FR3157903A1 - Fan for a ventilation device of a motor vehicle and method of balancing such a fan - Google Patents

Abstract

Fan for a ventilation device of a motor vehicle and method for balancing such a fan The present invention relates to a fan (10) for a ventilation device of a motor vehicle comprising: - an electric motor (14) comprising a stator (20) and a rotor (18), - a fan wheel (12) secured to the rotor (18), - an internal support (16a) made of plastic material on which the stator (20) is fixed, - an external support (16b) configured to ensure the fixing of the fan (10) on the motor vehicle and arranged at least partially around the internal support (16a), - a plurality of damping elements (28) arranged between the internal support (16a) and the external support (16b), in which the internal support (16a) comprises at least one holding element (32) forming a tubular channel configured to receive a pin of a balancing device of the fan (10). Fig. 1

Description

Fan for a ventilation device of a motor vehicle and method of balancing such a fan

The present invention relates to a fan configured to be arranged in a ventilation device of a motor vehicle and in particular in a heating, ventilation and air conditioning (HVAC) device. The fan makes it possible to ventilate the air inside the vehicle.

For this, the fan comprises a fan wheel comprising for example a plurality of blades and driven in rotation by an electric motor.

However, such a fan produces vibrations which can be significant depending on the size of the fan wheel and its weight and can lead to discomfort, particularly noise, for passengers in the motor vehicle. It is therefore advisable to limit these vibrations as much as possible.

To this end, it is necessary to have a well-balanced rotating assembly and to decouple the fan from the rest of the vehicle to limit the propagation of vibrations.

To achieve such decoupling, it is known to equip the fan with damping pads made of a flexible material to absorb vibrations. These damping pads are, for example, placed at the stator.

However, the presence of these damping pads can make balancing the fan difficult or even impossible since it is necessary to precisely measure the unbalance during the rotation of the fan wheel. However, the damping pads are designed precisely to dampen the vibrations linked to the unbalance and transmitted to the outside of the fan.

Furthermore, in order to reduce the cost and weight of vehicle equipment, more and more parts are made of plastic, particularly the parts used to support the electric motor driving the fan. Such plastic parts make it difficult to maintain the stator for proper balancing.

It is therefore necessary to find a solution that allows for a fan that can be easily balanced despite the use of plastic parts and that limits the vibrations transmitted to the rest of the vehicle when the fan is operating.

To this end, the invention relates to a fan for a ventilation device of a motor vehicle comprising:
- an electric motor comprising a stator and a rotor,
- a fan wheel attached to the rotor,
- an internal support made of plastic material on which the stator is fixed,
- an external support configured to ensure the attachment of the fan to the motor vehicle and arranged at least partially around the internal support,
- a plurality of damping elements arranged between the internal support and the external support,
wherein the internal support comprises at least one holding element forming a tubular channel configured to receive a pin of a fan balancing device.

Such a fan allows for easy balancing of the fan without the need to disassemble the fan while limiting the vibrations transmitted between the fan and the rest of the motor vehicle. The transmission of vibrations to the rest of the motor vehicle is therefore minimized by the balancing of the fan and the presence of damping elements so that passenger comfort is improved.

According to another aspect of the present invention, the tubular channel is a through-hole.

According to another aspect of the present invention, the tubular channel has a circular section. However, other section shapes may be used, for example a square or polygonal section or any shape allowing easy insertion of the pins into the tubular channel.

According to another aspect of the present invention, the inner support and the outer support are rings.

According to another aspect of the present invention, the internal support and the external support are made of plastic material, for example acrylonitrile butadiene styrene.

According to another aspect of the present invention, the damping elements are pads made of rubber, for example ethylene-propylene-diene monomer.

According to another aspect of the present invention, the fan comprises two holding elements arranged parallel to one side and the other of the internal support.

According to another aspect of the present invention, the internal support also comprises at least one holding housing configured to receive a holding arm of the balancing device to block axial translation along the axis of the holding element.

The present invention also relates to a method for balancing a fan as described previously by a balancing device comprising at least one pin of a shape complementary to the tubular channel of the holding element, the method comprising:
- a step of positioning the at least one holding pin in the tubular channel of the at least one respective holding element to at least partially hold the internal support by the at least one pin of the mounting device,
- a step of positioning at least one element for blocking the translation of the internal support along the axis of the tubular channel of the holding element,
- a fan balancing step in which the vibrations transmitted by the fan to the balancing device via the at least one spindle are measured when the fan is operated to rotate the fan wheel and then in which weights are fixed on the fan wheel at positions determined by the balancing device.

