Method for grounding a motor-fan unit, in particular for a motor vehicle, and corresponding motor-fan unit

Abstract

The invention relates to a method for grounding a motor-fan unit (1) comprising a fan wheel (3), a motor, a motor support (5), a control module (6), a metal assembly (7, 8) comprising at least two parts formed by a cover (7) and a heat sink (8). Said method comprises the following steps: arranging and fixing the cover (7) on the motor support (5), so as to cover the heat sink (8) and the control module (6), at least one connecting element (13) of one part of the metal assembly extending towards the other part, and under the effect of the fixing force, deforming the material of the part of the metal assembly which comes into contact with the connecting element and / or deforming the connecting element (13). The invention also relates to a corresponding motor-fan unit.

Description

Description Title of the invention: Method for grounding a motor-fan unit, in particular for a motor vehicle, and corresponding motor-fan unit Technical field

[0001] The invention relates to the field of motor-fan units or ventilation devices intended for example for vehicles, particularly motor vehicles. The invention relates in particular to a method for grounding such a motor-fan unit. The invention can be applied, for example, to heating, ventilation and / or air conditioning installations for vehicles, particularly motor vehicles, and comprising such a motor-fan unit. Technical background

[0002] Vehicles, particularly motor vehicles, are commonly equipped with a system, for example heating, ventilation and / or air conditioning, which creates an airflow in the passenger compartment. Such a system also makes it possible to manage the temperature and distribution of the airflow created within the passenger compartment. Such a system includes, among other things, a fan, particularly a blower type, comprising a fan wheel rotated by a drive motor, particularly an electric motor. The electric motor may in particular be electronically commutated, controlled by a control module.

[0003] An electronically commutated electric motor, or brushless direct current motor (also known as "brushless"), comprises a rotor and stator assembly, each of these components carrying electromagnetic elements whose interaction generates the movement of the rotor relative to the stator, and thus the movement of the fan wheel.

[0004] The stator typically consists of several windings and a stack of laminations. When electric currents flow through the windings, magnetic fields are produced. The rotor is equipped with a plurality of permanent magnets that also produce magnetic fields. The interaction of the magnetic fields produced by the stator windings with the magnetic fields produced by the rotor magnets generates the displacement of the rotor relative to the stator, and further the rotation of the fan wheel.

[0005] A known problem with this type of motor is that, when using the motor, the electromagnetic radiation produced can interfere with the use of other electronic devices located nearby. In order to limit the interference caused by this electromagnetic radiation, a known solution is to connect the sheet metal pack to ground. However, such a connection can be complicated and expensive due to the compactness of the electric motor.

[0006] Furthermore, the electric motor is assembled in the installation, for example heating, ventilation and / or air conditioning, by means of a motor support which includes a structure, allowing the fixing of the electric motor, more precisely the stator.

[0007] According to a known solution, a support part forming a heat sink is fixed to the motor mount and carries the motor control module. This is a metal part. In addition, the heat sink also forms a support for bearings mounted around the motor rotor shaft and the lamination pack.

[0008] A cover is usually attached to the heat sink to cover the control module. In some previous solutions, the cover is made of plastic. However, this results in a significant weight of the cover, which is reflected in the entire motor-fan assembly. A preferred solution is to use a metal cover, for example aluminum, which is lighter than a plastic cover.

[0009] The metal heat sink thus ensures that the entire motor and bearings are held in place, while also allowing the control module and the cover to be positioned, which ensures electrical continuity between all these elements and their grounding.

[0010] However, this requires the design of this single heat sink part with a complex shape to be able to connect all these elements together to ensure grounding.

[0011] The invention aims to propose an alternative for grounding one or more of the elements of the motor-fan unit, of simple design and implementation, while limiting the weight of the motor-fan unit. Summary of the invention

[0012] To this end, the invention relates to a method for grounding a motor-fan unit, in particular for a motor vehicle, the motor-fan unit comprising a fan wheel, a fan wheel drive motor, a motor mount, a motor control module, a metal assembly defining a housing for the control module, the metal assembly comprising at least two parts formed by a cover and a heat sink, the heat sink being received in a housing of the motor mount and the control module being mounted on the heat sink.

