Abstract:
This ventilation assembly for a motor vehicle comprises a fan ( 3 ), a support ( 4 ) for mounting the fan ( 3 ) in a motor vehicle and a securement ( 24 ) of the fan to the mounting support ( 4 ), the fan comprising a helix ( 6 ) and a motor ( 8 ) for driving the helix ( 6 ) in rotation. The securement ( 24 ) comprising a collar ( 26 ) for the radial clamping of the motor ( 8 ). Application, for example, to the ventilation of the cooling radiators of the heat engines of motor vehicles.

Description:
TECHNICAL FIELD 
   The present invention relates to a ventilation assembly for a motor vehicle, of the type comprising a fan, a support for mounting the fan in a motor vehicle and means for securing the fan to the mounting support, the fan comprising a helix and a motor for driving the helix in rotation. 
   BACKGROUND TO THE INVENTION 
   The invention is applicable in particular to the ventilation of heat exchangers placed in the front units of motor vehicles, for example to the ventilation of the cooling radiators of the heat engines of vehicles. 
   FR-2 766 235 describes an assembly of the above-mentioned type. The support there comprises a ring sector which receives the fan motor with radial clearance. The motor is secured to the support by means of screws extending through lugs which form an extension of the motor casing. 
   The securing of the motor to the support therefore requires the provision of securing lugs on the motor casing and, for each of the lugs, an operation of screwing and controlling the screwing torque applied. 
   The cost associated with the securing of the fan to the support is therefore relatively high. 
   An object of the invention is to solve that problem by providing an assembly of the above-mentioned type where the cost associated with securing the fan to its support is reduced. 
   SUMMARY OF THE INVENTION 
   To that end, the invention relates to an assembly of the above-mentioned type, characterised in that the securing means comprise a collar for the radial clamping of the motor. 
   According to particular embodiments, the assembly may comprise one or more of the following features taken in isolation or in any technically possible combination:
         the collar comprises at least two portions which are mobile relative to each other and means for causing the two mobile portions to approach each other;.   the approach means comprise a screw;   the approach means are means for approach by snapping-in;   the approach means are an over-centre mechanism;   the collar has a slot delimiting the two mobile portions;   the clamping collar is integral with the support;.   the securing means also comprise a wedging block which is to be inserted between the motor and the collar in order to clamp the motor radially;   the collar is substantially rigid;   the collar is fitted on the support and the support comprises flanges for bearing on the motor, which flanges are interposed between the clamping collar and the motor;   the clamping collar comprises tensioning means;   the tensioning means are an over-centre mechanism; and   the clamping collar is a spring for the radial clamping of the motor.       

   The invention relates also to a front unit of a motor vehicle, comprising a heat exchanger and a ventilation assembly, characterised in that the ventilation assembly is an assembly as defined above. 
   The invention relates also to a motor vehicle, characterised in that it comprises a module as defined above. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention will be better understood on reading the following description which is given purely by way of example with reference to the appended drawings in which: 
       FIG. 1  is a partly sectioned lateral diagrammatic view of the cooling module of the front unit of a motor vehicle according to a first embodiment of the invention, 
       FIG. 2  is a perspective diagrammatic view, taken from the front, of the fan (helix not shown) and of the support of the fan of the cooling module of the front unit of  FIG. 1 . 
       FIGS. 3 and 4  are enlarged perspective diagrammatic partial views taken from the rear, illustrating variants of the embodiment of  FIGS. 1 and 2 , 
       FIGS. 5 and 6  are enlarged perspective diagrammatic partial views taken from the front, illustrating two variants of a second embodiment of the invention, and 
       FIG. 7  is an exploded and enlarged perspective diagrammatic partial view taken from the-front and the top, illustrating a third embodiment of the invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   Throughout the following, the orientations used are the usual orientations of a motor vehicle. In particular, the terms “front” and “rear” are to be understood relative to the position of the driver and to the direction of travel of the vehicle which is symbolised by the arrow F in  FIG. 1 . 
     FIG. 1  illustrates a module  1  for cooling a front unit of a motor vehicle, comprising a heat exchanger  2 , a fan  3  located behind the exchanger  2 , and a support  4  for mounting the fan  3  on the heat exchanger  2 . 
   The heat exchanger  2  is, for example, a radiator for cooling the heat engine of the motor vehicle. The heat exchanger  2  is typically of a generally parallelepipedal shape and of small thickness. The heat exchanger  2  is disposed substantially vertically and transversely to the direction of travel F. The heat exchanger  2  comprises, in a conventional manner, two cases for collecting a fluid for cooling the heat engine, a nest of tubes connecting those collecting cases, and, for example, fins extending between the tubes. The collecting cases are, for example, disposed laterally. 
   Since such a structure is conventional, the elements mentioned above have not been shown in  FIG. 1 . 
   The fan  3  comprises a helix  6  and an electrical motor  8 , an output shaft  10  of which is connected to the helix  6  in order to drive it in rotation about its axis A which is substantially horizontal. 
