JP2008291755A - Motor fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize a motor fan more effectively suppressing external impact to a bearing. <P>SOLUTION: The present motor fan includes a motor having a housing, an impeller disposed within the housing, a rotor integrated with the impeller, a pair of ball bearings movably fitted on a bearing box to pivotally support the rotor, and a stator opposed to the inner circumferential surface of the rotor with a small gap interposed therebetween. The pair of ball bearings are fitted between opposed outer rim end surfaces via a spacer of an elastic member made of rubber or an elastomer molding formed to generate incremental repulsive force by compressing clearance therebetween. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an improvement for suppressing external impact on a ball bearing that pivotally supports a rotating portion with a motor fan.

JP 2000-192893 A

In a motor fan provided as a cooling means for an electronic device or the like according to the present invention, an external impact on a ball bearing that pivotally supports a rotating body during operation affects the life of the product. Although various improvement means have been proposed and put into practical use, it can be said that the actual situation is that they have not been able to meet the demands for ensuring reliability such as a long service life without stopping.

FIG. 5 shows an example of a well-known configuration of the centrifugal fan 1. As a means for suppressing external impact on the bearing during actual operation, many proposals have been made to adopt a buffer member related to the bearing holding structure, and details of an example are cited above. Although omitted as being based on the publication of the patent document, a configuration in which a buffer member is interposed on the outer peripheral surface of the outer ring of the ball bearing 7 is also put into practical use because of its cost advantage with a simple configuration.

The motor fan according to the prior art as described above has room for improvement as a measure for suppressing external impact, and its realization is a problem.

The motor fan 1 according to the present invention includes a casing 2 that forms a ventilation path 2-2, a rotatable impeller 3 that is disposed inside the casing 2, and a rotor that is integral with the impeller 3. 6, a pair of ball bearings 7 that are movably fitted to the bearing box 2-1 of the housing 2 and pivotally support the rotor 6, and a small gap on the inner peripheral surface of the rotor 6. An electric motor 4 having a stator 5 which is opposed and fixedly held on the outer peripheral surface of the bearing housing 2-1 is provided, so that one end face of the outer ring of both the pair of ball bearings is in contact with a spacer made of an elastic member. Fitted and also

The spacer 8 is formed so as to have an inclined surface in which the inner diameter side of the opposite end surfaces of the pair of ball bearings 7 is concave and the outer diameter side is convex, and the compression amount by compression by reducing the separation distance of the pair of ball bearings 7 Formed to obtain an incremental repulsive force against

An inner peripheral surface of the bearing housing is provided with an inner diameter cylinder contact surface 8-3 facing the inner ring end surfaces of both of the pair of ball bearings, and the inner diameter cylinder contact surface is a ball bearing in a normal state in which the spacer is inserted. Formed to face the inner ring end face with a gap, or

The spacer is divided into two, and the divided spacer is interposed between the outer ring end surface of each of the pair of ball bearings and the large-diameter end surface that communicates with the inner diameter cylinder contact surfaces on both sides and faces the outer ring end surfaces. Formed to be inserted, preferably

The spacer 8 is formed by rubber or elastomer molding.

The motor fan according to the present invention has excellent resistance to external impacts, and is extremely effective for extending the life and ensuring reliability.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of an example of a centrifugal fan according to the present invention.

In the present invention technology, the pair of ball bearings 7 that pivotally support the rotor 6 can be moved in the axial direction by loosely fitting the inner peripheral surface of the bearing housing 2-1 and the rotor shaft 6-2. A sleeve 8 made of an elastic member having flexibility is interposed between the pair of ball bearings 7 so as to be in contact with the side surfaces of the respective outer rings.

The above-mentioned sleeve 8 is formed by, for example, rubber or other elastomer, and is for mitigating the impact due to external force to the pair of ball bearings 7 that are loosely fitted and are movably in contact with both sides.

FIG. 2 is a partially enlarged view of an example of the spacer 8. By forming both end faces so as to have a conical shape 8-1, the applied impact is efficiently suppressed as the spacer 8 molded from a uniform material. Therefore, when a load impact is applied, the repulsive force is devised so as to gradually increase by compressing the distance between the pair of ball bearings 7.

