JPH07208457A - Bearing structural body - Google Patents

Abstract

PURPOSE:To provide a bearing structural body capable of supporting a shaft in both forward and backward directions, not only in radial but thrust directions, inside a bearing holder and rotatably supporting the shaft stably even when a vibrating force is applied thereto. CONSTITUTION:A shaft 16 supported in a bottomed cylindrical bearing holder 3 is supported in a radial direction by a sleeve bearing 15, and by making the tip 17 of the shaft 16 abut to a thrust receiving member 14 fixed on the bottom plate part 3b of the bearing holder 3, the shaft 16 is supported with respect to one direction of the thrust direction. Further, by making elastic contact with a washer slidably provided on the lower part of the shaft 16 in an axial direction being integral with the rotational direction with a thrust ring 19 supported inside the cylindrical part 3b, the shaft 16 is supported with respect to the other direction of the thrust direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing structure suitable for fan motors and the like.

[0002]

2. Description of the Related Art Conventionally, as a bearing structure in a fan motor or the like, a cylindrical bearing holder (bearing housing portion) is provided at the center of the motor housing so as to project, as disclosed in, for example, JP-A-5-168192. However, the shaft (rotary shaft) of the rotor is rotatably supported inside the bearing holder via a sleeve bearing (slide bearing).

In this case, the shaft is supported in the axial direction by offsetting the magnetic centers of the stator fixed to the outside of the bearing holder and the rotor magnet mounted on the rotor so as to face the stator, so that the shaft moves in the direction of the tip. While applying thrust force, a retaining ring is attached to the tip of the shaft to prevent it from slipping out of the sleeve bearing. A thrust plate is interposed between the sleeve bearing and the retaining ring.

[0004]

However, in the bearing structure having such a structure, the support of the shaft in the thrust direction with respect to the bearing holder can be performed only in one direction by the retaining ring, and both directions are supported independently. Therefore, there is a problem in that structural ingenuity such as shifting the magnetic center between the stator and the rotor magnet on the motor side is required.

This suggests that it is not possible to construct the bearing structure by itself, and
There is a drawback that it cannot be used to support other rotating bodies that do not require a stator and a rotor magnet.

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, there is a tendency that only linear support in the axial direction is used. As a result, when the deflection force acts on the shaft, a partial displacement force acts on the sleeve bearing, which causes a problem of noise.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to make the shaft inside the bearing holder not only in the radial direction but also in the thrust direction. It is an object of the present invention to provide a bearing structure that can be supported in both directions and that can stably and rotatably support a shaft even when a oscillating force is applied.

[0008]

To achieve the above object, a bearing structure of the present invention comprises a cylindrical bearing holder with a lid, a sleeve bearing fixed inside the cylindrical portion of the bearing holder, A shaft that is rotatably supported by a sleeve bearing, a thrust receiving member that is provided on the bottom surface of the bearing holder and is in contact with the end surface of the shaft, and an annular shape that is axially slidably supported on the end portion of the shaft. Washer, a thrust ring fixed to the inside of the cylindrical portion and arranged 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 that gives elastic force to elastically contact the washer with the thrust ring. And a contact surface between the washer and the thrust ring is formed as a mirror surface. It is intended.

In this case, the bearing holder may be fixed by press-fitting, welding or adhering to a mounting hole provided in the housing of the motor.

It is also preferable to form a screw on the base of the shaft for fixing the rotor of the motor.

Further, the elastic body is composed of a mounting ring and a plurality of leaf spring pieces extending from the mounting ring and arranged at equal intervals. A part of the mounting ring is engaged with the peripheral surface of the end portion of the shaft. It is desirable to stop the elastic body so as to integrally support the elastic body with respect to the shaft in the rotational direction, and to form a plurality of engaging holes on the lower surface of the washer at which the leaf spring pieces engage with each other at equal intervals.

It is preferable that a step portion having a small diameter on the bottom side is formed on the inner peripheral surface of the bearing holder near the bottom portion, and a washer is sandwiched between the step portion and the sleeve bearing.

