Ventilation Assembly

Abstract

A ventilation assembly for a vehicle has a stationary load-bearing structure, including an outer frame and an inner annular support element connected to the frame by means of a plurality of spokes. The support element has a cylindrical outer skirt. An electric motor has an inner stator fixed to the annular support element and an outer rotor which extends around the stator. A fan fixed to the rotor, has a hollow hub from which a plurality of blades extend. The hub extends around the rotor and has a front wall and an annular, side wall which surrounds the motor. The side wall of the hub of the fan partially penetrates inside the skirt of the annular support element in the axial direction.

Description

FIELD OF THE INVENTION

The present invention relates to a ventilation assembly, in particular for a heat exchanger, such as a radiator, of a motor vehicle.

BACKGROUND OF THE INVENTION

More specifically, the invention relates to a ventilation assembly of the type comprising: a stationary load-bearing structure, including an outer frame and an inner annular support element connected to the frame by means of a plurality of spokes or the like and having a substantially cylindrical outer skirt; an electric motor, such as a brushless motor, including an inner stator fixed to the annular support element of the load-bearing structure and an outer rotor which extends around the stator; and an impeller or fan, fixed to the rotor of the motor and having a hollow hub from which a plurality of outer blades extend; the hub having a front wall with, extending from its periphery, an at least approximately cylindrical, annular, side wall which surrounds the motor defining an annular recess with respect thereto.

In ventilation assemblies of this type according to the prior art the skirt of the annular support element and the side wall of the hub of the impeller or fan have respective edges directed towards each other and separated from each other, along the direction of the axis of the motor, by a large interspace.

During use on a motor vehicle, external agents, such as water, salt and other corrosive agents, may reach, via this annular interspace, the rotor and the stator of the electric motor which operates the fan and cause gradual oxidation thereof, with the formation of rust.

Hence there is a desire for a ventilation assembly in which the aforementioned drawback of the devices according to the prior art may be eliminated, or at least drastically reduced.

SUMMARY OF THE INVENTION

This is achieved in the present invention by the outer skirt of the support element and the side wall of the hub of the fan partially penetrate one inside the other in the axial direction.

This feature results in the formation, between the skirt of the support element and the side wall of the hub, of an essentially labyrinth-like path which prevents, or at least drastically reduces, the exposure of said motor to the abovementioned corrosive/oxidizing agents.

Accordingly, in one aspect thereof, the present invention provides a ventilation assembly, for a heat exchanger of a motor vehicle, comprising: a stationary load-bearing structure, including an outer frame and an inner support element connected to the frame by means of a plurality of spokes, the support element having a skirt; an electric motor, including an inner stator fixed to the annular support element of the load-bearing structure and an outer rotor which extends around the stator; and a fan, fixed to the rotor of the motor and having a hollow hub from which a plurality of blades extend; the hub and having a front wall and a side wall which extends around the rotor of the motor, wherein the skirt of the support element and the side wall of the hub partially penetrate one inside the other in the axial direction.

Conveniently the side wall of the hub of the fan extends radially inside the skirt of the annular support element.

Preferably, the side wall of the hub of the fan and the skirt of the support element have respective wall extensions made of molded plastic.

Preferably, the electric motor is a brushless motor.

Preferably, the inner support element is annular and the skirt is a cylindrical, outer skirt.

Preferably, the side wall of the hub extends axially from a periphery of the front wall.

Preferably, the side wall is annular.

Preferably, the side wall is cylindrical.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention will now be described, by way of example only, with reference to figures of the accompanying drawings. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same reference numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.

FIG. 1 is a partial perspective view of a ventilation assembly according to the preferred embodiment of the present invention; and

FIG. 2 is a partial, perspective, cross-sectional view of the ventilation assembly of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the drawings, 1 denotes overall a ventilation assembly according to the present invention which can be used in particular for cooling a heat exchanger, such as a radiator, of a motor vehicle.

The ventilation assembly 1 comprises a load-bearing structure, which is operationally stationary, being denoted overall by 2 in FIG. 1.

In a manner known per se, the load-bearing structure 2 comprises an outer frame 3 connected by means of a plurality of spokes 4 (FIG. 1) to an inner annular element 5.

As can be seen more clearly in FIG. 2, the ventilation assembly 1 comprises a D.C. electric motor, denoted overall by 6. This motor is for example a brushless motor and comprises an inner stator 7, which is fixed in a manner known per se to the annular support element 5 of the load-bearing structure 2, and an outer rotor 8 with permanent magnets which extends around the stator.

