Airflow generator for a motor vehicle cooling system

Abstract

Air flow generator (1) comprising a motor support (22) on which a stator (24) is fixed and further comprising a deflector (23), said deflector (23) comprising: - an inner ring (23a) comprising a central opening (231a) through which the stator (24) and a rotor (26) pass, and - an outer ring (23b) connected to said inner ring (23a) by means of elastic buffers (233), the motor support (22), the stator, (24) the rotor (26) as well as the inner (23a) and outer (23b) rings of the deflector (23) being coaxial around a longitudinal axis (X), the outer ring (23b) comprising at least three stop fingers (235) projecting in the direction of the longitudinal axis (X), the stop fingers (235) comprising a first stop face (235a) intended to come to the contact of a lower contact zone (236a) of the inner ring (23a) and a second abutment face (235b) intended to come into contact with an upper contact zone (226) of the engine support (22).Abstract figure: Fig 5.

Description

Title of the invention: Air flow generator for a motor vehicle cooling system

[0001] The present invention relates to the field of heating, ventilation and / or air conditioning devices for motor vehicles, and it relates more particularly to an air flow generator for such a device.

[0002] Motor vehicles are commonly equipped with heating, ventilation and / or air conditioning devices, which make it possible to generate one or more air flows and to manage the temperature and distribution thereof within the passenger compartment of the vehicle. These heating, ventilation and / or air conditioning devices comprise, among other things, an air flow generator started by an electric motor to generate an air flow. By air flow generator is meant a device for sucking in and / or blowing air. The electric motor is in particular an electronically commutated electric motor, controlled by a power supply module to drive a ventilation wheel in rotation.

[0003] Electronically commutated electric motors, or brushless DC motors (also known as "brushless"), comprise 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 furthermore the movement of the ventilation wheel. The rotor and the stator are mounted independently of each other in said motor, and it is necessary to ensure that the relative positioning of these two components is correct for optimal operation of the motor.

[0004] It is understood that when the engine is in operation, the stator is subjected to vibrations and stresses due to the rotational movement of the rotor, and it is desired that these vibrations are not transmitted to the structure of the vehicle, in order to avoid premature wear of the assembly but also to limit noise pollution. A decoupling element is then provided whose main role is to filter the acoustic frequencies and vibrations generated by the engine and to eliminate or, at the very least, to limit as much as possible, their transmission to the heating, ventilation and / or air conditioning device and to the structure of the vehicle.

[0005] This decoupling element is made of a material capable of fulfilling the expected role with respect to mechanical and acoustic vibrations (for example, an elastomeric material), said material being arranged between the stator of the motor and the connection to the housing. It can be provided that this material is in the form of a plurality of discrete elements distributed regularly angularly. Whatever the form taken by this decoupling element, it plays a role in limiting as much as possible, or even eliminating, in particular, any excessive relative movement of the support elements in relation to each other and, in particular, any tilting movement. However, the vibrations and relative movements of the elements of the air flow generator between them can have significant amplitudes which can lead to shocks between different fixed or mobile elements and thus cause premature deterioration and wear of the air flow generator.

[0006] One of the aims of the present invention is therefore to remedy at least partially the drawbacks of the prior art and to propose an improved air flow generator, in particular for a motor vehicle.

[0007] To this end, the present invention relates to an air flow generator comprising a motor support on which a stator is fixed, said air flow generator further comprising a deflector, said deflector comprising: - an inner ring comprising a central opening through which the stator and a rotor pass, said inner ring being secured to the motor support, and - an outer ring connected to said inner ring by means of elastic buffers, said outer ring being intended to be fixed to a stable structure, the motor support, the stator, the rotor as well as the internal and external rings of the deflector being coaxial around a longitudinal axis, the outer ring comprising at least three stop fingers projecting in the direction of the longitudinal axis, the stop fingers comprising a first stop face intended to come into contact with a lower contact zone of the internal ring and a second stop face intended to come into contact with an upper contact zone of the engine support.

[0008] According to one aspect of the invention, the stop fingers are made of the same material as the outer ring.

[0009] According to another aspect of the invention, the first and second stop faces of the stop fingers are covered with a layer of an elastomeric material.

[0010] According to another aspect of the invention, the layer of elastomer material is overmolded on the stop finger.

