Rotor assemblies for vehicle propulsion

#The present disclosure relates, in general, to rotor assemblies operable to generate thrust for the propulsion of a vehicle and, in particular, to rotor assemblies utilizing metallic coupling assemblies that provide centrifugal force load paths between composite rotor blades and the rotor hub.

#Many vehicles use rotor assemblies to generate thrust that propels the vehicle on or through the water or in the air. A typical rotor assembly has a rotating hub with a plurality of rotor blades radiating therefrom that exert a linear force upon a working fluid, such as water or air, when the rotor assembly is rotated. Specifically, due to the shape of the rotor blades, the rotational motion of the rotor assembly in the fluid causes a pressure difference between the forward and aft surfaces of the rotor blades according to Bernoulli’s principle. Many marine vehicles use screw propellers with helical blades that rotate on a horizontal shaft. Aircraft utilize a variety of rotor assemblies for propulsion including twisted airfoil shaped propellers on fixed wing aircraft, rotary wings on helicopters and proprotors on tiltrotor aircraft.

#Amphibious air-cushion vehicles that can travel over water and land supported by a downwardly ejected cushion of air are another type of vehicle that uses rotor assemblies to generate thrust. Certain air-cushion vehicles utilize dual ducted rotor assemblies having variable pitch rotor blades to control the speed and direction of the vehicle. The versatile amphibious capability of these vehicles not only enables them to traverse deep water, shallows and reefs but also enables them to drive onto land such as beaches. For example, large air-cushion vehicles such as the Landing Craft Air Cushion (LCAC) and the Ship-to-Shore Connector (SSC) are capable of accessing more than seventy percent of the world’s coastline for rapid deployment of large payloads such as vehicles, heavy equipment, supplies and troops. In addition, these large air-cushion vehicles are valuable in supporting humanitarian relief efforts throughout the world including delivering life-saving equipment, food, water and medical supplies.

#For a more complete understanding of the features and advantages of the present disclosure, reference is now made to the detailed description along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:

#FIGS. 1A-1C are schematic illustrations of an amphibious air-cushion vehicle having dual ducted rotor assemblies for generating thrust in accordance with embodiments of the present disclosure;

#FIGS. 2A-2B are schematic illustrations of a ducted rotor assembly for generating vehicle thrust in accordance with embodiments of the present disclosure;

#While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts, which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative and do not delimit the scope of the present disclosure. In the interest of clarity, not all features of an actual implementation may be described in the present disclosure. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer’s specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

#In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present disclosure, the devices, members, apparatuses, and the like described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction. As used herein, the term “coupled” may include direct or indirect coupling by any means, including moving and/or non-moving mechanical connections.

#Referring to FIGS. 1A-1C in the drawings, an amphibious air-cushion vehicle is schematically illustrated and generally designated 10. Vehicle 10 includes hull 12 having a bow portion 14, a stern portion 16, a port side 18 and a starboard side 20. In the illustrated embodiment, vehicle 10 includes an open deck space 22, a bow ramp 24 and a stern ramp 26 enabling roll-on/roll-off loading and unloading of cargo and equipment including, for example, high-speed offloading during a cargo drop scenario into a hostile landing area. Vehicle 10 is equipped with dual ducted air propulsors depicted as port rotor assembly 28 and starboard rotor assembly 30. Rotor assembly 28 is driven by a gas turbine engine 32 via a drive shaft 34. Rotor assembly 30 is driven by a gas turbine engine 36 via a drive shaft 38. Gas turbine engine 32 also drives a lift fan 40 and a bow thruster 42. Likewise, gas turbine engine 36 also drives a lift fan 44 and a bow thruster 46. Lift fans 40, 44 are used to produce large volumes air that form an air cushion below hull 12 and within a skirt 48 that lifts hull 12 such that vehicle 10 floats above a running surface such as water or land. Bow thrusters 42, 46 are used to enhance the maneuverability of vehicle 10 particularly at lower speeds. Vehicle 10 includes a pilot and copilot module 50 that supports the command and control station of vehicle 10. Vehicle 10 also includes a personnel and equipment module 52.