Abstract:
The invention relates to an aircraft wheel comprising a rim and a tire ( 20 ) received on the rim, the rim comprising two parts ( 1; 2 ) assembled with one another by means of assembly bolts ( 5 ), one of the parts comprising a recess ( 3 ) in which is arranged a seal ( 4 ) which is interposed between the two parts, the wheel being characterized in that at least one of the parts comprises at least one duct ( 6 ) extending beneath the seal so as to establish a leakage path between on one hand a volume of gas delimited by the rim and the tire, and on the other hand a space between the parts, the path being nominally closed by the seal when the bolts are tightened correctly but allowing gas to leak from said volume when the bolt associated with said opening is not tightened correctly or is absent.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a Divisional of U.S. application Ser. No. 14/640,278 filed Mar. 6, 2015, claiming priority based on French Application No. 14 52738 filed Mar. 28, 2014, the contents of all of which are incorporated herein by reference in their entirety. 
    
    
     The invention relates to an aircraft wheel comprising a duct establishing a leakage path in the wheel. 
     BACKGROUND OF THE INVENTION 
     Aircraft wheels are known which comprise a rim and a tyre received on the rim, the rim comprising two parts assembled by means of regularly distributed bolts. For example, the rim comprises two half-rims whose webs are pierced so as to receive bolts. Also known are rims, one of the flanges of which is removable and is assembled to the other flange by means of bolts. Typically, such an assembly may require in the region of twenty bolts. To that end, the two parts are pierced with opposing openings able to receive the bolts. Moreover, one of the parts usually comprises a recess in which is arranged a seal which is thus compressed between the two parts in order to ensure the leaktightness of the volume of gas delimited by the rim and the tyre. 
     However, a bolt may come loose such that the two parts are no longer correctly pressed against one another. Moreover, one of the bolts may be absent. This can cause damage to the wheel. 
     It proves however difficult to ascertain visually whether said bolt is loose. 
     OBJECT OF THE INVENTION 
     The invention has the object of proposing an aircraft wheel by means of which the abovementioned problem can be avoided. 
     SUMMARY OF THE INVENTION 
     With a view to achieving this aim, there is proposed an aircraft wheel comprising a rim and a tyre received on the rim, the rim comprising two parts assembled with one another by means of assembly bolts, one of the parts comprising a recess in which is arranged a seal which is interposed between the two parts. 
     According to the invention, one of the parts comprises at least one duct extending beneath the seal and opening into the recess so as to establish a leakage path between on one hand a volume delimited by the rim and the tyre and on the other hand a space between the parts, the path being nominally closed by the seal when the bolts are tightened correctly but allowing a leakage from said volume to the outside when one of the bolts adjacent to said opening is not tightened correctly or is absent. 
     Thus, in the event of a loose bolt, the duct makes it possible to cause an intentional leakage of the gas contained in the tyre to outside the wheel, which causes the tyre to deflate rapidly and visibly. It therefore proves simple to ascertain the existence of a problem upon seeing the deflated tyre, which prompts a more detailed investigation of the tightness of the various bolts. 
     Detecting a problem in the attachment between the two parts of the rim is thus thereby simplified. 
     Furthermore, the risk of the wheel being damaged by the problem in the attachment between the two parts of the rim is thus limited. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood in light of the following description of particular embodiments of the invention, with reference to the figures of the appended drawings, in which: 
         FIG. 1  is a view in longitudinal section of an aircraft wheel according to a first embodiment of the invention. 
         FIG. 2  is a partial front view of the half-rim  1   b  shown in  FIG. 1 , showing one of the ducts. 
         FIG. 3  is an enlarged view of the detail A shown in  FIG. 1 , an exaggerated space having been shown between the half-rims. 
         FIG. 4  is a further enlarged view of the detail A, without the seal and without the half-rim  2   a.    
         FIG. 5  is a view in longitudinal section of an aircraft wheel according to a second embodiment of the invention, in a plane passing through the axis of rotation of the wheel and extending, for half of the figure, through one of the assembly bolts and extending, for half of the figure, between two consecutive assembly bolts. 
