Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/32—Rotors specially for elastic fluids for axial flow pumps
  • F04D29/325—Rotors specially for elastic fluids for axial flow pumps for axial flow fans
  • F04D29/326—Rotors specially for elastic fluids for axial flow pumps for axial flow fans comprising a rotating shroud

Definitions

• Fan propeller and associated fan nozzle in particular for a motor vehicle
• the invention relates to ventilation devices, in particular for motor vehicles.
• a motor vehicle usually comprises a fan, also called motor-fan unit, consisting of a clean electric motor to rotate a propeller for accelerating a flow of air for cooling purposes.
• the propeller is generally associated with a fan nozzle which has the function of channeling the air flow so that it passes through one or more heat exchangers, mainly the engine cooling radiator of the vehicle, forming a cooling module .
• the nozzle comprises for this purpose a wall provided with a circular opening disposed opposite the helix to be traversed by the air flow under the effect of the movement of the propeller and / or the speed of the vehicle.
• a fan impeller usually comprises a hub adapted to be driven about an axis of rotation, blades extending radially outwardly from the hub and a profiled ring connecting the outer ends of the blades.
• This profiled ring has an annular wall intended to come opposite an annular edge of a fan nozzle.
• the fan nozzle comprises a wall provided with an opening surrounded by an annular border of given axis, which annular edge is intended to come opposite a profiled ring of a propeller suitable for circulating a flow of air through the opening of the nozzle.
• the ring of the helix which is also called “ferrule”
• the ring of the helix has a generally tubular shape, that is to say it has a cylindrical wall around the liner. axis of the propeller.
• This cylindrical wall may possibly extend by a flange on the upstream or downstream side, that is to say vis-à-vis the flow of air which is set in motion by the propeller.
• the annular edge of the nozzle which surrounds the opening for entry of the air flow, is generally cylindrical and arranged coaxially with the profiled ring of the helix. In this way, a tubular annular space is created between the profiled ring of the helix and the annular edge of the fan nozzle.
• the flow air that is set in motion by the propeller tends to be guided in a direction generally parallel to the axis of the propeller.
• the vehicle engine and its accessories are located just behind the propeller and sometimes very close to the latter.
• the object of the invention is in particular to overcome this drawback.
• a fan propeller of the type defined above wherein the annular wall of the profiled ring has a flat or frustoconical shape forming in radial section, with respect to a plane perpendicular to the axis of rotation of the helix, an acute angle between 0 and 60 °.
• the annular wall of the profiled ring has a flat shape and is therefore contained in a plane perpendicular to the axis of rotation of the helix.
• this annular wall has a frustoconical shape.
• the invention relates, in a second aspect, a fan nozzle of the type defined in introduction, in which the annular edge of the nozzle is of flat or frustoconical shape, forming in radial section, with respect to a plane perpendicular to the axis of the opening, an acute angle between 0 ° and 60 °.
• the circular border may have a flat shape or frustoconical shape.
• the invention relates, in a third aspect, to a ventilation device comprising a fan impeller as defined above and a fan nozzle as defined above, the annular wall of the profiled ring and the annular edge of the nozzle. being arranged facing each other by making the axis of rotation of the helix coincide with the axis of the opening of the nozzle.
• the annular wall and the annular border are substantially the same acute angle in radial section relative to a plane perpendicular to the axis, which allows to provide a substantially constant clearance over the entire radial extent.
• the clearance defined by the space between the annular wall of the helix and the annular edge of the nozzle is, for example, 2 to 5 mm, to define a satisfactory air gap between rotating and fixed part.
• This clearance also contributes to forming a duct, in cross section, which must limit the effects of recirculation between the downstream zone and the upstream zone, the latter being at lower pressure.
• the peripheral air flow which passes in the gap between the annular wall of the profiled ring and the annular edge of the nozzle is directed radially outwardly, in a direction perpendicular to the axis of the helix, or in a direction slightly inclined relative to this axis, this with a solution having a limited axial size.
