Flexible coupling means, a mechanical transmission, and an aircraft

Abstract

A coupling means having a first member provided with a first diaphragm and a second member provided with a second diaphragm. The coupling means include an additional device having a plurality of protrusions circumferentially distributed on a first cylinder of the first member and a plurality of abutments distributed circumferentially on a second cylinder of the second member, each protrusion presenting at least one sliding face facing a first bearing face of an abutment, each protrusion presenting a blocking face facing a face of the second member referred to as a second bearing face.

Claims

1. A coupling means provided with a first member suitable for being fastened to a first rotary unit and a second member suitable for being fastened to a second rotary unit, the first member being provided with a first diaphragm and the second member being provided with a second diaphragm that is secured to the first diaphragm in order to allow shifting between the first rotary unit and the second member, the coupling means including an additional torque transmission device for at least connecting together the first and second members in the event of at least one of the diaphragms or of a connection between the diaphragms rupturing; wherein the additional device has at least one plurality of protrusions distributed circumferentially on a first cylinder of the first member and a second plurality of abutments distributed circumferentially on a second cylinder of the second member, each protrusion presenting at least one face with two angles of inclination referred to as a sliding face facing a face with two angles of inclination of an abutment referred to as a first bearing face, each protrusion presenting a face referred to as a blocking face facing a face referred to as a second bearing face of the second member; wherein in the absence of rupture, first radial clearance lies between each protrusion of the first member and the second member in a direction passing via a radius (R1) of the first cylinder and second radial clearance lies between each bearing face of the second member and the first member in a direction passing via a radius (R2) of the second cylinder, first axial clearance lying between each protrusion and a respective first bearing face, and second axial clearance lying between each blocking face and a respective second bearing face in an axial direction parallel to an axis of rotation (AX3) of the first member and of the second member; and wherein each face with two angles of inclination presents a first angle of inclination (ALPHA) to enable a respective protrusion to be wedged between a respective first bearing face and a respective second bearing face by eliminating the axial clearances as a result of the protrusions turning relative to the bearing faces about the axis of rotation (AX3) in the event of rupture, each face with two angles of inclination presenting a second angle of inclination (BETA) for centering the first cylinder relative to the second cylinder following the relative turning.

2. A coupling means according to claim 1, wherein each face with two angles of inclination extends radially from a cylinder of a segment referred to as a bottom segment towards a segment referred to as a top segment, each segment extending circumferentially from a first end towards a second end, and the first angle of inclination (ALPHA) shifts the first end of each segment relative to the second end of the segment axially in a direction parallel to the axis of rotation.

3. A coupling means according to claim 1, wherein the first end of a segment represents the point of the segment closest to a reference plane (PREF) containing the diaphragm of the member having the segment, a line referred to as a tangential line passing via the first end and a point of the segment other than the first end, and the first angle of inclination (ALPHA) has a value lying in the range 15 degrees to 80 degrees, extending between the tangential line and the reference plane (PREF).

4. A coupling means according to claim 1, wherein each face having two angles of inclination extends radially from a cylinder of a segment referred to as a bottom segment towards a segment referred to as a top segment, each segment extending circumferentially from a first end towards a second end, the second angle of inclination (BETA) shifting the bottom segment axially from the top segment in a direction parallel to the axis of rotation.

5. A coupling means according to claim 4, wherein the bottom segment is connected by a line referred to as the line in elevation to the top segment in a radial plane (P1) orthogonal to a reference plane (PREF) containing the diaphragm of the member having the segments, and the second angle of inclination (BETA) has a value lying in the range 15 degrees to 80 degrees between the line extending in elevation and the reference plane.

6. A coupling means according to claim 1, wherein the first cylinder and the second cylinder are coaxial.

7. A coupling means according to claim 1, wherein the second cylinder is surrounded by the first cylinder.

8. A coupling means according to claim 1, wherein the first member has at least three protrusions.

9. A coupling means according to claim 1, wherein the protrusions are uniformly distributed circumferentially on a circumference of the first cylinder.

