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A propeller blade retention system and method of manufacture are disclosed. Because of the design, a truly integral hub is able to house a set of variable pitch blades. Each hub socket establishes a substantially cylindrical interface with its respective blade, making the blade slidably receivable f

A propeller blade retention system and method of manufacture are disclosed. Because of the design, a truly integral hub is able to house a set of variable pitch blades. Each hub socket establishes a substantially cylindrical interface with its respective blade, making the blade slidably receivable for installation. Each blade is allowed axial rotation, and held inside the socket by a set of angular contact bearings. A snap ring locks the blade against coming back out of the socket. An O-ring is provided in the interface to create a fluid seal. The hub alone accomplishes all of the required load-bearing and weather-seal functions.

대표청구항 ▼

1. A propeller system, said system comprising: a hub including a socket, the hub including an upper and a lower end, said socket having a substantially cylindrical internal surface;an adjustable-pitch blade received in said hub, said blade having an airfoil portion extending in an axially outward di

1. A propeller system, said system comprising: a hub including a socket, the hub including an upper and a lower end, said socket having a substantially cylindrical internal surface;an adjustable-pitch blade received in said hub, said blade having an airfoil portion extending in an axially outward direction from the socket, and a base portion included in the socket;a substantially cylindrical outer surface of said base portion of said blade, said outer surface of said base portion of said blade being slidably receivable in said substantially cylindrical internal surface of said socket;a locking assembly including a snap ring disposed adjacent the upper end of the hub, the snap ring securing a shim in position against a hub surface and a hub upcrop surface, the hub upcrop surface preventing dislocation of the shim in a direction parallel to the hub surface, wherein the locking assembly, when fully installed, prevents axial translation in the hub which is otherwise axially slidable;a sealing member received in an interface between said substantially cylindrical outer surface of said base portion of said blade and said substantially cylindrical internal surface of said socket, said sealing member forming a fluid barrier between an inside and an outside of said socket while still allowing for axial translation of said blade into said socket during installation and rotation of said blade to change pitch;an angular contact bearing arrangement located further inside said socket, said bearing arrangement including a set of bearing balls included between an inner race on said blade and an outer race on said hub, said inner race having an outer diameter which is small enough to enable passage through said substantially cylindrical internal surface of said socket during installation, said outer race having an inside diameter large enough to not interfere with said substantially cylindrical outer surface of said base portion of said blade during installation;the substantially cylindrical outer portion of the base portion of the blade presenting an outer bearing surface which is axially outward from the angular contact bearing balls, each of the angular contact bearing balls and the outer bearing surface transferring blade loads directly to the hub;an outboard roller bearing having a plurality of outboard rollers embedded into an annular slot in a collar for engagement with an inner surface of an outer bearing race, wherein the outer bearing race of the roller bearing is in direct contact with the hub; andan upper surface of the outer race of the angular contact bearing is in direct contact with a lower surface of the outer race of the roller bearing; and the inner surface of the outer bearing race of the roller bearing is radially flush with an inner surface of the outer race of the angular contact bearing. 2. The system of claim 1 wherein said hub is formed from substantially integral materials. 3. The system of claim 1 wherein said inner race of the angular contact bearing arrangement is formed as a substantially-integral part adapted to be installed all at once. 4. The system of claim 1 wherein said outer race of the angular contact bearing arrangement is formed as a substantially-integral part and is adapted to be installed all at once. 5. The system of claim 1 wherein an inner race of the outboard roller bearing is formed as an integral part of the collar, said outer race of the outboard roller bearing is formed as an integral part of said hub and said inner and outer races of the outboard roller bearing are able to be installed without compromising structural integrity. 6. The system of claim 1 wherein said substantially cylindrical outer surface exists on the collar provided on said base portion of said blade. 7. The system of claim 6 wherein said sealing member is an O-ring which is received in an annular channel defined in said substantially cylindrical outer surface of said collar on said base portion and bears against said substantially cylindrical internal surface of said socket. 8. The system of claim 1 wherein said sealing member forms a direct seal between the substantially cylindrical outer surface of the collar on the base portion and the substantially cylindrical internal surface of the socket and forms a complete fluid seal between the socket and the blade. 9. The system of claim 7 wherein said O-ring is received in an annular channel defined in said substantially cylindrical internal surface of said socket and bears against said substantially cylindrical outer surface of said collar. 10. The system of claim 6 wherein an upper portion of said substantially cylindrical outer surface on said collar defines an annular groove which receives the snap ring which, when installed in said annular groove, prevents said blade from falling into said socket when an upcrop portion on said socket is engaged. 11. The system of claim 10 wherein said snap ring prevents said blade from falling into said socket by resting on the shim nested in an annular notch defined in said upcrop portion of said socket. 12. The system of claim 1 wherein each of said: (i) outer diameter of said inner race of angular contact bearing arrangement, (ii) an inner diameter of said outer race of angular contact bearing arrangement, (iii) substantially cylindrical internal surface of said socket, and (iv) substantially cylindrical outer surface of said bottom portion of said blade are substantially in line when viewed in cross section. 