• Figure 1 is a half-view in axial and partial section of a fan propeller and an associated fan nozzle;
• Figure 2 is an enlarged detail of Figure 1;
• FIG. 3 is a view similar to Figure 2 in an alternative embodiment
• FIG. 4 is a front perspective view of a propeller according to the invention
• FIG. 5 is a rear perspective view of the helix of FIG. 4.
• the propeller 10 comprises a hub 14, also called “bowl”, adapted to be rotated about an axis of rotation XX.
• the hub 14 is keyed on a motor shaft 16 forming part of an electric motor (not shown) for driving the rotating propeller.
• Blades 18 extend radially outwardly from the hub 14 and are connected at their outer ends 20 by a profiled ring 22.
• This profiled ring 22 has an annular wall 24 which has a flat or frustoconical shape forming in radial section, relative to a plane perpendicular to the axis of rotation XX, an acute angle between 0 ° and 60 °, for example 45 °.
• this angle is 0 °, that is to say that the profiled ring 22 is made flat, its wall 24 extending in a plane perpendicular to the axis of rotation XX.
• the nozzle 12 comprises a wall 26 (shown partially) through which is formed a circular opening 28 whose axis coincides with the axis XX of the helix.
• This opening is surrounded by an annular border 30, having a shape of that of the annular wall 24.
• This annular edge 30 is intended to come opposite the profiled ring 22, that is to say more particularly of its annular wall 24.
• this angle is 0 °, that is to say that the annular edge 30 is formed flat and that it extends in a plane perpendicular to the axis of rotation XX .
• this annular border 30 can be made flat or frustoconical forming in radial section, by a plane perpendicular to the axis XX, an acute angle between 0 and 60 °, for example 45 °.
• the angular value chosen is the same for the annular wall of the profiled ring and the annular edge of the nozzle, which allows to provide a space or gap with a substantially constant clearance over the entire radial extent.
• the peripheral air flow that passes in the above-mentioned range extends radially outwards in the direction of the arrow F1, so that it can not block the flow of air passing through the propeller as shown by the arrow F2.
• this peripheral air flow is sent here in a generally radial direction.
• the main air flow which is set in motion by the propeller and which passes through the blades can be guided in a direction not parallel to the axis XX, which allows this flow of air to be deflected immediately. at the exit of the propeller to be able to circumvent the engine of the vehicle and / or its accessories, if the particular implementation of these requires it in the considered application.
• FIG. 3 shows an alternative embodiment in which the annular wall 24 of the profiled ring 22 has a frustoconical shape, as well as the annular edge 30 of the nozzle 12.
• the angle A thus formed is, in the example, neighbor of 30 °. However, it is possible to have different values, the angular range being between 0 and 60 °, for example 45 °.
• the propeller is advantageously made by molding in one piece, preferably plastic.
• a suitable plastics material is a polyamide filled with fibers or glass beads.
• the outer ends 20 of the blades 18 are each connected to an inner edge 32 of the annular wall 24 of the profiled ring 22 as shown in FIGS. 4 and 5.
• the ring is made flat, its annular wall 24 extending in a plane perpendicular to the axis XX.
• the outer ends 20 of the blades 18 are each connected to the inner edge 32 of the annular wall 24 by a connecting wall 34 which forms a spacer.
• These connecting walls 34 are molded and have a substantially triangular shape. They constitute cylindrical wall portions centered on the axis XX at the connection of the outer ends 20 of the blades 18 with the inner edge 32 of the profiled ring. Thus forms of bonding with reinforcement.
• the invention finds a particular application to the cooling fans of motor vehicles, without being limited to this particular application.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42289687

Family Applications (1)

Country Status (3)

Families Citing this family (1)

Family Cites Families (4)

• 2009
  • 2009-12-22 FR FR0906252A patent/FR2954419B1/fr not_active Expired - Fee Related
• 2010
  • 2010-12-09 EP EP10790556A patent/EP2516865A1/de not_active Withdrawn
  • 2010-12-09 WO PCT/EP2010/069310 patent/WO2011076583A1/fr active Application Filing

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events