JP3609112B2 - Bearing structure - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a bearing structure suitable for a fan motor or the like.
[0002]
[Prior art]
Conventionally, as a bearing structure in a fan motor or the like, as shown in, for example, Japanese Patent Laid-Open No. 5-168192, a cylindrical bearing holder (bearing housing portion) is projected at the center of the motor housing, and this bearing holder The shaft of the rotor (rotating shaft) is rotatably supported via a sleeve bearing (sliding bearing) inside.
[0003]
In this case, the shaft is supported in the axial direction by shifting the magnetic center between the stator fixed to the outside of the bearing holder and the rotor magnet attached to the rotor so as to face the stator, and thrusting the shaft in the direction of its tip. On the other hand, a retaining ring for retaining from the sleeve bearing is fixed to the tip of the shaft. A thrust plate is interposed between the sleeve bearing and the retaining ring.
[0004]
[Problems to be solved by the invention]
However, in the bearing structure having such a configuration, the thrust support of the shaft with respect to the bearing holder can be supported only in one direction by the retaining ring, and the both directions cannot be supported independently. There is a difficulty that requires structural ingenuity such as shifting the magnetic center between the rotor magnet and the rotor magnet.
[0005]
This suggests that it is impossible to construct the bearing structure alone, and therefore there is a drawback that it cannot be used to support other rotating bodies that do not require a stator and a rotor magnet. .
[0006]
Further, in the case of the shaft support structure as described above, since the shaft is supported in the radial direction by the sleeve bearing, when the shaft is supported in the thrust direction, the shaft tends to be supported only in the axial direction. When a deflection force acts on the shaft, a partial displacement force acts on the sleeve bearing, which causes a problem of noise.
[0007]
The present invention has been made in consideration of such problems of the prior art, and its object is to support the shaft inside the bearing holder in both the forward and reverse directions in the thrust direction as well as in the radial direction. In addition, an object of the present invention is to provide a bearing structure that can stably rotate and support a shaft even when a deflection force acts on the shaft.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a bearing structure of the present invention includes a covered cylindrical bearing holder, a sleeve bearing fixed to the inside of the cylindrical portion of the bearing holder, and rotatably supported by the sleeve bearing. A shaft, a thrust receiving member which is provided on the bottom surface of the bearing holder and abuts the end surface of the shaft, an annular washer supported on the end portion of the shaft so as to be axially slidable with respect to the shaft, and an inner side of the cylindrical portion A thrust ring that is fixed and disposed on the lower surface of the sleeve bearing so as to face the upper surface of the washer; and an elastic body that is supported by the shaft and imparts an elastic force that elastically contacts the washer with the thrust ring,
The abutting surfaces of the washer and the thrust ring are each formed as a mirror surface.
[0009]
In this case, the bearing holder may be fixed by press-fitting, welding, or adhering to a mounting hole formed in the motor housing.
[0010]
It is also preferable to form a screw for fixing the rotor of the motor at the base of the shaft.
[0011]
Further, the elastic body is composed of an attachment ring and a plurality of leaf spring pieces extending from the attachment ring and arranged at equal intervals, and a part of the attachment ring is locked to the peripheral surface of the end of the shaft. It is desirable to form notches for supporting the elastic body integrally with the shaft in the rotational direction, and to form a plurality of engagement holes with which the respective leaf spring pieces are engaged at equal intervals on the lower surface of the washer.
[0012]
And it is good to form the step part in which a bottom part side becomes a small diameter in the inner peripheral surface near the bottom part of a bearing holder, and to hold a thrust ring between this step part and a sleeve bearing.
[0013]
[Action]
In the bearing structure of the present invention configured as described above, the shaft is rotatably supported in the radial direction by the sleeve bearing fixed to the cylindrical portion of the bearing holder. With respect to the thrust direction of the shaft, the end surface of the shaft abuts against the thrust receiving member, thereby supporting the shaft in the end portion direction, and the washer supported by the shaft is applied to the lower surface of the sleeve bearing by the elastic force of the elastic body. The shaft is supported in the base direction by elastically contacting the lower surface of the thrust ring located from the end side of the shaft. Therefore, the shaft can be supported in all directions only inside the bearing holder.
[0014]
In this case, since the washer hits the thrust ring and the contact surfaces of the two are mirror surfaces, smooth rotation support can be achieved, and even when the deflection force acts on the shaft. This is absorbed by the elastic force of the elastic body so that the contact between the washer and the thrust ring is maintained, and stable rotation support is realized.
