Patent Publication Number: US-2021162435-A1

Title: Turbine, fluid-spraying device, associated facility and manufacturing method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit under 35 USC § 371 of PCT Application No. PCT/EP2019/068795 entitled TURBINE, FLUID-SPRAYING DEVICE, ASSOCIATED FACILITY AND MANUFACTURING METHOD, filed on Jul. 12, 2019 by inventor Denis Vanzetto. PCT Application No. PCT/EP2019/068795 claims priority of French Patent Application No. 18 56519, filed on Jul. 13, 2018. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a turbine and a fluid-spraying device. The present invention also relates to a fluid-spraying facility and a method for manufacturing such a facility. 
     BACKGROUND OF THE INVENTION 
     Fluid-spraying facilities comprising a spraying device mounted on a moving arm are used in many applications. These spraying devices frequently comprise a rotating bowl driven in rotation by a turbine, an injector for injecting the fluid into the bottom of the bowl and a skirt for generating jets of air for conformation of the sprayed stream of fluid. 
     These various elements are mounted at one end of the moving arm, for example by screwing. In particular, one end of the injector is received in a cavity of the arm, opposite intake ducts for the fluid to be sprayed. The turbine is fastened to the arm around the injector opposite air intake ducts for driving the turbine. The skirt surrounds the turbine and is in turn fastened to the arm opposite conformation air intake ducts. The bowl is fastened to the end of the rotor of the turbine, the bowl being surrounded by the skirt. 
     However, the various parts which make up the fluid-spraying device have complex geometries, and are therefore difficult to position relative to one another. In particular, the relative positioning of the skirt and of the bowl is difficult to master, since the bowl is mounted at one end of the injector while the skirt and injector are positioned relative to one another by their fastening, at the other end, to the arm. Small variations in positioning at the arm may therefore cause a substantial variation in relative positioning of the bowl and of the skirt. 
     However, any deviation in positioning of these parts relative to one another may result in imperfect conformation of the sprayed fluid stream, in particular if the rotating bowl and the skirt are incorrectly positioned. Further, such a fluid-spraying device is frequently disassembled and reassembled, whether to replace worn parts, to modify the characteristics of the device or because the ducts are clogged. The conformation of the sprayed fluid may therefore be subject to frequent significant variation during the use of the device, based on various disassembly and reassembly operations thereof. 
     There is therefore a need for a turbine making it possible to obtain a fluid-spraying device in which the conformation of the sprayed fluid is better controlled. 
     SUMMARY OF THE INVENTION 
     To this end, proposed is a turbine for a fluid-spraying device comprising a turbine body and a rotor configured to rotate a bowl relative to the body about a common axis of rotation, the rotor being surrounded by the turbine body in a plane perpendicular to the common axis, the turbine body being configured to guide the rotation of the rotor, the rotor being configured to be rotated by a stream of gas, the turbine body being configured to receive the stream of gas at the outlet of the rotor and delimiting at least one outlet duct configured to guide a first portion of the received stream into a space delimited in a plane perpendicular to the common axis by the bowl and the skirt. 
     Also proposed is a turbine for a fluid-spraying device comprising a turbine body and a rotor configured to rotate a bowl relative to the body about a common axis of rotation, the rotor being surrounded by the turbine body in a plane perpendicular to the common axis, the turbine body being configured to guide the rotation of the rotor, the turbine body being configured to guide the rotation of the rotor, the turbine body being adapted so that the injector and the skirt are mounted directly on the turbine body, the bowl being mounted directly on the rotor. 
     According to advantageous but optional embodiments, the turbine comprises one or more of the following features, considered alone or according to any technically possible combination(s):
         the turbine body includes a first end face and a second end face, the two end faces delimiting the body of the turbine along the common axis, the ratio between the gas stream flow rate passing through the second end face and the gas stream flow rate of the first portion of the stream being less than 1/100.   the turbine at least partially delimits an auxiliary passage able to conduct a second portion of the stream of gas from the rotor to the bottom of the bowl.   the turbine body is arranged so that during operation, the ratio between the flow rate of the first portion of the stream of gas and the second portion of the stream of gas is greater than or equal to 2, preferably greater than or equal to 3 and preferably greater than or equal to 10.   the turbine body has a first end face delimiting the turbine body along the common axis, the skirt bearing against the first end face, each outlet duct extending between two ends, the turbine body delimiting each of the outlet ducts from one of their ends to the other end, each outlet duct opening onto the first end face.   the turbine body includes a second end face delimiting the turbine body along the common axis, the injector being received in an opening arranged in the second end face, the opening having a first bearing face perpendicular to the common axis, the injector including a second bearing face, the second bearing face bearing against the first bearing face.       

     Also proposed is a fluid-spraying device, comprising a bowl, a turbine, the rotor being surrounded by the turbine body in a plane perpendicular to the common axis, the turbine body being configured to guide the rotation of the rotor, an injector configured to inject the fluid into the bottom of the bowl, and a skirt at least partially surrounding the bowl in a plane perpendicular to the common axis and configured to eject jets of gas in order to mold the sprayed fluid. 
     According to advantageous but optional embodiments, the fluid-spraying device comprises one or more of the following features, considered alone or according to any technically possible combination(s):
         an upstream direction and a downstream direction are defined for the common axis, the skirt being offset toward the downstream direction relative to the turbine body, the rotor having a first upstream face delimiting the rotor along the common axis, the turbine body delimiting a receiving chamber of the rotor, the chamber including a second upstream face delimiting the chamber along the common axis, the second upstream face facing the first upstream face and being offset along the upstream direction relative to the first upstream face, an annular groove centered on the common axis being arranged in the second upstream face, the annular groove being configured to receive the stream of gas and to transmit the first portion of the stream of gas to each outlet duct.   the second upstream face includes, for each outlet duct, a radial groove extending radially outward from the annular groove and configured to guide the first portion of the stream of gas from the annular groove to the outlet duct.   two outlet ducts, the radial grooves each extending from the annular groove along a rectilinear specific line, the two specific lines being combined.   an auxiliary passage able to conduct a second portion of the stream of gas from the rotor to the bottom of the bowl, at least one section of the auxiliary passage being arranged in the turbine body.   the injector is surrounded by the rotor in a plane perpendicular to the common axis, a free volume separating the rotor and the injector in a plane perpendicular to the common axis, the auxiliary passage comprising a duct configured to guide the second portion of the stream of gas to the free volume, the free volume being able to guide the second portion of the stream of gas to the bottom of the bowl.       

     Also proposed is an installation assembly, including a moving arm and a fluid-spraying device in which the turbine body is mounted directly on the arm. 
     The disclosure also describes a turbine for a fluid-spraying device, the turbine comprising a body and a rotor which is configured to rotatable about an axis, called common axis of rotation, the rotor being surrounded by the turbine body in a plane perpendicular to the common axis, the turbine further including a tube having an outer face and an inner face, the tube being mounted coaxially to the turbine body and intended to be mounted coaxially to the skirt, a first section of the tube being surrounded by the turbine body, a second section of the tube being intended to be surrounded by the skirt, the second section being offset along the downstream direction relative to the first section, the tube being rotatable about the common axis relative to the turbine body, the turbine body being configured to prevent a translation of the tube parallel to the common axis relative to the turbine body, the second section having, on the outer face, a first thread intended to engage a second thread arranged on the skirt in order to press the skirt against the turbine body. 