[0013] According to the invention, at least one part of the metal assembly comprises at least one connecting element, and said method comprises the following steps: arranging the cover on the engine support, so as to cover the heat sink and the control module, and so that at least one connecting element of one part of the metal assembly extends towards the other part of the metal assembly, fixing the cover to the engine support, and under the effect of the fixing force, deforming the material of the part of the metal assembly which comes into contact with the connecting element or deforming the connecting element, so as to ground the heat sink.

[0014] Under the effect of the fastening force, the material of the cover or the heat sink which comes into contact with the connecting element is deformed, and / or the connecting element is deformed. Thus, one of the heat sink or the cover comprises a connecting element and at least one of the connecting element and a contact zone opposite the connecting element deforms during the contacting of the connecting element with the contact zone. At the level of the deformation, a constrained contact is formed between the heat sink and the cover, ensuring the grounding of the heat sink.

[0015] The invention also relates to a motor-fan unit, in particular for a motor vehicle, the motor-fan unit comprising a fan wheel, a motor for driving the fan wheel, a motor support, a motor control module, a metal assembly defining a housing for the control module, the metal assembly comprising at least two parts formed by a cover and a heat sink, the heat sink being received in a housing of the motor support and the control module being mounted on the heat sink.

[0016] According to the invention, the cover is fixed to the engine support so as to cover the heat sink and the control module, and at least one part of the metal assembly comprises at least one connecting element extending towards the other part of the metal assembly, and configured to deform the material of the part of the metal assembly which comes into contact with the connecting element under the effect of the fixing force, or configured to be deformed by the part of the metal assembly which comes into contact with the connecting element under the effect of the fixing force.

[0017] The grounding method and / or the motor-fan unit may further comprise one or more of the following characteristics described below, taken separately or in combination.

[0018] The hood is grounded.

[0019] The deformation can be plastic or elastic.

[0020] The connecting element is made in one piece with the cover or heat sink.

[0021] According to a preferred embodiment, the part whose material is deformed is the more fragile and / or the less functional of the two parts of the metal assembly. For example, the connecting element is formed on the heat sink and the material of the facing cover deforms during fixing.

[0022] Alternatively, the heat sink material may be deformed by a bonding member formed on the cover.

[0023] According to yet another variant, the connecting element is, for example, flexible and deforms under the effect of the fastening force.

[0024] The hood is arranged on the engine mount such that the connecting element extends, is arranged, at least partly opposite a fixing element of the hood on the engine mount.

[0025] The connecting element extends, for example, parallel to the axis of rotation of the wheel.

[0026] The hood is arranged on the engine mount so that the connecting element is arranged at a distance from the hood fixing element on the engine mount, between 1mm and 30mm, preferably between 2mm and 10mm, in particular from 3mm to 5mm.

[0027] The fixing element can be a screw element.

[0028] The fixing step can be carried out by screwing.

[0029] The connecting element has, for example, a shape chosen from a pointed shape, a refined shape, a triangular shape, a tooth shape, a spike shape. In this case, the connecting element can indent the facing part of the metal assembly.

[0030] The connecting element may be arranged on a peripheral edge of the heat sink or on a peripheral edge of the cover.

[0031] For example, the peripheral edge of the heat sink is curved or folded towards the cover.

[0032] At least four connecting elements may be regularly distributed on the peripheral edge of the heat sink or cover.

[0033] The cover and / or heat sink may be made of aluminum or aluminum alloy.

[0034] The motor-fan unit may be intended for a heating, ventilation and / or air conditioning installation of a vehicle, particularly an automobile. Brief description of the drawings

[0035] Other advantages and characteristics of the invention will appear more clearly on reading the following description given by way of illustrative and non-limiting example, and the appended drawings among which:

[0036] [Fig. 1] is a perspective view of one embodiment of a motor-fan unit.

[0037] [Fig. 2] is an enlarged view of a portion of the motor-fan assembly of Figure 1.

[0038] In these figures, identical elements have the same reference numbers.