10. A coupling means according to claim 1, wherein each second bearing face is a portion of a single annular projection extending radially from the second cylinder, each blocking face being parallel to the annular projection.

11. A coupling means according to claim 10, wherein the annular projection is offset axially relative to the second diaphragm of the second member.

12. A coupling means according to claim 1, wherein the second member has a plurality of radial excrescences, each radial excrescence facing a respective abutment and including at least one respective second bearing face.

13. A coupling means according to claim 1, wherein at least one protrusion of the plurality of protrusions has two sliding faces.

14. A coupling means according to claim 1, wherein at least one protrusion of the plurality of protrusions has two blocking faces, each blocking face being a face with two angles of inclination.

15. A coupling means according to claim 1, wherein at least one abutment of the plurality of protrusions has two first bearing faces.

16. A coupling means according to claim 1, wherein the coupling means includes a first reversible fastener device for fastening a respective protrusion to the first member, and/or a second reversible fastener device for fastening a respective abutment to the second member.

17. A coupling means according to claim 1, wherein the coupling means comprises: the first member provided with the first cylinder in the form of a first hollow cylinder extending axially, a first base of the first diaphragm being secured to the first cylinder; the second member provided with the second cylinder in the form of a second hollow cylinder extending axially, a second base of the second diaphragm being secured to the second cylinder, a second outer periphery of the second diaphragm being fastened to a first outer periphery of the first diaphragm; the plurality of the protrusions secured to the first cylinder, each protrusion projecting into an internal space (INT) of the coupling means; and one abutment of the plurality of abutments per protrusion, each abutment being secured to the second cylinder and projecting into the internal space (INT), each protrusion being wedged against a respective abutment and a respective second bearing face of the second member in the event of a diaphragm rupturing.

18. A rotary mechanical transmission having a first rotary unit and a second rotary unit, wherein the mechanical transmission includes at least one coupling means according to claim 1.

19. An aircraft, wherein the aircraft includes a mechanical transmission according to claim 18.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail from the context of the following description of embodiments given by way of illustration and with reference to the accompanying figures, in which:

(2) FIG. 1 is a view showing an aircraft of the invention;

(3) FIGS. 2 to 6 and 8 are views showing coupling means in a first embodiment;

(4) FIG. 7 is a three-dimensional view showing a second embodiment; and

(5) FIGS. 9 to 15 are views showing the operation of the coupling means independently of the embodiment.

(6) Elements present in more than one of the figures are given the same references in each of them.

DETAILED DESCRIPTION OF THE INVENTION

(7) It should be observed that three mutually orthogonal directions X, Y, and Z are shown in some of the figures.

(8) The first direction X is said to be longitudinal. The terms longitudinal and axial relate to any direction parallel to the first direction X.

(9) The second direction Y is said to be transverse. Finally, the third direction Z is said to be in elevation. The term radial relates to any direction parallel to the second direction Y or to the third direction Z.

(10) FIG. 1 shows an aircraft 1 having a mechanical transmission 5 suitable for transmitting torque and rotary motion. The other elements of the aircraft 1 are not shown for reasons of concession.

(11) The mechanical transmission 5 has a first rotary unit 2 that is to be mechanically connected to a second rotary unit 3. Under such circumstances, the mechanical transmission 5 has at least one coupling means 10 interposed between the first rotary unit 2 and the second rotary unit 3.

(12) Each coupling means 10 has the function of mechanically connecting the first rotary unit 2 to the second rotary unit 3 while allowing axial and angular shifting between these rotary units.

(13) Under such circumstances, coupling means 10 of the invention comprise a first member 20 having a first diaphragm 22.

(14) More precisely, the first member 20 as shown has a first cylinder 21 that is hollow. This first cylinder 21 extends longitudinally from a first distal end 21 to a first proximal end 21 along a first axis of symmetry AX of the first member 20.

(15) A first annular base 23 of the first diaphragm 22 is then secured to the first proximal end 21. For example, this annular base is welded to the first proximal end 21.

(16) The first diaphragm is then annular in shape, extending radially from its first annular base 23 to a first outer periphery 24.