     According to one embodiment, the turbine body has a shape suitable for allowing air to be conveyed toward a skirt. 
     Also proposed is a fluid-spraying device, comprising a bowl, a turbine as previously described, an injector configured to inject the fluid into the bottom of the bowl, and a skirt at least partially surrounding the bowl in a plane perpendicular to the common axis and configured to eject jets of gas in order to mold the sprayed fluid. 
     According to advantageous but optional embodiments, the fluid-spraying device comprises one or more of the following features, considered alone or according to any technically possible combination(s):
         the outer face includes a shoulder perpendicular to the common axis, the turbine body including a bearing face bearing against the shoulder in order to prevent a translation along the downstream direction of the tube relative to the turbine body.   the first section is delimited along the common axis by the shoulder and has a length, measured along the common axis, greater than or equal to 5 millimeters.   the turbine body includes at least a first part and a second part which are fastened to one another, the second part being offset along the downstream direction relative to the first part, the tube being at least partially accommodated in a groove delimited along a direction parallel to the common axis by the first part and the second part, the second part bearing against the tube in order to prevent a translation of the tube along the downstream direction relative to the first part.   the inner face of the second section has, at least at one point, a normal direction, an angle being defined between the normal direction and a segment connecting this point to the common axis, the angle being measured in a plane perpendicular to the common axis and being strictly greater than 5 degrees.   a plurality of notches are arranged in the inner face of the second section.   each notch extends along a direction parallel to the common axis.   the tube has an end face delimiting the tube along the common axis, the end face facing the downstream direction, each notch opening onto the end face.   each notch has a bottom, a distance measured in a plane perpendicular to the common axis between the bottom and the common axis being defined for each notch, the skirt including an inner face having a symmetry of revolution about the common axis, a minimum diameter being defined for the inner face of the skirt, the distance from each notch being less than or equal to half of the minimum diameter of the skirt.   each notch has a cross-section in a plane perpendicular to the common axis, the cross-section of each notch being an arc of circle.       

     Also proposed is an assembly comprising a device and a tool configured to engage the inner face of the second section so as to transmit a force to the tube which tends to pivot the tube about the common axis relative to the turbine body. 
     There is therefore a need for a fluid-spraying device in which the conformation of the sprayed fluid is better controlled. 
     Also proposed is a facility including a moving arm and a fluid-spraying device as defined above, in which each of the rotor, the injector and the skirt is mounted on the arm by means of the turbine body. 
     Also proposed is a method for manufacturing a facility comprising a moving arm and a fluid-spraying device including a bowl, a turbine comprising a turbine body and a rotor configured to rotate the bowl relative to the body about a common axis of rotation, the rotor being surrounded by the turbine body in a plane perpendicular to the common axis, the turbine body being configured to guide the rotation of the rotor, an injector configured to inject the fluid into the bottom of the bowl, and a skirt surrounding the bowl at least partially in a plane perpendicular to the common axis and configured to eject jets of gas adapted to mold the sprayed fluid. The method includes steps for a) assembling the rotor, the injector and the skirt directly on the turbine body, b) assembling the bowl directly on the rotor, and c) assembling the turbine body directly on the arm, step c) being implemented after step a). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features and advantages of the invention will appear more clearly in light of the following disclosure, provided solely as a non-limiting example, and done in reference to the appended drawings, in which: 
         FIG. 1  is a cross-sectional view of a fluid-spraying device according to the invention, this device comprising a threaded tube and a turbine body comprising a flange, 
         FIG. 2  is an enlarged view of box II of  FIG. 1 , 
         FIG. 3  is a perspective view of a fluid-spraying device, 
         FIG. 4  is a perspective view of the flange of  FIG. 1 , 
         FIG. 5  is a cross-sectional view of the threaded tube of  FIG. 1 , 
         FIG. 6  is a perspective view of the threaded tube of  FIG. 5 , 
         FIG. 7  is a perspective view of the spraying device of  FIG. 1 , and 
         FIG. 8  is a perspective view of a tool provided to pivot the threaded tube of  FIG. 5  relative to the turbine body. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     A fluid-spraying facility  10  is partially shown in  FIG. 1 . 
     The facility  10  is configured to spray a fluid F. 
     As shown in  FIG. 3 , the facility  10  is connected to a support which is fastened on a robot. The assembly forms a “sprayer”. 
     The facility  10  includes a portion  15  and a spraying device  20  for spraying the fluid F. 
     The fluid F is in particular a coating device such as a paint or a varnish. For example, the fluid F is a paint or varnish provided to at least partially cover an automobile body panel. 
     The portion  15  supports the device  20 . The portion  15  is in particular configured to move the device  20  in space, in particular to orient the device  20  in a plurality of directions in space. 
     The portion  15  is for example an articulated arm comprising actuators able to pivot the various segments of the arm  15  relative to one another in order to move and orient the device  20  in space. 
     The portion  15  is further provided to supply the device  20  with a voltage or an electric current, with at least one stream of gas G and with a stream of the fluid F to be sprayed. 
     The gas G is for example air. 
     The portion  15  for example has a substantially planar fastening face  22 . The device  20  is mounted on the fastening face  22 . 
     The fastening face  22  is for example passed through by a plurality of supply ducts of the portion  15  for supplying gas G and fluid F, and by electrical power conductors of the device  20 . 
     The device  20  is configured to spray the fluid F. The device  20  includes a turbine  25 , a bowl  30 , a skirt  35  and an injector  40 . 
     The turbine  25  is configured to rotate the bowl  30  about an axis A, called “common axis.” In particular, the turbine  25  is configured to receive a first stream of gas G from the portion  15 , and to rotate the bowl  30  about the common axis A under the effect of the first stream of gas G. 
     The turbine  25  includes a rotor  45  and a body  50 , also sometimes called “stator.” 
     An upstream direction D 1  and a downstream direction D 2 , shown in  FIG. 1 , are defined for the common axis A. The upstream direction D 1  and the downstream direction D 2  are co-linear and opposite each other. 
     The upstream direction D 1  is such that the turbine  25  is offset relative to the skirt  35  along the upstream direction D 1 . 
     The downstream direction D 2  is such that the skirt  35  is offset along the downstream direction D 2  relative to the turbine  25 . 
     The turbine  25  is interposed between the skirt  35  and the fastening face  22  of the portion  15  along the common axis A. In particular, the fastening face  22 , the turbine  25  and the skirt  35  are superimposed in this order along the downstream direction D 2 . 
     The rotor  45 , the skirt  35  and the injector  40  are directly assembled on the turbine body  50 . 
     “Directly assembled” in particular means a relationship in which two parts are kept in position relative to one another by contact between these two parts. For example, any relative translational movement of these two parts is prevented by the contact between these two parts. Two parts which are secured in translation but movable in rotation relative to one another about the common axis may be qualified as “directly assembled” one on the other. 