[0039] 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, without departing from the scope of the invention, as defined by the claims. Detailed description

[0040] MOTOR-FAN UNIT

[0041] With reference to Figure 1, the invention relates to a motor-fan unit 1, in particular for a vehicle such as a motor vehicle. It may in particular be a motor-fan unit 1 for a heating, ventilation and / or air conditioning installation for a vehicle, in particular a motor vehicle.

[0042] The motor-fan unit 1 (or ventilation device) comprises in particular a fan wheel 3, an electric motor, and a motor support 5, hereinafter called motor support 5.

[0043] The fan wheel 3, in particular of the blower type, rotates around an axis of rotation A. The motor is intended to drive the fan wheel 3 in rotation around its axis A. In the present document, the terms “axial”, “coaxial” or “axially” are defined in relation to this axis A.

[0044] In particular, the motor is a brushless motor. The motor comprises a fixed stator part and a rotor (not visible in the figures), the rotor being movable relative to the stator part and capable of driving the fan wheel 3. The rotor is for example an external rotor. The rotor may have a cup shape fixed to a motor shaft. The fan wheel 3 may be fixed directly to the motor shaft. The motor and the fan wheel 3 are for example coaxial.

[0045] The rotor and the stator part may carry electromagnetic elements whose interaction generates the displacement of the rotor relative to the stator part, and the displacement of the fan wheel 3. In particular, the rotor may comprise magnets for example fixed on an internal face of the cup. The stator part may be internal, that is to say arranged inside the rotor. The stator part comprises a stator and for example stator windings.

[0046] The engine is intended to be controlled by a control module 6. The control module 6 may comprise an electronic card (not visible in the figures) having a control circuit and supporting a set of electronic components making it possible to control the engine, and at least one connector electrically connected to the electronic card for the electrical supply of the electronic card and, consequently, of the engine, when it is connected to an electrical harness, in particular of the vehicle. In particular, when the electronic card is powered, the stator windings can create a magnetic field causing the rotor to rotate and consequently the fan wheel 3.

[0047] A cover 7 is fixed to the engine support 5, so as to cover the control module 6. The cover 7 is metallic, advantageously made of aluminum or aluminum alloy.

[0048] The engine support 5 is intended to allow the motor-fan unit 1 to be fixed in the vehicle, in particular an automobile.

[0049] The motor support 5 may comprise a base 51 allowing the motor, in particular the stator, to be fixed. The base 51 may have at least a partial shape of revolution around an axis coinciding, for example, with the axis A of rotation of the fan wheel 3 in the assembled state of the motor-fan unit 1. The base 51 may be centered around this axis A. The axis A hereinafter designates both the axis of the base 51 and the axis of rotation of the fan wheel 3. The base 51 may extend mainly along a plane normal to the axis A. For example, the base 51 has a disc shape.

[0050] The base 51 is made of a plastic material. This base 51 therefore forms an electrical insulator.

[0051] The base 51 may further comprise a sealing and / or decoupling element such as an elastomer material. The elastomer material is, for example, polystyrene-b-poly(ethylene-butylene)-b-polystyrene or SEBS.

[0052] The base 51 can carry the control module 6. In particular, the control module 6 can be carried by a support part forming, for example, a heat sink 8.

[0053] The peripheral edge of the heat sink 8 is for example curved or folded towards the cover 7.

[0054] The heat sink 8 may be generally planar or substantially planar in shape. The heat sink 8 may extend mainly along a plane normal to the axis A. For example, it has the shape of a plate or a disc.

[0055] Advantageously, on the side opposite to the side on which the control module 6 is mounted, it is not necessary to provide a complex shape of the heat sink. thermal 8, to make a connection with a pack of stator sheets, bearings mounted around a rotor shaft.

[0056] The heat sink 8 is metallic, advantageously made of aluminum or aluminum alloy.

[0057] The heat sink 8 is received in a complementary receiving housing defined by the motor support 5, this housing being defined in particular by the base 51. It is in particular fixed on the base 51. The cover 7 is fixed on the motor support 5, in particular on the base 51, by covering the heat sink 8 and the control module 6. This fixing can be done by means of one or more fixing elements 9 such as screws.

