.

In the bearing mechanism 4, an inexpensive ferrite magnet is used as the rotor magnet 22, whereby manufacturing cost can be reduced more. Since the ferrite magnet has a weaker magnetic force than the neodymium magnet, it is necessary to increase the height in the axial direction of the rotor magnet 22 and the stator 3 to sufficiently secure the magnetic action. In the motor 1, even in such a structure, the center cylindrical part 212b extends downward and is formed below the axial direction. Thus, the rotor holder 21 is fastened near the bearing member 42. As a result, even if vibration caused by unbalance or the like of the rotor holder 21 occurs, the center cylindrical portion 212b is transmitted to the bearing member 42 as compared with the case where the central cylindrical portion 212b extends upward and is fastened from the upper side in the axial direction. Less vibration Therefore, the bearing member 42 can be made small. As a result, an increase in the manufacturing price of the motor 1 is suppressed.

The lower end of the center cylindrical part 212b which is the site | part to which the shaft 41 of the rotor holder 21 is fixed is located below the upper surface 311 of the stator core 31, and the shaft 41 of the rotor holder 21 is located. The position of fixation to the kPa) can be approached to the bearing member 42. As a result, the rotor holder 21 can be easily and stably supported. In the mounting plate 12, since the opening part 123 is cylindrical shape, the opening part 123 can be firmly fixed to the bearing holding cylinder part 431. As shown in FIG. By using a burring process, the opening part 123 can be formed easily. In the bearing holding member 43, since the outer peripheral surface 531 of the flange part 432 is circular, shaping | molding of the flange part 432 from a flat plate member can be performed easily. In addition, the flange portion 432 can be easily inserted into the hole portion 92 of the mounting target member 9.

In the outer circumferential surface 51 of the bearing holding cylindrical portion 431, an end portion 510 is formed at the boundary between the central portion 512 and the lower portion 513. Thereby, when press-fitting the bearing holding cylinder part 431 into the opening part 123 of the mounting plate 12, the press-in distance can be shortened. Moreover, since the edge part 510 is formed in the inclined surface and becomes a guide of insertion, assembly becomes easy.

As in the technique, the bearing member 42, the mounting plate 12, and the stator 3 are press-fitted to the bearing retaining member 43. The circuit board 13 is caulked to the mounting plate 12. In this way, the press 1 and the caulking are used for assembling each part of the motor 1, whereby the motor 1 can be manufactured without using expensive equipment. The same applies to the following embodiments.

(Second Embodiment)

7 is a cross-sectional view of the motor 1a according to the second embodiment. In the motor 1a, the fall prevention part 46 is attached to the shaft 41 under the bearing member 42. As shown in FIG. On the upper side of the bearing member 42, a fall prevention portion 47 is mounted to the shaft 41. In FIG. 7, the illustration of the parallel oblique line with respect to the cross section of the fall prevention parts 46 and 47 is abbreviate | omitted. Hereinafter, the fall prevention part 46 is called "lower fall prevention part 46", and the fall prevention part 47 is called "upper fall prevention part 47". The upper end surface 422 of the bearing member 42 is located below the center in the axial direction of the stator 3, that is, the center in the axial direction of the stator core 31. In the center part 212a of the cover part 212 of the rotor holder 21, the center cylindrical part 212c extended upward from the lower end of a recess is provided. The upper portion of the shaft 41 is fixed to the central cylindrical portion 212c.

In the motor 1a, the thickness of the bearing holding member 43a is thinner than the bearing holding member 43 shown in FIG. Specifically, the thickness of the bearing retaining member 43a is 1.2 mm. The flange portion 432 of the bearing holding member 43a has a plurality of step portions 433 which protrude from the upper surface 533 toward the mounting plate 12. The step portion 433 is provided by half blanking processing. The other structure of the motor 1a is substantially the same as that of the motor 1 according to the first embodiment. Hereinafter, the same configuration will be described with the same reference numeral.

8 is a plan view of the bearing holding member 43a. The step portion 433 of the flange portion 432 has an arc shape with the center axis J1 as the center. The three step portions 433 are arranged at equal intervals with respect to the circumferential direction. As shown in FIG. 7, the upper end of the stepped portion 433 contacts the lower surface 124 of the mounting plate 12 in an annular shape to support the mounting plate 12 from below. The distance between the upper surface 533 of the flange portion 432 and the lower surface 124 of the mounting plate 12 is equal to the height in the axial direction of the step portion 433. In this way, in the motor 1a, the step portion 433 serves as a spacer portion for determining the distance between the mounting plate 12 and the flange portion 432 in the axial direction.