According to another aspect of the present invention, the weights are made by staples and are fixed on blades of the fan wheel.

According to another aspect of the present invention, the vibrations transmitted by the fan are measured by accelerometers arranged on the balancing device.

Other advantages and characteristics will appear on reading the description of several illustrative but non-limiting examples of the present invention, as well as the appended drawings in which:

FIG. 1 There FIG. 1 is a schematic perspective and sectional representation of a fan according to an embodiment of the present invention;

FIG. 2 There FIG. 2 is a schematic top view of an internal support and an external support of the fan of the FIG. 1 ;

FIG. 3 There FIG. 3 is a schematic perspective representation of a platform of the internal support of the fan of the FIG. 1 ;

FIG. 4 There FIG. 4 is a schematic perspective representation of a retaining element and a retaining housing of the internal support of the fan of the FIG. 1 .

FIG. 5 There FIG. 5 is a flowchart of the steps of a method of balancing a fan according to the present invention.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Single features of different embodiments may also be combined or interchanged to provide other embodiments.

In this description, certain elements or parameters may be indexed, such as first element or second element, as well as first parameter and second parameter, or first criterion and second criterion, etc. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria that are close, but not identical. This indexing does not imply a priority of one element, parameter or criterion over another and such names can easily be interchanged without departing from the scope of this description. This indexing also does not imply an order in time, for example, to assess this or that criterion.

There FIG. 1 schematically illustrates a fan 10 for a motor vehicle ventilation device, for example a motor vehicle heating, ventilation and/or air conditioning installation. The FIG. 1 is a perspective and sectional view.

The fan 10 comprises a fan wheel 12, an electric motor 14, and a support device 16 for the electric motor 14. The fan wheel 12 rotates about an axis A1. The electric motor 14 is intended to drive the fan wheel 12 in rotation about the axis A1. The fan wheel 12 comprises, for example, a plurality of blades distributed around the periphery of the fan wheel 12.

The electric motor 14 comprises a stator 20 and an associated rotor 18. This is an external rotor 18 in that it is associated with a stator 20 arranged radially inside the rotor 18 but other configurations are possible.

The rotor 18 may in particular comprise a cup 22 symmetrical by rotation around the axis A1, in the shape of a bell. The rotor 20 also comprises magnets 24 fixed here to an internal face of the cup 22, in particular on a cylindrical strip of the internal face of the cup 22. The cup 22 of the rotor 18 is fixed, at its center, to a shaft 26 of axis A1. The shaft 26 constitutes the output (or rotation) shaft of the electric motor 14, driving the fan wheel 12. For this purpose, the fan wheel 12 is here directly fixed on the shaft 26.

The stator 20 can be symmetrical by rotation around the axis A1. The stator 20 comprises a barrel 46 extending mainly in the direction of the axis A1. The cup 22 of the rotor 18 comes in particular to cover one end of the barrel 46 opposite its base 46a.

The support device 16 of the electric motor 14 is in particular intended to allow the fan 10 to be fixed in a motor vehicle, by limiting the transmission of vibrations generated by the electric motor 14 and/or the fan wheel 12 in the motor vehicle and/or external constraints towards the electric motor 14 and/or the fan wheel 12.

For this, the support device 16 comprises an internal support 16a and an external support 16b arranged at least partially around the internal support 16a and damping elements 28 are arranged between the internal support 16a and the external support 16b as shown in the FIG. 2 .

The external support 16b is for example made of a ring made of plastic material, for example acrylonitrile butadiene styrene. FIG. 5 represents an example of external support 16b. The external support 16b is configured to ensure the attachment of the fan 12 to the motor vehicle, for example via screws positioned in orifices 30 located at the periphery of the external support 16b.

In the example of the FIG. 2 , the support device 16 comprises six damping elements 28 interposed between the internal support 16a and the external support 16b. The damping elements 28 are for example made of pads made of rubber, for example ethylene-propylene-diene monomer or elastomeric material. However, other materials for limiting the transmission of vibrations between the internal support 16a and the external support 16b can also be used. The damping elements 28 have for example an H shape but other shapes are also possible. In the present example, the damping elements 28 are arranged in pairs, the pairs being distributed around the periphery of the internal support 16a but other arrangements are possible, for example a regular distribution of all the damping pads 28 around the internal support 16a. A different number of damping elements 28 is also possible.

The internal support 16a comprises for example a ring called an internal ring (visible on the FIG. 2 ) which may be made of plastic material, for example acrylonitrile butadiene styrene. The damping elements 28 are positioned in contact with an external surface of the internal ring.