[0058] The cover 7 is therefore fixed directly onto the base 51. The heat sink 8 can therefore be designed with a simple shape on the side receiving the control module 6. It is not necessary to provide a complex shape for the heat sink 8 to allow the cover 7 to be fixed.

[0059] Furthermore, the base 51 may also be intended to be fixed, directly or indirectly, to a structural element of the vehicle, for example a vehicle heating, ventilation and / or air conditioning installation.

[0060] In the example illustrated, the motor-fan unit 1 comprises a fixing interface 11 to which the base 51 is fixed. The base 51 can in particular be received in a cavity of the fixing interface 11.

[0061] The fixing interface 11 may have a shape of revolution around the axis A. The fixing interface 11 and the base 51 are for example coaxial.

[0062] The fixing interface 11 is arranged on the periphery of the base 51.

[0063] The fixing interface 11 makes it possible, for example, to fix the engine support 5 to a structure of the vehicle. For this, the fixing interface 11 may be intended to be fixed to a structure in the vehicle, such as a housing of the heating, ventilation and / or air conditioning system.

[0064] This fixing interface 11 can advantageously also have an air deflector function allowing, during operation of the motor-fan unit 1, to deflect at least part of the air set in motion by the fan wheel 3 towards the control module 6 and / or towards the motor.

[0065] Furthermore, the heat sink 8 and the cover 7 form at least in part a metal assembly of the motor-fan unit 1, the cover 7 being grounded. This metal assembly 7, 8 defines a housing for the control module 6. The control module 6 is thus encapsulated between the heat sink 8 and the cover 7, both of which are metal, for example made of aluminum, which makes it possible to limit the electromagnetic radiation of the components of the control module 6.

[0066] At least one part of the metal assembly, i.e. in particular the cover 7 or the heat sink 8, comprises at least one connecting element 13. This connecting element 13 extends towards the other part of the metal assembly 7, 8.

[0067] In the illustrated example, the connecting element 13 is part of the heat sink 8 and extends towards the cover 7. The connecting element 13 is for example arranged on a peripheral edge of the heat sink 8.

[0068] Alternatively, the connecting element 13 can be integrated into the cover 7 and extend towards the heat sink 8. The connecting element 13 is for example arranged on a peripheral edge of the cover 7.

[0069] It may be a protrusion, made from a single piece, for example integral with the cover 7 or the heat sink 8. This connecting element 13 therefore forms a projection relative to a general plane defined by the cover 7 or the heat sink 8.

[0070] In addition, the connecting element 13 is provided near a fixing element 9, such as a screw for example.

[0071] The connecting element 13 can extend at least partly opposite this fixing element 9 when the cover 7 is fixed to the engine support 5.

[0072] As a non-limiting example, the connecting element 13 may be arranged at a distance from the fixing element 9, between 1 mm and 30 mm, preferably between 2 mm and 10 mm, in particular from 3 mm to 5 mm. This distance is chosen according to a compromise, so that the connecting element 13 is not too close to the fixing element 9 in order to prevent the material from tearing, nor too far away to avoid a detachment, a separation between the connecting element 13 and the cover 7 or the heat sink 8 opposite in the event of vibrations for example.

[0073] The connecting element 13, better visible in Figure 2, can extend axially, that is to say parallel to the axis A, in the direction of the other part of the metal assembly 7, 8.

[0074] When fixing the cover 7 to the engine support 5, in particular to the base 51, the material of at least one part of the metal assembly 7, 8 is deformed by the other part.

[0075] The connecting element 13 is therefore arranged opposite and is intended to come into contact with a corresponding contact zone 15 on the other part of the metal assembly 7, 8, that is to say of the heat sink 8 if the connecting element 13 belongs to the cover 7 or conversely the contact zone is on the cover 7 if the connecting element 13 belongs to the heat sink 8. This punctual contacting makes it possible to ensure electrical continuity between the heat sink 8 and the cover 7.