9 is a cross-sectional view showing the lower vicinity of the bearing member 42. The lower fall prevention part 46 is provided with the metal fixing ring 461, the metal washer 462, and the annular resin plate 463. In the lower fall prevention part 46, below the bearing member 42, the resin plate 463, the washer 462, and the fixing ring 461 are arrange | positioned toward the lower part sequentially. The fixed ring 461 is a C-shaped fixed ring. The inner circumferential portion of the fixing ring 461 is fitted to the annular groove portion 412 provided in the circumferential direction on the outer circumferential surface 411 of the shaft 41. The washer 462 and the resin plate 463 are attached to the shaft 41 in an insertable state. The presence of the stationary ring 461 prevents the washer 462 disposed above the stationary ring 461 from escaping from the shaft 41. In addition, in FIG. 9, the resin plate 463 is shown in the state which contacted the lower end surface 421 of the bearing member 42. As shown in FIG. However, the lubricating oil adheres to the washer 462, so that the resin plate 463 may be in contact with the upper surface of the washer 462.

In the motor 1a, by providing the lower fall prevention part 46, the shaft 41 is prevented from moving upward. In addition, since the resin plate 463 is disposed between the washer 462 and the bearing member 42, wear or damage of the lower portion of the bearing member 42 is prevented.

FIG. 10 is a view of the lower fall prevention part 46 and the shaft 41 of FIG. 9 viewed from below. In FIG. 10, a parallel diagonal line is given to the shaft 41. Washer 462 has two projections 462a. The projection 462a protrudes downward, that is, toward the front side of the paper in FIG. 10. The two protrusions 462a are arranged side by side with the central axis J1 interposed therebetween. The fixed ring 461 includes an annular portion 461b centered on the central axis J1, and a protrusion 461a protruding radially outward from the portion 461b. The protrusion 462a and the protrusion 461a are arranged side by side in the circumferential direction. Exactly, the presence range with respect to the radial direction of the projection part 462a overlaps with the existence range with respect to the radial direction of the projection part 461a, and does not overlap with the existence range with respect to the radial direction of the part 461b.

When the motor 1a is driven, the one projection 462a and the projection 461a are fixed to each other in the circumferential direction, thereby preventing the relative rotation of the washer 462 relative to the fixing ring 461. As a result, wear of the washer 462 is suppressed. In the motor 1a, since two projection parts 462a exist, even if the projection part 461a exceeds one projection part 462a, it fixes with respect to the remaining projection part 462a and the circumferential direction.

Thereby, the relative rotation of the washer 462 with respect to the stationary ring 461 is suppressed more reliably. In addition, when the magnitude | size of the projection part 462a is small, the projection part 462a may be fitted in the area | region provided inside the protrusion part 461a.

11 is a cross-sectional view showing the upper vicinity of the bearing member 42. The upper fall prevention part 47 is provided with the metal fixing ring 471, the metal washer 472, and the annular resin plate 473. As shown in FIG. In the upper fall prevention part 47, on the upper side of the bearing member 42, the resin plate 473, the washer 472, and the fixing ring 471 are arrange | positioned toward the upper side sequentially. The inner circumferential portion of the fixing ring 471 is fitted to the annular groove portion 413 provided in the circumferential direction on the outer circumferential surface 411 of the shaft 41. The washer 472 and the resin plate 473 are attached to the shaft 41 in the insertion state which can be spaced-fit. The presence of the retaining ring 471 prevents the washer 472 from escaping from the shaft 41.

In the motor 1a, by providing the upper fall prevention part 47, the shaft 41 is prevented from moving downward. In addition, since the resin plate 473 is disposed between the washer 472 and the bearing member 42, wear or damage of the upper portion of the bearing member 42 is prevented.

On the upper surface of the washer 472, the protrusion is provided in the same manner as the washer 462 of the lower fall prevention portion 46 of FIG. The protrusion protrudes upward. In the upper fall prevention part 47, similarly to the lower fall prevention part 46, the protrusion part and the protrusion part which protrudes radially outward of the fixing ring 471 are mutually fixed with respect to the circumferential direction. This can hinder the relative rotation of the washer 472 relative to the stationary ring 471.