[0015]
【Example】
Embodiments of the present invention will be described in detail with reference to the drawings.
First, a first embodiment in which the bearing structure of the present invention is applied to a fan motor will be described with reference to FIGS.
[0016]
FIG. 1 shows the structure of a motor part of a fan motor. The resin bracket 1 is formed by integrally molding a shallow dish-like support portion 2 having an upper opening and a bottomed cylindrical bearing holder 3 protruding upward at the center portion.
[0017]
A stator 4 is fixed to the outer periphery of the central portion of the cylindrical portion 3 a of the bearing holder 3. The stator 4 is formed by mounting a pair of insulators 6 and 7 on a stator core 5 formed by laminating a plurality of laminations from above and below, and winding a coil 8 thereon. The stator 4 is externally fitted to the cylindrical portion 3a, and is prevented from coming off by fitting the annular protrusion 9 provided on the upper insulator 6 into the annular concave groove 10 of the cylindrical portion 3a.
[0018]
The circuit board 12 disposed immediately above the support portion 2 of the housing 2 is supported by the stator 4 by fitting the cylindrical portion 11 provided on the inner peripheral side of the lower insulator 7 into the center hole thereof, and the insulator 7 The curled pin 13 of the coil 8 led out further downward is soldered to the circuit board 12.
[0019]
A thrust receiving member 14 having a short cylindrical shape is embedded in the upper center portion of the bottom plate portion 3 b of the bearing holder 3. Inside the bearing holder 3, a vertical shaft 16 is rotatably supported via a sleeve bearing 15, and a hemispherical tip 17 at the lower end of the shaft 16 is rotatably abutted against the upper surface of the thrust receiving member 14. ing.
[0020]
The sleeve bearing 15 includes a long outer layer 15a with emphasis on oil-impregnation fixed to the inner peripheral surface of the cylindrical part 3a by press-fitting and the like, and a short dimension with emphasis on wear resistance located on the inner periphery of both ends of the outer peripheral layer 15a. The sleeve 18 is prevented from coming off and oil leakage is prevented by a cap 18 that is composed of the two inner peripheral layers 15b and is fitted to the upper end of the cylindrical portion 3a.
[0021]
An annular thrust ring 19 made of heat resistant resin is disposed on the lower surface of the sleeve bearing 15. That is, a step portion 20 having a small diameter on the bottom side is formed near the bottom of the inner periphery of the cylindrical portion 3a. The thrust ring 19 is inserted into the cylindrical portion 3a using the step portion 20 for positioning, and the sleeve bearing 15 is The thrust ring 19 is pressed into the cylindrical portion 3 a and the thrust ring 19 is clamped and fixed by the step portion 20 and the sleeve bearing 15. The lower surface of the thrust ring 19 is formed in a mirror surface.
[0022]
An annular washer 21 that is rotatable and slidable in the axial direction is provided on the lower outer periphery of the shaft 16. The washer 21 is made of stainless steel or the like, and its upper surface is formed as a mirror surface, and a pair of outer circumferential grooves 22 are formed on the lower surface of the washer 21 every 180 degrees.
[0023]
The washer 21 is supported integrally with the shaft 16 by a leaf spring structure 23 that is an elastic body, and is elastically biased upward to bring the washer 21 into elastic contact with the thrust ring 19.
[0024]
That is, as shown in FIGS. 2 and 3, the leaf spring structure 23 includes a substantially truncated cone-shaped attachment ring 23 a and tapered surface-shaped locking portions formed at two positions of 180 degrees of the attachment ring 23 a. 23b and a pair of leaf spring pieces 23c formed extending from the locking portion 23b in the outer circumferential direction. Then, the mounting ring 23 a is inserted into the shaft 16 from below, and both the locking portions 23 b are locked in a pair of notch grooves 24 formed on the peripheral surface of the lower end portion of the shaft 16, and inserted into the shaft 16. By inserting and engaging a pair of leaf spring pieces 23c into the groove 22 of the washer 21 from below, the washer 21 is supported so as to be slidable in the thrust direction integrally with the shaft 16.