[0011] According to another aspect of the invention, the central opening of the outer ring has a diameter greater than the diameter of the motor support so that said motor support is arranged within said central opening, the outer ring having an upper internal wall so as to exceed the height of the motor support, the stop fingers projecting from said upper internal wall of the outer ring.

[0012] According to another aspect of the invention, the face of the internal ring facing the engine support comprises at least one lower peripheral wall projecting towards the engine support, the lower contact zone of the internal ring being the free edge of said lower peripheral wall.

[0013] According to another aspect of the invention, the second face of the engine support comprises an upper peripheral wall projecting towards the internal ring, the upper contact zone of the engine support being the free edge of said upper peripheral wall.

[0014] According to another aspect of the invention, the stop fingers are equally distributed on the internal periphery of the external ring.

[0015] According to another aspect of the invention, the stop fingers are distributed, on the external ring, on radial axes starting from the longitudinal axis separated by a maximum angle of 120°.

[0016] According to another aspect of the invention, the distance between the stop finger and the lower contact zone of the internal ring as well as the distance between the stop finger and the upper contact zone of the engine support are less than or equal to 2 mm.

[0017] Other characteristics and advantages of the invention will emerge from the following description, given by way of example, without limitation, with reference to the drawings appended below.

[0018] [Fig-1] [Fig.l] shows a schematic representation in exploded perspective of a airflow generator,

[0019] [Fig.2] [Fig.2] shows a schematic perspective representation of a die deflector of an air flow generator,

[0020] [Fig.3] [Fig.3] shows a schematic representation in exploded perspective of the deflector of [Fig.2],

[0021] [Fig.4] [Fig.4] shows a schematic perspective representation of the ring external of the deflector of figures 2 and 3,

[0022] [Fig.5] [Fig.5] shows a schematic representation in perspective and in section of a portion of the deflector of [Fig.2].

[0023] In these figures, identical elements have the same reference numbers.

[0024] 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 and / or interchanged to provide other embodiments.

[0025] In the present description, certain elements or parameters may be indexed, such as for example first element or second element as well as first parameter and second parameter or even 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.

[0026] [Fig. 1] illustrates an air flow generator 1 for sucking and blowing air. The air flow generator 1 comprises a motor unit 2 and an electronic control unit 3 located in the extension of one another along a main longitudinal axis X (illustrated by a dotted line). The electronic control unit 3 is thus positioned to power the motor unit 2 while limiting the magnetic disturbances generated by its own internal elements which will be described later.

[0027] The motor unit 2 consists of a brushless electric motor, also called an electronically commutated electric motor. It is capable of driving a ventilation wheel 28 in rotation via an output shaft 260 of said motor unit 2, extending along said longitudinal axis X.

[0028] The motor unit 2 mainly comprises a stator 24 provided with an excitation winding and a rotor 26, carrying the output shaft 260 capable of driving the ventilation wheel 28. The rotor 26 is arranged around the stator 24 to be driven in rotation under the effect of magnetic fields generated by the winding and the magnets associated with the rotor 26.

[0029] The rotor 26 may in particular comprise a cup 264 symmetrical by rotation about the longitudinal axis X, in the shape of a bell. The rotor 26 also comprises magnets (not shown) fixed to an internal face of the cup 264, in particular on a cylindrical strip of the internal face of the cup 264. The cup 264 of the rotor 26 is fixed, at its center, to the output shaft 260. The output shaft 260 constitutes the output (or rotation) shaft of the electric motor 14, driving the fan wheel 12. For this purpose, the fan wheel 26 is here directly fixed on the output shaft 260.

[0030] The stator 24 may be symmetrical by rotation around the longitudinal axis X. The stator 24 may in particular comprise a barrel 240 extending mainly in the direction of the longitudinal axis X. The cup 264 of the rotor 26 in particular covers one end of the barrel 240 opposite its base (not visible).

[0031] As illustrated in [Fig.l], the barrel 240 comprises in particular a base and an internal channel (not visible). The internal channel passes right through the barrel 240 in the direction of the longitudinal axis X. The internal channel may be generally cylindrical. The internal channel may in particular comprise at least one housing intended to receive a bearing ring in which the shaft 260 is inserted. Preferably, two housings are formed in the internal channel of the barrel 240. Each housing is intended to receive a bearing ring, in particular a ball bearing. These housings are more particularly arranged respectively at the ends of the internal channel. The shaft 260 is received partly in the internal channel of the stator 24, free to rotate around the longitudinal axis X relative to the stator 24, by means of the bearing rings. The bearing rings can in particular be held within their respective housings by means of an internal elastic ring such as a circlip.

