Abstract:
A movement-constraining assembly for a fluid-conveying system comprises a fluid-conveying tube defining an inner passage for fluid to pass therethrough. The tube is adapted to be connected to components of the fluid-conveying system at opposed ends thereof. A blocking ring is mounted to the tube with complementary surfaces between the tube and the blocking ring to block rotation between the tube and the blocking ring, the blocking ring having a first joint portion. A base is adapted to be secured to a structure, and having a second joint portion operatively joined to the first joint portion of the blocking ring to form a joint blocking at least an axial rotational degree of freedom of the fluid-conveying tube and allowing at least one translational degree of freedom of the tube relative to the structure. A method for constraining movement of a fluid-conveying tube of a fluid conveying-system is also provided.

Description:
TECHNICAL FIELD 
     The present disclosure relates to fluid-conveying systems and to movement-constraining assemblies therefor. 
     BACKGROUND OF THE ART 
     Tubes (a.k.a. tubing, piping, pipes, etc) are conventionally used in hydraulic or pneumatic circuits or similar applications to convey fluids between components. Depending on the applications, tubes may be subjected to rattling, vibrations, thermal variations, whereby tubes move relative to surrounding structures. One known application in which tubes may move is in aircraft. As an example, tubes may be coupled to one another or to components by threading engagement. If the tubes become unscrewed because of vibrations, rotations, etc, fluid leaks may result. 
     SUMMARY 
     In accordance with an embodiment of the present disclosure, there is provided a movement-constraining assembly for a fluid-conveying system, comprising: a fluid-conveying tube defining an inner passage for fluid to pass therethrough, the tube adapted to be connected to components of the fluid-conveying system at opposed ends thereof; a blocking ring mounted to the tube with complementary surfaces between the tube and the blocking ring to block rotation between the tube and the blocking ring, the blocking ring having a first joint portion; and a base adapted to be secured to a structure, and having a second joint portion operatively joined to the first joint portion of the blocking ring to form a joint blocking at least an axial rotational degree of freedom of the fluid-conveying tube and allowing at least one translational degree of freedom of the tube relative to the structure. 
     In accordance with another embodiment, there is provided a method for constraining movement of a fluid-conveying tube of a fluid conveying-system comprising: connecting the fluid-conveying tube at a first end to a component of a fluid-conveying system; securing a base having a joint portion to a structure adjacent to the fluid-conveying tube as connected to said component; installing a blocking ring on the fluid-conveying tube by engaging complementary surfaces therebetween to block rotation between the tube and the blocking ring, the blocking ring have a joint portion; and operatively joining the joint portions of the base and of the blocking ring to form a blocking at least an axial rotational degree of freedom of the fluid-conveying tube and allowing at least one translational degree of freedom of the tube relative to the structure. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an enlarged perspective view of a movement-constraining assembly for fluid-conveying system in accordance with the present disclosure; 
         FIG. 2  is an assembly view of the assembly of  FIG. 1 ; 
         FIG. 3  is a perspective view of an exemplary embodiment of a tube of the assembly of  FIG. 1 ; 
         FIG. 4  is a plan view of the assembly of  FIG. 1 ; 
         FIG. 5  is an elevation view showing a blocking ring being installed on the tube in the assembly of  FIG. 1 ; 
         FIG. 6  is a plan view of the blocking ring of  FIG. 5  being oriented to a proper orientation; 
         FIG. 7  is an elevation view of the blocking ring on an interface of the tube further to  FIG. 6 ; 
         FIG. 8  is a perspective view of a retaining clip being installed on the interface further to  FIG. 7 ; and 
         FIG. 9  is a perspective view of the assembly as assembled further to  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings and more particularly to  FIGS. 1 and 2 , a movement-constraining assembly for tubes of a fluid-conveying system is generally shown at  10 . The movement-constraining assembly  10  comprises a tube  20 , a blocking ring  30 , a retaining ring  40  and a base  50 . 
     The tube  20  is connected at opposed ends to components of a fluid-conveying system, such as other tubes or pipes of an hydraulic circuit, or equipment e.g., tank, injection system, etc. The tube  20  is also part of the fluid-conveying system as its inner passage serves for conveying fluids. In the illustrated embodiment, the tube  20  is in the vicinity of the casing A or like structural component, and is shown connected at one end to a tube B having a coupler C. 
     The blocking ring  30  is coupled to the tube  20  and will cooperate with the base  50  to form a joint constraining movement of the tube  20 , for instance by forming an anti-rotation feature while imposing no axial nor radial constraints. 