(17) Furthermore, the first distal end 21 of the first cylinder may include first fastener means (not shown in FIG. 1). The first fastener means then serve to secure the first member 20 to a rotary unit or to any other coupling means. In the example of FIG. 1, the first cylinder 21 is secured to the first rotary unit 2.

(18) Furthermore, the coupling means 10 comprise a second member 30 provided with a second diaphragm 32.

(19) The second member 30 shown comprises a hollow cylindrical body 35. This body 35 extends longitudinally from a distal termination 35 to a proximal termination 35 along a second axis of symmetry AX2 of the second member. In the absence of any misalignment, the coupling means performs rotary motion about an axis of revolution AX that coincides with the first axis of symmetry AX and with the second axis of symmetry AX2.

(20) Furthermore, the proximal termination 35 of the body 35 may include second fastener means (not shown in FIG. 1). The second fastener means then serve to secure the second member 30 to a second rotary unit or to other coupling means. In the example of FIG. 1, the body 35 is secured to other coupling means.

(21) In addition, a second annular base 33 of the second diaphragm 32 is secured to the proximal termination 35. For example, this annular base is welded to the proximal termination 35.

(22) The second diaphragm is then annular in shape, extending radially from its second annular base 33 to a second outer periphery 34.

(23) Under such circumstances, coupling means are provided with a fastener system for linking the first outer periphery 24 to the second outer periphery 34. This fastener system may include a bead of welding or indeed a plurality of bolts, for example.

(24) The flexibility of the diaphragms enables the coupling mechanism to accommodate axial and/or angular shifting between the first member and the second member, and consequently between the two rotary units.

(25) Furthermore, the second member 30 may include a second cylinder 31. The second cylinder extends the body 35 axially along the second axis of symmetry AX2 towards the first member. The second cylinder 31 thus extends axially from an end 31 secured to the body and to the base of the diaphragm towards a free end 31.

(26) The second cylinder 31 then extends inside the first cylinder 21, the second cylinder 31 and the first cylinder 21 being coaxial in the absence of misalignment.

(27) In an alternative that is not shown, the first cylinder 21 extends inside the second cylinder 31. Under such circumstances, the second member comprises only the second diaphragm and the second cylinder, the second cylinder extending axially from the second diaphragm in order to be secured to a rotary unit or to other coupling means. In contrast, the first member has a body secured to the first diaphragm and to a rotary unit or to other coupling means, the first cylinder extending this body axially within the second cylinder.

(28) In summary, in the alternative, the first cylinder is arranged inside the second cylinder or the first cylinder surrounds the second cylinder.

(29) Independently of the alternative, a space referred to as the internal space INT lies radially between the first cylinder 21 and the second cylinder 31.

(30) Furthermore, the coupling means 10 are provided with an additional device 40 suitable for mechanically connecting the first member 20 to the second member 30.

(31) The additional device has a plurality of protrusions 50 arranged on the second member 30. Each protrusion 50 extends radially from the first cylinder 21 into the internal space INT.

(32) Each protrusion 50 also extends axially along a direction 300 parallel to the first axis of symmetry AX1 of the first cylinder. In particular, each protrusion extends axially from a face referred to as the sliding face 51 towards a face referred to as the blocking face 52.

(33) Furthermore, the additional device has a plurality of abutments 60 arranged on the second member 30. Each abutment 60 extends radially from the second cylinder 31 into the internal space INT.

(34) Each abutment 60 also extends axially along a direction 301 parallel to the second axis of symmetry AX2 of the second cylinder. Each abutment 60 has a first bearing face 61. Each first bearing face 61 can then co-operate with a sliding face 51 of a protrusion. The first bearing face 61 then faces the sliding face 51 circumferentially and/or axially.

(35) Furthermore, the second member 30 has at least one face referred to as a second bearing face 62 circumferentially and/or axially facing a blocking face 52 of at least one protrusion 50.

(36) Furthermore, the sliding faces 51 of the protrusions 50 and the first bearing faces 61 of the abutments are faces with two angles of inclination, i.e. faces presenting two distinct slopes, for example. Optionally, the blocking faces 52 and the second bearing faces 62 are also faces with two angles of inclination.

