Interface and a method for mounting together a piece of equipment and a rotary drive source in a rotorcraft power plant

1. An axial mounting interface between a piece of equipment and a rotary drive source, said interface comprising:

a first frame provided with first fastener means for fastening to the drive source;

a second frame provided with second fastener means for fastening to the equipment;

assembly means between the first frame and the second frame in order to hold them together; and

means for mutually centering the first frame and the second frame, said means comprising at least two mounting shafts carried in parallel by the first frame in an axial orientation, the mounting shafts co-operating with respective windows included in the second frame, wherein the mounting shafts are arranged as rails for supporting and axially guiding the second frame relative to the first frame, said rails being removably mounted on the first frame via easily-reversible junction means and co-operating with open windows in the second frame, the openings of said windows opening out to allow the rails to pass transversely into respective windows from the outside of the second frame, wherein the rails are mounted on first radially peripheral lugs of the first frame, and wherein the windows are arranged in second radially peripheral lugs of the second frame, and wherein a second support lug of the equipment is arranged as a hook and in that a second pivoting abutment lug of the equipment is arranged as a stop.

2. An axial mounting interface between a piece of equipment and a rotary drive source, said interface comprising:

a first frame provided with first fastener means for fastening to the drive source;

a second frame provided with second fastener means for fastening to the equipment;

assembly means between the first frame and the second frame in order to hold them together; and

means for mutually centering the first frame and the second frame, said means comprising at least two mounting shafts carried in parallel by the first frame in an axial orientation, the mounting shafts co-operating with respective windows included in the second frame, wherein the mounting shafts are arranged as rails for supporting and axially guiding the second frame relative to the first frame, said rails being removably mounted on the first frame via easily-reversible junction means and co-operating with open windows in the second frame, the openings of said windows opening out to allow the rails to pass transversely into respective windows from the outside of the second frame, wherein one window provides a pivoting rest for supporting the equipment, another window providing an abutment rest against said pivoting.

3. A mounting interface according to claim 2 , wherein the rails are mounted on first radially peripheral lugs of the first frame, and wherein the windows are arranged in second radially peripheral lugs of the second frame.

4. A mounting interface according to claim 3 , wherein a second support lug of the equipment is arranged as a hook and in that a second pivoting abutment lug of the equipment is arranged as a stop.

5. A mounting interface according to claim 3 , wherein said assembly means comprise means for mutually engaging facing first and second lugs.

6. A mounting interface according to claim 3 , wherein the assembly means are of the type for providing connection by bolting the first and second lugs together.

7. A mounting interface according to claim 2 , wherein said easily-reversible junction means are either of the mutual engagement type or of the screw-fastening type.

8. A mounting interface according to claim 2 , wherein the first fastener means are of the screw-fastener type, making use of bearing fastener members in an axial orientation against blocks provided on a plate of the first frame.

9. A mounting interface according to claim 2 , wherein the second fastener means are of the clamping collar type.

10. A method of separating a drive source and a piece of equipment implementing a mounting interface according to claim 2 , wherein the separation method comprises the following operations:

sliding the rails through the corresponding windows and joining the rails to the first frame via the easily-reversible junction means;

mutually separating the first and second frames by disengaging the assembly means;

pushing the piece of equipment away from the drive source by sliding the equipment axially along the rails; and

removing the piece of equipment by unhooking it and moving it away from the drive source in the transverse direction (T).

11. A rotorcraft power plant including at least one drive source in rotary connection with at least one said piece of equipment via a mounting interface according to claim 2 .

12. A rotorcraft power plant according to claim 11 , wherein the piece of equipment is either a reversible electrical machine in rotary engagement on an engine of the power plant, or an accessory in rotary engagement on a power transmission gearbox.

13. A method of assembling together a drive source and a piece of equipment by using a mounting interface comprising:

a first frame provided with first fastener means for fastening to the drive source;

a second frame provided with second fastener means for fastening to the equipment;

assembly means between the first frame and the second frame in order to hold them together; and

means for mutually centering the first frame and the second frame, said means comprising at least two mounting shafts carried in parallel by the first frame in an axial orientation, the mounting shafts co-operating with respective windows included in the second frame, wherein the mounting shafts are arranged as rails for supporting and axially guiding the second frame relative to the first frame, said rails being removably mounted on the first frame via easily-reversible junction means and co-operating with open windows in the second frame, the openings of said windows opening out to allow the rails to pass transversely into respective windows from the outside of the second frame, wherein the assembly method comprises the following operations:

fastening the first frame and the second frame respectively to the drive source and to the piece of equipment, respectively by using the first fastener means and the second fastener means;

joining the rails to the first frame by using the easily-reversible junction means;

moving the piece of equipment fitted with the second frame towards the rails in a direction (T) that is transverse relative to the axial direction (A) in which the drive source and the piece of equipment extend;

hooking the piece of equipment by gravity on a rail via a support window and allowing the piece of equipment to pivot under the effect of its own weight to bear against the other rail via an abutment window;

causing the piece of equipment as supported and guided by the rails to slide from a position in which the first and second frames are spaced apart from each other towards an assembly position in which the piece of equipment is rotatably engaged on the drive source and in which the first frame and the second frame are axially in contact;

securing the first and second frames together by the assembly means; and

removing the rails from the first frame by breaking the junction provided by the easily-reversible junction means.

14. An assembly method according to claim 13 , wherein the operation of sliding the equipment axially comprises the following steps:

bringing the piece of equipment towards the drive source by sliding axially along the rails until a shaft of the piece of equipment and a shaft of the drive source are in mutual rotary engagement;

when necessary, if there is a radial offset between the drive source and the piece of equipment, moving the piece of equipment axially away from the drive source and turning the shaft of the piece of equipment so as to adjust its radial position; and

repeating said step of axially sliding the piece of equipment towards the drive source and in the event of achieving rotary engagement, finalizing the axial approach of the piece of equipment towards the drive source into the assembled position.