     In particular, at least one face of each of the parts is in contact with the other part to ensure the fastening of the two parts to one another. 
     A first part screwed to a second part by a screw jointly passing through the first part and the second part is for example directly assembled on the second part if the two parts are in contact with one another. 
     On the contrary, two parts are not directly assembled one on the other if they are not in contact with one another but are each fastened to a single other part. 
     In particular, when the rotor  45 , the skirt  35  and the injector  40  are directly mounted on the turbine body  50 , the turbine body  50  is able to allow a relative positioning of the rotor  45 , the skirt  35  and the injector  40 . In other words, the turbine body  50  keeps the rotor  45 , the skirt  35  and the injector  40  in position relative to one another. 
     Thus, the turbine body  50 , the rotor  45 , the skirt  35  and the injector  40  form a set of parts which are secured in translation relative to one another. 
     Further, the turbine body  50  has a shape which is suitable for allowing air to be conveyed toward the skirt  35 . 
     The rotor  45  is assembled directly on the turbine body  50 . 
     The rotor  45  is rotatable about the common axis A relative to the turbine body  50 . 
     The rotor  45  is in particular configured to be rotated relative to the turbine body  50  by the first stream of gas G. 
     The rotor  45  delimits a first receiving chamber  52  of the injector  40 . 
     The rotor  45  includes a first section  55  and a second section  60 . 
     The first chamber  52  extends along the common axis A. 
     The first chamber  52  for example has a symmetry of revolution about the common axis A. In particular, the first chamber  52  is cylindrical about the common axis A. 
     A first inner diameter is defined for the first chamber  52 . The first inner diameter is between 10 millimeters (mm) and 20 mm. 
     The first chamber  52  passes through the rotor  45  along the common axis A. In particular, the first chamber  52  passes through both the first section  55  and the second section  60  along the common axis A. 
     The first section  55  is offset along the downstream direction D 2  relative to the second section  60 . The first section  55  is delimited along the upstream direction D 1  by the second section  60 . 
     The first section  55  has a first outer diameter. The first outer diameter is between 20 mm and 40 mm. The first section  55  is configured to rotate the bowl  30  about the common axis A. 
     The first section  55  has a first downstream end  65  which is able to cooperate with the bowl  30  in order to secure the first section  55  and the bowl  30 , and a first upstream end  70  which is fastened to the second section  60 . Among the first downstream end  65  and the first upstream end  70 , the first downstream end  65  is offset along the downstream direction D 2  relative to the first upstream end  70 . 
     The first section  55  has a cylindrical outer face about the common axis A which is able to cooperate with the turbine body  50  in order to guide the rotation of the rotor  45  about the common axis A. The outer face of the first section  55  delimits the first section in a plane perpendicular to the common axis A. 
     The second section  60  has a first upstream face  75 , a first side face  80  and a first downstream face  85 . 
     The second section  60  is delimited along the common axis A by the first upstream face  75  and by the first downstream face  85 . 
     The first upstream face  75  is offset along the upstream direction D 1  relative to the first downstream face  85 . 
     The first upstream face  75  is perpendicular to the common axis A. The first upstream face  75  faces the upstream direction D 1 . 
     The first upstream face  75  is substantially planar. 
     The first upstream face  75  is passed through along the common axis by the first chamber  52 . 
     The first upstream face  75  includes, in a known manner, drive members  88  configured to rotate the rotor  45  when the first stream of gas G is oriented over the drive members  88 . 
     The drive members  88  in particular comprise a set of blades. 
     According to the example of  FIG. 2 , the drive members  88  are arranged on a perimeter of the first upstream face  75 . 
     The first side face  80  delimits the second section  60  in a plane perpendicular to the common axis  80 . 
     The first side face  80  is cylindrical about the common axis A. 
     The first side face  80  has a second outer diameter. The second outer diameter is between 50 mm and 60 mm. 
     The first downstream face  85  surrounds the first section  55  in a plane perpendicular to the common axis A. 
     The first downstream face  85  faces the downstream direction D 2 . 
     The first downstream face  85  is substantially planar. 
     The turbine body  50  is assembled directly on the portion  15 . For example, the turbine body  50  is secured in rotation and in translation with the portion  15 . 
     In particular, the turbine body  50  is fastened to the fastening face  22  of the portion  15 , for example by a plurality of screws. 
     Thus, the rotor  45 , the injector  40  and the skirt  35  are each assembled on the portion  15  by means of the turbine body  50 . 
     According to the example spraying device  20  shown in  FIGS. 1 and 2 , the turbine body  50  includes a first part  50 A, called flange  50 A, a second part  50 B, a third part  50 C and a fourth part  50 D. 
     It should be noted that the number and the arrangement of the various parts  50 A to  50 D making up the turbine body  50  may vary. This is in particular the case for the third part  50 C and the fourth part  50 D. 
     The flange  50 A, the second part  50 B, the third part  50 C and the fourth part  50 D are aligned in this order along the common axis A, the flange  50 A being offset along the upstream direction D 1  relative to the second part  50 B, which is offset along the upstream direction D 1  relative to the third part  50 C, which in turn is offset along the upstream direction D 1  relative to the fourth part  50 D. 
     The flange  50 A is interposed between the second part  50 B and the fastening face  22 . 
     The turbine body  50  has a first end face  90  and a second end face  95 . The turbine body  50  is delimited along the common axis A by the first end face  90  and by the second end face  95 . 
     The turbine body  50  is configured to receive the first stream of gas G from the portion  15 , in particular through the fastening face  22 , and to supply the rotor  45  with the first stream of gas G in order to rotate the rotor  45 . For example, the turbine body  50  is configured to guide the first stream of gas G to the drive members  88 . 
     The turbine body  50  is also configured to receive the first stream of gas G at the outlet of the rotor  45  and to guide the first stream of gas G to the outside of the spraying device  20 . 
     The turbine body  50  is further configured to guide a first portion P 1  of the first stream of gas G received from the rotor  45  to the skirt  35 . To this end, the turbine body  50  delimits at least a first outlet duct  97 . According to the example shown in  FIG. 1 , the turbine body  50  delimits two such first outlet ducts  97 . 
     The turbine body  50  is further configured to receive a second stream of gas G from the portion  15  and to supply the skirt  35  with the second stream of gas G without the second stream of gas G rotating the rotor  45 . 
     The turbine body  50  surrounds the rotor  45  in a plane perpendicular to the common axis A. 
     The turbine body  50  is configured to rotate the rotor  45 . 
     The turbine body  50  delimits a second receiving chamber of the rotor  45  and a third receiving chamber  57  of the injector  40 . 
     The turbine body  50  is further configured to guide a second portion P 2  of the first stream of gas G received from the rotor  45  to the second chamber. To this end, the turbine body  50  delimits at least one second outlet duct  100 . According to the example shown in  FIG. 1 , the turbine body  50  delimits two such second outlet ducts  100 . 
     The first end face  90  is arranged in the fourth part  50 D. 