     The retaining ring  40  may be part of the assembly  10  and is one contemplated solution to hold the blocking ring  30  captive on the tube  20 . 
     The bracket  50  is the interface between the casing A or like structural component and the blocking ring  30 . As an alternative to the casing A, the bracket  50  may be connected to any structural or stable component, for instance of a gas turbine engine when the assembly  10  is used in the context of a gas turbine engine. As an example, the casing A may be part of an oil tank, etc. 
     Referring to  FIG. 3 , the tube  20  is shown in greater detail. The tube  20  has an elongated tubular body  21  forming an inner passage for fluid flow therethrough. In an embodiment, the tube  20  is an oil tube that is part of an hydraulic system. The tube  20  is thus made of any appropriate material selected as a function of the contemplated use, such as metals, polymers, and/or composites, etc. The tube  20  is connected at opposed ends to components of the fluid-conveying system, for instance of a gas turbine engine and/or to other tubes, such as the tube B as shown in  FIG. 1 . One of the ends of the tube  20  may be a threaded connector end  22  by which the tube  20  will be threadingly engaged to a component. The opposite end is illustrated as being a tapped connector end  23 . The tapped connector end  23  is configured to be coupled to the tube B as in  FIG. 1 , by way of coupler C. Although the embodiment of  FIG. 3  shows a threaded connector end  22  and a tapped connector end  23 , both ends may be threaded or tapped. Likewise, other connector configurations could be used as well, such as quick coupling, barb, etc, in any appropriate combination. 
     Still referring to  FIG. 3 , the tube  20  has an interface  25 . The interface  25  has a generally cylindrical configuration, although it is not circular peripherally, but rather has a plurality of longitudinal flats  26 . The flats  26  are paired into a plurality of axial channels peripherally distributed over the outer surface of the interface  25 . All axial channels in the illustrated embodiment are shaped as troughs formed by the pairs of flats  26  may generally be of a same dimension and spaced apart uniformly along the outer surface of the interface  25 . This trough configuration of the interface  25  is one of numerous configurations considered (splines, etc), with  FIGS. 1 and 2  showing for example interface  25 ′ having an hexagonal shape with six flats  26 ′ in lieu of axial channels. The flats  26  and  26 ′ may be any concavity in the outer surface of the interface  25  forming surfaces complementary to that of the blocking ring  30 , as described below. 
     A flange  27  is positioned along the tube  20  and is adjacent to the interface  25 . The flange  27  may be integral with the tube  20 , or releasably connected to the tube  20 . A groove  28  is carved into the outer surface of the interface  25 . The flange  27  and the groove  28  may lie in parallel planes, with a longitudinal axis of the tube  20  being normal to these parallel planes. 
     Referring to  FIGS. 4, 5 and 6 , the blocking ring  30  is shown in greater detail. The blocking ring  30  has a plurality of inner flats  31 . The inner flats  31  are paired to define axial channels, which axial channels are compatible in terms of dimensions with the shape of the interface  25  of the tube  20 . Accordingly, in the manner shown in  FIGS. 6 and 7 , the blocking ring  30  may be slid onto the interface  25 , with sliding engagement between the inner surface of the blocking ring  30  and the interface  25 , in such a way that the blocking ring  30  is prevented from rotating about the interface  25  when engaged to the tube  20 . The inner flats  31  form surfaces complementary to that of that interface  25 , whereby the blocking ring  30  is fixed in rotation to the interface  25  when coupled. 
     In the illustrated embodiment, the troughs-like axial channels formed with the inner flats  31  of the blocking ring  30  double the amount of troughs formed by the flats  26  of the interface  25 . Accordingly, some form of orientation indexing joint is defined therebetween, to select the orientation of the blocking ring  30  on the interface  25 . By having a relative higher number of complementary surfaces in at least one of the interface  25  and the blocking ring  30 , numerous indexing orientations may be possible to achieve a desired orientation for the blocking ring  30 . In the illustrated embodiment, the blocking ring  30  is shown having twenty-four axial channels formed with the inner flats  31 , for twelve axial channels of flats  26 . 
     Referring to  FIGS. 4, 5 and 6 , the blocking ring  30  is shown having outer flats  32  on its outer surface. The outer flats  32  give a decagonal shape to the blocking ring  30 . This is one of the numerous configurations considered—for instance other regular convex polygons are well suited sectional shapes for the outer surface of the blocking ring  30 . In the illustrated embodiments, the outer flats  32  are substantially flat. The outer surface of the blocking ring  30  (i.e., by way of the outer flats  32 ) forms a first joint portion, by which the blocking ring  30  will form a joint with the base  50 , as detailed below. 
