Two-tone isolator assembly
The invention proposes to address the vibration transfer function transmitted by a turbo-fan engine or equivalent to the aircraft structure, with two types of isolators mounted on a unique assembly but with a different physical response to the transfer function, an absorbing one and a resonating one. The difference in nature of such responses induces a non-interaction effect between the two isolators. The invention concerns more specifically a two-tone isolator assembly adapted to be mounted on an aircraft or equivalent comprising in particular a head, a cabin yoke and a power engine structure having a longitudinal axis crossed by a radial plan. The two-tone isolator assembly comprises, located at the head side of the aircraft, at least one support for, at least, one fluid mount isolator and two dynamic absorbers, and mechanical means to couple said support to the power engine structure and to the cabin yoke. Said assembly is designed to link the fluid mount isolator at once to the power engine structure and to the cabin yoke, whereas the dynamic absorber is only linked to the cabin structure. Furthermore, the dynamic absorbers are supported to move in the radial plan of the power engine structure.
1. A two-tone isolator assembly adapted to be mounted on an aircraft or equivalent comprising a head, a cabin, a yoke connected to the cabin and a power engine structure having a longitudinal axis crossed by a radial plan, wherein said two-tone isolator assembly comprises, located at the head side of the aircraft, at least one support for, at least, one fluid mount isolator and two dynamic absorbers, and mechanical means to couple said support to the power engine structure and to the cabin yoke, said assembly being designed to link the fluid mount isolator at once to said power engine structure and to said cabin yoke, whereas the dynamic absorbers are only linked to the cabin structure, and wherein the dynamic absorbers are supported to move in said radial plane of said power engine structure, wherein said isolator assembly comprises at least one support coupled to the cabin yoke, the support comprising one transversal basic combination of a couple of dynamic absorbers sandwiching a central fluid mount linked to said power engine structure, the fluid mount housing having transversal shafts to mount the dynamic absorbers.
2. A two-tone isolator assembly according to claim 1 , wherein a tuning to specific major tones is achieved by adjusting compression in the dynamic absorbers and stiffness of the fluid mount isolators, the fluid isolators being specifically directed to tune a lower major tone whereas the dynamic absorbers are specifically directed to tune an upper major tone.
3. A two-tone isolator assembly according to claim 1 , wherein said isolator assembly comprises two basic traversal combinations.
4. A two-tone isolator assembly according to claim 1 , wherein the dynamic absorbers comprise hybrid compounds of metallic alloy and resilient material.
5. A two-tone isolator assembly according to claim 4 , wherein the resilient material is rubber or elastomeric material.
6. A two-tone isolator assembly according to claim 4 , wherein the metallic alloy is composed of a carbon-tungsten steel.
7. A two-tone isolator assembly according to claim 4 , wherein the metallic alloy is bonded to a resilient washer.
8. A two-tone isolator assembly according to claim 7 , wherein the metallic alloy forms a ring surrounding the resilient washer.
9. A two-tone isolator assembly according to claim 4 , wherein the resilient washer is sandwiched between two metallic washers to tune the resilient washer by compression.