     The first end face  90  is offset along the downstream direction D 2  relative to the second end face  95 . The first end face  90  faces the downstream direction D 2 . 
     The second end face  95  is in particular arranged in the flange  50 A. In particular, the flange  50 A is delimited by the second end face  95  along the common axis A. 
     The second end face  95  bears against the fastening face  22  of the portion  15 . The second end face  95  is substantially planar. 
     The second chamber includes a bearing which is stationary and secured to the turbine body  50 . 
     The bearing allows the injection and maintenance of a film of air with the rotor  45  to allow its rotation at a high speed. 
     The second chamber also includes an element able to produce sounds detectable by a microphone, the injection of air being specific. The element makes it possible to estimate the speed of the turbine  25 . 
     The first cavity  105  and the second cavity  110  communicate with one another. 
     The first cavity  105  and the second cavity  110  are each cylindrical with a circular base about the common axis A. 
     The first cavity  105  is offset along the downstream direction D 2  relative to the second cavity  110 . 
     The first cavity  105  accommodates the first section  55  of the rotor  45 . 
     The first cavity  105  is configured to guide the rotation of the first section  55  of the rotor  45 . 
     The second cavity  110  accommodates the second section  60  of the rotor  45 . 
     The second cavity  110  is delimited along the common axis A by a second upstream face  115  and a second downstream face  120  of the turbine body  50 . 
     The second cavity  110  is substantially cylindrical about the common axis A. 
     The second section  60  of the rotor  45  is inserted between the second upstream face  115  and the second downstream face  120  along the common axis A. For example, the second section  60  is clamped by the second upstream face  115  and the second downstream face  120 . 
     The second upstream face  115  is for example arranged in the flange  50 A, which is shown alone in  FIG. 3 . 
     In particular, the flange  50 A is delimited along the common axis A by the second end face  95  and by the second upstream face  115 . The flange  50 A is in particular passed through from the second end face  95  to the second upstream face  115  by a passage assembly provided to allow the passage of electrical conductors, streams of fluid F and streams of gas G. 
     The second upstream face  115  is offset along the upstream direction D 1  relative to the second downstream face  120 . 
     The second upstream face  115  is opposite the first upstream face  75  of the rotor  45 . 
     The second upstream face  115  for example includes guide members  125  which are able to allow the rotor  45  to rotate [relative] to the turbine body  50 . These guide members  125  are for example microperforated parts which make it possible to create a film of air. The guide members  125  are for example accommodated in an annular channel  127  centered on the common axis and arranged in the second upstream face  115 . 
     The second upstream face  115  is perpendicular to the common axis A. 
     The second upstream face  115  includes an annular groove  130  and at least one radial groove  135 . For example, the second upstream face  115  includes two radial grooves  135 , one for each first outlet duct  97 . 
     The annular groove  130  and the radial groove(s)  135  are arranged in the flange  50 A. 
     The annular groove  130  is configured to collect the first stream of gas G leaving the rotor  45 . In particular, the annular groove  130  is opposite the drive members  88 . 
     The annular groove  130  is configured to transmit the first portion P 1  of each first stream of gas G to each first outlet duct  97 . In particular, the annular groove  130  is configured to transmit the first portion P 1  to each first outlet duct  97  via the corresponding radial groove  135 . 
     The annular groove  130  is further configured to transmit each second portion P 2  of the first stream of gas G received from the rotor  45  to the corresponding second outlet duct  100 . 
     The annular groove  130  is centered on the common axis A. In particular, the annular groove  130  is delimited by two cylindrical faces about the common axis A of the turbine body  50 . 
     The annular groove  130  has an outer diameter of between 40 mm and 45 mm. The annular groove  130  has an inner diameter of between 45 mm and 50 mm. 
     The annular groove  130  has a depth, measured along the common axis A, of between 1 mm and 10 mm. 
     Each radial groove  135  extends along a rectilinear specific line L 1  contained in a plane perpendicular to the common axis A and is concurrent with the common axis A. The specific lines L 1  of the radial grooves  135  are for example combined with one another. In other words, the radial grooves  135  are diametrically opposite. 
     Each radial groove  135  extends radially outward from the annular groove  130 . The annular groove  130  is in particular inserted between the two radial grooves  135 . 
     Each radial groove  135  emerges in the annular groove  130 . 
     Each radial groove  135  has a length, measured from the annular groove  130  along the specific line L 1 , of between 15 mm and 20 mm. 
     Each radial groove  135  has a width, measured in a plane perpendicular to the common axis A and along a direction perpendicular to the specific line L 1 , of between 10 mm and 18 mm. 
     Each radial groove  135  has a depth, measured along the common axis A, of between 5 mm and 15 mm. The depth of the radial groove  135  is for example equal to the depth of the annular groove  130 . 
     The second downstream face  120  is perpendicular to the common axis A. The second downstream face  120  is opposite the second upstream face  115 . 
     The second downstream face  120  is substantially planar. 
     The second downstream face  120  is able to prevent the rotor  45  from moving in the downstream direction D 2  relative to the turbine body  50 . 
     The second downstream face  120  bears against the first downstream face  85 , for example by means of guide members  125 . 
     Each first outlet duct  97  is for example jointly delimited by the second part  50 B, the third part  50 C and the fourth part  50 D. In particular, each first outlet duct  97  includes a plurality of sections emerging one in the other, these sections each being delimited by one of the second part  50 B, the third part  50 C and the fourth part  50 D. 
     Each first outlet duct  97  is configured to conduct a first portion P 1  of the first stream of gas G from the annular groove  130  to the skirt  35 . 
     In particular, each first outlet duct  97  opens onto the first end face  90 , which is opposite the skirt  35 . According to the embodiment shown in  FIGS. 1 and 2 , each first outlet duct  97  is configured to conduct the corresponding first portion P 1  into the free space separating the bowl  30  from the skirt  35 . 
     Each first outlet duct  97  opens into the corresponding radial groove  135 . 
     Each first outlet duct  97  is entirely delimited by the turbine body  50 . In other words, each first outlet duct  97  is arranged in the turbine body  50  and only therein. The first portion P 1  circulating in the first outlet duct  97  is therefore only in contact with the turbine body  50  while the first portion P 1  circulates in the first outlet duct  97 . 
     Each first outlet duct  97  therefore forms, with the corresponding radial groove  135  and with the annular groove  130 , a passage connecting the rotor  45  to the first end face  90 . This passage is entirely delimited by the turbine body  50 . 
     Each second outlet duct  100  is for example arranged in the flange  50 A. 
     Each second outlet duct  100  is configured to transmit a second portion P 2  of the first stream of gas G from the annular groove  130  to the third chamber  57 . 
     Each second outlet duct  100  is entirely delimited by the turbine body  50 . In other words, each second outlet duct  100  is arranged in the turbine body  50  and only therein. The second portion P 2  circulating in the second outlet duct  100  is therefore only in contact with the turbine body  50  while the second portion P 2  circulates in the second outlet duct  100 . 
     Each second outlet duct  100  therefore forms, with the annular groove  130 , a passage connecting the rotor  45  to the third chamber  57 . This passage is entirely delimited by the turbine body  50 . 
