FR3045740B1 - PROPELLER FOR A MOTOR FAN GROUP OF A COOLING SYSTEM OF A VEHICLE ENGINE - Google Patents

Abstract

The invention relates to a propeller (3) for a motor-fan unit (1) comprising a ferrule (2) delimiting an air flow passage through which the blades (6), the propeller ( 3) having a hub (5) adapted to be rotatably connected to a shaft of a drive motor (4), each blade (6) extending radially from the hub (5) by their inner end (61). each blade having a leading edge (62) and a trailing edge (63). According to the invention, the propeller comprises means for angular displacement (7) of the blades with respect to the hub so that the pitch of the blades is able to vary between an opening configuration according to which the leading edges and leakage (62, 63) of two adjacent blades are spaced apart from each other and a closure configuration of the air passage of the ferrule according to which these edges are brought together so that the blades form a wall of shutting off the air passage. The invention also relates to a motor-fan unit having such a propeller and a vehicle equipped with this motor-fan unit.

Description

Propeller for a motorcycle fan unit of a vehicle engine cooling system

TECHNICAL FIELD OF THE INVENTION The invention relates to the field of cooling devices for motor vehicles, in particular for cooling an internal combustion engine. The invention relates more particularly to a propeller for a motor-fan unit of a cooling system of a vehicle engine. The invention also relates to a motor-fan unit equipped with such a propeller and a vehicle equipped with such a motor-fan unit.

State of the art

Conventionally, motor vehicles include a cooling device for performing a heat exchange between a coolant and air. This is the reason why many vehicles are equipped with at least one heat exchanger on the front face so that the movement of the vehicle causes a relative movement of the air through the heat exchanger. When this relative movement of the air is insufficient, it is known to use the assistance of a motor-fan unit. The latter consists of a fixed volute on which a propeller is rotated by an electric motor.

In order to improve the coefficient of penetration into the air of the vehicle equipped with such a heat exchanger, it is known to arrange preferably at the front of the beam of the heat exchanger, a controlled shutter device. between a beam closing position and an opening position allowing air to flow through the heat exchanger. One of the disadvantages of adding an articulated blade frame lies in its size, which excludes it from certain categories of vehicle.

Another disadvantage lies in the fact that in the passive state of the motor-fan unit, the cooling air circulating through the propeller tends to cause its rotation, which causes premature wear of the wear parts of the propeller. engine, including its brooms.

OBJECT OF THE INVENTION The object of the invention is to remedy all of the aforementioned drawbacks and relates to a propeller for a motor-fan unit comprising a ferrule delimiting an air flow passage through which extend blades, the propeller having a central hub adapted to be rotatably connected to a shaft of a drive motor, each blade extending radially from the hub by their inner end, each blade having a leading edge and a trailing edge. The propeller object of the invention is all the more remarkable that it comprises a means of angular displacement of the blades relative to the hub so that the pitch of the blades is able to vary between at least one opening configuration according to wherein the leading and trailing edges of two adjacent blades are spaced apart from each other and a closure configuration of the air passage of the shell according to which these same edges are brought together so that the blades form a closing wall of the air passage. The propeller of the invention is intended to improve the efficiency of a vehicle, to limit the premature wear of some parts usually rotating, while allowing to generate if necessary a forced air flow.

Thanks to the propeller of the invention, the blades of the propeller are able to pivot between a configuration of free flow of air and a configuration of interruption of the flow of the air flow, and vice versa . The circulation of air through the propeller usually results in a rotation of the electric motor, so premature wear of the latter when the need for forced air flow is not required. In contrast, in its configuration of interruption of such a flow of air flow, the propeller is fixed in rotation. With the variable pitch propeller of the invention, the latter is able to form a shutter screen extending to the right of a heat exchanger, which tends to prohibit its rotation, which improves the operating life. of the motor. This also improves the efficiency of the vehicle, especially with respect to its coefficient of penetration into the air, which is then reduced when the propeller is in its closed configuration of the air passage.

According to the invention, said means for angular displacement of the blades may comprise a support connected to rotation to the hub, a disk movable in translation along the axis of rotation of the hub, and an electromagnet.

