초록 ▼

A coaxial rotary coupling (11) includes a hollow inner tube (4) and a hollow outer tube (7), with inner and outer splines (12 and 13) in mutual engagement. The coupling (11) further includes: approach elements for longitudinally approaching the inner and outer tubes (4, 7) together with elements pre

A coaxial rotary coupling (11) includes a hollow inner tube (4) and a hollow outer tube (7), with inner and outer splines (12 and 13) in mutual engagement. The coupling (11) further includes: approach elements for longitudinally approaching the inner and outer tubes (4, 7) together with elements presenting a wedge arrangement for causing the inner and outer tubes (4, 7) to turn (23) relative to each other in opposite directions so as to limit tangential assembly slack; a soleplate (16) of the driven tube (7); and a flange (17); the driving tubes (4) having complementary splines (12, 13, 18) together with dogs including force-transformation ramps (31) that are distributed peripherally within the coupling (11).

대표청구항 ▼

1. A coaxial rotary coupling (11) comprising a hollow inner tube (4) and an outer tube (7), the tubes (4; 7) being provided with complementary splines (12; 13) in mutual engagement and extending in a longitudinal direction (X), said coupling (11) further including longitudinal approach means (21) fo

1. A coaxial rotary coupling (11) comprising a hollow inner tube (4) and an outer tube (7), the tubes (4; 7) being provided with complementary splines (12; 13) in mutual engagement and extending in a longitudinal direction (X), said coupling (11) further including longitudinal approach means (21) for longitudinally approaching the inner and outer tubes (4, 7), together with at least one wedge arrangement (19A, 20A, 31) that acts, under the effect of said approach means (21), to cause the inner and outer tubes (4, 7) to pivot (23) relative to each other in opposite directions so as to compensate for assembly slack (24), wherein the coupling (11) comprises: a soleplate (16) rigidly secured to a base (15) of one of said tubes that is a driven tube (4; 7), which soleplate projects radially;a peripheral flange (17) mounted on the other one of said tubes (4; 7) that is a driving tube, said flange (17) having splines (18) complementary to the said splines (12) of the driven tube (4; 7) and in engagement therewith; anddogs, firstly on a bottom face (19) of the soleplate (16) and secondly on a top face (20) of the peripheral flange (17), each dog (19A, 20A) possessing at least one transformation ramp (31) forming a wedge arrangement, while the longitudinal approach means (21) are distributed within the coupling (11) and radially spaced apart from said splines (12, 13, 18), such that in the tangential slack take-up position, the splines (12, 13) of the driving tube (7; 4) are in engagement with the splines (18) of the flange (17) via the flanks thereof, and downstream therefrom the splines (13, 12) of the driven tube (4; 7) are in engagement with the splines (12, 13) of the driving tube (7; 4) via the flanks thereof. 2. A coupling (11) according to claim 1, wherein the soleplate (16) is rigidly secured to a base (15) of the driven tube, which is external (7) and extends radially outwards from the coupling (11), said peripheral flange (17) is mounted on the driving tube, which is internal (4) and outwardly projecting, said flange (17), which is also external, having splines (18) complementary to the splines of the internal tube (4) and in engagement therewith, while the longitudinal approach means (21) are distributed around the coupling (11) externally relative to said splines (12, 13, 18), such that in the tangential slack take-up position, the splines (12) of the internal tube (4) are in engagement with the splines (18) of the external flange (17) via the flanks thereof, and downstream therefrom the splines (13) of the internal tube (7) are in engagement with the splines (12) of the external tube (4) via the flanks thereof. 3. A coupling (11) according to claim 1, wherein the soleplate (16) is rigidly secured to a base (15) of the driven tube, which is internal (4) and extends radially outwards from the coupling (11), said peripheral flange (17) is mounted on the driving tube, which is external (7) and projects inwards, said flange (17) also being internal and having splines (18) complementary to the splines (13) of the external tube (7) and in engagement therewith, while the longitudinal approach means (21) are distributed inside the coupling (11), internally relative to said splines (12, 13, 18), such that in the tangential slack take-up position, the splines (13) of the external tube (7) are in engagement with the splines (18) of the internal flange (17) via the flanks thereof, and downstream therefrom the splines (21) of the internal tube (4) are in engagement with the splines (13) of the external tube (7) via the flanks thereof. 4. A coupling (11) according to claim 1, wherein the approach means (21) also act as means for preventing the flange (17) from moving on the driving tube (7; 4) in the longitudinal direction (X). 5. A coupling (11) according to claim 1, wherein in a radial direction (Y), the approach means (21) are disposed in register with dogs (19A, 20A) having holes (30) and screw-and-nut fasteners (26) of said approach means (21) located upstream and downstream from each dog (19A, 20A) around the periphery of the flange (17) and the soleplate (16). 6. A coupling (11) according to claim 1, wherein each dog (19A, 20A) includes a substantially plane force-transformation ramp (31) that is provided between a top (28) of the dog and only one of the bottoms (29) adjacent thereto, a ramp (31) being interposed downstream from such a bottom (29) and upstream from said top (28). 7. A coupling (11) according to claim 1, wherein, in view perpendicular to a radial direction (Y), each force-transformation ramp (31) forms a plane that slopes relative to the longitudinal and radial directions (X and Y), from left to right and from top to bottom, and defines an angle (35) relative to the longitudinal direction (X) that is of the order of 30 degrees. 8. A coupling (11) according to claim 1, wherein, in view perpendicular to a radial direction (Y), each force-transformation ramp (31) forms a plane sloping relative to the longitudinal and radial directions (X and Y), from left or right and from bottom to top, and defines an angle (35) relative to the longitudinal direction that is of the order of 30 degrees. 9. A coupling (11) according to claim 1, wherein, in projection onto a tangential plane parallel to the longitudinal direction (X), each dog (19A or 20A) presents a height equal to the distance between the bottom and top edges (32 and 33) and/or substantially twice a width distance between said edges (32, 33) in projection onto a plane perpendicular to said longitudinal direction (X). 10. A coupling (11) according to claim 1, wherein an engagement width dimension equal to a distance in the radial direction (Y) between outer and inner rims (25 and 34) of each dog (19A or 20A) is substantially equal to a thickness, not including the flange (17), of the coupling (11) in said radial direction (Y), said thickness corresponding substantially to the radial thickness of the driving tube (7; 4) with its splines (12) plus the thickness of the driven tube (4; 7) with its splines (13), and/or said engagement width of the dogs (19A, 20A) is substantially equal to half an outside diameter of a shell (5) of the driving tube (7; 4), not including the splines (12). 11. A coupling (11) according to claim 10, wherein said engagement width of the dogs (19A, 20A) is substantially equal in the radial direction (Y) to half an inside diameter of a shell (14) of the driven tube (4; 7), not including the splines (13). 12. A rotor (2) for a rotary wing aircraft (1) having at least one coupling (11) according to claim 1 incorporated therein, wherein the inner hollow tube (4), and the outer hollow tube (7) have respective stiffnesses in twisting that are substantially equal, even though their respective materials may have different moduluses of elasticity. 13. A rotary wing aircraft (1), in particular a convertible rotorcraft (1), of the type including at least one rotor (2) according to claim 12, wherein the driving hollow tube (4; 7), which is connected firstly via a first end to a transmission such as a speed-reducing gearbox, and which is connected secondly via a second end to a hub (41) for supporting blades (8), and the driven hollow tube (7; 4), which is connected to said hub (41) and to the peripheral flange (17) having force-transformation ramps (31), together surround a longitudinal duct (6) for passing equipment (40) of the rotorcraft (1).