As mentioned above, although the motor 1a which concerns on 2nd Embodiment was demonstrated, in the lower fall prevention part 46, the washer 462 can be prevented from deviating from the shaft 41 by the fixing ring 461. Therefore, the washer 462 can be easily inserted into the shaft 41 without press-fitting the shaft 41. As a result, the lower fall prevention portion 46 can be easily configured around the shaft 41. The same applies to the upper fall prevention part 47.

In the case of constituting the release preventing portion without using the fixing ring, it is conceivable to press the annular member formed by press working, sintering or the like into the shaft. However, in such a motor, it is necessary to thicken the annular member in order to secure the interference value. In addition, when the diameter of the shaft is small, sufficient indentation strength may not be ensured. As a result, there is a fear that the washer is released from the shaft. On the other hand, even when the diameter of the shaft 41 is small in the motor 1a, by providing the fixing ring 461, the washer 462 is reliably prevented from escaping from the shaft 41. The same applies to the upper fall prevention part 47. In the motor 1a, the lower fall prevention part 46 and the upper fall prevention part 47 simplify the fall prevention structure which can fully bear the thrust direction load which generate | occur | produces at the time of the drive of the motor 1a, etc. Can be configured. Since a fall prevention structure can be comprised easily, productivity of the motor 1a can be improved.

Since the thickness of the bearing holding member 43a is thin, the material cost of the bearing holding member 43a can be suppressed. In addition, the motor 1a can be reduced in weight. In the bearing holding member 43a, the step portion 433 is present in the flange portion 432 so that the outer circumferential surface 531 of the flange portion 432 can be spaced downward from the lower surface 124 of the mounting plate 12. have. As a result, even if the thickness of the flange part 432 is made thin, the outer peripheral surface 531 can fully contact the inner peripheral surface of the hole part 92 of the mounting object member 9 of FIG. 4 with respect to the radial direction.

In the motor 1a, since the mounting plate 12 is press-fitted to the bearing retaining member 43a in the same manner as in the first embodiment, the number of assembly operations can be reduced, and the manufacturing cost can be reduced. Further, in the first press-fitting range 711 (see FIG. 6) in which the stator core 31 is press-fitted into the bearing retaining cylindrical portion 431, the first portion is provided between the bearing member 42 and the bearing retaining cylindrical portion 431. A gap 721 is provided. This suppresses the deformation of the upper portion of the inner circumferential surface 61 of the bearing member 42. Similarly, in the second press-in range 712 in which the mounting plate 12 is press-fitted into the bearing retaining cylindrical portion 431, a second gap 722 is formed between the bearing member 42 and the bearing retaining cylindrical portion 431. Prepared. Thereby, the deformation | transformation of the lower part of the inner peripheral surface 61 of the bearing member 42 is suppressed. The same applies to other embodiments described below.

12 is a diagram illustrating a part of a motor according to another example. The mounting plate 12 of the motor 1a includes a plurality of stepped portions 125. The stepped portion 125 protrudes from the lower surface 124 of the mounting plate 12 toward the upper surface of the flange portion 432. The step part 125 is provided by half blanking process. The plurality of stepped portions 125 are provided at equal intervals in the circumferential direction similarly to the stepped portion 433 illustrated in FIG. 8. In the motor 1a, the stepped portion 125 is provided as a spacer portion between the mounting plate 12 and the flange portion 432. Thereby, even when the thickness of the flange part 432 is thin, the outer peripheral surface 531 of the flange part 432 can fully contact the inner peripheral surface of the hole part 92 of the mounting object member 9.

13 is a diagram illustrating a part of a motor according to still another example. An annular spacer portion 14 is provided between the mounting plate 12 and the flange portion 432. Also in the case shown in FIG. 13, the presence of the spacer portion 14 makes it possible to easily determine the distance between the mounting plate 12 and the flange portion 432 in the axial direction. As a result, the flange portion 432 can be sufficiently brought into contact with the hole portion 92 of the mounting target member 9 in the radial direction. In addition, the spacer portion does not necessarily need to be annular, and may be, for example, substantially C-shaped in plan view.

(Third Embodiment)

It is a figure which shows the lower vicinity of the bearing member of the motor which concerns on 3rd Embodiment. The fixing ring 464 of resin is provided in the motor lower fall prevention part 46a instead of the metal fixing ring. The inner circumferential portion of the fixing ring 464 is fitted into the groove portion 412 of the outer circumferential surface 411 of the shaft 41. An upper fall prevention part is provided above the bearing member 42. The upper fall prevention part is the same as the upper fall prevention part 47 of FIG. 11 except that the fixing ring of resin is provided. The other structure of the motor is the same as that of the motor 1a shown in FIG. Hereinafter, the same code | symbol is attached | subjected to the same structure.