According to the invention, the helix may comprise two half-shells, each half-shell comprising a receiving means forming, for each blade, a transverse rotation bearing of a rotation shaft projecting out of a inner end of the blade.

According to the invention, the movable disc of the angular displacement means may comprise for each blade, a housing for receiving an eccentric projecting out of the rotation shaft of each blade on the hub.

According to the invention, said support may be a sliding guide along which the mobile disc is slidable under the effect of a traction force generated by the electromagnet.

According to the invention, a half-shell may be connected to the ferrule by connecting arms, and may be shaped in order to cooperate by complementarity of form with the support of said means for angular displacement of the blades.

According to the invention, the propeller may comprise at least one return spring exerting a force opposing the traction force of the electromagnet.

According to the invention, an outer end of each blade can be rotatably mounted on the shell of the propeller.

According to the invention, the mobile disk may comprise a magnet attachment interface so that the mobile disk is disposed inside the hub and the magnet of the electromagnet is disposed outside. hub. The invention also relates to a motor-fan unit comprising a propeller connected to rotation of a shaft of a drive motor, the propeller being in accordance with any of the aforementioned characteristics.

The motor-fan unit may comprise an electromagnet, a coil of which may be integral with a housing of the drive motor. The invention also aims at protecting a vehicle, in particular of the type of an automobile, comprising a motor-fan unit mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS Other advantages and features will emerge more clearly from the following description of the particular embodiment of the invention, given by way of nonlimiting example and represented in the accompanying drawings, in which: FIG. a perspective view of a helix in an interruption configuration of a flow of air through the blades, according to the invention; FIG. 2 is a perspective view of the helix of FIG. 1, in a configuration of free air circulation between the blades of the propeller, according to the invention; 3 shows a rear perspective view, the helix of Figure 1 to make visible in a partial section inside a hub of the propeller Figure 4 is a representation of a motorcycle fan unit comprising the propeller of the invention, seen from above according to the cross section plane IV-IV transverse of Figure 3; Figure 5 is an enlargement of the hub of Figure 3, shown in a partial perspective view, partly illustrating a means of angular displacement of the blades relative to the hub according to the invention.

Description of particular embodiments

In the following description, identical or similar elements will bear the same numbers and reference numbers. Expressions such as "back" and "front", "left" and "right", "upper" and "lower" and "longitudinal", "transverse" and "vertical" orientations will respectively be defined with reference to the X triad, Y, Z and the definitions given in the description. In particular, the longitudinal direction X corresponds to the direction of travel in the forward direction of a motor vehicle (not shown in the figures), which also corresponds to the inverted direction of flow of the cooling air through the propeller of the invention, also through the motor-fan unit carrying such a propeller.

Referring to the figures, the fan motor unit 1, more particularly the propeller 3 on board this fan motor unit, proposes a system for improving the efficiency of the vehicle in the air, by reducing the penetration coefficient in the air. vehicle air.

To do this, the propeller 3 of the motor-fan unit 1 which is able to create a forced air flow intended to pass through at least one heat exchanger of a cooling device, is remarkable in that it comprises blades 6 which are rotatably mounted relative to a central hub of the propeller. Such a design advantageously makes it possible to position the helix 3 in different configurations ranging from an aperture configuration in which the helix is able to cause an air flow during its rotation, to a closure configuration in which the propeller is a partition that blocks the flow of air which improves the performance of the vehicle.

The hub 5 on which are mounted the various blades 6 of the propeller comprises a clean bowl to be wedged on a motor shaft 4 to be rotated in a given direction of rotation.

The motor 4 is an electric motor which is connected to a control unit. The control of its power can be achieved by a frequency modulation device.

Each blade 6 has a profile delimited by an inner line of curved shape and an outer line of curved shape and shaped so that these two lines meet in a leading edge 62 and a trailing edge 63.