     The third chamber  57  is arranged in the flange  50 A. 
     The third chamber  57  is configured to partially accommodate the injector  40 . 
     The third chamber  57  is offset along the upstream direction D 1  relative to the second chamber. 
     The third chamber  57  opens onto the second end face  95  and onto the second upstream face  115 . The third chamber  57  therefore communicates with the second chamber, in particular with the second cavity  110  of the second chamber. 
     The third chamber  57  includes a third cavity  140  and a fourth cavity  145 . 
     Each of the third cavity  140  and the fourth cavity  145  is cylindrical about the common axis A. 
     The third cavity  140  is inserted between the fourth cavity  145  and the second cavity  110 . 
     The third cavity  140  has a diameter of between 12 mm and 15 mm. The third cavity  140  has a length, measured along the common axis A, of between 10 mm and 30 mm. Each second outlet duct  100  opens into the third cavity  140 . 
     The first bearing face  150  is annular, and centered on the common axis A. The first bearing face  150  is substantially planar. The first bearing face  150  is perpendicular to the common axis A. 
     The first bearing face  150  delimits the fourth cavity  145  along the downstream direction D 2 . 
     The first bearing face  150  is provided to bear against the injector  40  so as to prevent the injector  40  from moving along the downstream direction D 2  relative to the turbine body  50 . 
     The bowl  30  is assembled directly on the rotor  45 . In particular, the bowl  30  is fastened to the first upstream end  65  of the first section  55  of the rotor  45 . The rotor  45  is then inserted between the bowl  30  and the second upstream face  115  along the common axis A. 
     The bowl  30  is configured to be rotated about the common axis A by the rotor  45  in order to generate the stream of fluid F to be sprayed. 
     The bowl  30  is configured to receive the fluid F to be sprayed from the injector  40  at the bottom  151  of the bowl  30 . 
     The bowl  30  protrudes relative to the skirt  35  along the downstream direction D 2 . 
     The skirt  35  is configured to generate a set of jets of gas G, these jets being suitable for molding the sprayed fluid F. For example, the skirt  35  is configured to receive the first stream and the second stream of gas G and to generate the jets of gas G from the first and second received streams. 
     The skirt  35  surrounds the bowl  30  in a plane perpendicular to the common axis A. The skirt  35  in particular delimits an opening  152  for receiving the bowl  30 . This opening  152  opens onto the face of the skirt which delimits the skirt  35  in the downstream direction D 2 . 
     The skirt  35  bears against the first end face  90  of the turbine body  50 . The turbine body  90  is inserted, along the common axis A, between the fastening face  20  of the portion  15  and the skirt  35 . 
     The skirt  35  is fastened to the turbine body  50  so as to eliminate all of the degrees of freedom between the turbine body and the skirt  50 . 
     The injector  40  is configured to inject the stream of fluid F to be sprayed in the bottom  151  of the bowl  30 . 
     The injector  40  is assembled directly on the turbine body  50 . In particular, the injector  40  is received at least partially in the third chamber  57 . 
     The injector  40  is configured so that, when the injector  40  is received in the third chamber  57 , a relative translational movement of the injector  40  with respect to the turbine body  50  in a plane perpendicular to the common axis A is prevented. 
     Optionally, the injector  40  is further fastened to the turbine body  50  by fastening means such as screws in order to prevent a respective rotation of the injector  40  and of the turbine body  50  about the common axis A, and/or to prevent a relative translation of these two parts along the common axis A. 
     The injector  40  is received in the first chamber  52  arranged in the rotor  45 . 
     The injector  40  is configured to allow a relative rotational movement about the common axis A between the rotor  45  and the injector  40 . In particular, the injector  40  is not in contact with the walls of the rotor  45  which delimit the first chamber  52 . 
     The rotor  45  and the injector  40  delimit a free volume, which corresponds to the section of the first chamber  52  which is complementary to the injector  40 . 
     The injector  40  includes an injection member  155  and an injector body  160 . 
     The injector  40  is configured so that the free volume is in communication with the bottom  151  of the bowl  30 . For example, the injection member  155  is received in a cavity of the bowl  30  opening into the bottom  151  of the bowl  30 , and has an outer diameter which is strictly inside the inner diameter of this cavity, such that a gas, in particular the gas G, is able to circulate from the free volume to the bottom  151  of the bowl  30  in the interval comprised between the walls of this cavity and the injection member  155 . 
     Further, the injector  40  is configured so that each second outlet duct  100  is in communication with the free space. Thus, the second outlet duct  100  and the free space forming auxiliary duct which is able to transmit the second portion P 2  of the first stream of gas G from the annular groove  130  to the bottom  151  of the bowl  30 . 
     The injection member  155  is configured to inject the stream of fluid F to be sprayed in the bottom  151  of the bowl  30 . 
     The injection member  155  is offset along the second direction D 2  relative to the injector body  160 . 
     The injector body  160  is configured to receive the stream of fluid to be sprayed F from the portion  15 , and to transmit the stream of fluid to be sprayed F to the injection member  155 . 
     The injector body  160  includes a third section  165 , a fourth section  170 , a fifth section  172  and a collar  175 . 
     The third section  165 , the fourth section  170 , the fifth section  172  and the collar  175  are offset in this order relative to one another along the upstream direction D 1 . 
     The injection member  155  is assembled on the third section  165 . 
     The third section  165  is cylindrical about the common axis A. The third section  165  is delimited along the common axis by the injection member  155  and by the fifth section  172 . 
     The diameter of the third section  165  is between 5 mm and 15 mm. 
     The fourth section  170  is delimited along the common axis A by the collar  175  and by the fifth section  172 . 
     The fourth section  170  is accommodated in the third cavity  140 . 
     The fourth section  170  is cylindrical about the common axis A. 
     The diameter of the fourth section  170  is strictly greater than the diameter of the third section  165 . 
     The fourth section  170  has a length, measured along the common axis, strictly less than the distance between the end of each second duct  100  and the fourth cavity  145 , such that each second duct  100  opens into the third cavity  140  opposite the fifth section  172 . 
     The fifth section  172  is inserted along the common axis A between the third section  135  and the fourth section  170 . 
     The fifth section  172  is delimited along the common axis A by the third section  135  and the fourth section  170 . 
     The fifth section  172  is in the form of a frustum centered on the common axis A. The diameter of the fifth section  172  decreases from an end delimited by the fourth section  170  to another end delimited by the third section  165 . 
     In particular, opposite the end of each second outlet duct  100  which opens into the third cavity  140 , the diameter of the fifth section  172  is strictly less than the diameter of this third cavity. 
     In this way, the second portion P 2  of the first stream of gas G can be delivered by the second outlet duct  100  into the free volume. 
     The collar  175  is cylindrical about the common axis A. 
     The collar  175  has a thickness, measured along the common axis, which is substantially equal to the length of the fourth cavity  145 . 
