Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/20—Casings or enclosures characterised by the shape, form or construction thereof with channels or ducts for flow of cooling medium
  • H02K5/207—Casings or enclosures characterised by the shape, form or construction thereof with channels or ducts for flow of cooling medium with openings in the casing specially adapted for ambient air
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/18—Casings or enclosures characterised by the shape, form or construction thereof with ribs or fins for improving heat transfer

Definitions

• the invention relates to an internal ventilation system of a rotary electric machine of the type comprising, inside a carcass, a stator mounted fixed in the latter and a rotor mounted rotatably in the stator, the ventilation system comprising in particular at least one fan integral with the rotor and capable of creating a flow of cooling air inside the carcass, axial air intake openings made in the carcass and air inlets cooling air discharge, formed in said carcass in a ring facing the periphery of the fan and separated from each other by stiffening fins of the carcass in the area of the gills.
• the invention also relates to a rotary electric machine comprising such a ventilation system.
• the object of the present invention is to propose a ventilation system of the type indicated above, which overcomes this drawback.
• the ventilation system according to the invention is characterized in that the angle inclination of the fins relative to the tangent is between 38 ° and 52 °.
• the angle is advantageous to choose the angle at a value of 45 °.
• FIG. 1 is an axial sectional view of an alternator according to the state of the art
• FIG. 2 is a simplified schematic view of a ventilation system according to the invention, showing a fan and vents for evacuation of cooling air.
• FIG. 3 is a perspective view of a front bearing provided with ventilation openings according to the invention.
• FIG. 4 illustrates another advantageous characteristic of the ventilation system according to the invention.
• FIG. 5 is a radial view of the interior of a stator developed flat.
• the reference 1 designates an openwork alternator carcass of general shape of revolution which coaxially surrounds a stator 4 provided with windings 5 inside which is rotatably mounted a rotor 6 of the claw type comprising a shaft 7 supported by the carcass by means of front 9 and rear bearings 10.
• the rotor consists of two pole pieces respectively front 12 and rear 13 and a winding 14.
• Each pole piece 12, 13 carries on its part forming a plate a fan respectively front 15 and rear 16.
• the fans are integral in rotation with their respective carrier pole piece.
• the stator 4 is carried internally by the carcass 1. As shown diagrammatically in the figure, each fan carries on its external free face a plurality of ventilation blades 18.
• the carcass 1 is formed by two hollow parts called respectively front bearing 19 and rear bearing 21.
• bearings are assembled together for example using screws 26 and each comprise a generally transversely oriented part connected by one through a connection zone to an axially oriented crown.
• the bearings centrally support the bearings 9, 10 in their transverse part, knowing that the front bearing is adjacent to the alternator drive pulley and the rear bearing to the rectifier bridge (not referenced) which the alternator comprises .
• the transverse parts of the bearings are provided with axial air intake orifices 20.
• the crown of the bearings extends at the outer periphery thereof and internally carries the stator 4, more precisely the body which the latter has for carrying the windings 5.
• This ring is provided with openings 22 called gills.
• the louvers 22 are axially oblong in shape and also affect the external periphery of the transverse part of the bearing concerned.
• the vents 22 extend on either side of the body of the stator 4 and are located outside of the projecting parts, called chignons, windings 5 and fans.
• the louvers 22 therefore comprise an axial orientation part, called the axial opening, affecting only the crown of the bearing.
• the axial openings have an axial length equal to the height of a cylindrical portion of the crown defined by a first circle corresponding to the bottom of the openings adjacent to the stator body and by another circle corresponding to the edge of the axial openings of the openings.
• FIG. 3 shows in perspective the openings 22 delimited by fins 24.
• the fans are configured to create a flow of cooling air, the components of which are indicated by arrow lines, by drawing in ambient air through axial intake ports 20. A portion of the cooling air indicated by arrow F is evacuated through vents 22.
• the invention relates to the internal ventilation system essentially comprising a fan 15 or 16 and the vents 22 for evacuating the air flow created by the fan and illustrated by the arrow F.
• the fan is designated as in FIG. 1 by the reference 16
• the fan blades by the reference 18
• the ventilation openings carry the reference 22.
• the openings 22 are obtained by providing in the appropriate openings made in the peripheral face of the bearing of the fins 24 which extend parallel to the axis of the alternator and are inclined at a predetermined angle relative to the direction radial R.
• the fins 24 have the function of mechanically stiffening the bearing.
• the fins 24 have an angle of inclination relative to the tangent perpendicular to the radial direction, between 38 ° and 52 °, preferably 45 °.
• the angle of inclination with respect to the radial direction R is between (90 ° -38 °) and (90 ° -52 °)
• the fins should have an inclination substantially parallel to the direction of flow of the cooling air to be discharged through the vents, for each fan / carcass or bearing combination, to avoid significant pressure losses, it has been found that when choosing inclinations in the above-mentioned value range from 38 ° to 52 °, good fan / bearing compatibility is preserved in a large number of such fan / bearing combinations, with relatively low pressure losses and reduced air separation. The ventilation system is therefore quieter.
• the radial opening factor of the openings must advantageously be at least 40% insofar as an increase in the radial opening surface increases, so significant, the cooling efficiency of the fans, namely in particular the electronic components at the rear bearing of the alternator and the windings.
• Figure 4 illustrates another measure to optimize the cooling of the alternator. Indeed, this figure illustrates that the fan blades should not overlap by more than a third, namely the distance 1 of their length of rope L the axial openings as indicated at 20 in Figure 1 of the carcass or front and rear bearings.
• the outside diameter of the axial openings must be chosen according to the inside and outside diameters of the fan.
• F is a multiplying coefficient which is determined according to the mechanical configuration of the electric machine, by iterative calculation.
• the fins 24 are arranged so as to angularly coincide with these areas of high winding density and thus do not create additional obstacles in front of the air passages 34 in line with the teeth 33 of the stator. To this end, the fins 24 are therefore radially aligned with the grooves 32 of the stator.
• the fins are radially aligned on only part of the set of grooves 32 of the stator.
• the pitch of the fins can be a multiple of the pitch of the grooves / teeth of the stator.
• the fins can radially superimpose the grooves 32 of the stator in a random pitch 35.
• At least 70% of the fins are radially aligned with the grooves of the stator.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Motor Or Generator Cooling System (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=29725000

Family Applications (1)

Country Status (5)

Families Citing this family (11)

Family Cites Families (16)

• 2002
  • 2002-06-28 FR FR0208134A patent/FR2841705B1/fr not_active Expired - Fee Related
• 2003
  • 2003-06-30 EP EP03748192A patent/EP1532721A2/de not_active Withdrawn
  • 2003-06-30 JP JP2004516898A patent/JP2005532019A/ja active Pending
  • 2003-06-30 US US10/518,674 patent/US7138735B2/en not_active Expired - Lifetime
  • 2003-06-30 WO PCT/FR2003/002023 patent/WO2004004096A2/fr active Application Filing

Non-Patent Citations (1)

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