[0032] The barrel 240 also comprises a plurality of branches extending radially relative to the longitudinal axis X. The branches protrude in particular from the barrel 240. The barrel 240 and more particularly its branches 31 are made of an electrically non-conductive material, for example plastic. The barrel 240 may in particular be a single piece in that there is continuity of material between the branches and the barrel 240. An alternative not shown may also be that the branches are made on an independent part having an annular central part from which the branches protrude and fixed to the barrel 240. The barrel 240 is for example made by molding, in particular by injection molding.

[0033] A stack of metal sheets is arranged on the branches of the barrel 240. The stator 24 also includes an insulator covering the stack of metal sheets. The stack of metal sheets is thus held and sandwiched between the branches of the barrel 240 and the insulator. The insulator is also made of an electrically non-conductive material.

[0034] The branches form a winding support around which at least one winding 242 is wound. Each winding 242 corresponds to a phase of the electric motor. A three-phase electric motor thus comprises a multiple of three series of windings 242, for example twelve. The windings 242 are made by windings of a metal wire, generally copper, surrounding the branches of the stator 24. These windings are made so as to be in contact only with the branches of the barrel 240 so as not to be in electrical contact with the stack of metal sheets.

[0035] The stator 24, more particularly the base of the barrel 240, is in particular fixed to a motor support 22, for example by means of screws. This motor support 22 is also made of an electrically non-conductive material. The motor support 22 may also be symmetrical by rotation around the longitudinal axis X and have a central opening above which the barrel 240 is fixed. The rotor 26 and in particular the external edges of the cup 264 may in particular pass directly above said support 16.

[0036] Opposite a first face of the motor support 22 from which the stator 24 projects, a printed circuit 34 is fixed on a second face of the motor support 22, for example by means of screws. The printed circuit 34 comprises in particular electrical and electronic components in order to control the air flow generator 1 and to ensure the electrical supply of the windings 242 of the stator 24. Each winding 242 is electrically connected to the printed circuit 34 and to its power supply. This connection of the windings 242 can in particular be achieved by metal tabs 244 projecting from the stator 24 and passing through the motor support 22.

[0037] A metal plate 32 is arranged between the printed circuit 34 and the motor support 22. The metal plate 32 is connected to the electrical ground. The electrical connections of the windings 242 pass through the metal plate 32 without electrical contact through orifices (not shown). This metal plate 32 plays various roles, in particular grounding, heat sink and protection against electromagnetic waves.

[0038] The metal plate 32 and the printed circuit 34 are advantageously covered by a cover 36. When the electronic control unit 3 is assembled, the printed circuit 34, the metal plate 32 and the cover 36 are held together by means of through-fixing means (not shown), for example screws.

[0039] The air flow generator 1 also comprises a cover or deflector 23 symmetrical by rotation around the longitudinal axis X arranged between the motor support 22 and the external edges of the fan wheel 28. This deflector 23 comprises in particular a central opening 231a, 231b through which the stator 24 and the rotor 26 pass.

[0040] As illustrated in more detail in Figures 2 to 4, the deflector 23 more particularly comprises a so-called internal ring 23a fixed to the engine support 22 and a so-called external ring 23b connected to said internal ring 23a.

[0041] The internal ring 23a comprises in particular a central opening 231a through which the stator 24 and a rotor 26 pass. The internal ring 23a is in particular secured to the motor support 22. The internal ring 23a can be fixed to the motor support 22 by means of screws or clips 232 as illustrated in [Fig.3].

[0042] The outer ring 23b is connected to said inner ring 23a by means of elastic buffers 233. The outer ring 23b comprises in particular a central opening 231b whose diameter is greater than or equal to the diameter of the inner ring 23a. The support 22 is arranged in the central opening 231b of the outer ring 23b so that the inner ring 24a is above said central opening 231b. The elastic buffers 233 are connected between the top of the outer ring 23b and the periphery of the inner ring 23a. The outer ring 23b is in particular intended to be fixed to a stable structure, for example in a structural housing of a heating, ventilation and / or air conditioning device (not shown) within a motor vehicle.A sealing lip 250 (visible in figures 3 and 5) may in particular be arranged between the support 22 and the external ring 22b in order in particular to prevent dust and / or water from reaching the electronic control unit 3.

