JP2015132262A - electric fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric fan made to overcome drawbacks of the prior art.SOLUTION: An electric fan for cooling a heat exchanger of a motor vehicle has an electric motor (5) including a rotor (8) and a stator (6), and an axial impeller (4) including a central hub (9) from which a plurality of blades (10) extends. The hub is connected to the rotor (8) of the motor (5) at a number of connecting points (12). At each connecting point (12), the hub (9) of the impeller (4) is connected to the rotor (8) of the electric motor (5) by means of an individual connecting device (13) including a resilient vibration damper (14).

Description

  The present invention relates to an electric fan, and more particularly to a cooling fan for a heat exchanger of an automobile.

  More particularly, the present invention includes an electric motor having a rotor and a stator and a central hub from which a plurality of blades extend, the hub of the motor being at one or more connection points or regions. An electric fan of the type provided with an axial impeller coupled to the motor is provided.

  The electric motor of this type of electric fan generates considerable vibrations when it is activated, which is transmitted to the impeller and generates a slight annoying acoustic noise, especially at low speeds.

  Therefore, an electric fan of this kind is desired which is designed to overcome the above-mentioned drawbacks of prior art electric fans.

  According to the present invention, this is the above-described mold wherein the impeller hub is connected to the rotor of the electric motor by a respective connecting device having an elastic vibration damper at each of the one or more connecting points or connecting regions. This is achieved with an electric fan.

  Accordingly, the present invention, in one aspect thereof, includes an electric motor having a rotor and a stator and a central hub from which a plurality of blades extend, the hub being at one or more connection points or regions. An electric fan for an automotive heat exchanger, comprising an axial impeller coupled to a rotor of the vehicle, wherein each coupling having an elastic vibration damper at the one or more coupling points or coupling areas A device connects the impeller hub to the rotor of the electric motor.

  The impeller hub has a generally bowl-like shape having an end wall coupled to at least a substantially cylindrical annular side wall, and the rotor of the electric motor is located in the interior of the impeller hub near the end wall of the hub. It is preferable that the upper end surface is connected to the hub by the plurality of connecting devices each having an upper end surface (crown) extending in the direction and each having an elastic vibration damper.

  Each of the one or more coupling devices includes an annular damping member made of an elastic material, and the damping member is disposed in the through-opening portion of the hub, and a fastening member that fastens the hub to the rotor of the motor. It is preferable to penetrate.

  The elastic material is preferably an elastomer material.

  It is preferable that a substantially rigid tubular element is interposed between each damping member and the corresponding fastening member.

  The tubular element is preferably made of a metallic material.

  The fastening member is a screw or a bolt having an end head, and the rigid tubular element is formed at one end between a corresponding head of the screw or bolt and the damping member. It is preferable to have.

  One or each of the elastic vibration dampers preferably has a cylindrical ring shape and has an outer peripheral groove that engages with an edge of the through opening of the hub of the impeller.

1 is a perspective front view of an electric cooling fan according to the present invention. In particular, FIG. 2 is an enlarged partial perspective view showing a hub of the impeller of FIG. 1. FIG. 3 is a partial cross-sectional view taken along line III-III in FIG. 2.

  Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawing figures. In the figures, identical structures, elements or components that appear in more than one figure are generally labeled with the same reference number in all the figures in which they appear. The dimensions of the components and structures shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily to scale.

  In each figure, the whole electric fan according to the present invention is denoted by reference numeral 1. As is well known, the electric fan 1 includes a substantially plate-like support structure or cowl 2 having a circular main opening 3 to which an impeller (indicated by 4 as a whole) is rotatably attached. The impeller 4 is connected to the rotor 8 of the electric motor. Although this electric motor is not visible in FIGS. 1 and 2, a part of this electric motor is shown in FIG.

  The electric motor 5 includes a stator 6 fixed to the support structure or the cowl 2 by a plurality of spokes 7 in a known manner, for example, as shown in FIG. The electric motor 5 also includes a rotor 8 having an axial end surface or upper end surface.

  The impeller 4 includes a central hub 9 from which a plurality of curved blades 10 extend, and the outermost end of the blade 10 is coupled to the outer ring 11 (FIG. 1). The hub 9 of the impeller 4 is connected to the rotor 8 of the electric motor 5 at one or more connection points or connection areas.

  In the embodiment illustrated in each figure, the hub 9 is above the rotor 8 of the motor 5 at three connection points or connection areas (denoted 12) arranged at the same distance d from the impeller axis XX. Connected to the end face (FIG. 3).