[0076] In particular, at least one of the connecting element 13 and the contact zone 15 may deform when they come into contact during the fixing of the hood 7 on the engine support 5.

[0077] For example, the connecting element 13 is intended to deform the material of the contact zone 15 opposite under the effect of the fixing force.

[0078] According to a preferred embodiment, the part of the metal assembly 7, 8 whose material is deformed is the most fragile and / or the least functional of the two parts 7, 8. For example, the connecting element 13 is formed on the heat sink 8 and it is the material of the facing cover 7 which deforms when the cover 7 is fixed to the engine support 5.

[0079] At the contact zone 15, the other part, i.e. the cover 7 or the heat sink 8, may have a reduced thickness compared to the thickness of the rest of the cover 7 or the heat sink 8. Alternatively or additionally, the other part may have a smaller thickness, at least at the contact zone 15, than the thickness of the connecting element 13 at least at the contact point. This reduced thickness at least in the contact zone 15 facilitates deformation.

[0080] Alternatively, it is the connecting element 13 which may be intended to be deformed by the facing zone 15 of the metal assembly 7, 8 which comes into contact with the connecting element 13 under the effect of the fixing force.

[0081] Furthermore, the connecting element 13, in particular when it is configured to deform the contact zone 15 opposite provided on the cover 7 or alternatively on the heat sink 8, may have a shape facilitating an indentation of the other part, such as a triangular shape, a pointed shape, a refined shape, a tooth shape, a spike shape. The shape of the connecting element 13 may become refined in the direction of the contact zone 15. The connecting element 13 may therefore have a wider base at the heat sink 8, or the cover 7, and a finer apex or point closest to the contact zone 15 of the other part.

[0082] In this case, when fixing the cover 7 to the engine support 5, the connecting element 13 indents the contact zone 15 opposite. For example, a connecting element 13 with such a shape on the heat sink 8 (or alternatively on the cover 7), can indent the cover 7 (or alternatively the heat sink 8).

[0083] According to another alternative, the connecting element 13, in particular when it is configured to be deformed, can be more flexible than the contact zone 15 opposite. It can be envisaged, for example, that the connecting element 13 is produced by a flexible tab or a flexible strip. Such an element can, for example, be cut out and made integrally with the cover 7 or, alternatively, the heat sink 8.

[0084] Finally, more than one connecting element 13 may be provided. For example, at least four connecting elements 13 may be regularly distributed, in particular on the peripheral edge of the heat sink 8 or the cover 7.

[0085] GROUNDING PROCESS

[0086] Referring to Figures 1 and 2, a method of grounding the motor-fan unit 1 is described below.

[0087] During a step, the cover 7 is arranged on the engine support 5, in particular on the base 51, so as to cover the heat sink 8 and the control module 7. The connecting element or the connecting elements 13 on the heat sink 8 or on the cover 7 extends or extends in the direction of the other part of the metal assembly 7, 8, in particular of the contact zone 15 opposite.

[0088] The connecting element 13 can be made in one piece with the cover 7 or the heat sink 8, during a preliminary step.

[0089] When the cover 7 is arranged on the engine support 5, the connecting element 13 extends at least partly opposite a fixing element 9 of the cover 7 on the engine support 5, such as a screw. More precisely, the connecting element 13 is arranged close to the fixing element 9, for example at a distance of between 1 mm and 30 mm, preferably between 2 mm and 10 mm, in particular from 3 mm to 5 mm.

[0090] The cover 7 is then fixed to the engine support 5, for example by screwing. At least one of the connecting element 13 and the contact zone 15 opposite it deforms when the connecting element 13 comes into contact with the contact zone 15 during this fixing.

[0091] In other words, under the effect of the fixing force, the material of the part of the metal assembly 7, 8 which comes into contact with the connecting element 13 is deformed and / or the connecting element 13 is deformed.

[0092] For example, the connecting element 13 is formed on the heat sink 8 and the material of the cover 7 at the contact area 15 facing the connecting element 13 deforms during attachment. Alternatively, the connecting element 13 may be formed on the cover 7 and the material of the heat sink 8 at the contact area facing the connecting element 13 deforms during attachment. According to these variants, the connecting element 13 is rigid.