(37) Such faces with two angles of inclination present a first angle of inclination and a second angle of inclination BETA with a reference plane PREF of the diaphragm of the member having these faces. Such a reference plane PREF may represent the plane in which the outer peripheries 24, 34 of the diaphragms 22, 32 in question lie. The reference plane PREF of a member is also orthogonal to the axis of symmetry of the member.

(38) With reference to FIG. 2, each face with two angles of inclination extends radially from a cylinder of a bottom segment 70 towards a top segment 80. The bottom segment of a face with two angles of inclination is situated at the interface between the face with two angles of inclination and the corresponding cylinder.

(39) The second angle of inclination BETA then makes it possible for the bottom segment 70 to be shifted axially from the top segment 80 along a direction 300 parallel to the axis of rotation of the member in question. The second angle of inclination of a face having two angles of inclination is designed to tend to move a protrusion of the second cylinder radially away following relative rotation of the first member relative to the second member.

(40) In addition, the bottom segment 70 may be connected by a line, referred to as the elevation line 84, to the top segment 80 in a radial plane P1 corresponding to the plane of the sheet of FIG. 2. This radial plane is orthogonal to the reference plane PREF containing the diaphragms 22, 32 of the members 20, 30 having these segments 70, 80. Under such circumstances, the second angle of inclination BETA reaches a value lying in the range 15 degrees to 80 degrees by extending between said elevation line and said reference plane.

(41) With reference to FIG. 3, each segment 70, 80 also extends circumferentially from a first end 71, 82 to a second end 72, 82.

(42) The first angle of inclination ALPHA then shifts the first end 71, 81 of each segment 70, 80 relative to the second end 72, 82 of the segment, axially in a direction 300 parallel to the axis of symmetry of the segment.

(43) With reference to FIG. 4, the first end 71, 81 of a segment 70, 80 represents the point of the segment that is closest to the reference plane PREF of the angle of inclination 20, 30 having the segment 70, 80.

(44) Under such circumstances, for each point 73 of a segment, a line referred to as the tangential line 74 passes via the first end 71, 81 of the segment at the point 73. For this point 73 of the segment, the first angle of inclination ALPHA reaches a value lying in the range 15 degrees to 80 degrees, extending between said tangential line 74 and the reference plane PREF.

(45) Furthermore, and with reference to FIG. 5, the protrusions 50 of the first member are distributed circumferentially on a first annular wall 91 of the first cylinder. This first wall 91 faces a second annular wall 92 of the second cylinder. The protrusions are thus arranged on a circle.

(46) More precisely, the first member has at least three protrusions 50, and in particular it has five protrusions 50 as shown in FIG. 5.

(47) Furthermore, the protrusions 50 may be uniformly distributed around the circumference of the first cylinder 21. Two adjacent protrusions are thus separated by an angle equal to the quotient of an angle of 360 degrees divided by the number of protrusions, i.e. an angle of 72 degrees in FIG. 5.

(48) Likewise, the abutments 60 of the first member 30 are circumferentially distributed on a second annular wall 92 of the second cylinder. The abutments 60 are thus arranged on a circle.

(49) More precisely, the second member has at least five abutments 60 as shown in FIG. 5.

(50) Furthermore, the abutments 60 may be uniformly distributed around the circumference of the second cylinder 31. Two adjacent abutments 60 are thus separated by an angle equal to the quotient of an angle of 360 degrees divided by the number of abutments 60, i.e. an angle of 72 degrees in FIG. 5.

(51) Furthermore, and in a first embodiment as shown in FIG. 5 in particular, each second bearing face 62 represents a portion of a single annular projection 64.

(52) This annular projection extends radially from said second cylinder 31 over the entire circumference of the second cylinder.

(53) Under such circumstances, each blocking face 52 is parallel to the annular projection 64.

(54) Optionally, the annular projection may be conical and may present the above-described second angle of inclination BETA.

(55) In the variant of FIG. 5, the annular projection may be a portion of the second diaphragm 32.