In the lower fall prevention part 46a, by using the fixing ring 464 of the resin, wear of the washer 462 can be suppressed even when the washer 462 rotates relative to the fixing ring 464. Similarly to the second embodiment, in the lower fall prevention portion 46a, the washer 462 is prevented from escaping from the shaft 41 by the fixing ring 464, so that the washer 462 is easily attached to the shaft 41. Can be inserted. As a result, the lower fall prevention portion 46a can be easily configured around the shaft 41. The same is true for the upper fall prevention part.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible.

In the said embodiment, as long as the outer peripheral surface 531 of the flange part 432 can perform positioning of the center axis J1, the outer peripheral surface 531 may be various shapes other than circular shape. For example, it may be a shape in which a part of a circular outer circumference is notched, or a square in which each portion is chamfered.

In the first embodiment, if the lower end surface 421 of the bearing member 42 is located below the upper end of the second press-fit range 712, more preferably below the upper surface 533 of the flange portion 432, It does not necessarily need to be the same position as the lower surface 532 of the flange portion 432 with respect to the axial direction. Even in this case, deformation of the lower part of the inner peripheral surface 61 of the bearing member 42 is suppressed by the second gap 722 while the bearing member 42 approaches the output side of the shaft 41. The upper end of the bearing member 42 may be located below the center in the axial direction of the stator 3. In 2nd and 3rd embodiment, the position of the lower end surface 421 of the bearing member 42 in the axial direction is the same as the upper surface 533 of the flange part 432, or is located below the upper surface 533. Also good.

In the above embodiment, the diameters of the upper portion 621 and the central portion 622 of the outer circumferential surface 62 of the bearing member 42 are the same, and the upper portion 521 of the inner circumferential surface 52 of the bearing retaining cylindrical portion 431 is formed. The diameter may be larger than the diameter of the central portion 522. Similarly, the diameter of the lower portion 623 of the outer circumferential surface 62 of the bearing member 42 is made smaller than the diameter of the central portion 622, and the central portion 522 and the lower portion of the inner circumferential surface 52 of the bearing retaining cylindrical portion 431 The diameter of 523 may be the same. In this manner, the first gap 721 and the second gap 722 may be formed by various methods. In addition, by making the diameter of the lower portion 523 of the inner circumferential surface 52 of the bearing holding cylindrical portion 431 larger than other portions, the bearing holding members 43 and 43a can be easily manufactured by pressing from the flat plate member.

The mounting plate 12 does not have to be completely plate-shaped, and various three-dimensional portions necessary for mounting on the mounting target member 9 may exist. The mounting structure in the attaching part 121 may also be a structure other than screwing. The opening 123 of the mounting plate 12 does not necessarily need to be cylindrical, and the cylindrical portion may be omitted. That is, the opening part 123 may be a flat plate-shaped site in which a passage is formed. In this case, the bearing holding cylindrical portion 431 is press-fitted into the inner circumferential surface of the passage.

In the second embodiment, the number of the stepped portions 433 of the flange portion 432 may be a number other than three. When the number of the stepped portions 433 is two, the two stepped portions 433 are disposed substantially in a straight line with the central axis J1 interposed therebetween. In the case where three or more stepped portions 433 are provided, the plurality of stepped portions 433 are not necessarily arranged at equal intervals in the circumferential direction, provided that the plurality of stepped portions 433 are substantially annular about the central axis J1. When only one step part 433 is provided, it is preferable that the existence range with respect to the circumferential direction is 180 degree or more. The shape of the stepped section 433 is not limited to an arc shape, but may be other various shapes such as a circular shape and a point sequence shape. The same applies to the stepped portion 125 of the mounting plate 12.

In the lower fall prevention part 46, an E-shaped fixing ring may be used as the fixing ring. In this case, for example, one projection 462a is provided in the washer 462, and the projection 462a is disposed between both ends of the arc-shaped portion of the E-shaped fixing ring. At the time of driving the motor 1a, the protrusion 462a is fixed to one end and the circumferential direction. As described above, in the motor 1a, various shapes of fixing rings are available, and at the time of rotation, part of the fixing ring is fixed with the protrusion 462a in the circumferential direction, thereby rotating the washer 462 relative to the fixing ring. Fixing is easily realized. The same applies to the upper fall prevention part 47. In addition, in the case of a metal fixing ring, it is preferable that a C type fixing ring is used for strength.