[0025]
The shaft 16 supporting the washer 21 and the leaf spring structure 23 in this manner is inserted into the cylindrical portion 3a of the bearing holder 3, and then the thrust receiving member 19 and the sleeve bearing 15 are fixed in the cylindrical portion 3a. At this time, when the thrust receiving member 19 is fixed between the stepped portion 20 and the sleeve bearing 15, both the leaf spring pieces 23c bend through the washer 21, and the washer 21 is caused by the elastic return force of the both leaf spring pieces 23c. The mirror surface (upper surface) is elastically contacted with the mirror surface (lower surface) of the thrust receiving member 19.
[0026]
A flange-like rotor frame 26 of a fan impeller 25 is attached to the base portion of the shaft 16. The base portion of the shaft 16 is provided such that an attachment shaft portion 27 inserted into the center hole of the rotor frame and a screw portion 28 formed with a male screw are sequentially reduced in diameter, and the attachment shaft portion 27 is attached to the rotor frame 26. The impeller 25 is attached to the shaft 16 by inserting the nut 30 into the threaded portion 28 led out into the recessed groove 29 on the upper surface of the rotor frame 26 until it is in contact with the stepped portion on the front end side. The screw portion 28 and the nut 30 are accommodated in the concave groove 29.
[0027]
An annular rotor magnet 32 is attached to the inner peripheral surface of the cylindrical portion of the rotor frame 26 via a yoke 31. The rotor magnet 32 faces the outer peripheral surface of the stator 4 with a slight gap, and the magnetic center of the stator 4 and the magnetic center of the rotor magnet 32 are substantially coincident with each other.
[0028]
In the bearing structure having such a configuration, the thrust receiving member fixed to the bottom plate portion 3b of the bearing holder 3 while the shaft 16 supported in the bearing holder 3 is supported in the radial direction by the sleeve bearing 15. 14, the shaft 16 is supported in one direction in the thrust direction by abutting the tip 17 of the shaft 16, and a washer 21 that is supported by the lower portion of the shaft 16 so as to be slidable in the axial direction integrally with the rotation direction is a cylindrical portion. The shaft 16 is supported with respect to the other direction in the thrust direction by elastically contacting the thrust ring 19 supported in 3a.
[0029]
Therefore, the shaft 16 can be reliably supported in all directions only in the bearing holder 3. Therefore, there is no need to obtain a thrust force by shifting the mutual magnetic centers of the stator 5 and the rotor magnet 32 as in the prior art, and the rotation of the rotor (impeller 25) with high efficiency by matching the mutual magnetic centers of the two. Can be obtained.
[0030]
In addition, since the washer 21 and the thrust ring 19 that rotate together with the shaft 16 are supported by bringing their mirror surfaces into contact with each other, there is no loss due to friction or the like, and smooth rotation can be obtained. Moreover, since the washer 21 is pressed by the pair of leaf spring pieces 23c and brought into elastic contact with the thrust ring 19, a uniform surface contact can be obtained, and even if a deflection force acts on the shaft 16, this can be absorbed by the spring force, Stable rotation can be obtained without generating vibration that causes noise.
[0031]
In particular, when the rotor frame 26 is attached by forming the screw portion 28 at the base portion of the shaft 16 as in the embodiment, not only the trouble of integrating the shaft 16 into the rotor frame 26 by insert molding or the like can be saved, There is an advantage that assembly is simplified, and replacement of only the impeller 25 is facilitated.
[0032]
Next, a second embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals as those shown above denote the same or corresponding ones.
[0033]
In this embodiment, a bottomed cylindrical bearing housing 3 is constituted alone, and a shaft 16 is supported in the bearing holder 3 by a sleeve bearing 15 so as to be rotatable in a radial direction. The thrust receiving member 14 fixed to the bottom plate 3b is in contact with the hemispherical tip portion 17 of the shaft 16 to support the shaft 16 in one direction of the thrust direction. A washer 21 slidable in the direction is elastically contacted by a thrust ring 19 supported in the cylindrical portion 3a by a leaf spring structure 23 to support the shaft 16 in the other direction of the thrust direction. .
[0034]
According to this configuration, the bearing structure can be unitized, and the impeller can be supported in the same manner as in the first embodiment by appropriately incorporating the bearing structure in a motor housing or the like. There is an advantage that can be formed alone. The bearing structure can be incorporated into the housing or the like by press-fitting, welding, bonding, or the like.
[0035]
Furthermore, the bearing structure can be used not only to support the rotor of the motor but also to support other rotating bodies.
[0036]
As mentioned above, although the specific example of the bearing structure according to this invention was demonstrated, this invention is not limited to these Examples, A various deformation | transformation thru | or correction | amendment are possible without deviating from the scope of the present invention.