  In the illustrated embodiment, the hub 9 of the impeller 4 is generally bowl-shaped with an end wall 9a connected to at least a generally cylindrical annular side wall 9b. The upper end surface of the rotor 8 of the electric motor 5 extends inside the hub 9 in the vicinity of the end wall 9a of the hub 9, and has an elastic vibration damper 13 at each of the three connection points or connection regions 12. The upper end surface is connected to the hub 9 by a more detailed description below.

  With particular reference to FIG. 3, each coupling device 13 comprises an annular damping member 14 made of an elastic material, preferably an elastomeric material (vulcanized rubber). The damping member 14 is disposed in the through opening 9c of the end wall 9a of the hub 9 of the impeller. The damping member 14 has an essentially cylindrical ring shape, and has an outer peripheral groove 14a that engages with an end edge of the through opening 9c of the hub 9 of the impeller 4 at an intermediate portion in the axial direction thereof.

  A corresponding member 15 for fastening the impeller to the upper end surface of the rotor 8 of the electric drive motor 5 passes through the damping member 14. The fastening member 15 is, for example, a screw or a bolt having an end head 15a. Between the annular damping member 14 and the screw or bolt 15 there is a tubular element 16 of a substantially hard material, for example a metallic material. The rigid tubular element 16 conveniently has a flange-like end former 16a interposed between the head 15a of the screw or bolt 15 and the adjacent end of the annular damping member 14.

  The threaded shank of the screw or bolt 15 engages the corresponding opening in the upper end surface of the rotor 8.

  Tests conducted by the Applicant have demonstrated that acoustic noise generated particularly in the range of about 100 Hz to 1 kHz is significantly reduced (about 10 dBA or more) using the solution according to the invention.

  In the description and claims of this application, the verbs “comprising”, “including”, and “having” and variations thereof are used in a generic sense to define the presence of the element or feature being described and added It does not exclude the presence of other elements or features.

  It will be appreciated that the individual features of the invention that have been described in connection with separate embodiments for clarity may be provided in combination in one embodiment. Conversely, various features of the invention described in connection with one embodiment for the sake of brevity may be provided individually or in any suitable combination.

  It will be apparent to those skilled in the art that the above embodiments are merely exemplary and that various other modifications can be made without departing from the scope of the invention as defined in the claims.

DESCRIPTION OF SYMBOLS 1 Electric fan 2 Support structure or cowl 3 Main opening part 4 Impeller 5 Electric motor 6 Stator 7 Spoke 8 Rotor 9 Hub 9a End wall 9b Side wall 9c Through-opening part 10 Blade 11 Peripheral ring 12 Connection point or connection area 13 Connection apparatus 14 Damping member 14a Outer peripheral groove 15 Screw or bolt 15a End head 16 Tubular element 16a End forming body

Claims (8)

An electric motor having a rotor and a stator;
An axial impeller having a central hub from which a plurality of blades extends, the hub being connected to the rotor of the motor at one or more connection points or areas;
An electric fan for a heat exchanger of an automobile comprising:
The electric fan, wherein a hub of the impeller is connected to a rotor of the electric motor by a connecting device including an elastic vibration damper at the one or more connecting points or connecting regions.   The impeller hub has a generally bowl-like shape having an end wall coupled to at least a substantially cylindrical annular side wall, and the rotor of the electric motor is located in the interior of the impeller hub near the end wall of the hub. 2. The electric fan according to claim 1, wherein the upper end surface is connected to the hub by the plurality of connecting devices each having an upper end surface extending in a direction and having an elastic vibration damper.   Each of the one or more coupling devices includes an annular damping member made of an elastic material, and the damping member is disposed in the through-opening portion of the hub, and a fastening member that fastens the hub to the rotor of the motor. The electric fan according to claim 1, wherein the electric fan is penetrated.   The electric fan according to claim 3, wherein each damping member is made of an elastomer material.   5. The electric fan according to claim 3, wherein a substantially rigid tubular element is interposed between the damping member and the corresponding fastening member. 6.   The electric fan according to claim 5, wherein the tubular element is made of a metal material.   The fastening member is a screw or a bolt having an end head, and the rigid tubular element is formed at one end between a corresponding head of the screw or bolt and the damping member. The electric fan according to claim 5 or 6, characterized by comprising:   One or each of the elastic vibration dampers has a cylindrical ring shape, and has an outer peripheral groove that engages with an edge of the through-opening portion of the hub of the impeller. The electric fan according to any one of the above.