In the lower fall prevention part 46, the number of the projection part 462a of the washer 462 may be three or more. As long as the projection 462a is firmly fixed to the fixing ring 461 in the circumferential direction, the number of the projections 462a may be one. If the washer 462 can be easily inserted into the shaft 41, the washer 462 may be lightly press-fitted into the shaft 41. The same applies to the upper fall prevention part 47.

In the said embodiment, the stator core 31 does not need to be attached directly to the outer peripheral surface 51 of the bearing holding cylinder part 431, and may be attached indirectly. A neodymium magnet may be used as the rotor magnet 22. On the circuit board 13, an electronic component constituting a circuit such as an IC (integrated circuit) may be mounted. In the first embodiment, the pinion gear (not shown) may be omitted. That is, the gear may be arranged without providing the fall prevention portion 45, and the gear itself may function as the fall prevention portion. The center cylindrical portion 212b of the rotor holder 21 may be provided so as to be bent upward from the center portion 212a. In this case, the bearing member 42 can be made small by lengthening the length of the spacer 44 in the axial direction. In contrast, with respect to the second embodiment, the rotor holder 21 and the shaft 41 may be joined by the same structure as in the first embodiment.

The configurations in the above embodiments and each modification may be appropriately combined as long as they do not contradict each other.

This invention can be used for the motor of various uses.

1, 1a: motor 3: stator
9: mounting target member 12: mounting plate
14 spacer portion 21 rotor holder
22: rotor magnet 31: stator core
41 shaft 42 bearing member
43, 43a: bearing holding member 46, 46a: lower fall prevention part
47: upper part fall prevention part 51: outer peripheral surface (of bearing bearing cylindrical part)
92: hole part (of the member to be mounted)
121: mounting portion 123: opening
124: lower surface of mounting plate 125, 433
211: cylindrical portion 211a: inner peripheral surface (cylindrical portion)
212b, 212c: central cylindrical portion 311: upper surface (of stator core)
411: (circle) outer peripheral surface 412, 413: groove
422: top surface (of a bearing member) 431: bearing retainer cylindrical portion
432: flange portion 461, 464, 471: retaining ring
461a: protrusions 462, 472: washers
462a: protrusion 463, 473: resin plate
531: Outer peripheral surface (flange portion) 533: Upper surface (flange portion)
711 to 713: indentation range 721 to 723: first to third gaps
J1: central axis

Claims (13)

