Device for connecting mechanical parts with axial clearance
A connecting device for connecting two mechanical parts includes a rod having a section between a stop and a threaded portion. The rod is inserted into the parts, and a nut is screwed onto the threaded portion in order to hold the parts between the stop and the nut. An anti-rotation system blocks rotation of the nut and includes a washer interacting with the rod to be constrained to rotate with it. The washer has two protuberances, each engaged in a notch of shape complementary to the rod. The anti-rotation system has a ring with an inner periphery of with a shape complementary to that of an outer periphery of the nut in order to be secured to the nut. The ring is secured to the washer by a screw.
1 . A connecting device for connecting together two separate mechanical parts, said device comprising:
a rod having a longitudinal axis (X-X) and comprising a section configured to be inserted at least partly into aligned clevises of said mechanical parts, said section extending between an axial stop and a threaded portion of the rod,
a nut configured to be screwed onto said threaded portion of said rod so as to hold said two mechanical parts between said axial stop and said nut, and
an anti-rotation system configured to block the nut from rotating, said anti-rotation system comprising:
a washer mounted around said rod and having a shape complementary with said rod such that said washer is configured to be rotationally secured to said rod, said washer comprising at least one protuberance extending inwards with respect to said longitudinal axis (X-X), the at least one protuberance being engaged in a notch of a complementary shape in said rod, and
a ring mounted around the nut, said ring comprising an internal periphery complementary in shape to that of an external periphery of said nut so that said ring is secured in rotation to said nut,
wherein said anti-rotation system further comprises a screw which is configured to ensure that said ring and said washer are secured axially in rotation,
said ring further comprising:
an axial slot configured to minimize a mounting clearance on said nut,
two circumferential ends which are located on opposing sides of said axial slot, each of said circumferential ends extending into an attachment tab, each tab comprising a central orifice for the passage of said screw, said washer comprising a protrusion configured to be interposed between said tabs, said protrusion comprising an orifice for the passage of said screw.
2 . The connecting device according to claim 1 , wherein the at least one protuberance of said washer comprises between two and four protuberances, said protuberances being arranged in a regular manner around said longitudinal axis (X-X).
3 . The connecting device according to claim 1 , wherein said internal periphery of the ring comprises a toothing and said external periphery of the nut is hexagonal.
4 . The connecting device according to claim 1 , wherein said screw extends in a plane perpendicular to said longitudinal axis (X-X).
5 . The connecting device according to claim 1 , wherein said screw is screwed into a tightening nut which comprises at least one transverse recess configured to be aligned with a transverse orifice of said screw for the passage of an immobilizing element.
6 . The connecting device according to claim 5 , wherein said immobilizing element is one of a pin or a brake wire.
7 . A mechanical assembly for an aircraft comprising mechanical parts connected together by a connecting device according to claim 1 .
8 . The connecting device according to claim 1 , wherein the attachment tabs are parallel to each other and extend along the axis (X-X) from a surface of the ring with which the washer come into contact.
9 . A method for assembling two mechanical parts, using the connecting device according to claim 1 , the method comprising the following successive steps:
inserting said rod into said aligned clevises of said two mechanical parts until said axial stop bears against one of said two mechanical parts;
mounting said washer around said rod against the other of said two mechanical parts;
screwing the nut onto the threaded portion of said rod until the nut is in a position of contact with said washer;
mounting the ring around the nut;
unscrewing said nut from said contact position to a stop position;
interposing the protrusion of the washer between the tabs of the ring, and
blocking said nut in rotation in said stop position by said screw, the screw passing through the orifices of the tabs and the orifice of the protrusion and being screwed into a tightening nut.