Curved bearing contact system
In some embodiments, systems and methods are described for a gear contact system configured to support radial, thrust, and moment loads, the system comprising a first gear comprising a first roller having a first roller bearing surface, the first roller bearing surface having a convex curvature defined by a first radius of curvature; and a second gear comprising a second roller having a second roller bearing surface, the second roller bearing surface having a concave curvature defined by a second radius of curvature.
1. A gear contact system configured to support radial, thrust, and moment loads, the system comprising:
a first gear comprising a first roller having a first roller bearing surface, the first roller bearing surface having a convex curvature defined by a first radius of curvature; and
a second gear comprising a second roller having a second roller bearing surface, the second roller bearing surface having a concave curvature defined by a second radius of curvature, wherein the second radius of curvature is larger than the first radius of curvature, the second roller bearing surface of the second roller mating with the first roller bearing surface of the first roller at the pitch diameter of the two gears at least a point, such that a line tangent to the point is at an angle with respect to the rotation axis of the first gear,
wherein the gear contact system is used in a planetary gear system having an input stage assembly comprising an input sun gear, at least one input planet gear, and an input ring gear; and
at least one output stage assembly comprising an output planet gear, the at least one output planet gear coupled to the at least one input gear, and an output ring gear,
wherein the at least one output stage assembly further comprises an output sun gear and the input stage assembly further comprises a motor having an external rotor disposed inside an interior region of the input sun gear,
wherein the motor drives the input sun gear, the input ring gear is fixed, the output sun gear is idle, and the output ring gear is driven by the input sun gear.
2. The system of claim 1 , wherein the angle is between 0 and 90 degrees.
3. The system of claim 1 , wherein the angle is between 30 and 60 degrees.
4. The system of claim 1 , wherein the angle is between 40 and 50 degrees.
5. The system of claim 1 , wherein the angle is 45 degrees.
6. The system of claim 1 , wherein the roller bearing surfaces comprise a material that comprises at least one of stainless steel or Nitronic steel.
7. The system of claim 1 , wherein the gear contact system is used in a planetary gear system having at least one sun gear, at least two planet gears, and at least one ring gear.
8. The system of claim 1 , wherein the motor drives the input sun gear, the input ring gear is fixed, the output sun gear is driven by the input sun gear, and the output ring is idle.
9. The system of claim 1 , wherein the motor drives the input ring gear, the input sun gear is fixed, the output sun gear is driven by the input ring gear, and the output ring is idle.
10. The system of claim 1 , wherein the motor drives the input ring gear, the input sun gear is fixed, the output sun gear is idle, and the output ring is driven by the input ring gear.
11. The system of claim 1 , further comprising a ball bearing raceway grooved between the input stage and the output stage at the interface between the input sun gear and output sun gear.
12. The system of claim 1 , further comprising a ball bearing raceway grooved between the input stage and the output stage at the interface between the input ring gear and output ring gear.
13. The system of claim 1 , wherein a couple between the at least one input planet gear and the at least one output planet gear is pre-stressed.
14. The system of claim 1 , further comprising a carrier configured to keep one input planet gear parallel with at least one other input planet gear on a radial plane perpendicular to the axis of rotation when the planetary gear system is subjected to high external loads.
15. A method of using the gear contact system of claim 1 , wherein radial, thrust, and moment loads are stabilized.