   In a conventional manner, the helix  6  may comprise a central hub, by way of which it is connected to the output shaft  10 , and blades which extend the hub radially outwards. The radially outer ends of the blades are, in the example shown, connected to one another by a circular collar  12 . However, such a collar  12  does not have to be present. 
   The blades of the helix  6  are oriented to create a stream of air flowing towards the rear and therefore to suck in air through the heat exchanger  2 . The fan  3  is therefore in a configuration generally referred to as the “sucking” configuration. 
   Conventionally, the fan  3  improves by forced convection the exchange of heat between the outside air and the heat engine cooling fluid circulating in the heat exchanger. 
   The support  4  comprises fairing  14  for channeling the stream of air created by the fan  3 . The fairing covers the rear face of the heat exchanger  2 . 
   As can be seen in  FIG. 2 , the fairing  14  is extended laterally on each side by two securing lugs  16  located one above the other. 
   Each lug  16  has been engaged, by vertical downward displacement, in receiving housings (not shown) provided on the collecting cases of the heat exchanger  2 . 
   Thus, the support  4  is secured to the heat exchanger  2 . 
   A circular central opening  18  is formed in the fairing  14 . The fairing  14  is extended, around the opening  18 , by a circular skirt  20  which extends towards the rear. The helix  6  is accommodated in the skirt  20 . 
   The support  4  comprises arms  22  which extend from the skirt  20  towards the centre of the opening  18 . The radially inner ends of the arms  22  are connected to means  24  for securing the fan  3  to the support  4 . 
   The securing means  24  comprise a collar  26 , two half-collars  28  of which are connected by a lateral articulation region  30 . A slot  31  is provided on the opposite side to the articulation region  30  and delimits the two half-collars  28 . 
   Owing to the articulation region  30 , the two half-collars  28  are mobile relative to each other between a position in which they are spaced from each other and a position in which they have been caused to approach each other illustrated by  FIG. 2 . The fairing  14 , the lugs  16 , the arms  22  and the collar  26  are, for example, formed in one piece from plastics material. 
   The securing means  24  comprise, at right-angles to the slot  31 , means  32  for causing the two half-collars  28  to approach each other. The means  32  comprise a bolt  34 , the screw of which bears on a shoulder  36  fixedly joined to the upper half-collar  28 , and the nut of which bears on a shoulder  38  fixedly joined to the lower half-collar  28 . 
   The motor  8  is located in the collar  26  between the two half-collars  28 , and the bolt  34  has been screwed up so that the half-collars  28  are in the position in which they have been caused to approach each other. The collar  26  then tightens on the lateral wall  40  of the casing or frame of the motor  8 , on which wall it produces radial forces oriented towards the inside. 
   The motor  8  is thus secured axially and angularly relative to the support  4 . 
   It will be appreciated that the lower half-collar  28  comprises an opening for receiving a connector  42  for the electrical connection of the motor  8  to a source of electrical power. 
   The securing of the fan  3  to the support  4  therefore requires only a single screwing operation and does not make it necessary for the casing of the motor  8  to be provided with securing lugs. 
   The costs associated with the securing of the fan  3  are therefore reduced. 
   If it is desired to secure a smaller motor  8  to the support  4  shown, it is possible to surround the lateral wall  40  of its casing with an adapter ring which would then be interposed between the collar  26  and the motor  8 . The collar  26  would then exert its radial clamping forces directly on the adapter ring. 
     FIG. 3  illustrates a variant which is distinguished from the embodiment of  FIGS. 1 and 2  by the nature of the approach means  32  which are means for approach by snapping-in. 
   The approach means  32  comprise a clip  44  articulated by an upper portion  45  to the upper half-collar  28 . After passing onto a ramp surface  46 , the lower region of the clip  44  is capable of engaging behind a retaining shoulder  48  fixedly joined to the lower half-collar  28 . It is in that position that the clip  44  is represented in  FIG. 3 . 
   The clip  44  comprises a lower gripping portion  50  which enables the clip  44  to be freed from the shoulder  48  and to be moved away from the lower half-collar  28  by pivoting relative to the upper half-collar  28 . The half-collars  28  then return resiliently to the position in which they are spaced from each other. In that position, the motor  8  can be inserted into or removed from the collar  26 . 
   When the clip  44  is engaged behind the shoulder  48 , the half-collars  28  are in the position in which they have been caused to approach each other. The collar  26  thus ensures radial clamping of the motor  8  which is secured in position relative to the support  4 . 
   That variant does not require any screwing operation to secure the fan  3  to the support  4 . The costs associated with the securing operation are therefore even further reduced. 
     FIG. 4  illustrates another variant which is distinguished from that of  FIG. 3  by the fact that the approach means  32  comprise an over-centre mechanism. 
   More precisely, the upper portion  45  of the clip  44  is then articulated to a control member  51  which is itself articulated by a lower portion  52  to the upper half-collar  28 . The articulation portions  45  and  52  are spaced from each other so that the clip  44  and the control member  51  form an over-centre mechanism. The clip  44  no longer comprises a gripping region. 
