Patent Application
20050053495
The invention concerns a device for supporting an electric motor driving a turbine, in particular for an automobile heating, ventilation and/or air conditioning apparatus.
It concerns more particularly a device for supporting an electric motor driving a turbine, in which the electric motor comprises an enclosure and a shaft driving the turbine, which defines a rotation axis, the device comprising a shaped box having a bottom wall connected to a peripheral wall in order to delimit a housing for receiving the motor enclosure, which opens out in a reception volute of the turbine.
The motor-turbine assembly, also referred to as a “powered ventilator” or “fan”, is intended to pump out an air flow and finds a preferential application in automobile heating, ventilation and/or air-conditioning apparatus. The motor-turbine assembly can then serve to send an air flow into a treatment box of the heating, ventilation and/or air-conditioning apparatus in order to produce a treated air flow, or to send a flow of treated air coming from such a treatment box to nozzles placed at chosen points in the vehicle cabin.
One of the problems posed by such a support device is that of cooling the electric motor which drives the turbine.
For this purpose it is known, as taught for example by the publication FR-A-2 412 976, how to interrupt the peripheral wall of the support device in order to define at least one channel for cooling the motor, this channel generally being delimited by two opposite side walls which extend in a substantially radial direction with respect to the rotation axis of the motor.
This known solution requires special tools for producing the support device, which is normally formed by moulding from a plastics material.
In addition, the presence of the cooling channel, which projects outside the box, gives rise to a not inconsiderable bulk.
The aim of the invention is in particular to overcome the aforementioned drawbacks.
It aims in particular to procure a support device of the type defined above which makes it possible to cool the electric motor whilst eliminating the cooling channel used in the state of the art.
The invention aims in particular to procure such a support device which makes it possible to effect the cooling of the electric motor by simple means, without requiring expensive tools and without increasing the size of the box of the device.
It also aims to procure such a support device for an electric motor driving a turbine, which finds a particular application in automobile heating, ventilation and/or air-conditioning apparatus.
The invention proposes for this purpose a device for supporting an electric motor driving a turbine, as defined in the introduction, in which the bottom wall has in it at least two holes at a distance from the rotation axis of the motor in order to allow the passage of a cooling air flow which passes through the enclosure of the motor and rejoins the volute.
Thus the cooling of the motor takes place under controlled conditions by virtue of the presence of holes provided in the bottom wall of the box to allow the passage of an air flow which is sucked by the turbine and is sent into the volute.
This solution makes it possible to obtain effective cooling without the need for particular tools for producing the box and without providing a cooling channel as in the prior solutions.
In a preferred embodiment of the invention, the holes are circulated and calibrated so as to control the flow rate of the cooling air flow which passes through the electric motor.
The result is that the cooling air flow which rejoins the volute does not interfere with the behaviour of the air flow which is entrained by the turbine.
The holes are preferably at equal distances from the axis and at equal angular intervals.
In a preferred embodiment of the invention, the bottom wall has in it three holes situated at angular intervals of 120°.
According to another characteristic of the invention, the bottom wall extends at a distance from one end of the shaft, which is opposite to another end of the shaft, on which the turbine is keyed.
According to another characteristic of the invention, the cylindrical wall is attached to a substantially annular front wall forming part of the volute.
In another aspect, the invention concerns an apparatus for heating, ventilating and/or air conditioning the cabin of an automobile, of the type comprising at least one air blower having an electric motor driving a turbine, in which the electric motor is supported by a device as defined above.
In one application, the air blower is produced as a main blower mounted at the inlet to an air treatment box which the apparatus comprises, this main blower being arranged so as to send a flow of air to be treated into the air treatment box.
In another application, the air blower is produced as a relay blower mounted at the outlet from an air treatment box which the apparatus has, this relay blower being arranged so as to send a flow of treated air coming from the air treatment box to at least one distribution nozzle situated at a chosen location inside the cabin.
In the latter case, the electric motor of the relay blower advantageously has a consumption of less than 120 watts, the motor support device having circular holes whose diameter is less than or equal to 4 mm.
In the following description, given solely by way of example, reference is made to the accompanying drawings, in which:
The support device of FIGS. 1 to 3 comprises a shaped box 10 obtained by moulding a plastics material. The box 10 has a bottom wall 12 connected to one end of a cylindrically-shaped peripheral wall 14 of axis XX. At its other end, the peripheral wall 14 is connected to an annular-shaped front wall 16. The bottom wall 12, circular in shape, lies in a plane perpendicular to the axis XX.