         FIG. 6  is an enlarged view in section of the detail B shown in  FIG. 5 , an exaggerated space having been shown between the rim parts. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     According to a first embodiment, the wheel shown in  FIGS. 1 and 2  comprises, in a manner known per se, two half-rims  1 ,  2  which each comprise a rim portion  1   a ,  2   a , a web  1   b ,  2   b , and a half-hub  1   c ,  2   c . One of the half-rims  1  comprises a recess  3  created in its web  1   b  and in which is arranged a seal  4 . 
     The half-rims  1 ,  2  are brought together in a direction parallel to an axis of rotation of the wheel X and comprise centring surfaces to ensure proper relative positioning of the half-rims  1 ,  2 . The half-rims are held in position by assembly bolts  5  arranged in openings  7  pierced opposite one another in the half-rims (only one bolt is shown here, but there are several, typically 4 to 24, regularly distributed). 
     In a manner known per se, the bolts  5  are screwed in and tightened in order to assemble the two half-rims  1 ,  2  after mounting a tyre  20  on the rim portions  1   a ,  1   b . In this position, the seal  4  is compressed between the two half-rims  1 ,  2  and thus prevents the gas contained in a volume delimited by the tyre  20  and the two half-rims  1 ,  2  from escaping to outside the wheel. 
     As shown in  FIGS. 3 and 4 , and in accordance with the invention, the half-rim  1   a  comprising the recess  3  comprises a plurality of ducts  6  (only one of which is shown in the figures). Each duct  6  extends between two assembly bolts  5  of the wheel. The half-rim  1  therefore comprises as many ducts  6  as bolts  5 . Preferably, each duct  6  extends equidistant from the two associated openings  7  in the half-rim  1 . 
     Moreover, each duct  6  extends beneath the seal  4  and opens at one of its ends into the recess  3  and at the other of its ends at the join between the two webs  1   b ,  2   b.    
     Thus, each duct  6  is arranged so as to establish a leakage path between the volume delimited by the tyre and the outside, passing through the space between the half-rims. 
     When the bolts  5  are all tightened correctly, these paths are blocked by the seal  4 . When one of the bolts  5  is not tightened correctly or is absent, the two half-rims  1 ,  2  move apart from each other at said bolt  5  such that the seal  4  is no longer correctly compressed by the two half-rims  1 ,  2  at that point. The seal  4  cannot then prevent the gas from escaping via the leakage path established by the two ducts adjacent to said bolt  5 . The tyre deflates, which can be observed by the maintenance teams or by measuring the pressure in the tyre. 
     With reference to  FIG. 4 , the half-rim  1  comprising the recess  3  is formed such that the end of its web  1   b  designed to be opposite the web  2   b  of the other half-rim  2  comprises successively, in the direction of the axis of rotation of the wheel X towards the other web  2   b , a radius  10 , a channel  11  here forming the recess  3  and a shoulder  12 . Here, the shoulder  12  has a height for example of the order of 0.8 millimeters. 
     The half-rim  1  is machined by milling at the shoulder  12  so as to locally remove said shoulder  12  at various points in order to form the various ducts  6 . Each duct  6  thus formed extends from the channel  11  to the face  13  of the web  1   b  which is opposite the other web  2   b . Here, the duct has a bottom which is inclined with respect to the axis of rotation X and has a maximum depth at the outlet on the face  13  (typically of the order of 2 millimeters). 
     It thus proves very simple to form the ducts  6  even on already existing half-rims. 
     With reference to  FIGS. 5 and 6 , a second embodiment of the invention will now be described. In contrast to the first embodiment, the rim of the aircraft wheel comprises a main part  101  and a removable part  102  forming a flange  121  in place of the two half-rims  1 ,  2 . 
     The main part  101  comprises, in a manner known per se, a hub  101   c , an annular outer portion  101   a  designed to receive a tyre  120  and formed so as to have a flange  122  at one of its ends, the other of its ends  123  being formed to receive the removable part  102  which is fitted onto the annular outer portion  101   a  once the tyre  120  is in place. The main part  101  comprises, furthermore, a web  101   b  extending between the hub  101   c  and the annular outer portion  101   a . Here, the main part  101  comprises a recess  103  created in its web  101   b  and in which is arranged a seal  104 . 