   In the position represented in  FIG. 4 , the clip  44  is engaged behind the retaining shoulder  48  and keeps the half-collars  28  in the position in which they have been caused to approach each other. The collar  26  then clamps the motor  8  radially, ensuring that it is secured in position relative to the support  4 . 
   In order to free the motor  8 , the control member  51  is pivoted to the right in  FIG. 4 . 
   In the course of such a pivoting movement, the mechanism passes an over-centre position and it is then possible to disengage the clip  44  from the shoulder  48 . The half-collars  28  then return resiliently to the position in which they are spaced from each other. The motor  8  can thus be removed. The insertion of the motor  8  into the collar  26  is also effected with the half-collars  28  in the position in which they are spaced apart from each other. 
     FIG. 5  illustrates a second embodiment of the invention. 
   In  FIG. 5 , only three arms  22  are shown instead of the five arms  22  in the previous Figures. However, the principles described hereinafter can be applied with a different number of arms  22 . 
   Each arm  22  is extended by a flange  53  for bearing on the lateral wall  40  of the casing of the motor  8 . The flange  53  is integral with the arm  22 . The flanges  53  have the general shape of ring sectors. 
   The flanges  53  have front shoulders  54  projecting radially outwards. The flanges  53  are connected by their rear regions to the arms  22 . 
   The means  24  for securing the motor  8  to the support  4  comprise, in addition to the flanges  53 , a clamping collar  56 , for example produced from metal wire, which surrounds the flanges  53  externally. The arms  22  and the shoulders  54  retain the collar  56  axially relative to the support  4 . 
   The collar  56  comprises tensioning means  58 . The means  58  are, in the example represented, an over-centre mechanism which comprises a control member  60  and a connecting member  61 . 
   The connecting member  61  is articulated by a portion  62  to a first end of the collar  56  and by an opposite portion  63  to the control member  60 . The control member  60  is articulated by a portion  64  to the other end of the collar  56 . The articulation portions  63  and  64  are spaced from each other. 
   In the position illustrated by  FIG. 5 , the collar  56  is tensioned by the means  58  and exerts via the flanges  53  radial clamping forces on the lateral wall  40  of the motor  8 , so that the motor  8  is secured in position relative to the support  4 . 
   In order to free the motor  8 , the control member  60  is pivoted upwards in  FIG. 5 . After passing an over-centre position, the collar  56  is no longer tensioned and the flanges  53  are no longer placed against the lateral wall  40  of the motor  8 . The motor  8  can then be released. 
   The insertion of the motor  8  into the collar  56  is also effected with the collar  56  relaxed. 
   Tensioning means  58  other than an over-centre mechanism may be used, such as notched means. 
   Likewise, the collar  56  is not necessarily a collar of metal wire. It may be any other type of collar. 
     FIG. 6  illustrates, from another viewing angle, another variant of the second embodiment in which the collar  56  is constituted by a helical spring the two ends  65  of which are curved so that they can be gripped. 
   When the ends  65  are caused to approach each other against the resilient return action of the collar  56 , the collar  56  relaxes and loosens its grip so that the motor  8  can be released from the collar  56  or inserted into it. 
   Conversely, when no force is applied to the ends  65 , the collar  56  returns resiliently to the tensioned position and places the flanges  53  against the lateral wall  40  of the motor  8 . The motor  8  is thus secured in position relative to the support  4 . 
     FIG. 7  illustrates a third embodiment which is distinguished from that of  FIG. 1  in that the means  24  for securing the motor  8  in position comprise a rigid circular collar  66  which connects the radially inner ends of the arms  22 . Three grooves  68  are formed inside the collar  66 . Those grooves  68  extend axially and are, for example, offset angularly by approximately 120° relative to one another. 
   The securing means  24  comprise, in addition to the clamping collar  66 , a wedging block  70  which comprises three wedges  72  connected by-a band  74 . 
   It will be appreciated that the band  74  does not extend between two wedges  72 , so that a reduction in the diameter of the wedging block  70  at the moment of clamping, and the passage of the connector  42  for connecting the electrical motor  8  are permitted. It will be appreciated that the three grooves  68  are a little wider than the wedges  72  in order to permit clearance of the latter during clamping. 
   The wedges  72  have a converging form so that their radial thickness decreases from the front to the rear. The wedges  72  are provided with outwardly projecting snap-in fingers  76 . 
   In order to secure the motor  8  to the support  4 , the motor  8  is inserted into the collar  66  and then the block  70  is introduced axially by displacing it towards the rear. The wedges  72  then slide in the grooves  68  until the raised snap-in portions  76  engage behind the rear edge  78  of the collar  66 . The block  70  is then retained-by the fingers  76  relative to the collar  66  against forward displacement. The collar  66  then clamps the lateral wall  40  of the motor  8  radially via the block  70 . 
   The motor  8  is then fixed rigidly relative to the support  4 . Rearward displacement of the block  70  would lead to even greater clamping of the motor  8  owing to the shape of the wedges. The securing in position of the motor  8  is therefore satisfactory. 
   More generally, the above principles may be applied to modules  1  for cooling front units in which the fan  3  is not in “sucking” configuration but in “blowing” configuration with the fan  3  located in front of the heat exchanger  2 .