[0043] In the example illustrated, the deflector 23 more particularly comprises six elastic buffers 233. These elastic buffers 233 are grouped into three groups each comprising two elastic buffers 233. These groups are distributed equally over the circumference of the deflector 23 so as to be able to absorb vibrations in all orientations.

[0044] The elastic buffers 233 thus have a shock absorber role in order to absorb the vibrations and relative movements of the internal ring 23a connected to the engine support 22 and therefore undergoing the vibrations linked to the rotation of the rotor 26 and the ventilation wheel 28 relative to the external ring 23b fixed to a stable structure of the motor vehicle. This thus makes it possible to limit the vibrations on the one hand but also to limit the noise of the air flow generator 1.

[0045] The motor support 22, the stator, 24 the rotor 26 as well as the internal 23a and external 23b rings of the deflector 23 are coaxial around a longitudinal axis X,

[0046] As illustrated in Figures 3 to 4 and in particular the sectional view of [Fig.5], the outer ring 23b comprises at least three stop fingers 235 projecting in the direction of the longitudinal axis X. These stop fingers 235 comprise a first stop face 235a intended to come into contact with a lower contact zone 236a of the inner ring 23a and a second stop face 235b intended to come into contact with an upper contact zone 226 of the engine support 22.

[0047] By upper, we mean here an element or a face of an element oriented upwards according to the arbitrary representation of figures 1 to 5 or else oriented towards the ventilation wheel 28. Conversely, by lower, we mean here an element or a face of an element oriented downwards according to the arbitrary representation of figures 1 to 5 or else oriented away from the ventilation wheel 28.

[0048] The stop fingers 235 make it possible in particular to limit the amplitude of the relative movements between the external ring 23b which is fixed because it is connected to a stable structure of the motor vehicle and the rest of the air flow generator 1, in particular the engine support 22 and internal ring 23a pair. At a stop finger 235, the downward movements of the engine support 22 and the internal ring 23a are limited when the first stop face 235a of the stop finger 235 comes into contact with the lower contact zone 236a of the internal ring 23a. The upward movements of the engine support 22 and the internal ring 23a are limited when the second stop face 235b of the stop finger 235 comes into contact with the upper contact zone 226 of the engine support 22.The fact that there are at least three stop fingers 235 thus makes it possible to limit the amplitude of the relative movements between the external ring 23b and the engine support pair 22 / internal ring 23a in all directions parallel or inclined relative to the longitudinal axis X.

[0049] The stop fingers 235 can more particularly come from the same material as the ring external 23b. The stop fingers 235 can thus, for example, be produced at the same time as the external ring 23b, for example by molding.

[0050] As visible in [Fig. 5], the first 235a and second 235b stop faces of the stop fingers 235 may be covered with a layer of an elastomer material. This layer of elastomer material makes it possible in particular to absorb shocks when the stop fingers 235 reach the stop and thus makes it possible to reduce these impact noises.

[0051] The layer of elastomer material can in particular be overmolded on the stop finger 235 in order to limit costs.

[0052] As described above and visible in particular in Figures 2, 3 and 5, the central opening 231b of the external ring 23b has a diameter greater than the diameter of the motor support 22 so that said motor support 22 is arranged within said central opening 231b. The external ring 23b can thus comprise an upper internal wall 238 so as to exceed the height of the motor support 22, and from which the stop fingers 235 project. The stop fingers 235 thus overhang the motor support 22.

[0053] The face of the internal ring 23a facing the motor support 22 may comprise at least one lower peripheral wall 239 projecting towards the motor support 22. The lower contact zone 236a of the internal ring 23a may thus be the free edge of said lower peripheral wall 239. This lower peripheral wall 239 may for example only be present locally, directly above a stop finger 235, or extend over the entire circumference of the internal ring 23a.

[0054] The second face 226 of the motor support 22 may comprise an upper peripheral wall 229 projecting towards the internal ring 23a. The upper contact zone 226 of the motor support 22 may thus be the free edge of said upper peripheral wall 229. This upper peripheral wall 229 may for example only be present locally, directly above a stop finger 235, or extend over the entire circumference of the motor support 22.