[0093] Alternatively, the connecting element 13 is a flexible element of the heat sink 8 or the cover 7 and deforms when it comes into contact with the associated contact zone 15 during fixing.

[0094] Maintaining contact is ensured by the plastic or elastic deformation between the connecting element 13 and the associated contact zone 15. This results in a constrained contact at the level of the deformation, which allows electrical continuity between the cover 7 and the heat sink 8, and thus grounding of the heat sink 8.

Claims

Claims

1. Method for grounding a motor-fan unit (1) in particular for a motor vehicle, the motor-fan unit (1) comprising a fan wheel (3), a motor for driving the fan wheel (3), a motor support (5), a control module (6) of the motor, a metal assembly (7, 8) defining a housing for the control module (6), the metal assembly (7, 8) comprising at least two parts formed by a cover (7) and a heat sink (8), the heat sink (8) being received in a housing of the motor support (5) and the control module (6) being mounted on the heat sink (8), characterized in that at least one part of the metal assembly (7, 8) comprises at least one connecting element (13), and in that said method comprises the following steps: arranging the cover (7) on the motor support (5), so as to cover the heat sink (8) and the control module (6),and so that at least one connecting element (13) of a part of the metal assembly (7, 8) extends towards the other part of the metal assembly (7, 8), fixing the cover (7) to the engine support (5), and under the effect of the fixing force, deforming the material of the part of the metal assembly (7, 8) which comes into contact with the connecting element (13) and / or deforming the connecting element (13), so as to ground the heat sink (8).,

2. Grounding method according to the preceding claim, comprising a step for producing the connecting element (13) in one piece with the cover (7) or the heat sink (8).

3. Grounding method according to one of the preceding claims, wherein the cover (7) is arranged on the engine support (5) so that the connecting element (13) extends at least partly opposite a fixing element (9) of the cover (7) on the engine support (5).

4. Grounding method according to one of the preceding claims, wherein the cover (7) is arranged on the engine support (5) so that the connecting element (13) is arranged at a distance from a fixing element (9) of the cover (7) on the engine support (5), between 1 mm and 30 mm, preferably between 2 mm and 10 mm, in particular from 3 mm to 5 mm.

5. A grounding method according to one of the preceding claims, wherein the fixing step is carried out by screwing.

6. Motor-fan unit (1) in particular for a motor vehicle, the motor-fan unit comprising a fan wheel (3), a motor for driving the fan wheel (3), a motor support (5), a control module (6) of the motor, a metal assembly (7, 8) defining a housing for the control module (6), the metal assembly (7, 8) comprising at least two parts formed by a cover (7) and a heat sink (8), the heat sink (8) being received in a housing of the motor support (5) and the control module (6) being mounted on the heat sink (8), characterized in that: the cover (7) is fixed to the motor support (5) so as to cover the heat sink (8) and the control module (6), and at least one part of the metal assembly (7, 8) comprises at least one connecting element (13) extending towards the other part of the metal assembly (7, 8),and configured to deform the material of the part of the metal assembly (7, 8) which comes into contact with the connecting element (13) under the effect of the fixing force, or configured to be deformed by the part of the metal assembly (7, 8) which comes into contact with the connecting element (13) under the effect of the fixing force.,

7. Motor-fan unit (1) according to the preceding claim, in which the connecting element (13) has a shape chosen from a pointed shape, a refined shape, a triangular shape, a tooth shape, a spike shape.

8. Motor-fan unit (1) according to one of claims 6 or 7, in which the connecting element (13) is arranged at least partly opposite a fixing element (9) of the cover (7) on the engine support (5).

9. Motor-fan unit (1) according to one of claims 6 to 8, in which the connecting element (13) is arranged at a distance from a fixing element (9) of the cover (7) on the motor support (5), between 1mm and 30mm, preferably between 2mm and 10mm, in particular from 3mm to 5mm.

10. Motor-fan unit (1) according to one of the preceding claims, in which the cover (7) and / or the heat sink (8) is made of aluminum or aluminum alloy.

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