     The main part  101  and the removable part  102  are brought together in a direction parallel to an axis of rotation of the wheel X and comprise centring surfaces in order to ensure the proper relative positioning of the main part  101  and of the removable part  102 . The two parts  101 ,  102  are held in position by assembly bolts  105  arranged in openings pierced opposite one another in the two parts  101 ,  102  of the rim. 
     In a manner known per se, the bolts  105  are screwed in and tightened in order to assemble the two parts  101 ,  102  once the tyre  120  is mounted on the annular outer portion  101   a . In this position, the seal  104  is compressed between the two parts  101 ,  102  and thus prevents the gas contained in a volume delimited by the tyre  120  and the rim from escaping to outside the wheel. 
     As shown in  FIG. 6 , and in accordance with the invention, the main part  101  comprises a plurality of ducts  106  (only one of which is shown in the figures). Each duct  106  extends between two assembly bolts  105  of the wheel. The main part  101  thus comprises as many ducts  106  as bolts. Preferably, each duct  106  extends equidistant from the two associated openings in the main part  101 . 
     Moreover, each duct  106  extends beneath the seal  104  and opens at one of its ends into the recess  103  and at the other of its ends at the join between the web  101   b  of the main part  101  and a web  102   b  of the removable part  102 . 
     Thus, each duct  106  is arranged so as to establish a leakage path between the volume delimited by the tyre  120  and the outside, passing via the space between the main part  101  and the removable part  102 . 
     Here, the main part  101  is formed such that the end of its web  101   b  designed to be opposite the web  102   b  of the removable part  102  comprises successively, in the direction of the axis of rotation of the wheel X towards the removable part  102 , a radius, a channel here forming the recess and a shoulder. Here, the shoulder has for example a height of the order of 0.8 millimeters. 
     The main part  101  is machined by milling at the shoulder so as to locally remove said shoulder at various points to form the various ducts  106 . Each duct  106  thus formed extends from the channel to the face of the web  101   b  which is opposite the web  102   b  of the removable part  102 . Here, the duct  106  has a bottom which is inclined with respect to the axis of rotation X and has a maximum depth at the outlet on the face of the web  101   b  which is opposite the web  102   b  (typically of the order of 2 millimeters). 
     The invention is not limited to that which has just been described, but on the contrary encompasses any variant within the scope defined by the claims. 
     Although in the example shown the half-rims each comprise one half-hub, it would of course be possible to envisage any other division, as long as the half-rims are assembled by means of assembly bolts. 
     The aircraft wheel could comprise a different number of ducts from that indicated. 
     Of course, the duct could take on a different shape to that shown. Thus, although here the duct has a bottom which is inclined relative to an axis of rotation of the wheel, the duct could have a bottom which is parallel to said axis. The duct could have other dimensions to those described, although the duct must have suitable dimensions so as to avoid the seal collapsing inside the duct when the bolts are tightened correctly, which would impair the leaktightness of the volume of gas. For example, although here the half-rim, or the main part, is machined to a depth of 2.4 millimeters, it would be possible to machine the half-rim, or the main part, to another depth for example a depth between 0.8 and 2.4 millimeters at the face of the part of the rim at the join with the other part of the rim. If the half-rim, or the main part, comprises a shoulder on which the web of the other half-rim, or of the removable part, is designed to rest, the half-rim, or the main part, will be machined so as to locally remove said shoulder entirely. The duct will thus have a smooth inner surface which will make it easier for the gas to escape. 
     Finally, the duct or ducts may be cut into that one of the half-rims which does not comprise the recess for receiving the seal, provided that these ducts are nominally plugged by the seal when the bolts are correctly tightened. Equally, the duct or ducts may be cut into the removable part which does not comprise the recess for receiving the seal, provided that these ducts are nominally plugged by the seal when the bolts are correctly tightened.