(56) In the variant of FIG. 6, the annular projection 64 is axially offset relative to the second diaphragm 32 of the second member 30. The annular projection is then in the form of a shoulder.

(57) Independently of the embodiment, FIG. 6 shows coupling means comprising a first reversible fastener device 95 for fastening a protrusion 50 of the first member 20, such as screw fastener means, for example. Likewise, a second reversible fastener device 90 can fasten at least one abutment of the second member 30.

(58) In the second embodiment shown in FIG. 7, the second member 30 has a plurality of radial excrescences 65. Each radial excrescence 65 faces an abutment 60, being axially offset relative to the abutment.

(59) Under such circumstances, the radial excrescence has at least one second bearing face 62. FIG. 7 shows a radial excrescence having two second bearing faces 62.

(60) Furthermore, and independently of the embodiment, at least one protrusion 50 may include two sliding faces 51 that are distinct and that meet and form an edge 510. Likewise, at least one protrusion 50 may have two distinct blocking faces 52 that meet and form an edge 520, each blocking face 52 being a face with two angles of inclination.

(61) Consequently, at least one abutment 60 may have two distinct first bearing faces 61 that meet and form an edge 610. Where appropriate, a radial excrescence may have two second bearing faces 61.

(62) Consequently, FIG. 7 shows coupling means in a second embodiment provided with abutments having two first bearing surfaces, protrusions having two sliding faces and two blocking faces, and radial excrescences having two second bearing faces.

(63) FIG. 8 shows coupling means in the first embodiment having abutments with two first bearing surfaces, one annular projection, and protrusions having two sliding faces and one blocking face.

(64) FIGS. 9 to 14 show the operation of the invention.

(65) With reference to FIG. 9, in a normal mode of operation, the protrusions 50 of the first inclination are not in contact with the second inclination.

(66) In FIG. 9, each protrusion may be arranged axially between a first bearing face 61 and a second bearing face 62.

(67) Nevertheless, a protrusion may be arranged in the gap lying circumferentially between two abutments 60.

(68) Whatever the arrangement of the protrusions 50, first axial clearance 201 lies between each protrusion 50 and a first bearing face 61 of an abutment 60 in an axial direction 300 parallel to the axis of rotation AX3 of the first member 20 and of the second member 30. Likewise, second axial clearance 202 lies between each blocking face 52 of a protrusion and a second bearing face 62.

(69) In addition, and with reference to FIG. 10, first radial clearance 101 lies between each protrusion 50 of the second member 30 in a direction passing via a radius R1 of the first cylinder 21. Furthermore, second radial clearance 102 lies between each bearing face of the first member 20 in a direction passing via a radius R2 of the second cylinder 31.

(70) With reference to FIG. 11, in the event of a diaphragm rupturing or of the connection between the diaphragms rupturing, the protrusions 50 turn relative to the abutments 60 along arrow F1.

(71) This relative movement may be progressive. Specifically, the diaphragms may deform before rupture proper occurs. Such deformation tends to lead to the protrusions moving relative to the abutments.

(72) Under such circumstances, the sliding face of a protrusion comes into contact against the first bearing face 61.

(73) With reference to FIG. 12, the first axial clearance 201 is then eliminated.

(74) Furthermore, and with reference to FIG. 13, the first angle of inclination of the first bearing face 61 and of the sliding face tends to cause the protrusion to move axially along arrow F2 towards the second bearing face 62. The protrusion nevertheless remains in contact with the first bearing face 61.

(75) With reference to FIG. 14, the first and second axial clearances 201 and 202 are then eliminated.

(76) In contrast, the radial clearances remain.

(77) Specifically, and with reference to FIG. 15, the second angle of inclination tends to generate radial forces on the protrusions, these radial forces being represented by arrows F3.

(78) Since the coupling means comprise a plurality of protrusions, the radial forces serve to center the first member relative to the second member while conserving the radial clearances.

(79) Each protrusion of the first member is then wedged relative to the second member and enables torque and motion to be transmitted between the first member and the second member.

(80) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.