     The blocking ring  30  has a height  33  shown in  FIG. 7 . The height  33  generally corresponds to the space between the flange  27  and the groove  28  in the tube  20 . Accordingly, when the retaining ring  40  is installed on the interface  25  and is held captive in the groove  28 , the blocking ring  30  may be held captive between the retaining ring  40  and the flange  27 . It is pointed out that that the tube  20  may have a groove and retaining ring instead of the flange  27 . Moreover, other configurations are considered to hold the blocking ring  30  in an axial position along the tube  20 . For instance, there may be some interference or friction fit between the interface  25  and the blocking ring  30 , to hold the blocking ring  30  in the selected axial position. 
     The retaining ring  40  is also known as an axially installed retaining ring, or an external circlip. Therefore, in conventional fashion, the retaining ring  40  has a pair of lugs  41  with holes  42  adjacent to a gap between ends of the retaining ring  40 . Pliers may be used to space apart the ends of the retaining ring  40  to elastically deform the retaining ring  40  when positioning same into the groove  28  of the tube  20 , or when removing the retaining ring  40 . 
     Referring to  FIGS. 1, 2 and 4 , the base  50  is shown having a base plate  51 . The base plate  51  is illustrated as being a generally flat plate with holes by which the base  50  may be connected to a flange of casing A as in  FIG. 1 . Other configurations are considered as well, as long as the base  50  may be connected securely to structural parts. The shape of the base  50  may be dictated by the structure to which it will be connected. Arms  52  form a second joint portion and project from the base plate  51  and have abutment surfaces  53  separated by a gap  54 . The abutment surfaces  53  may be substantially flat, as in the illustrated embodiment. 
     Now that the various components of the movement-constraining assembly  10  have been described, an installation and functionality thereof will be described. Referring to  FIG. 5 , the tube  20  has been previously connected to a component and the base  50  has been secured to a structure. It is observed that the dimension of the tube  20  and of the base  50  is selected in such a way that the interface  25  is generally between the abutment surfaces  53  of the base  50 . As shown in  FIG. 5 , the blocking ring  30  is positioned adjacent to the interface  25 , but axially offset therefrom. 
     Referring to  FIG. 6 , an orientation of the blocking ring  30  relative to the interface  25  is adjusted, by a rotation of the blocking ring  30  about its axis. Once a suitable orientation has been reached, the blocking ring  30  may be slid onto the interface  25  in the manner shown in  FIG. 7 , whereby the ring  30  is blocked from rotating about the tube  20 . It is desired that the outer flats  32  (a.k.a. first joint portion) be generally parallel to the abutment surfaces  53  of the arms  52  (a.k.a. second joint portion) in such a way that the outer flats  32  slide against the abutment surfaces  53  of the base  50 , thereby forming a movement-constraining joint between the blocking ring  30  and the base  50 , as shown in  FIG. 8 . It is observed that, by way of the cooperation between the abutment surfaces  53  of the base  50  and the outer flats  32  of the blocking ring  30 , the blocking ring  30  and thus the tube  20  are prevented from rotating about the longitudinal axis of the tube  20 . However, some play is allowed in the axial direction (for instance, as a result of thermal expansion) or in a radial direction (for instance, as a result of rattling in the environment of the movement-constraining assembly  10 ). Hence, the joint formed between the blocking ring  30  and the base  50  blocks an axial rotational degree of freedom and allows at least one radial rotational degree of freedom of the tube  20  (shown as θ). The joint also allows at least one axial translational degree of freedom of the tube relative to the structure (shown as X), and likely another translational degree of freedom (shown as Y). The retaining ring  40  may then be installed in the groove  28  so as to hold the blocking ring  30  captive. Once the arrangement is reached, as in  FIG. 9 , it is possible to couple the open end of the tube  20 , i.e. the tapped connector end  23  in  FIG. 9 , to a component of the fluid-conveying system. In some circumstances, the connection of the tube  20  via connector end  23  may be performed prior to the formation of the joint between the blocking ring  30  and base  50 . 
     If the tube  20  must be attended to, the retaining ring  40  may be removed, to then slide the blocking ring  30  away from engagement with the base  50 , to undo the joint therebetween.