[0055] As shown in Figures 3 and 4, the stop fingers 235 can be equally distributed over the inner periphery of the outer ring 23b. In the example illustrated, the outer ring 23b more particularly comprises six stop fingers 235. These stop fingers 235 are grouped into three groups each comprising two stop fingers 235. These groups are equally distributed over the circumference of the outer ring 23b so as to be able to limit the relative movements between the outer ring 23b and the engine support 22 / inner ring 23a pair in all directions parallel or inclined relative to the longitudinal axis X.

[0056] The stop fingers 235 may in particular be distributed, on the external ring 23b, on radial axes Y starting from the longitudinal axis X and separated by a maximum angle of 120°. This distribution also makes it possible to limit the relative movements between the external ring 23b and the engine support pair 22 / internal ring 23a according to all directions parallel or inclined to the longitudinal axis X.

[0057] As visible in [Fig.5] in sectional view, the distance between the stop finger 235 and the lower contact zone 236a of the internal ring 23a is preferably less than or equal to 2mm. Similarly, the distance between the stop finger 235 and the upper contact zone 236a of the motor support 22 is also preferably less than or equal to 2mm.

[0058] Thus, it is clear that the air flow generator 1, due to the presence of the stop fingers 235, makes it possible to limit the amplitude of the vibration movements of the motor itself and thus makes it possible to prevent the ventilation wheel 28 from, for example, hitting the internal walls of a heating, ventilation and / or air conditioning device generating noise as well as risks of deterioration of the air flow generator 1.

Claims

Claims

1. Air flow generator (1) comprising a motor support (22) on which a stator (24) is fixed, said air flow generator (1) further comprising a deflector (23), said deflector (23) comprising: - an inner ring (23a) comprising a central opening (231a) through which the stator (24) and a rotor (26) pass, said inner ring (23a) being integral with the motor support (22), and - an outer ring (23b) connected to said inner ring (23a) by means of elastic buffers (233), said outer ring (23b) being intended to be fixed to a stable structure, the motor support (22), the stator, (24) the rotor (26) as well as the inner (23a) and outer (23b) rings of the deflector (23) being coaxial around a longitudinal axis (X), characterized in that the outer ring (23b) comprises at least three stop fingers (235) projecting in the direction of the longitudinal axis (X),the stop fingers (235) comprising a first stop face (235a) intended to come into contact with a lower contact zone (236a) of the internal ring (23a) and a second stop face (235b) intended to come into contact with an upper contact zone (226) of the engine support (22).,

2. Air flow generator (1) according to the preceding claim, characterized in that the stop fingers (235) are made of the same material as the external ring (23b).

3. Air flow generator (1) according to any one of the preceding claims, characterized in that the first (235a) and second (235b) stop faces of the stop fingers (235) are covered with a layer of an elastomeric material.

4. Air flow generator (1) according to the preceding claim, characterized in that the layer of elastomer material is overmolded to the stop finger (235).

5. Air flow generator (1) according to any one of the preceding claims, characterized in that the central opening (231b) of the outer ring (23b) has a diameter greater than the diameter of the motor support (22) so that said motor support (22) is arranged within said central opening (231b), the outer ring (23b) comprising a upper internal wall (238) so as to exceed the height of the engine support (22), the stop fingers (235) projecting from said upper internal wall (238) of the external ring (23b).

6. Air flow generator (1) according to any one of the preceding claims, characterized in that the face of the internal ring (23a) facing the motor support (22) comprises at least one lower peripheral wall (239) projecting in the direction of the motor support (22), the lower contact zone (236a) of the internal ring (23a) being the free edge of said lower peripheral wall (239).

7. Air flow generator (1) according to any one of the preceding claims, characterized in that the second face (226) of the motor support (22) comprises an upper peripheral wall (229) projecting towards the internal ring (23a), the upper contact zone (226) of the motor support (22) being the free edge of said upper peripheral wall (229).

8. Air flow generator (1) according to any one of the preceding claims, characterized in that the stop fingers (235) are equally distributed on the internal periphery of the external ring (23b).

9. Air flow generator (1) according to any one of the preceding claims, characterized in that the stop fingers (235) are distributed, on the external ring (23b), on radial axes (Y) starting from the longitudinal axis (X) separated by a maximum angle of 120°.

10. Air flow generator (1) according to any one of the preceding claims, characterized in that the distance between the stop finger (235) and the lower contact zone (236a) of the inner ring (23a) as well as the distance between the stop finger (235) and the upper contact zone (236a) of the motor support (22) are less than or equal to 2 mm.

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