JP2008267238A - Centrifugal fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To implement a more effective cooling means responding to increase in the amount of heat generated by a motor and its control circuit accompanying size reduction or enhanced performance of a centrifugal fan. <P>SOLUTION: The centrifugal fan has a casing, a multiblade impeller, and the motor and its control circuit disposed in a rotor boss holding the multiblade impeller. A ventilation hole is formed to a cylinder part near a top surface of the rotor boss, and another ventilation hole is formed to a circuit board or a portion near a circuit board opposed part of the casing, and ribs communicating to peripheries of respective ventilation holes are formed to an inner surface of the rotor boss. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a centrifugal fan, and more particularly to a centrifugal fan that requires consideration for a temperature increase of a motor itself including a control circuit.

JP 2001-132698 A) Japanese Patent Laid-Open No. 2005-073378)

As for the above-mentioned publicly known documents, details are omitted as referring to the respective publications, but as a means for enhancing the heat dissipation effect in the heat generation countermeasures of the motor and its control circuit that rely on miniaturization and high performance in the centrifugal fan, This is a proposal to increase the ventilation to the rotor boss and the motor built in the casing and the control circuit arranged in the vicinity, and realizes the corresponding effects respectively.

  In either case, a ventilation hole is formed in a rotor boss or a casing that blocks outside air in order to increase ventilation to the motor and its control circuit.

The problem to be solved by the centrifugal fan according to the prior art as described above is the realization of a more effective cooling means corresponding to the increase in the heat generation amount of the motor and its control circuit accompanying the downsizing and high performance. is there.

A centrifugal fan according to the present invention includes a casing, a multi-blade impeller that is rotatably mounted in the casing, a motor that is disposed inside a rotor boss that holds the multi-blade impeller, and a control circuit. In the cylindrical portion close to the top surface of the rotor boss, a vent hole is provided,

The circuit board constituting the control circuit inside the rotor boss or the casing facing the circuit board is also provided with a vent hole.

The centrifugal fan according to the present invention can effectively forcibly air-cool the motor and the control circuit in response to an increase in the amount of heat generated by the motor and its control circuit with downsizing and high performance.

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

FIG. 1 shows an example in which a ventilation hole is formed in a cylindrical portion near the top surface of a rotor boss as a first embodiment. In a centrifugal fan, a suction port on a side surface of a casing is generated by pressure generated by rotation of a multiblade impeller. The air flow toward the discharge port on the outer peripheral surface is generated, but at that time, the vent hole formed near the top surface in the rotor boss cylindrical portion facing the inner peripheral surface of the multiblade impeller is closed. It will function to suck out the air at a high temperature around the motor and the control circuit, which are also installed in the space.

In other words, it is possible to more effectively discharge high-temperature air to the outside due to heat generated by the motor and control circuit inside the rotor boss in a form that overlaps with the flow of external air flowing in from the suction port. Is.

2 predicts that the heat generation amount is high in order to make the exhaust cooling function of the air vent formed near the top surface of the rotor boss cylindrical portion in the first example shown in FIG. 1 more effective. The example which added the 2nd ventilation hole to the circuit board for improving the air permeability of the electronic component vicinity of the control circuit to be shown is shown.

In this example, in addition to the effect of the first example shown in FIG. 1 described above, an air flow is generated by another second ventilation hole formed in the circuit board. The cooling effect by ventilation around the motor to be increased.

FIG. 3 shows a high calorific value as another means for effectively using the exhaust cooling function of the air vent formed in the vicinity of the top surface of the rotor boss cylindrical portion in the first example shown in FIG. In order to improve the air permeability in the vicinity of the electronic component of the control circuit, which is predicted, an example in which a third air hole is added to the casing facing the circuit board is shown.

In this example, as a means to be added to or replaced with the second example described above, the ventilation cooling effect on the electronic component which is a heating element or the adjacent motor side due to the inflow of outside air from the ventilation hole of the casing facing the circuit board is enhanced. become.

Further, although not shown in the drawings, as a means for enhancing the exhaust effect from the vent hole formed in the vicinity of the top surface of the rotor boss cylindrical portion, the inner surface of the cylinder portion from the axial center side is provided inside the top surface portion of the rotor boss. It is also effective to form a vent path for heated air by attaching a rib that extends toward the vent and communicates with the vent hole.

The centrifugal fan according to the present invention can realize application expansion corresponding to an increase in the heat generation amount of the motor and the control circuit due to further downsizing and higher performance by effective cooling means.

It is a half sectional view of the 1st example of the centrifugal fan concerning the present invention. It is a half sectional view of the 2nd example of the centrifugal fan concerning the present invention. It is a half sectional view of the 3rd example of the centrifugal fan concerning the present invention. It is a half cross-sectional view of an example of a centrifugal fan according to the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Centrifugal fan 2 Casing 2-1 Third vent hole (perforated in casing) 3 Multi-blade impeller 4 Rotor boss 4-1 (perforated in rotor boss cylindrical portion) Vent 4-2 Ventilation holes (perforated in the top of the rotor boss)
DESCRIPTION OF SYMBOLS 5 Motor 6 Control circuit 7 Circuit board 7-1 2nd ventilation hole (perforated in a circuit board) 8 (Heat generation) Electronic component F State of ventilation

Claims (4)

A casing having a cochlea shape, a rotatable multi-blade impeller having a main wing planted in an annular hub that is integrated with the cup-shaped rotor boss, and is disposed in the rotor boss; In a centrifugal fan having a motor for driving the multi-blade impeller disposed, and a control circuit provided integrally with the motor for controlling the rotation of the motor.
A centrifugal fan, wherein a ventilation hole is provided in a cylindrical portion near the top surface of the rotor boss. The centrifugal fan according to claim 1, wherein a vent hole is also provided in a circuit board constituting a control circuit inside the rotor boss. The centrifugal fan according to claim 1 or 2, wherein a ventilation hole is also provided in a casing facing a circuit board constituting a control circuit inside the rotor boss. 2. The rib provided on the inner surface of the rotor boss extends from the axial center side toward the inner surface of the cylindrical portion and communicates with a peripheral portion of the air hole near the top surface of the cylindrical portion. 4. The centrifugal fan according to any one of 3 above.

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