The electric motor 6 has an associated electronic control circuit 9 (FIG. 2), the components of which, generically indicated by 10, are mounted on a board 12 which is in a heat-exchanging relationship with an essentially plate-shaped heat dissipater 11 which extends transversely with respect to the axis A-A of the motor 6.

The ventilation assembly 1 further comprises an impeller or fan, denoted overall by 20 in the drawings. This fan 20 is fixed to the rotor 8 of the electric motor 6 at the end of the stator 7 remote from the heat dissipater 11.

The fan 20 comprises a hollow hub 13 having, extending therefrom, a plurality of blades 14, the radially outer lying ends of which are connected to a ring 15 which extends inside an essentially circular opening of the outer frame 3 of the load-bearing structure 2 (FIG. 1).

The hub 13 of the fan 20 has a front wall 13a (see in particular FIG. 2) intended to be acted on by the air flow introduced during operation by the fan.

The hub 13 also has an at least approximately cylindrical, annular, side wall 13b which surrounds the electric motor 6, defining an annular recess with respect thereto.

As can be seen more clearly in FIG. 2, the annular support element 5 of the stationary load-bearing structure 2 has an essentially cylindrical outer skirt 5a which extends axially towards the hub 13 of the fan 20.

Conveniently, the skirt 5a of the support element 5 is coaxial with the axis A-A of the motor 6 and extends radially outside the cylindrical, annular, side wall 13b of the hub 13 of the impeller or fan 20.

As can be seen in particular when viewing FIG. 2, the skirt 5a of the support element 5 and the annular wall 13b of the hub 13 of the fan 20 partially penetrate one inside the other, in the axial direction, namely along the axis A-A of the motor.

In the embodiment shown by way of example this is obtained owing to the fact that the side wall 13b of the hub 13 and the skirt 5a of the support element 5 have respective wall extensions 13c and 5b conveniently made of moulded plastic.

In FIG. 2, the wall extensions 5b and 13c have been shown as add-ons or extended parts of the skirt 5a of the support element 5 and the side wall 13b of the fan hub 13, respectively. This has been done, however, purely in order to illustrate in qualitative terms the degree of increase in the axial length of said skirt and said side wall. Conveniently, the wall extensions 5b and 13c are in reality formed integrally with the annular support element 5 and with the hub 13, respectively, during molding thereof.

As can be understood from FIG. 2, the partial penetrating arrangement, in the axial direction, of the hub 13 and the annular support element 5 one inside the other creates, for the corrosive/oxidizing agents which are potentially aggressive for the motor 6 during operation, an essentially labyrinth-like path which is able to reduce drastically the damage caused by these agents.

This allows the metal parts of the motor 6 to be made with a reduction in the amount of protective treatment, with consequent cost-savings.

In the description and claims of the present application, each of the verbs “comprise”, “include”, “contain” and “have”, and variations thereof, are used in an inclusive sense, to specify the presence of the stated item or feature but do not preclude the presence of additional items or features.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of example only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined by the appended claims.

Claims

1. Ventilation assembly, for a heat exchanger of a motor vehicle, comprising: a stationary load-bearing structure, including an outer frame and an inner support element connected to the frame by means of a plurality of spokes, the support element having a skirt;an electric motor, including an inner stator fixed to the annular support element of the load-bearing structure and an outer rotor which extends around the stator; anda fan, fixed to the rotor of the motor and having a hollow hub from which a plurality of blades extend; the hub and having a front wall and a side wall which extends around the rotor of the motor,wherein the skirt of the support element and the side wall of the hub partially penetrate one inside the other in the axial direction.

2. The ventilation assembly of claim 1, wherein the side wall of the hub of the fan extends radially inside the skirt of the support element of the stationary load-bearing structure.

3. The ventilation assembly of claim 1, wherein the side wall of the hub of the fan and the skirt of the support element have respective wall extensions made of molded plastic.

4. The ventilation assembly of claim 1, wherein the electric motor is a brushless motor.

5. The ventilation assembly of claim 1, wherein the inner support element is annular and the skirt is a cylindrical, outer skirt.

6. The ventilation assembly of claim 1, wherein the side wall of the hub extends axially from a periphery of the front wall.

7. The ventilation assembly of claim 1, wherein the side wall is annular.

8. The ventilation assembly of claim 1, wherein the side wall is cylindrical.