A shaft disposed about a central axis facing upward and downward,
A cylindrical rotor holder having a lid fixed to the top of the shaft,
A rotor magnet fixed to an inner circumferential surface of the cylindrical portion of the rotor holder,
A bearing member which is a containing sintered bearing for rotatably supporting the shaft about the central axis;
A bearing holding member into which the bearing member is inserted;
A stator disposed in the radially inner side of the rotor magnet;
A mounting plate fixed to the bearing holding member,
The bearing holding member,
A bearing holding cylinder portion into which the bearing member is inserted;
A flange portion that extends radially outward from a lower end of the bearing holding cylindrical portion,
The stator is fixed to an outer circumferential surface of the bearing holding cylinder portion,
A lower end of the shaft protrudes downwardly from the flange portion,
The outer circumferential surface 531 of the flange portion includes a positioning surface that determines the position of the central axis with respect to the mounting target member by being fitted to the hole of the mounting target member.
The mounting plate,
An opening through which the bearing holding cylinder portion is press-fitted;
A mounting portion fixed to the mounting target member;
The lower surface of the mounting plate is in contact with the upper surface of the flange portion,
In the axial direction, a press-fitting range in which the mounting plate is press-fitted into the bearing-holding cylindrical part overlaps with a presence range of the bearing member, and a gap is provided between the bearing-member and the bearing-holding cylindrical part in the press-fitting range.
motor. A shaft disposed about a central axis facing upward and downward,
A cylindrical rotor holder having a lid fixed to the top of the shaft,
A rotor magnet fixed to an inner circumferential surface of the cylindrical portion of the rotor holder,
A bearing member which is a containing sintered bearing for rotatably supporting the shaft about the central axis;
A bearing holding member into which the bearing member is inserted;
A stator disposed in the radially inner side of the rotor magnet;
A mounting plate fixed to the bearing holding member,
The bearing holding member,
A bearing holding cylinder portion into which the bearing member is inserted;
A flange portion that extends radially outward from a lower end of the bearing holding cylindrical portion,
The stator is fixed to an outer circumferential surface of the bearing holding cylinder portion,
A lower end of the shaft protrudes downwardly from the flange portion,
The outer circumferential surface 531 of the flange portion includes a positioning surface that determines the position of the central axis with respect to the mounting target member by being fitted to the hole of the mounting target member.
The mounting plate,
An opening through which the bearing holding cylinder portion is press-fitted;
A mounting portion fixed to the mounting target member;
Between the mounting plate and the flange portion, a spacer portion for determining a distance between the mounting plate and the flange portion in the axial direction is provided.
motor. 3. The method of claim 2,
The spacer portion is a stepped portion that protrudes from the upper surface of the flange portion toward the mounting plate or protrudes from the lower surface of the mounting plate toward the flange portion.
motor. A shaft disposed about a central axis facing upward and downward,
A cylindrical rotor holder having a lid fixed to the top of the shaft,
A rotor magnet fixed to an inner circumferential surface of the cylindrical portion of the rotor holder,
A bearing member which is a containing sintered bearing for rotatably supporting the shaft about the central axis;
A bearing holding member into which the bearing member is inserted;
A stator disposed in the radially inner side of the rotor magnet;
A mounting plate fixed to the bearing holding member;
A fall prevention part mounted to the shaft at a lower side of the bearing member;
The bearing holding member,
A bearing holding cylinder portion into which the bearing member is inserted;
A flange portion that extends radially outward from a lower end of the bearing holding cylindrical portion,
The stator is fixed to an outer circumferential surface of the bearing holding cylinder portion,
A lower end of the shaft protrudes downwardly from the flange portion,
The outer circumferential surface 531 of the flange portion includes a positioning surface that determines the position of the central axis with respect to the mounting target member by being fitted to the hole of the mounting target member.
The mounting plate,
An opening through which the bearing holding cylinder portion is press-fitted;
A mounting portion fixed to the mounting target member;
The fall prevention unit,
A metal fixing ring fitted to the groove formed in the circumferential direction on the outer circumferential surface of the shaft;
A washer of metal inserted into the shaft and disposed above the fixing ring;
An annular resin plate disposed between the washer and the bearing member;
The washer has a protrusion projecting downward,
The protrusion and a portion of the fixing ring are fixed to each other in the circumferential direction around the central axis
motor. The method of claim 4, wherein
The fixed ring is a C-type fixed ring
motor. A shaft disposed about a central axis facing upward and downward,
A cylindrical rotor holder having a lid fixed to the top of the shaft,
A rotor magnet fixed to an inner circumferential surface of the cylindrical portion of the rotor holder,
A bearing member which is a containing sintered bearing for rotatably supporting the shaft about the central axis;
A bearing holding member into which the bearing member is inserted;
A stator disposed in the radially inner side of the rotor magnet;
A mounting plate fixed to the bearing holding member;
A fall prevention part mounted to the shaft at a lower side of the bearing member;
A bearing holding cylinder portion into which the bearing member is inserted;
A flange portion that extends radially outward from a lower end of the bearing holding cylindrical portion,
The stator is fixed to an outer circumferential surface of the bearing holding cylinder portion,
A lower end of the shaft protrudes downwardly from the flange portion,
The outer circumferential surface 531 of the flange portion includes a positioning surface that determines the position of the central axis with respect to the mounting target member by being fitted to the hole of the mounting target member.
The mounting plate,
An opening through which the bearing holding cylinder portion is press-fitted;
A mounting part fixed to the mounting target member,
The fall prevention unit,
A fixing ring of resin fitted to the groove portion formed in the circumferential direction on the outer circumferential surface of the shaft;
A washer of metal inserted into the shaft and disposed above the fixing ring;
An annular resin plate disposed between the washer and the bearing member.
motor. 7. The method according to any one of claims 1 to 6,
The opening of the mounting plate is cylindrical
motor. The method of claim 7, wherein
The opening of the cylindrical shape is formed by a burring process
motor. 7. The method according to any one of claims 1 to 6,
The outer circumferential surface 531 of the flange portion is circular with respect to the central axis.
motor. 7. The method according to any one of claims 1 to 6,
A lower end of a portion fixed to the shaft of the rotor holder is located below an upper surface of the stator core of the stator.
motor. 11. The method of claim 10,
The rotor magnet is a ferrite magnet
motor. 7. The method according to any one of claims 1 to 6,
The lower end of the bearing member is located below the upper surface of the flange portion
motor. 7. The method according to any one of claims 1 to 6,
The upper end of the bearing member is located below the center in the axial direction of the stator
motor.

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