Electric fan

• US 8,581,453 B2
• Filed: 03/03/2010
• Issued: 11/12/2013
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Sanyo Denki Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Denki Company Limited (Panasonic Holdings Corporation)
• Inventors: Wada, Yoshihiro, Watanabe, Michinori
• Primary Examiner(s): Kim, John K
• Application Number:
  US12/716,554
• Publication Number:
  US 20100225182A1
• Time in Patent Office: 1,350 Days
• Field of Search: 310/43, 310/51, 310/90
• US Class Current: 310/51
• CPC Class Codes: H02K 5/24 specially adapted for suppression or reduction of noise or vibrations
• CPC Class Codes: H02K 9/04 having means for generating a flow of cooling medium
• CPC Class Codes: H02K 9/06 with fans or impellers driven by the machine shaft

Abstract

A fan casing, webs, and a motor casing are integrally formed of a resin material by injection molding to configure a fan housing. An electrically grounded electromagnetic noise guard and a bearing holder to which an outer race of a ball bearing are electrically connected by an electrically-conducting path member provided in the fan casing by means of insert molding. Thus, the ball bearing may sufficiently be prevented from suffering electric corrosion in an electric fan of which a fan housing is made of an insulating resin.

Claims

1. An electric fan comprising:

a fan housing made of an insulating resin and including an air channel having a suction port and a discharge port;

a bearing holder fixed to the fan housing;

at least one ball bearing that is made of a metal and is held by the bearing holder;

a motor including a stator and a rotary shaft made of a metal and supported by the at least one ball bearing;

an impeller fixed on the rotary shaft to rotate in the air channel; and

an electromagnetic noise guard made of a metal and disposed over the suction port or the discharge port of the air channel and electrically grounded, wherein

the bearing holder is made of a metal; and

,

the electromagnetic noise guard and the outer race of the at least one ball bearing are electrically connected by an electrically connecting means including an electrically-conducting path member that is insert molded into fan housing and connected to the bearing holder and the electromagnetic noise guard so as to be capable of electrical conduction.

2. The electric fan according to claim 1, wherein

the fan housing comprises a fan casing including the air channel, a motor casing which is provided with the bearing holder and to which the stator of the motor is fixed, and a plurality of webs connecting the fan casing and the motor casing;

and

the fan casing, the webs, and the motor casing are integrally formed of the insulating resin by means of injection molding to configure the fan housing.

3. The electric fan according to claim 1, wherein

the outer race of the at least one ball bearing is fitted in the bearing holder, an inner race of the at least one ball bearing is fitted with the rotary shaft of the motor, and a plurality of rolling elements are disposed between the inner race and the outer race via a lubricant.

4. The electric fan according to claim 1, wherein

the bearing holder is made of a metal;

and

the electromagnetic noise guard and the outer race of the at least one ball bearing are electrically connected by an electrically connecting means including an electrically-conducting path member that is disposed along an outer surface of the fan housing and connected to the bearing holder and the electromagnetic noise guard so as to be capable of electrical conduction.

5. The electric fan according to claim 1, wherein

the electromagnetic noise guard includes at least one closed loop conductor made of a metal and opposed to the suction port or the discharge port;

and

a conductor holding means for holding the closed loop conductor.

6. The electric fan according to claim 2, wherein

the electromagnetic noise guard includes at least one closed loop conductor made of a metal and opposed to the suction port or the discharge port;

and

a conductor holding means for holding the closed loop conductor.

7. The electric fan according to claim 3, wherein

the electromagnetic noise guard includes at least one closed loop conductor made of a metal and opposed to the suction port or the discharge port;

and

a conductor holding means for holding the closed loop conductor.

8. The electric fan according to claim 4, wherein

the electromagnetic noise guard includes at least one closed loop conductor made of a metal and opposed to the suction port or the discharge port;

and

a conductor holding means for holding the closed loop conductor.