     The diameter of the collar  175  is substantially equal to the diameter of the fourth cavity  180 . The collar  175  has a second bearing face  180  and a third bearing face  185 . The collar  175  is delimited along the common axis A by the second and third bearing faces  180  and  185 . The thickness of the collar  175  is measured between the second and third bearing faces  180  and  185 . 
     The second bearing face  180  is perpendicular to the common axis A. 
     The second bearing face  180  bears against the first bearing face  150 . Thus, a translation of the injector  40  along the downstream direction D 2  relative to the turbine body  50  is prevented. 
     The third bearing face  180  for example bears against the fastening face  22  of the portion  15  when the spraying device  20  is fastened to the portion  15 , such that the collar  75  is clamped between the fastening face  22  and the first bearing face  150  arranged in the turbine body  50 . In particular, the third bearing face  180  and the second bearing face  95  are coplanar. 
     It should be noted that in certain considered embodiments, the thickness of the collar  175  is strictly less than the length of the fourth cavity  145 , such that the third bearing face  180  does not bear against the fastening face  22 . 
     A method for manufacturing the facility  10  will now be described. 
     In a first step, the rotor  45 , the skirt  35  and the injector  40  are assembled directly on the turbine body  50 . 
     For example, the second, third and fourth parts  50 B,  50 C and  50 D are fastened to one another. The rotor  45  is next inserted into the second chamber by a translation along the downstream direction D 2 , then the flange  50 A is fastened to the second part  50 B in order to grip the second section  60  of the rotor  45 . The rotor  45  is therefore fastened to the turbine body  50  by a mechanical link allowing a single degree of freedom, which is a rotation along the common axis A. 
     The injector  40  is inserted into the second and third chambers  52 ,  57  by a translational movement along the downstream direction D 2  until the second bearing face  180  is pressed against the first bearing face  150 . The injector  40  is then fastened to the turbine body by a mechanical link allowing only a relative translation along the upstream direction D 1  between these two parts, and optionally a relative rotation about the common axis A. 
     Optionally, the injector  40  is further fastened to the turbine body  50  by fastening members so as to eliminate all of the remaining degrees of freedom between these two parts. 
     The skirt  35  is next positioned against the turbine body  50  such that the skirt  35  bears against the first end face  90 . The skirt  35  is fastened to the turbine body  50  so as to eliminate all of the degrees of freedom between the skirt  35  and the turbine body  50 . 
     Thus, at the end of the first step, an assembly is obtained comprising the turbine body  50 , the rotor  45 , the skirt  35  and the injector  40 . The various elements of this assembly are secured to one another in translation. 
     During a second step, the bowl  30  is assembled on the rotor  45  in order to form the spraying device  20 . 
     The third step is carried out after the first step. 
     During a third step, the assembly comprising the turbine body  50 , the rotor  45 , the skirt  35  and the injector  40  is assembled on the portion  15 . 
     In particular, the turbine body  50  is assembled directly on the portion  15 , for example by bearing of the second end face  95  against the fastening face  22  and by screws jointly passing through the portion  15  and the turbine body  50 . Thus, the turbine body  50  and the portion  15  form a mechanical link eliminating all of the degrees of freedom between the turbine body  50  and the portion  15 . 
     According to one embodiment, the third step is carried out after the second step. For example, the spraying device  20 , further comprising the bowl  30 , is fastened to the portion  15 . 
     Since the rotor  45 , the skirt  35  and the injector  40  are all directly assembled on the turbine body  50 , the relative positioning of these parts is improved. Likewise, the precision of the positioning of the skirt  35  and the injector  40  relative to the bowl  30  is improved, in particular with respect to the known devices where the skirt  35  and the injector  40  are fastened to the portion  15  and not to the turbine body  50 . Indeed, the number of parts involved in the positioning of the bowl  30  with respect to the skirt  35  and to the injector  40  is decreased, since only the turbine body  50  and the rotor  45  connect the bowl  30  to the skirt  35  and to the injector  40 . 
     The improvement in the positioning of the bowl  30  with respect to the skirt  35  and to the injector  40  allows better control of the molding of the sprayed fluid F, since the jets of gas G to mold the jet of fluid F are better positioned with respect to the bowl  30 . 
     Furthermore, the replacement of the spraying device  20  is made faster, since it is possible to preassemble the rotor  45 , the skirt  35  and the injector  40  on the turbine body  50 , and to preassemble the bowl  30  on the rotor  45 , before fastening the device  20  thus obtained simply on the portion  15 , solely by fastening the turbine body  50  to the portion  15 . 
     The presence of the first duct  97  makes it possible to inject the first portion P 1  of the first stream G between the bowl  30  and the skirt  35 , this air serving as compensation air to fill the vacuum below the bowl related to the rotation of the bowl and to the injection of the skirt airs. 
     This makes it possible to divert the air directly into the turbine. This results in a better delayed differentiation over all of the different sprayer bodies. Further, avoiding grooves in the plastic body provides more solidity for the latter and allows greater positioning and piercing inclines, therefore more space in smaller bodies. This also makes it possible to avoid very cold exhaust air in a zone where metal inserts comingle to provide high voltage and plastic with all of the constraints associated with the various expansions of the materials. 
     More specifically, the stream of cold air circulating internally inside the turbine, the stream of cold air whose temperature can be as cold as −40°, does not come into contact with an interface between plastic and metal elements. Indeed, since the two materials have different expansion coefficients, the exposure to cold air could cause sealing problems. 
     Therefore, notwithstanding the fact that the use of a metal turbine as reference makes it possible to improve precision, the chosen conformation for the turbine also makes it possible to improve the durability of the sealing in the sprayer. 
     The auxiliary passage makes it possible to inject the second portion P 2  into the bottom  151  of the bowl  30  and thus to fill a vacuum that could be caused there by the rotation of the bowl  30 . 
     Furthermore, the portion  15  and in particular the fastening face  22  are simplified when the ducts  97  and  100  are arranged in the turbine body  50 , since it is the turbine body  50  which receives the first stream of gas G leaving the rotor  45 . It is therefore not necessary to mold the fastening face  22  so as to receive and discharge the first stream of gas G leaving the rotor. 
     Further, the relative positioning of the injector  40  with respect to the turbine body  50  is better controlled. This results in better control of the distribution of the first stream of gas G, leaving the rotor  45 , between the first portion P 1  and the second portion P 2 . 
     According to certain embodiments, the turbine body  25  is arranged so that during operation, the ratio between the flow rate of the first portion P 1  of the stream of gas and the second portion P 2  of the stream of gas is greater than or equal to 2, preferably greater than or equal to 3 and preferably greater than or equal to 10. Such an effect is in particular obtained by a careful choice of the size of the outlet duct  97  and the size of the auxiliary passage. 
     The annular groove  130  allows a collection of the first stream of gas G leaving the rotor  45  with a very reduced axial bulk. The dimensions of the spraying device  20  are therefore reduced. 
     The radial grooves  135  make it possible to recover an increasing amount of exhaust air without re-compressing it so as not to slow the turbine  25 . When the radial grooves  135  are diametrically opposite one another, the first portions P 1  of the streams of gas G collected by the ducts  97  are equal. The stream of gas G injected between the skirt  35  and the bowl  30  is then more spatially homogeneous. 