The internal support 16a also includes a platform 161 (visible on the FIG. 3 ) fixed to the inner ring on which the stator 18 of the electric motor 14 is fixed and which can also be made of plastic material, for example acrylonitrile butadiene styrene. The platform 161 is for example fixed to the inner ring 16a by screws. Alternatively, the platform 161 can be made of the same material as the inner ring 16a. The platform 161 is arranged at an axial end of the fan 10 opposite the fan wheel 12 so that its access is easy.

The internal support 16a comprises at least one holding element 32 forming a tubular channel, for example of circular section, configured to receive a pin of a balancing device of the fan 10. Other section shapes of the tubular channel may also be used, for example a triangular, square, polygonal or elliptical section. In addition, the section of the tubular channel may not be constant, the section may for example decrease between its ends (cone-shaped or portion of cone-shaped shape in the case of a circular section). In the example of the FIG. 3 , the number of holding elements 32 is two and the two holding elements 32 are arranged parallel to each other on one side and the other of the internal support 16a. More precisely, the holding elements 32 are arranged diametrically opposite relative to the center of the platform 161 which has a generally circular shape. The holding elements 32 are arranged on the external face of the platform 161.

As can be seen better on the FIG. 4 , the holding elements 32 form a tubular channel or orifice, which can be through, so that a pin of a balancing device can be positioned in the holding elements 32 via a translation as indicated by the arrows F. The tubular channel can also be perforated to limit the weight of the holding elements 32.

The internal support 16a may also comprise at least one holding housing 34 configured to receive a holding arm of the balancing device as indicated by the arrows F' to block the axial translation along the axis of the tubular channel of the holding elements 32. The holding housing 34 has for example a tubular shape whose axis is parallel to the axis of the tubular channel of the holding elements 32. The bottom (blind part) of the holding housing 34 is arranged so that the introduction of the end of the holding arm into the holding housing 34 is carried out in a direction indicated by the arrows F' opposite to the direction F corresponding to the direction of introduction of the pins into the holding elements 32.

Alternatively, another element for blocking the translation of the internal support 16a along the axis of the tubular channel of the holding element 32 relative to the balancing device can be used. For example, the spindle of the balancing device can be configured to receive an element such as a washer or a pin configured to be inserted into a groove provided in one end of the spindle. The washer or pin also comes into contact with the end of the tubular channel of the holding element 32 and thus makes it possible to block the axial movement of the spindle relative to the holding element 32. Other blocking elements making it possible to block the translation of the internal support 16a relative to the balancing device along the axis of the tubular channel of the holding element 32 can also be used.

In order to carry out the balancing, it is necessary to secure the stator 20 of the electric motor 14 to the balancing device. For this, the location of the platform 161 at an axial end of the fan 10 allows easy access to the holding elements 32 and to the holding housings 34 according to the arrows F and F' respectively by the pins and the holding arms of the balancing device. The positioning of the pins (whose shape is complementary to the tubular channels of the holding elements 32) of the balancing device in the tubular channels of the holding elements 32 makes it possible to block the movement of the internal support 16a (relative to the balancing device) in all directions except in the direction of the axis of the tubular channels of the holding elements 32. The positioning of the end of the holding arms of the balancing device in the holding housings 34 makes it possible to block the translation in the direction of the axis of the tubular channel of the holding elements 32 so that when the pins are positioned in the tubular channel of the holding elements 32 and the end of the holding arms are positioned in the holding housings 34, the internal support 16a is integral with the balancing device. A balancing process can then be carried out by the balancing device.

The number and position of the holding elements 32 and the holding housings 34 may be different, for example a single holding element 32 and a single holding housing 34.

Such a configuration therefore makes it possible to maintain the internal support 16a during balancing and thus to be able to achieve balancing that is not disturbed by the damping elements 28. Indeed, the purpose of carrying out a balancing method is to measure the unbalance of the fan 10 during its operation so as to position weights making it possible to reduce the unbalance. However, such an unbalance measurement cannot be carried out correctly if damping elements such as the damping elements 28 are positioned between the holding arms of the balancing device and the device whose unbalance is to be reduced, here the assembly comprising the electric motor 14 and the fan wheel 12.

The present invention also relates to a method for balancing the fan 10 described previously by a balancing device comprising at least one pin having a shape complementary to the tubular channels of the holding elements 32 and at least one holding arm whose end is configured to be positioned in a holding housing 34.

There FIG. 5 represents a flowchart of the different stages of the process.

The first step 101 concerns a step of positioning the at least one holding pin in the tubular channel of the at least one of the respective holding elements 32 as represented by the arrows F in FIGS. 3 and 4. In the present case, the two pins can be positioned simultaneously or one after the other in the tubular channels of the respective holding elements.