FIG. 3 shows another example of the technology of the present invention, in which the spacer 8-2 is divided into two parts, and an inner peripheral surface 8-3 facing the ball bearing inner ring end surface is formed on the inner peripheral surface of the bearing box. In this example, the divided spacers 8-2 are in contact with and attached to both the outer end surfaces communicating with the barrel contact surface.

FIG. 4 is a partially enlarged view of the spacer 8-2 in the example of FIG. 3 described above. In the inner peripheral surface intermediate portion of the bearing box, an inner diameter cylinder contact surface 8- facing the inner ring end surfaces of both of the pair of ball bearings. 3 shows an example in which the inner diameter cylinder contact surface is formed so as to be opposed to the ball bearing inner ring end surface with a gap in a normal state in which the spacer is inserted.

In addition, the inner diameter cylinder contact | abutting formation part of the said bearing housing inner peripheral surface is not limited to being integrally formed in a bearing housing, but can also be provided as an independent member which comprises another body.

The above description is an example of a centrifugal fan, but is not limited to a centrifugal fan, and can also be applied to an axial fan.

The motor fan according to the present invention can enhance the effect of mitigating external impact on the bearing, which is most related to the life of the motor fan, and leads to expanded applications with improved reliability.

2 is a schematic sectional view of an example of a centrifugal fan according to the present invention. FIG. 2 is an enlarged schematic diagram illustrating a spacer and a ball bearing contact portion in the example of FIG. 1. 4 is a schematic sectional view of another example of a centrifugal fan according to the present invention. FIG. 4 is an enlarged schematic diagram illustrating a spacer and a ball bearing contact portion in the example of FIG. 3. 1 is a schematic sectional view of an example of a centrifugal fan according to the prior art.

Explanation of symbols

1 Centrifugal fan (example of motor fan)
2 Housing 2-1 Bearing box 2-2 Ventilation path 3 Impeller 4 Electric motor 5 Stator 6 Rotor 6-1 Rotor hub 6-2 Rotor shaft 7 Ball bearing 8 Spacer 8-1 Conical inclined end face 8 -2 Divided spacers 8-3 Inner diameter cylinder contact surface 9 Pressurized spring
10 Lead wire

Claims (5)

A housing that forms a ventilation path, a rotatable impeller disposed inside the housing, a rotor having a permanent magnet that is integral with the impeller and holding the permanent magnet, and a rotor; A pair of ball bearings, which are movably fitted in a bearing box integral with the housing and pivotally support the rotor, are opposed to the inner peripheral surface of the rotor via a small gap, and the outer periphery of the bearing box In a motor fan including an electric motor having a stator fixedly held on a surface,
The motor fan according to claim 1, wherein one end face of the outer ring facing the pair of ball bearings is in contact with a spacer made of an elastic member. The spacer is formed so as to have an inclined surface in which the inner diameter side of the end surfaces facing the pair of ball bearings is concave and the outer diameter side is convex, and by gradually compressing the distance between the pair of ball bearings, the spacer is gradually increased. The motor fan according to claim 1, wherein the motor fan is formed so as to obtain a repulsive force. An inner diameter cylinder contact surface facing the inner ring end faces of both of the pair of ball bearings is provided at an intermediate portion of the inner peripheral surface of the bearing housing, and the inner diameter cylinder contact surface is in a normal state where the spacer is inserted, 3. The motor fan according to claim 1, wherein the motor fan is formed to face each other with a gap. The spacer is divided into two parts, and the divided spacers are interposed between the outer ring end surfaces of each of the pair of ball bearings and the large-diameter end surfaces that communicate with the inner diameter cylinder contact surfaces on both sides and face the respective outer ring end surfaces. The motor fan according to any one of claims 1 to 3, wherein the motor fan is inserted. The motor fan according to any one of claims 1 to 4, wherein the spacer is formed by molding with rubber or elastomer.

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