[0013]

In the bearing structure of the present invention constructed 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. For the thrust direction of the shaft,
The end face of the shaft contacts the thrust receiving member to support the shaft in the end direction, and the washer supported by the shaft is attached to the lower surface of the thrust ring located on the lower surface of the sleeve bearing by the elastic force of the elastic body. The elastic support from the end side supports the shaft in the base direction. Therefore, the shaft can be supported in all directions only inside the bearing holder.

In this case, since the washer comes into contact with the thrust ring and the abutting surfaces of the two are formed as mirror surfaces of each other, smooth rotation support can be performed, and when the runout force acts on the shaft. Even if there is, this is absorbed by the elastic force of the elastic body, the surface contact between the washer and the thrust ring is held, and stable rotation support is realized.

[0015]

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. 1 to 3.

FIG. 1 shows the structure of the motor portion of the fan motor. The bracket 1 made of resin is configured by integrally molding a shallow dish-shaped support portion 2 having an upper opening and a bottomed cylindrical bearing holder 3 projecting upward in the central portion.

A stator 4 is fixed to the outer periphery of the central portion of the cylindrical portion 3a of the bearing holder 3. The stator 4 includes a stator core 5 formed by laminating a plurality of laminations, and a pair of insulators 6 and 7 mounted from above and below, and a coil 8 wound around the insulator. Then, the stator 4 is externally fitted to the cylindrical portion 3a, and the upper insulator 6
The annular projection 9 provided on the above is fitted into the annular groove 10 of the cylindrical portion 3a to prevent the annular projection 9 from coming off.

The circuit board 12 arranged directly above the supporting portion 2 of the housing 2 is supported by the stator 4 by fitting a cylindrical portion 11 provided on the inner peripheral side of the lower insulator 7 into a central hole thereof. The barb pins 13 of the coil 8 led out from the insulator 7 are soldered to the circuit board 12.

A thrust receiving member 14 in the form of a short cylinder is embedded in the central upper portion of the bottom plate portion 3b 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 on the upper surface of the thrust receiving member 14. ing.

The sleeve bearing 15 has a long outer peripheral layer 15a fixed to the inner peripheral surface of the cylindrical portion 3a by press fitting or the like, and a long outer peripheral layer 15a which emphasizes oil impregnation and wear resistance emphasized on the inner periphery of both ends of the outer peripheral layer 15a. It is composed of two short inner peripheral layers 15b, and the cap 18 fitted to the upper end of the cylindrical portion 3a prevents the sleeve bearing 15 from coming off and prevents oil from leaking.

An annular thrust ring 19 made of heat-resistant resin is arranged 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 portion of the inner circumference of the cylindrical portion 3a, and the thrust ring 19 is inserted into the cylindrical portion 3a for positioning the step portion 20, and the sleeve bearing 15 is The thrust ring 19 is pressed into the cylindrical portion 3a, and the step portion 20
The thrust ring 19 is sandwiched and fixed by the sleeve bearing 15 and the sleeve bearing 15. The lower surface of the thrust ring 19 is formed as a mirror surface.

An annular washer 21 is provided on the outer periphery of the lower portion of the shaft 16 so as to be rotatable and slidable in the axial direction. The washer 21 is made of stainless steel or the like, and the upper surface of the washer 21 is mirror-finished.
A pair of outer circumferential grooves 22 are formed on the lower surface of the sheet at intervals of 180 degrees.

The washer 21 is supported integrally with the shaft 16 in the rotational direction by a leaf spring structure 23, which is an elastic body, and is elastically biased upward so that the washer 21 elastically contacts the thrust ring 19.

That is, as shown in FIGS. 2 and 3, the leaf spring structure 23 has a substantially frustoconical mounting ring 23a and a tapered surface formed at two positions of this mounting ring 23a at every 180 degrees. It is composed of a locking portion 23b and a pair of leaf spring pieces 23c extending outward from the locking portion 23b. Then, the mounting ring 23a is inserted into the shaft 16 from below, both the locking portions 23b are respectively locked in the pair of cutout grooves 24 formed on the peripheral surface of the lower end portion of the shaft 16, and are inserted into the shaft 16. By inserting and engaging the pair of leaf spring pieces 23c into the groove 22 of the washer 21 from below, the washer 21 is supported on the shaft 16 so as to be rotatable in one body in the thrust direction and slidable in the thrust direction.