The box 10 thus delimits an internal housing 20 open on the side of the front wall 16 and intended to house the enclosure 22 of an electric motor 24. The enclosure 22 of the motor is held in the housing 20 by conventional means, not shown here, which also damp the motor vibrations.
The electric motor 24 comprises a rotation shaft 26 extending in the direction of the axis XX, which also constitutes the rotation axis of the motor. The rotation shaft 26 has a first end 28 contained in the box and situated at a short distance from the wall 12, and a second end 30 to which a turbine 32 of the centrifugal type is keyed. This turbine is advantageously moulded in a single piece from plastics material and comprises a wheel 34 keyed to the end 31 of the shaft 26 and a multiplicity of radial blades 35 provided at the peripheral part of the wheel 34. The structure of this centrifugal turbine 32, which is known per se, is more clearly visible in the perspective view in
The housing 20 of the box 10 opens out in a volute 36 which receives the turbine 32. This volute is produced in two parts by moulding a plastics material. It comprises a part 38 fitted on the periphery of the front wall 16 and a part 40 fitted on the part 38. The front wall 16 comprises a plurality of lugs 42, here three in number, which cooperate with lugs 44 moulded in one piece with the part 38. The lugs 42 are fixed respectively to the lugs 44 by screws, not shown, as indicated at 45.
The part 40 delimits a circular opening 46, centred on the axis XX, to allow the admission of a flow of air as depicted by the arrows A, in the axial direction. This air is then accelerated by the turbine 32, driven by the motor 24, in the centrifugal direction. The air thus accelerated is discharged, in the tangential direction, by an outlet (not visible in
To provide cooling of the motor, the bottom wall 12 of the box has (
This air flow enters the housing 20, then passes through the enclosure 22 of the motor through openings conventionally provided in the enclosure, in order then to rejoin the volute. This air flow, whose flow rate is controlled and much lower than the flow rate of the air flow A, is mixed with this air flow A and is discharged with it from the volute 36. The diffusion of the air flow F in the motor enclosure is distributed uniformly through the brushes, the cage, the winding and other components of the motor.
Because the holes 48 are limited in number and have a calibrated diameter, the flow rate of the air flow F can be controlled and limited so as to not interfere with the flow of the air flow A.
This is because the temperature of the air flow F is increased when it passes through the motor, and this increase in temperature must not be able to unfavourably affect the temperature of the air flow A which is discharged from the volute, especially when this air flow A is a cold air flow, possibly refrigerated.
In the perspective view in
Reference is now made to
On the volute 36 there is mounted an inlet conduit 54 which has an inlet opening 56 and an outlet opening 58, the latter being connected to the opening 46 of the volute. This inlet conduit 54 is intended to route an air flow as shown by the arrow A. This air flow is then accelerated tangentially by the turbine and discharged through an outlet conduit 60 which extends in the tangential direction of the volute. This air flow is discharged in the direction of the arrow B.
The blower 52 in
The box 64 is supplied from a main blower 66 which is produced in accordance with the teachings of FIGS. 1 to 4. This blower 66 comprises a support 10 similar to that described previously and connected to an inlet interface 64 for admitting, into the support, either external air taken from outside the automobile cabin or recirculated air taken from inside the cabin, or a mixture of these two air flows, in a manner known per se. The air flow is then sent into the box through an inlet conduit 70.
The air treatment box 64 comprises two outlets 72 intended to send the treated air into different regions of the cabin, for example towards the rear seats of the vehicle. The two outlets 72 are connected by conduits 74 to two relay blowers 52 similar to the one in
The respective electric motors of the main blower 66 and the relay blowers 52 are each cooled by cooling means of the type described with reference to FIGS. 1 to 3.
As already indicated, the invention makes it possible to control the flow rate of the cooling air flow for the motor. Thus, in the case of a relay blower 52, the electric motor of the latter will preferably have a consumption of less than 120 watts. In this case, the motor support device will preferably comprise circular holes whose diameter will be less than or equal to 4 mm.
Naturally the invention is not limited to the embodiments described above by way of example and extends to other variants.
In particular, the invention is open to many variations, in particular with regard to the number, position and dimensions of the holes provided in the bottom wall of the support device.
The invention finds a preferential application to automobile heating, ventilation and/or air-conditioning apparatus.
| Number | Date | Country | Kind |
|---|---|---|---|
| 03 10649 | Sep 2003 | FR | national |