     The bearing of the first and second bearing faces  150  and  180  allows precise and simple positioning of the injector  40  relative to the turbine body  50 . 
     In order to simplify the description of the first example above, it has not been described in detail how the skirt  35  is fastened to the turbine body  50  after the bearing of the skirt  35  against the first end face  90 . 
     Many fastening means can be used to eliminate all of the degrees of freedom between the skirt  35  and the turbine body  50 , for example screws jointly passing through the skirt  35  and the turbine body  50 . It should be noted that other means can be used to directly assemble the skirt  35  on the turbine body  50 . For example, the skirt  35  and the turbine body  50  have complementary screw pitches to one another so as to allow the skirt  35  to be screwed on the turbine body  50 . 
     According to the specific embodiment shown in  FIGS. 1 and 2 , the fluid-spraying device  20  further includes a threaded tube  190 , visible in particular in  FIG. 2  and shown alone in  FIGS. 4 and 5 . 
     The skirt  35  has an inner face  193 . The inner face  193  of the skirt  35  is the face of the skirt  35  which surrounds the bowl  30  and which is opposite the bowl  30 . In particular, the inner face  193  delimits the opening  152  in which the bowl  30  is received. 
     The inner face  193  has a symmetry of revolution about the common axis A. 
     A minimum diameter is defined for the inner face  193  of the skirt  35 . The minimum diameter is measured in a plane perpendicular to the common axis A between the two diametrically opposite points of the inner face  193  which are closest to one another. 
     The inner face  193  has a thread  195 . The thread  195  surrounds the bowl  30  in a plane perpendicular to the common axis A. 
     The threaded tube  190  is sometimes called “nut” or “loose nut.” 
     The threaded tube  190  is assembled coaxially to the skirt  35  and to the turbine body  50 . In particular, the threaded tube  190  is centered on the common axis A. 
     The threaded tube  190  is assembled directly on the turbine body  50 . In particular, the threaded tube  190  is secured to the turbine body  50  in translation. 
     According to one embodiment, the turbine body  50  delimits an annular groove  197  receiving at least one section of the threaded tube  190  and has faces able to prevent a relative translation of the threaded tube  190  and of the turbine body  50 . 
     The annular groove  197  is for example arranged in the third part  50 C and extends along the common axis A from a downstream surface of the third part  50 C, this downstream surface delimiting the third part along the downstream direction D 2 . 
     The threaded tube  190  is rotatable about the common axis A with respect to the turbine body  50 . 
     The threaded tube  190  is for example made from steel. 
     The threaded tube  190  has a symmetry of revolution about the common axis A. 
     The threaded tube  190  has an inner face  200  and an outer face  205 . The threaded tube  190  is delimited by the inner face  200  and by the outer face  205  in a plane perpendicular to the common axis A. 
     The threaded tube  190  includes at least a primary section  210  and a secondary section  215 . According to the example of  FIG. 4 , the threaded tube  190  further includes a tertiary section  220  inserted between the primary section  215  and the secondary section  215  along the common axis A. 
     The primary section  210  is offset along the upstream direction D 1  relative to the tertiary section  220 . 
     The primary section  210  is in the form of a cylinder with an annular base. In other words, the primary section  210  is delimited by two cylindrical surfaces each centered on the common axis A. The primary section  210  is in particular delimited by these two surfaces in a plane perpendicular to the common axis A. 
     The primary section  210  has a third downstream face  225  and a third upstream face  230 . 
     The primary section  210  is surrounded by the turbine body  50  in a plane perpendicular to the common axis A. The primary section  210  is in particular accommodated in the opening  152 . 
     The primary section  210  is accommodated in the annular groove  197 . In particular, the faces of the turbine body  50  which delimit the annular groove  197  in a plane perpendicular to the common axis A are configured to prevent a translation of the threaded tube  190  relative to the turbine body  50  in a plane perpendicular to the common axis A. 
     The primary section  210  has an outer diameter of between 45 mm and 60 mm. 
     The primary section  210  has an inner diameter of between 40 mm and 55 mm. 
     The primary section  210  is delimited along the downstream direction D 2  by the third downstream face  225 . The third downstream face  225  is perpendicular to the common axis A. The third downstream face  225  faces the downstream direction D 2 . 
     The third downstream face  225  surrounds the tertiary section  220  in a plane perpendicular to the common axis A. The third downstream face  225  therefore forms a shoulder, since the outer diameter of the tertiary section  220  is strictly less than the outer diameter of the primary section  210 . 
     The primary section  210  has a length, measured along the common axis A from the third downstream face  225 , of between 5 mm and 20 mm. In particular, the length of the primary section  210  is greater than or equal to 40 mm. 
     The third downstream face  225  bears against a face  235  of the turbine body  50  in order to prevent a translation of the threaded tube  190  relative to the turbine body  50  along the downstream direction D 2 . 
     The face  235  is for example perpendicular to the common axis A. The face  235  faces the upstream direction D 1 . The face  235  is for example arranged in the fourth part  50 D. The face  235  is, along the common axis A, opposite the annular groove  197 . Thus, the face  235  delimits the annular groove  197  along the common axis A, in particular along the downstream direction D 2 . 
     The secondary section  215  is offset along the upstream direction D 1  relative to the tertiary section  220 . 
     The secondary section  215  is in the form of a cylinder with an annular base. 
     The secondary section  215  is surrounded by the skirt  35  in a plane perpendicular to the common axis A. For example, the secondary section  215  surrounds the bowl  30  in a plane perpendicular to the common axis A. The secondary section  215  is therefore inserted coaxially between the skirt  35  and the bowl  30 . 
     The secondary section  215  has an outer diameter of between 40 mm and 60 mm. 
     The secondary section  215  has an inner diameter of between 30 mm and 55 mm. 
     The secondary section  215  has a length, measured along the common axis A, of between 5 mm and 20 mm. 
     The secondary section  215  has a third end face  237  delimiting the secondary section  215  along the common axis A. The third end face  237  is perpendicular to the common axis A. The third end face  237  in particular delimits the secondary section  215  along the downstream direction D 2 . The third end face  237  therefore faces the downstream direction D 2 . 
     The secondary section  215  has, on its outer face  205 , a thread  240  configured to engage the thread  195  of the inner face  193  of the skirt  35  so as to exert a force on the skirt  35  tending to move the skirt  35 , relative to the threaded tube  190 , along the upstream direction D 1 . 
     Thus, since the third downstream face  225  bears against the face  235  of the turbine body  50  in order to prevent a translation of the threaded tube toward the downstream direction D 1  with respect to the turbine body  50 , a force tending to bring the skirt  35  closer to the turbine body  50  along the common axis and therefore to press the skirt  35  against the turbine body  50  is exerted by the tube  190  when the two threads  195  and  240  are engaged with one another. 
     The inner face  200  of the secondary section  215  is configured to cooperate with a tool  250  in order to transmit a force tending to rotate the threaded tube  190  about the common axis A. In particular, the inner face  200  of the secondary section  215  does not have a symmetry of revolution about the common axis A. 
