JP2005291050A - Centrifugal fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the temperature rise of a bearing which affects a service life. <P>SOLUTION: This centrifugal fan has a snail-like casing, a rotating machine mounted in the snail-like casing, and a rotor hub fixedly held to a rotating shaft to hold a rotor of the rotating machine and a multiblade impeller rotatably. The rotor hub is formed of a good heat conductor such as metal, and a bearing box for fitting a bearing to which the rotating shaft is journaled, is preferably formed of a difficult heat conductor such as resin and formed by molding integrally with the snail-like casing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a temperature rise suppression means for a bearing related to the life of a centrifugal fan.

Japanese Unexamined Patent Publication No. 07-046811

  In the centrifugal fan and the like according to the present invention, the need for improving performance and extending the life is not alleviated even as the miniaturization progresses, and the brushless DC motor that is frequently used as a power source for these is also equipped with a drive circuit. Therefore, as seen in the above-mentioned prior application, it is indispensable to consider the heat dissipation of the electronic components that make up the drive circuit, and the bearing temperature rise directly related to the life As is well known, suppression is also an important issue.

  FIG. 3 is an example of the above-described conventional configuration, and the rotor hub 2-1 is usually formed by resin molding integrally with the impeller. Moreover, the bearing box which is hold | maintained at the center part of the casing 1, and has fitted the circuit board which forms a stator and a drive circuit in the outer peripheral surface is normally formed with the metal member.

  FIG. 4 shows another known example, which shows a rotor hub integrated with a rotor yoke formed of a metal member. Since the rotor hub formed of metal is exposed to ventilation, Although the heat dissipation is promoted, the shape of the head of the rotor hub is damaged, and smooth ventilation is not performed, so that the cooling effect is not sufficient.

  The conventional configuration as described above is effective as a high temperature avoidance measure on the heat radiation surface of the electronic component directly related to performance and operation, but the stator held on the outer peripheral surface is connected to the winding for driving. Heat generated by energization is directly fitted to the inner peripheral surface, leading to a rise in the temperature of the bearing related to the life, and improvement has been left as a problem in terms of influence on the life.

The centrifugal fan according to the present invention has a suction port that opens in the axial direction and a discharge port that opens in the circumferential direction, and the cochlea has a shape in which the annular inner peripheral surface sequentially expands from the upstream side toward the downstream side. And a rotor mounted in the cochlear casing, and a rotor hub fixedly held on a rotating shaft and rotatably holding a rotor of the rotating machine and a multiblade impeller. The hub has a cross-section arc-shaped head and is formed of a good heat conductor such as metal. Preferably, a bearing box on which a bearing member that supports the rotating shaft is fitted is integrally formed with the cochlear casing. Is formed.

  The centrifugal fan according to the present invention increases heat dissipation due to ventilation associated with the operation of the fan, reduces the temperature rise of the bearing, and achieves a long life. If the bearing box is formed of a heat-resistant conductor such as a resin, it is possible to achieve a longer life by suppressing heat propagation from the stator side. Further, by forming the bearing box with a heat-resistant electric member such as a resin, heat propagation from the stator side can be suppressed, and a longer life can be realized.

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

  FIG. 1 is a half cross-sectional view showing a first embodiment, in which the leading portion of the rotor hub 2-1 has a large arc shape and is formed of a metal member or the like having excellent thermal conductivity, and has an arc-shaped surface. The heat generated in the rotor hub 2-1 and the heat dissipation of the bearing 5 are increased by the airflow flowing through the

  By integrally forming the bearing box (1-1) with a resin as a heat-resistant conductive member integrally with the casing 1 formed by resin molding, it depends on the stator 3 and the drive circuit of the rotating machine fixed to the outer peripheral surface. Heat generation is made difficult to propagate to the bearing 5 fitted on the inner peripheral surface.

  FIG. 2 is a half sectional view for explaining the second embodiment. The bearing box 1-1 is made of a metallic good heat conductor. As in the first embodiment, the rotor hub 2-1 has a large arc at the top, is formed of a metal member having excellent thermal conductivity, and the rotor hub is ventilated by air flowing through the arc-shaped surface. It is the structure which raises the dissipation of the heat which generate | occur | produces in the inside of 2-1, and the heat which generate | occur | produces from the stator 3 via the bearing box 1-1 and the bearing 5. FIG.

  This configuration is effective for extending the life of the entire product, although the thermal influence on the bearing 5 is retreated compared to FIG.

  The centrifugal fan according to the present invention can be widely used to realize a long life which is important among many needs.

It is a half sectional view explaining the 1st example concerning the present invention. It is a half sectional view explaining the 2nd example concerning the present invention. It is a half sectional view explaining the example of a prior art. It is a half sectional view explaining another example of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 1-1 Bearing box (1-1) Bearing box integral with casing 2 Multi-blade impeller 2-1 Rotor hub 2-1 'Metallic rotor hub in the prior art 3 Stator 3-1 Winding 4 Rotor shaft 5 Bearing 6 Inflow ventilation

Claims (2)

A cochlear casing having a suction port that opens in the axial direction and a discharge port that opens in the circumferential direction, and an annular inner peripheral surface that sequentially expands from the upstream side toward the downstream side, and the cochlear casing A centrifugal fan comprising: a rotary machine installed in a rotary shaft; and a rotor hub fixedly held on a rotary shaft and rotatably holding a rotor of the rotary machine and a multiblade impeller. A centrifugal fan having an arcuate head and formed of a good heat conductor such as metal. 2. The centrifugal fan according to claim 1, wherein in the centrifugal fan, a bearing box into which a bearing member on which a rotating shaft is pivotally supported is integrally formed with a cochlear casing.