[0037]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
In the bearing holder, the shaft is rotatably supported by the sleeve bearing in the radial direction, while the end of the shaft 16 is brought into contact with the thrust receiving member on the bottom surface of the bearing holder to support the shaft in one direction of the thrust direction. In addition, the shaft can be supported in the other direction in the thrust direction by elastically contacting a thrust ring supported in the cylindrical portion with a washer slidable in the axial direction at the lower part of the shaft. The shaft can be reliably supported in all directions.
[0038]
For this reason, when applied to a fan motor or the like, there is no need to obtain a thrust force by shifting the mutual magnetic centers of the stator and the rotor magnet as in the prior art. It is possible to obtain rotation of the rotor.
[0039]
In addition, the washer and thrust ring rotating together with the shaft are supported by bringing their mirror surfaces into contact with each other, so that there is no loss due to friction, etc., and smooth rotation is obtained. Because it is elastically contacted with the ring, even contact with the surface can be obtained, and even if vibration force is applied to the shaft, it can be absorbed by the elastic force of the elastic body, and vibration that causes noise generation does not occur and stable rotation is achieved. can get.
[0040]
In addition, if the screw part is formed at the base of the shaft, for example, when attaching the rotor of the motor to the shaft, there is an advantage that not only the trouble of integrating the shaft into the rotor by insert molding etc. can be saved, but also the assembly is simplified, It is easy to replace only the rotor.
[0040]
Furthermore, if the bearing holder is configured to be attached to the motor housing, the bearing structure can be unitized, and can be formed alone, making it easy to manufacture as well as parts. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment when a bearing structure according to the present invention is applied to a fan motor.
2 is an exploded perspective view of the shaft, washer, and leaf spring structure of FIG. 1; FIG.
3 shows the leaf spring structure of FIG. 1, in which (A) is a bottom view and (B) is a side view. FIG.
FIG. 4 is a cross-sectional view showing another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 3 Bearing holder 3a Cylindrical part 14 Thrust receiving member 15 Sleeve bearing 15a Outer peripheral layer 15b Inner peripheral layer 16 Shaft 19 Thrust ring 21 Washer 23 Leaf spring structure 23c Leaf spring piece 26 Rotor frame 28 Screw part

Claims (7)

A covered cylindrical bearing holder;
A sleeve bearing fixed inside the cylindrical portion of the bearing holder;
A shaft rotatably supported by the sleeve bearing;
A thrust receiving member provided on the bottom surface of the bearing holder and in contact with the end surface of the shaft;
An annular washer supported at the end of the shaft so as to be slidable in the axial direction with respect to the shaft;
A thrust ring fixed to the inside of the cylindrical portion and disposed on the lower surface of the sleeve bearing so as to face the upper surface of the washer;
An elastic body that is supported by the shaft and imparts an elastic force that elastically contacts the washer with the thrust ring, and
The bearing structure according to claim 1, wherein the abutting surfaces of the washer and the thrust ring are mirror surfaces. The bearing structure according to claim 1, wherein the bearing holder includes a cylindrical body integrally formed with a motor housing. The bearing structure according to claim 1, wherein the bearing holder is fixed by press-fitting, welding, or adhering to a mounting hole formed in a motor housing. The bearing structure according to claim 1, wherein a screw for fixing a rotor of the motor is formed at a base portion of the shaft. The sleeve bearing has two outer peripheral layers with a long emphasis on oil-impregnation fixed to the inner peripheral surface of the cylindrical portion of the bearing holder, and two short ones with an emphasis on wear resistance located on the inner periphery of both ends of the outer peripheral layer. The bearing structure according to claim 1, comprising an inner circumferential layer. The elastic body includes an attachment ring and a plurality of leaf spring pieces extending from the attachment ring and arranged at equal intervals, and a part of the attachment ring is locked to the peripheral surface of the end of the shaft. A notch for integrally supporting the elastic body in the rotational direction with respect to the shaft is formed, and a plurality of engagement holes for engaging the leaf spring pieces are formed at equal intervals on the lower surface of the washer. The bearing structure according to 1. The bearing structure according to claim 1, wherein a step portion having a small diameter on the bottom portion side is formed on an inner peripheral surface near the bottom portion of the bearing holder, and the thrust ring is sandwiched between the step portion and the sleeve bearing. body.

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