COMPOSITE REINFORCED RING GEAR
First Claim
Patent Images
1. A composite reinforced ring gear, comprising:
- a metal rim having a rim inner circumference and a rim outer circumference;
a set of engagement features formed on the rim inner circumference; and
a composite backing positioned circumferentially around the rim outer circumference.
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Accused Products
Abstract
A hybrid composite reinforced ring gear minimizing radial deformation during high RPM conditions includes a composite backing secured to a metal rim. In use, at operating temperature the composite backing contracts while the metal rim expands thus creating a compressive stress on the metal rim and significantly reduces radial deformation due to centrifugal forces as compared to an all steel ring gear.
10 Citations
20 Claims
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1. A composite reinforced ring gear, comprising:
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a metal rim having a rim inner circumference and a rim outer circumference; a set of engagement features formed on the rim inner circumference; and a composite backing positioned circumferentially around the rim outer circumference.
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2. The composite reinforced ring gear of claim 1, wherein the composite backing has a lower density than the metal rim.
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3. The composite reinforced ring gear of claim 1, wherein the composite backing has a lower coefficient of thermal expansion than the metal rim.
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4. The composite reinforced ring gear of claim 1, wherein at an operating temperature, the composite backing imparts a radial compressive stress on the metal rim.
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5. The composite reinforced ring gear of claim 1, wherein at an operating temperature, the composite backing affects radial deformation of the metal rim.
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6. The composite reinforced ring gear of claim 1, wherein at an operating temperature, the metal rim expands and the composite backing contracts.
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7. The composite reinforced ring gear of claim 1, further comprising a sacrificial layer between the metal rim and the composite backing.
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8. The composite reinforced ring gear of claim 1, further comprising an adhesive layer between the metal rim and the composite backing.
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9. The composite reinforced ring gear of claim 1, further comprising a set of mating tabs between the metal rim and the composite backing.
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10. A power train system of a rotorcraft, comprising:
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an engine operatively connected to a gearbox; a rotor mast operatively connected to the gearbox; and the gearbox having a composite reinforced ring gear, the composite reinforced ring gear comprising; a metal rim affixed to a composite backing; and a set of teeth extending inward from the metal rim.
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11. The power train system of claim 10, wherein the composite backing has a lower density than the metal rim.
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12. The power train system of claim 10, wherein the composite backing has a lower coefficient of thermal expansion than the metal rim.
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13. The power train system of claim 10, wherein at an operating temperature, the composite backing imparts a radial compressive stress on the metal rim.
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14. The power train system of claim 10, wherein at an operating temperature, the composite backing affects radial deformation of the metal rim.
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15. The power train system of claim 10, wherein at an operating temperature, the metal rim expands and the composite backing contracts.
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16. The power train system of claim 10, further comprising a sacrificial bonding layer between the metal rim and the composite backing.
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17. A method, comprising:
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operating a rotorcraft comprising a composite reinforced ring gear, wherein the operating comprises rotating the composite reinforced ring gear at a speed; the composite reinforced ring gear comprising; a metal rim having a thickness between an outer circumference and an inner circumference; teeth formed on the inner circumference of the metal rim; and a composite backing having an interference fit around the outer circumference of the metal rim, wherein a lower coefficient of thermal expansion (CTE) of the composite backing is less than the CTE of the metal rim.
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18. The method of claim 17, wherein the speed ranges between 5,000 and 15,000 RPM.
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19. The method of claim 17, further comprising compressing the metal rim.
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20. The method of claim 17, further comprising affecting radial deformation of the metal rim.
Specification