     The inner face  200  of the second section  215  has, at least at one point, a normal direction perpendicular at this point to the inner face  200 , an angle between this normal direction and a segment connecting this point to the common axis A being strictly greater than 5 degrees. The angle is measured in a plane perpendicular to the common axis A. 
     In other words, the inner face  200  of the secondary section  215  move at least 5 degrees away from a cylindrical surface about the common axis A at least at one point. 
     For example, at least one notch  245  is arranged in the inner face  200  of the secondary section  215 . According to the example shown in  FIGS. 4 to 6 , a plurality of notches  245  is arranged in the inner face  200  of the secondary section  215 , in particular  25  notches  245 . It should be noted that the number of notches  245  may vary. 
     The spraying device  20  is shown in  FIG. 6 , in a configuration where the bowl  30  has been removed from the spraying device  20 . The notches  245  are then visible at the bottom of the opening  152  delimited by the skirt  35 . 
     Each notch  245  opens onto the third end face  237 . 
     Each notch  245  extends along a direction parallel to the common axis A. In particular, each notch  245  extends from the third end face  237 . 
     Thus, a tool may be inserted into the notches  245  from the third end face  237  by a translation along the upstream direction D 1 . 
     Each notch  245  has a uniform cross-section along the common axis A. In particular, the shape and the dimensions of each notch  245  are invariant by translation along a direction parallel to the common axis A along the notch  245 . 
     Each notch  245  for example has an arcuate cross-section in a plane perpendicular to the common axis A. 
     Each notch  245  has a depth of between 0.5 mm and 3 mm. 
     Each notch  245  has a bottom  255 . The bottom  255  is the set of points of the notch  245  positioned at a distance, measured between the considered point and the common axis A in a plane perpendicular to the common axis A, strictly greater than the distances of all of the other points. 
     When the notch  245  has an arcuate cross-section, the bottom  255  is a line extending along a direction parallel to the common axis A. 
     Each point of the bottom  255  of each notch  245  is positioned at a distance dl from the common axis A, the distance dl being less than or equal to half of the minimum diameter of the inner face of the skirt  35 . 
     The tertiary section  220  is cylindrical with an annular base. The tertiary section  220  connects the primary section  210  to the secondary section  215 . 
     The secondary section  220  is in particular inserted in a plane perpendicular to the common axis A between the second part  50 B and the fourth part  50 D. 
     The tool  250  is configured to engage the inner face  200  of the secondary section  215  in order to rotate the threaded tube  190  about the common axis A. The tool  250  is in particular configured to transmit a force to the threaded tube  190  tending to pivot the tube  190  about the common axis A with respect to the turbine body  50 . 
     In particular, the tool  250  is configured to engage the notch or notches  245  in order to transmit the rotational force to the threaded tube  190 . 
     The tool  250  comprises a head  260 , visible in  FIG. 7 , and a handle. 
     The head  260  includes a body  265 , a base  270  and a set of protrusions  275 . 
     The head  260  is for example monobloc. 
     The head extends along a specific axis AP. 
     The body  265  has an outer face  280  delimiting the body  265  in a plane perpendicular to the specific axis. 
     The outer face  280  is cylindrical about the specific axis AP. The outer face  280  has a diameter of between 30 mm and 60 mm. 
     The base  270  is able to allow the handle to be fastened to the head  260 . For example, the base  270  extends from the body  265  along the specific axis AP and has an impression  285  able to cooperate with the handle so as to allow the handle to be fastened to the head  260 . 
     Each protrusion  275  extends radially outward from the outer face  280  of the body  265 . 
     Each protrusion  275  is configured to be engaged in a notch  245  in order to rotate the threaded tube  190 . In particular, the protrusions  275  are configured to be engaged simultaneously in the notches  245  by a translational movement of the tool  250  along the specific axis AP, the specific axis AP being combined with the common axis A of the spraying device  20 . 
     Each protrusion  275  has a thickness, measured in a plane perpendicular to the specific axis AP, from the outer face  280 , of between 0.5 mm and 5 mm. 
     The handle is provided to be fastened to the head and to rotate the head  260  about the specific axis AP. 
     According to one embodiment, the handle is able to allow an operator to control a tightening torque transmitted by the tool  250  to the tube  190 . For example, the handle is a torque wrench, a head of which is engaged in the impression  285  in order to rotate the head  270  about the specific axis AP. 
     It should be noted that other types of tools may be considered to rotate the threaded tube  190  relative to the turbine body  50 , in particular if the shape of the threaded tube  190  and in particular the shape and/or the number of the notches  245  are modified. 
     Owing to the use of the threaded tube  190 , the skirt  35  is effectively pressed against the first end face  90  by the engagement of the two threads  195  and  240 . The skirt  35  is therefore kept in position relative to the turbine body  50  with no tool engaging on the outside of the skirt  35 . The spraying device  20  therefore does not assume that notches are arranged on the outer surface of the skirt  35 . 
     On the contrary, the threaded tube  190  is inserted at least partially between the skirt  35  and the bowl  30  and is therefore protected against the depositing of coating products. 
     The threaded tube  190  therefore allows more reproducible clamping of the skirt  35  against the turbine body  50 , and more precise positioning. 
     The shoulder  225  makes it possible to effectively block the translation of the threaded tube  190  along the common axis A while allowing the rotation about this axis. A turbine body  50  in which the groove  197  for receiving the first section  210  is delimited along the common axis A by two separate parts  50 C and  50 D of the turbine body  50  makes it possible to easily fasten the tube  190  to the turbine body by placing the first section  210  in the groove  197  of the third part  50 C, then by fastening the fourth part  50 D to the third part  50 C. 
     When the length of the first section  210  is greater than or equal to 40 mm, the first section  210  prevents any particles generated by the rubbing of the shoulder  225  against the fourth part  50 D from being carried by the streams of gas G which are present in the zone between the bowl  30  and the skirt  35 . 
     The non-cylindrical configuration of the inner face  200  of the second section  215  makes it possible to maneuver the tube  190  easily, and in particular to set it in rotation about the common axis A relative to the turbine body  50 , from the opening  152  of the skirt  35 . The fastening and the separation of the skirt  35  and of the turbine body  50  are therefore simplified. 
     The notches  245  make it possible to effectively maneuver the threaded tube  190  simply. When they open onto the third end face  237 , it is particularly easy to insert the tool  250  by a simple translation along the upstream direction D 1 . 
     This is particularly true when the bottom of each notch  245  is further positioned at a distance less than or equal to half of the minimum diameter of the inner face  193  of the skirt  35 , since the tool  250  is then inserted through the opening  152  of the skirt  35  in order to insert the protrusions  275  into the notches  245 . This configuration in particular allows a simple geometry of the tool  250 , visible in  FIG. 7 . This tool  250  allows a very effective transmission of force, since several protrusions  275  are inserted simultaneously into the notches  245 . 
     It should be noted that the assembly of the skirt  35  onto the turbine body  50  via the threaded tube  190  may be implemented in embodiments where the injector  40  is not assembled directly on the turbine body  50 .