A blade 6 is also defined by an inner end 61 and an outer end 64. The inner end 61 is connected to the hub 5 of the propeller. The propeller comprises a ferrule 2 delimiting an outer ring of the propeller, the effect of which is to reduce the noise nuisance caused by the displacement of the blades 6. Such an outer ring of the propeller 3 is intended to cooperate by cooperation and complementarity. with an opening in an air suction volute to improve the flow of air by reducing turbulence when the propeller 3 is rotated by the motor 4. The outer end 64 of each blade 6 is then rotatably mounted on the shell 2. For this purpose, the shell 2 comprises housings, one per blade, in each of which is disposed an axis of rotation of one of the blades 6. The housing is preferably of the type of a hole passing right through the outer ring formed by the shell 2. Each blade 6 comprises a rotation shaft projecting out of its outer end 64.

The ferrule 2 is preferably connected to a hub 5 of the propeller by connecting arms 21 visible in FIGS. 3 to 5. From the hub 5, which is of the type of a bowl, radially extend a plurality of blades 6 whose inner end 61 is attached to the hub and the outer end 64 is connected to an outer ring forming said ferrule 2.

The motor 4 is shown schematically in FIG. 4, in an arrangement downstream of the propeller 3 with respect to the direction of flow of the air, which is indicated by the arrows F. The arrangement of the motor 4 relative to the propeller can be different, that is to say it can be arranged upstream of the latter without departing from the scope of the invention.

Whatever the type of arrangement, the motor 4 comprises a rotor rotatably connected to the hub 5 by a not shown drive shaft extending along the axis 8 of rotation. The propeller 3 of the invention is remarkable in that these blades 6 are movable in rotation relative to the hub 5, about an axis 11 of rotation extending radially out of the hub 5.

In Figure 2, the propeller 3 is in a traditional configuration of free movement of air between its blades. The pitch of the propeller 3 allows it to generate a forced air flow when, in this opening configuration of the blades, the drive motor 4 causes the rotation of the propeller 3. The leading edges 62 and leakage 63 extend in transverse parallel planes spaced X. The gap between the leading edge 61 of a blade 6 and the trailing edge 63 of another blade 6 which is directly adjacent thereto, allows an air flow through the propeller 3.

In Figures 1 and 3, the propeller 3 is in a closed configuration of the air passage defined by the ferrule. In this configuration, the airflow is interrupted. Compared with the configuration of the propeller 3 of FIG. 2, here the blades 6 are represented in a pivoted state at an angle preferably comprised between 5 and 20 ° around the axes 11 of rotation passing through the hub 5. The edges Attack 62 and leak 63 blades 6 can thus extend substantially in the same and only transverse plane YZ axis. The propeller 3 then has a quasi-zero pitch so that its rotation can not generate an air flow sufficient to achieve a heat exchange between the air and a coolant-type fluid, for example, flowing in a heat exchanger.

Such a configuration of the blades 6 gives the propeller 3 a shutter role to block any air flow through the passage of the propeller, whether natural when the vehicle is moving or forced when the engine drive 3 is in operating mode.

In the following will be described in detail said means of angular displacement 7 of the blades relative to the hub so that they can move between extreme positions of opening and closing and at least an intermediate position of quasi-closure in which a reduced airflow can flow between the blades 6.

Each blade 6 comprises a rotation shaft 65 projecting out of its inner end 61. The rotation shaft 65 pivots about an axis of rotation coinciding with the axis of rotation of the outer end 64 on the ferrule 2. The rotation shaft 65 comprises at its free end an eccentric 66.

A displacement of the eccentric, of the type of a translational movement parallel to the axis 8 of rotation of the helix 3, generates concomitantly the rotation of the blade 8 around the axis of rotation 11.

The angular displacement device 7 comprises a disk 72 movable in translation disposed inside the bowl forming the hub 5. The movable disk 72 is provided with housings 54 for receiving the eccentrics 66. Each receiving housing 54 can be of the type d an oblong Z-axis slot. The actual design of the housings 54 is subject to that of the eccentrics 66 so that the latter 66 is slidably displaced along the Z axis when the angular displacement device 7 is made movable by X axis translation.