The shaft 16 supporting the washer 21 and the leaf spring structure 23 in this way is inserted into the cylindrical portion 3a of the bearing holder 3, and then the thrust receiving member 1 is inserted.
9 and the sleeve bearing 15 are fixed in the cylindrical portion 3a. At this time, when fixing the thrust receiving member 19 between the step portion 20 and the sleeve bearing 15, both leaf spring pieces 23c are bent through the washer 21, and the elastic return force of the both leaf spring pieces 23c causes the washer 21 to move. The mirror surface (upper surface) of is elastically contacted with the mirror surface (lower surface) of the thrust receiving member 19.

A bowl-shaped rotor frame 26 of a fan impeller 25 is attached to the base of the shaft 16. The base portion of the shaft 16 includes a mounting shaft portion 27 that is inserted into the center hole of the rotor frame and a screw portion 28 that is formed with a male screw.
Are provided so that the diameter becomes smaller in order, and the mounting shaft portion 27 is inserted into the rotor frame 26 until it abuts against the step portion on the tip end side thereof, and the concave groove 29 on the upper surface of the rotor frame 26 is inserted.
The impeller 25 is attached to the shaft 16 by screwing the nut 30 into the threaded portion 28 that has been drawn out.
The screw portion 28 and the nut 30 are housed in the groove 29.

On the inner peripheral surface of the cylindrical portion of the rotor frame 26,
An annular rotor magnet 32 is attached via a yoke 31. The rotor magnet 32 faces the outer peripheral surface of the stator 4 with a slight gap, and
And the magnetic center of the rotor magnet 32 substantially coincide with each other.

In the bearing structure having such a structure,
The shaft 16 supported in the bearing holder 3 is supported in the radial direction by the sleeve bearing 15, while the tip portion 17 of the shaft 16 abuts on the thrust receiving member 14 fixed to the bottom plate portion 3b of the bearing holder 3. The shaft 16 is supported in one direction of the thrust direction, and the washer 21 supported by the lower portion of the shaft 16 integrally in the rotational direction so as to be slidable in the axial direction elastically contacts the thrust ring 19 supported in the cylindrical portion 3a. Thus, the shaft 16 is supported in the other thrust direction.

Therefore, the shaft 16 can be reliably supported in all directions only inside the bearing holder 3. Therefore, unlike the conventional case, it is not necessary to shift the mutual magnetic centers of the stator 5 and the rotor magnet 32 to obtain the thrust force, and the mutual magnetic centers of the two are made to coincide with each other to efficiently rotate the rotor (impeller 25). Can be obtained.

Moreover, since the washer 21 and the thrust ring 19 which rotate together with the shaft 16 are supported by bringing their respective 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 to make elastic contact with the thrust ring 19, uniform contact can be obtained, and the shaft 16
Even if a swaying force is applied to the slab, the swaying force can be absorbed by the spring force, and the stable rotation can be obtained without the occurrence of vibration that causes noise.

In particular, if the screw frame 28 is formed on the base of the shaft 16 and the rotor frame 26 is attached to the rotor frame 26 as in the embodiment, it is not necessary to integrate the shaft 16 into the rotor frame 26 by insert molding or the like. In addition, there is an advantage that the assembly is simple, and replacement of only the impeller 25 is easy.

Next, a second embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals as those used above denote the same or corresponding ones.

In the structure shown in this embodiment, the bottomed cylindrical bearing housing 3 is independently constituted, and the shaft 16 is rotatably supported in the bearing holder 3 by the sleeve bearing 15 in the radial direction. The hemispherical end portion 17 of the shaft 16 is brought into contact with the thrust receiving member 14 fixed to the bottom plate portion 3b of the holder 3 to support the shaft 16 in one direction of thrust,
Further, a washer 21 which is slidable in the axial direction integrally with the lower portion of the shaft 16 in the rotational direction is elastically contacted by the leaf spring structure 23 to the thrust ring 19 supported in the cylindrical portion 3a to move the shaft 16 in the thrust direction. It is designed to be supported in the other direction.

According to this construction, the bearing structure can be unitized, and by appropriately incorporating it into the motor housing or the like, the impeller can be supported and the like as in the case of the first embodiment. There is an advantage that the bearing structure can be formed independently. The bearing structure can be incorporated into the housing or the like by press fitting, welding, bonding, or the like.