The second step 102 concerns a step of positioning at least one element for blocking the translation of the internal support 16a along the axis of the tubular channel of the holding element 32. The blocking element is for example produced by a holding arm whose end is positioned in a holding housing 34 as represented by the arrows F' in FIGS. 3 and 4. This positioning of the holding arm in the holding housings 34 makes it possible to block the translation in the direction of the axis of the tubular channel of the holding elements 32 and thus secure the balancing device to the internal support 16a.

Once positioned in the holding elements 32 and in the holding housings 34, the pins and the holding arms make it possible to hold the internal support 16a in position so that there are no damping elements 28 between the balancing device and the electric motor 14. The internal support 16a is thus held directly by the balancing device.

The third step 103 relates to a step of balancing the fan comprising a first sub-step 1031 in which the vibrations transmitted by the fan 10 to the balancing device are measured via the at least one spindle and the at least one holding arm when the fan 10 is actuated to rotate the fan wheel 12. These vibrations are for example measured by accelerometers arranged on the balancing device. The balancing device is configured to determine an unbalance of the fan wheel 12 and to determine the mass and the position of the weights to be added to the fan wheel 12 to obtain a balanced fan wheel, i.e. without unbalance.

The third step 103 also comprises a second sub-step 1032 which concerns the positioning of the weights on the fan wheel 12. The weights are for example fixed on the blades or fins 120 of the fan wheel 12. The weights can be produced in the form of staples. The positioning can be carried out automatically by the balancing device.

Thus, the use of a fan 10 comprising an internal support 16a supporting the stator 20 and an external support 16b fixed to the motor vehicle between which damping elements 28 are arranged makes it possible to limit the transmission of vibrations from the fan 10 to the other elements of the motor vehicle. In addition, the use of holding elements 32 provided in the internal support 16a, accessible and configured to receive pins of the balancing device, makes it possible to simply fix the balancing device to the electric motor 14 to carry out a method of balancing the fan 10 without the need to dismantle the fan 10 and without damping elements 28 disturbing the measurements during the balancing method.

Claims (11)

Fan (10) for a ventilation device of a motor vehicle comprising:
- an electric motor (14) comprising a stator (20) and a rotor (18),
- a fan wheel (12) secured to the rotor (18),
- an internal support (16a) made of plastic material on which the stator (20) is fixed,
- an external support (16b) configured to ensure the attachment of the fan (10) to the motor vehicle and arranged at least partially around the internal support (16a),
- a plurality of damping elements (28) arranged between the internal support (16a) and the external support (16b),
characterized in that the internal support (16a) comprises at least one holding element (32) forming a tubular channel configured to receive a pin of a fan balancing device (10). A fan (10) according to claim 1 wherein the tubular channel is a through hole. Fan (10) according to one of the preceding claims in which the tubular channel has a circular section. Fan (10) according to one of the preceding claims in which the internal support (16a) and the external support (16b) are rings. Fan (10) according to one of the preceding claims in which the internal support (16a) and the external support (16b) are made of plastic material, for example acrylonitrile butadiene styrene. Fan (10) according to one of the preceding claims in which the damping elements (28) are pads made of rubber, for example ethylene-propylene-diene monomer. Fan (10) according to one of the preceding claims comprising two holding elements (32) arranged parallel on one side and the other of the internal support (16a). Fan (10) according to one of the preceding claims in which the internal support (16a) also comprises at least one holding housing (34) configured to receive a holding arm of the balancing device to block the axial translation along the axis of the at least one holding element (32). Method for balancing a fan (10) according to one of the preceding claims by a balancing device comprising at least one pin of a shape complementary to the tubular channel of the holding element (32), the method comprising:

• a step (101) of positioning the at least one holding pin in the tubular channel of the at least one respective holding element (32) to at least partially hold the internal support (16a) by the at least one pin of the mounting device,
• a step (102) of positioning at least one element for blocking the translation of the internal support (16a) along the axis of the tubular channel of the holding element (32),
• a step (103) of balancing the fan in which the vibrations transmitted by the fan (10) to the balancing device via the at least one spindle are measured when the fan (10) is operated to rotate the fan wheel (12) and then in which weights are fixed on the fan wheel (12) at positions determined by the balancing device.

Balancing method according to the preceding claim in which the weights are produced by staples and are fixed on fins (120) of the fan wheel (12). Balancing method according to claim 9 or 10 wherein the vibrations transmitted by the fan (10) are measured by accelerometers arranged on the balancing device.