The angular displacement device 7 comprises a moving means of the disc 72 movable along the axis 8 of rotation. Such a means for moving the disc 72 comprises an electromagnet 9 consisting of a magnet 91 integral with the movable disk 72 and a coil 92 which can be secured to a housing of the drive motor 4. The magnet 91 may be a magnetic disk as partially shown in FIGS. 3 to 5.

The coil 92 may be arranged on a structural element of a support frame on which is arranged the motor-fan unit.

The coil 92 may be a part of the winding of the motor 4 so that the angular displacement of the blades 6 of the closure configuration towards the opening configuration is carried out concurrently with the rotation of the propeller 3.

The movable disc 72 can be made by molding a plastic material.

Advantageously, the use of the plastic material allows the mobile disk 72 to be connected to the magnet 91 by overmoulding so that the movable disc 72 is integral in translation with the magnet 91.

Said angular displacement means 7 of the blades 6 comprises a support 71 reversibly assembled to the hub 5, preferably by screwing.

The hub 5 consists of at least two half-shells 51 and 52 assembled to each other in opposition from the front to define a chamber inside which is arranged at least the movable disc 72. One of the half-shells 51, of the type of a bowl, comprises the connecting arms 21 to the shell 2. The other of the half-shells 52 also of the type of a bowl comprises, at its wall of bottom, a substantially cylindrical opening which is closed by the support 71 of said angular displacement means 7.

The hub 5 comprises a receiving means 53 forming, for each blade 6, a transverse bearing intended for the rotation of a shaft 65 of rotation of the blade projecting out of its inner end 61. The outer peripheral edges of the blades two half-shells 51 and 52 comprise notches forming said receiving means 53. Each notch substantially has a semi-circular arc section. The notches are in pairs arranged opposite each other so that the assembly of the two half-shells by their outer peripheral edge allows for tubes forming bearings on which the rotation shafts 65 of the blades are able to rotate.

The means of angular displacement 7 of the blades comprises a return spring 10 which is arranged between the movable disc 72 and the support 71. The return spring 10 works in compression so that it opposes the approach of the disc 71 and support 72 under the influence of the electromagnet 9 connected to a control unit (not shown).

The means for angular displacement 7 of the blades comprises a device for guiding the disc 72 movable on the support 71 in translation. Such a guiding device is in the form of a ramp of tubular section projecting out of a groove. inner face of the support 71 on which is slidably mounted a guided wall of substantially complementary shape which is provided on the movable disk 72.

The return spring is arranged around the ramp of the support 71 and the guided wall of the disc 72.

In order to limit the translational movement of the disc 72 along the axis 8 of rotation, said angular displacement means 7 comprises means of abutment of the disc 72 on the support 71. The stops, more particularly their thickness, are subject to the profile of the blades so that in the opening configuration of the air passage, the relative position of the blades 6 on the hub 5 is limited. By way of nonlimiting example, such abutting means is formed by ribs disposed on the disc 72 and the support 71. Such ribs also make it possible to increase the rigidity of the disc 72 and the support 71 to the deformation. The stops have a circular profile so that they extend coaxially with said guide device of the disk 72 on the support 71, mentioned above. The radial distance between the above-mentioned guiding device and said abutment means delimits annular section housings respectively disposed on the movable disk 72 and the support 71, each housing receiving one end of the return spring.

In the absence of the need for cooling, the blades 6 of the propeller 3 of the invention are in the closed configuration of the air passage. The spring 10 exerts on the mobile disc 72 a thrust force which moves the disc 72 away from the support 71 so that the magnet 91 abuts against an outer face of the support 71.

When the heat exchange device (not shown) requires cooling, the control unit circulates a current in the coil 92 so that the magnetic field thus created by the current in the coil tends to bring the disk 72 closer to the coil. support 71. The return spring 10 is compressed. The moving of the movable disk 72 of the support 71 causes a displacement of the receiving housing 54 of the eccentric 66, in a translational movement along the axis 8 of rotation. The eccentric 66 generates a rotation of the shafts 65 of rotation of the blades 6 on said receiving means 53 of the hub 5.