13. A method of assembling a propeller system, said method comprising: manufacturing an integral hub, the hub including an upper end and lower end;causing a blade-receiving socket to be formed in said hub, said socket having a substantially cylindrical internal surface;producing a blade to have a base portion which has a substantially cylindrical outer surface which is receivable in and slidably mates with said substantially cylindrical internal surface of said socket;providing an angular contact bearing arrangement inside said socket, said bearing arrangement including an inner race and an outer race, the outer race in contact with said hub, said angular contact bearing arrangement preventing said blade from coming out of said hub socket, while allowing for rotation on a center axis of said blade;providing an outboard roller bearing having a plurality of outboard rollers embedded into an annular slot in a collar for contact with an inner surface of an outer bearing race of said outboard roller bearing, wherein the collar is integral with an inner race of the outboard roller bearing, wherein said inner surface of said outer race of said outboard roller bearing is radially flush with an inner surface of said outer race of said angular contact bearing arrangement; and an upper surface of the outer race of the angular contact bearing is in direct contact with a lower surface of the outer race of the roller bearing;including a locking mechanism to secure said blade against sliding into said hub after installation when blade is at an upright angle, the locking mechanism including a snap ring disposed adjacent the upper end of the hub, the snap ring securing a shim in position against a hub surface and a hub upcrop surface, the hub upcrop surface preventing dislocation of the shim in a direction parallel to the hub surface, wherein the locking mechanism, when fully installed, prevents axial translation of the hub which is otherwise axially slidable; andestablishing a ring-shaped seal between said substantially cylindrical outer surface of said base portion of said blade and said substantially cylindrical internal surface of said socket, the ring-shaped seal preventing the outflow of fluids through the substantially cylindrical internal surface and the substantially cylindrical outer surface. 14. The method of claim 13 comprising: executing said manufacturing step by machining forged metal. 15. The method of claim 13 comprising: installing said angular contact bearing arrangement to include the inner race on said blade and the outer race in said hub;adapting said inner race of said angular contact bearing to have an outer diameter small enough to enable passage through said substantially cylindrical internal surface of said socket during installation;adapting said outer race of said angular contact bearing to have an inside diameter which prevents interference with said substantially cylindrical outer surface of said bottom portion of said blade during installation; andinserting a set of bearing balls between said inner and outer races of said angular contact bearing arrangement. 16. The method of claim 15 comprising: adapting said outer race of said angular contact bearing to be installed integrally through an opening in said hub other than said socket. 17. The method of claim 13 comprising: establishing said seal by including an O-ring in an annular channel defined in said substantially cylindrical outer surface of said base portion of said blade such that said O-ring seals against said substantially cylindrical internal surface of said socket. 18. The method of claim 13 comprising: establishing said seal by including an O-ring in an annular channel defined in said substantially cylindrical internal surface of said socket such that said O-ring seals against said substantially cylindrical outer surface of said base portion of said blade. 19. The method of claim 13 comprising: orienting said seal such that said seal is engaged upon a sliding installation of said blade inside said socket and remains engaged while a set of ball bearings are installed into said angular contact bearing arrangement. 20. A propeller blade retention system comprising: an integral hub including a plurality of sockets, the integral hub having an upper and lower end;each of said sockets being adapted to establish a substantially cylindrical interface with a respective set of blades such that each of said blades is slidably receivable for installation into each of said sockets, and also resist bending loads during use;each of said blades being held inside and made axially rotatable by an angular contact bearing arrangement having a set of bearing balls, wherein the set of bearing balls rotate against a lower bearing surface;each of said blades having an upper bearing surface located above the set of bearing balls and defined by the substantially cylindrical interface;the angular contact bearing arrangement disposed inside said socket, said bearing arrangement including an inner race and an outer race, the outer race in contact with said hub, said angular contact bearing arrangement preventing said blade from coming out of said hub socket, while allowing for rotation on a center axis of said blade;an outboard roller bearing having a plurality of outboard rollers embedded into an annular slot in a collar for contact with an inner surface of an outer bearing race of said outboard roller bearing, wherein the collar is integral with an inner race of the outboard roller bearing and the inner surface of said outer race of said outboard roller bearing is radially flush with an inner surface of said outer race of said angular contact bearing arrangement; and an upper surface of said outer race of said angular contact bearing arrangement is directly in contact with a lower surface of said outer race of said outboard roller bearings;each of said blades being secured against falling into the hub after installation by a locking mechanism, the locking mechanism including a snap ring disposed adjacent the upper end of the hub and a shim secured in position against a hub surface and a hub upcrop surface, the hub upcrop surface preventing dislocation of the shim in a direction parallel to the hub surface; anda sealing member provided in the substantially cylindrical interface to create a seal. 21. A propeller bearing against a race on an integral hub comprising: the integral hub including a plurality of sockets, the hub including an upper end and a lower end;each of said sockets being adapted to receive a blade such that each blade is slidably receivable for installation into each of said sockets, and also resist bending loads during use;each of said blades being secured inside and made axially rotatable by a set of angular contact bearing balls, the angular contact bearing balls bearing against an outer race on the sockets to prevent each blade from translating outward from the hub;the angular contact bearing balls also bearing against an inner race;an outboard roller bearing having a plurality of outboard rollers embedded into an annular slot in a collar for engagement with an inner surface of an outer bearing race, wherein the collar is integral with an inner race of the roller bearing and an upper surface of the outer race of the angular contact bearing is directly in contact with a lower surface of the outer bearing race of the outboard roller bearing; and the inner surface of the outer bearing race of the roller bearing is radially flush with an inner surface of the outer race of the angular contact bearing;each of said blades being secured against translating back into the hub after installation by a locking mechanism comprising a snap ring disposed adjacent the upper end of the hub, the snap ring securing a shim in position against a hub surface and a hub upcrop surface, the hub upcrop surface preventing movement of the shim in a direction parallel to the hub surface; anda sealing member provided in a substantially cylindrical interface to contain a fluid in the hub.