Further, the bearing structure can be used not only for supporting the rotor of the motor but also for supporting other rotating bodies.

The specific examples of the bearing structure according to the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and corrections can be made without departing from the scope of the present invention. is there.

[0037]

Since the present invention is constructed as described above, it has the following effects. 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. At the same time, a washer slidable in the axial direction at the lower part of the shaft can be elastically contacted to the thrust ring supported in the cylindrical part by an elastic body to support the shaft in the other direction of the thrust direction, only inside the bearing holder. It is possible to reliably support the shaft in all directions.

Therefore, when it is applied to a fan motor or the like, it is not necessary to shift the mutual magnetic centers of the stator and the rotor magnet to obtain the thrust force as in the conventional case, and the mutual magnetic centers of both are made to coincide with each other. It is possible to obtain efficient rotation of the rotor.

Moreover, since the washer and the thrust ring which rotate together with the shaft are supported by bringing their respective mirror surfaces into contact with each other, there is no loss due to friction or the like, smooth rotation can be obtained, and the washer is pressed by the elastic body. Since it makes elastic contact with the thrust ring, a uniform surface contact is obtained,
Even if a deflection force acts on the shaft, this can be absorbed by the elastic force of the elastic body, and vibration that causes noise is not generated,
Stable rotation can be obtained.

If a threaded portion is formed on the base of the shaft, for example, when attaching the rotor of the motor to the shaft,
Not only the labor for integrating the shaft into the rotor by insert molding or the like can be saved, but there is an advantage that the assembly is simple, and replacement of only the rotor becomes easy.

Further, if the bearing holder is attached to the motor housing, the bearing structure can be made into a unit and can be formed separately, which not only facilitates the production but also makes it a part. You can also

[Brief description of 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.

FIG. 2 is an exploded perspective view of the shaft, washer, and leaf spring structure of FIG.

FIG. 3 shows the leaf spring structure of FIG. 1, (A) is a bottom view,
(B) is a side view.

FIG. 4 is a 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)

[Claims] 1. A cylindrical bearing holder with a lid, a sleeve bearing fixed inside a cylindrical portion of the bearing holder, a shaft rotatably supported by the sleeve bearing, and a bottom surface of the bearing holder. A thrust receiving member with which the end surface of the shaft abuts, an annular washer supported at the end portion of the shaft so as to be slidable in the axial direction with respect to the shaft, and a lower surface of the sleeve bearing fixed inside the cylindrical portion. A thrust ring disposed opposite to the upper surface of the washer, and an elastic body that is supported by the shaft and that applies an elastic force to elastically contact the washer with the thrust ring, the washer and the thrust ring A bearing structure, wherein the mutual abutting surfaces of the respective are formed into mirror surfaces. 2. The bearing structure according to claim 1, wherein the bearing holder is formed of a cylindrical body integrally formed with a motor housing. 3. The bearing structure according to claim 1, wherein the bearing holder is fixed by press-fitting, welding, or adhering to a mounting hole provided in a housing of the motor. 4. The bearing structure according to claim 1, wherein a screw for fixing a rotor of the motor is formed on a base portion of the shaft. 5. The sleeve bearing comprises a long outer peripheral layer fixed to the inner peripheral surface of the cylindrical portion of the bearing holder and emphasizing oil impermeability, and short outer wear layers positioned on inner periphery of both ends of the outer peripheral layer. The bearing structure according to claim 1, wherein the bearing structure is composed of two sized inner peripheral layers. 6. The elastic body includes a mounting ring and a plurality of leaf spring pieces extending from the mounting ring and arranged at equal intervals, and a part of the mounting ring is provided on an end peripheral surface of the shaft. A notch for locking the elastic body integrally with the shaft in the rotational direction is formed, and a plurality of engaging holes for engaging the leaf spring pieces are formed at equal intervals on the lower surface of the washer. The bearing structure according to claim 1, wherein 7. A step portion having a small diameter on the bottom side is formed on an inner peripheral surface of the bearing holder near the bottom portion, and the washer is held between the step portion and the sleeve bearing. The bearing structure described.