The current may be of variable intensity so that it generates a tensile force of variable intensity. The difference between the leading edges 62 and adjacent blade 6 leaks 6 is variable between a minimum distance associated with the configuration of closing the air passage and a maximum deviation associated with the total opening configuration of the air passage. 'air.

The relative position of the blades 6 on the hub 5 can thus vary between at least one opening configuration and the configuration of closing the air passage which is delimited in part by the volute 2.

The relative position of the blades 6 on the hub 5 is dependent on the tensile force generated by the electromagnet 9 so that, depending on the intensity of the current flowing in the coil, the blades 6 can be moved in a configuration of opening among several.

The fan motor unit 1 equipped with the propeller 3 is remarkable in that it allows improved management of the air flow through the heat exchanger, while increasing the efficiency of the vehicle. The variable pitch propeller 3 between an opening configuration and a configuration for closing the air passage of the volute 1 allows optimized airflow management, both when the propeller stops and when the forced rotation of the propeller 3 by the motor 4 of the fan motor unit 1. The propeller 3 is preferably intended for application in a motor-fan unit 1 on board a motor vehicle. It can of course find other applications in which a need for closing an air passage and a need for forced flow of air are sought.

Preferably, the propeller 3 is a constituent element of a motorcycle fan unit for a motor vehicle, in that it allows the forced flow of air through a heat exchange device. The invention therefore relates to a vehicle equipped with such a motor-fan unit.

Claims (10)

claims Propeller (3) for a motor-fan unit (1) comprising a shell (2) delimiting an air flow passage through which blades (6) extend, the propeller (3) comprising a hub (5) adapted to be rotatably connected to a shaft of a drive motor (4), each blade (6) extending radially from the hub (5) by their inner end (61), each blade having a leading edge (62) and a trailing edge (63), characterized in that the helix comprises means for angular displacement (7) of the blades with respect to the hub so that the pitch of the blades is adapted to vary between at least one aperture configuration in which the leading and trailing edges (62, 63) of two adjacent blades are spaced apart from each other and a configuration of closure of the air passage of the ferrule according to which these same edges are brought together so that the blades form a closing wall of the passag of air and in that said means for angular displacement (7) of the blades (6) comprises a support (71) rotatably connected to the hub (5), a disc (72) movable in translation along the axis (8) of rotation of the hub, and an electromagnet (9), 2. Propeller (3) according to claim 1, characterized in that the hub (5) comprises two half-shells (51, 52), each half-shell comprising a receiving means (53) forming, for each blade (6 ), a transverse rotation bearing of a rotation shaft (65) projecting out of an inner end (61) of the blade (6). 3. Propeller (3) according to claim 2, characterized in that the disk (72) comprises for each blade (6), a receiving housing (54) of an eccentric (66) projecting out of the shaft (65) for rotating each blade (6) on the hub (5). 4. Propeller (3) according to claim 3, characterized in that said support (71) is a sliding guide along which the movable disk (72) is slidable under the effect of a traction force generated by the electromagnet (9). 5. Propeller (3) according to claim 4, characterized in that a half-shell (52) is connected to the shell (2) by connecting arms (21), and is shaped to cooperate by complementarity of form with the support (71) of said angular displacement means (7) of the blades (6). 6. Propeller (3) according to one of claims 4 and 5, characterized in that it comprises at least one return spring (10) exerting a force opposing the traction force of the electromagnet (9) . 7. Propeller (3) according to any one of the preceding claims, characterized in that an outer end (64) of each blade (6) is rotatably mounted on the shell (2) of the propeller. 8. Propeller (3) according to claim 1 in combination with any one of claims 2 to 7, characterized in that the movable disc (72) comprises an attachment interface (73) of a magnet (91) of such so that the movable disk (72) is arranged at the bottom of the hub (5) and the magnet (91) of the electromagnet (9) is arranged outside the hub. Motor-fan unit (1) comprising a propeller (3) connected to rotation of a shaft of a drive motor (4), characterized in that the propeller (3) is in accordance with any one Claims 1 to 8. Vehicle, in particular of the type of an automobile, comprising a motor-fan unit (1) according to claim 9.