Abstract: A prop rotor hub includes a constant velocity joint in the same plane as a prop blade yoke. Torque is transmitted from a shaft to the blades through the CV joint, hub plates attached to the CV joint, and the yoke, which is attached to the hub plates. Providing all elements in a substantially planar arrangement results in a hub assembly which has significantly less height than a traditional design. The hub itself is in-plane with the yoke, resulting in a more efficient torque transmission from the mast to the rotor.

Abstract: A constant velocity joint (10) is provided specifically for connecting a yoke (14) to a mast (12) in a helicopter and more generally (200) for interconnecting a first shaft (202) to a second shaft (204) for bidirectional drive. The constant velocity joint employs a carrier (40, 218) which is formed with a series of apertures for receiving elastomeric bearing assemblies (42, 80, 220). The elastomeric bearing assemblies are provided with a spherical elastomeric bearing (60) and a cylindrical elastomeric bearing (48). Certain of the elastomeric bearing assemblies connect the carrier to one of the rotating members while the remaining elastomeric bearing assemblies connect the other rotating member to the carrier. The axis of symmetry (67) of the carrier always bisects the angle of misalignment between the two rotating shafts or members to assure that a constant velocity joint is achieved.

Abstract: A constant velocity joint (200) for interconnecting a first shaft (202) to a second shaft (204) for bidirectional drive is provided. The constant velocity joint employs a carrier (218) which is formed with a series of apertures for receiving elastomeric bearing assemblies (220). The elastomeric bearing assemblies are provided with a spherical elastomeric bearing (60) and a cylindrical elastomeric bearing (48). Certain of the elastomeric bearing assemblies connect the carrier to one of the rotated members while the remaining elastomeric bearing assemblies connect the other rotating member to the carrier. The axis of symmetry of the carrier (218) will always bisect the angle of misalignment between the two rotating shafts to assure that a constant velocity joint is achieved.

Abstract: A constant velocity joint (10) is provided specifically for connecting a yoke (14) to a mast (12) in a helicopter and more generally (200) for interconnecting a first shaft (202) to a second shaft (204) for bidirectional drive. The constant velocity joint employs a carrier (40, 218) which is formed with a series of apertures for receiving elastomeric bearing assemblies (42, 80, 220). The elastomeric bearing assemblies are provided with a spherical elastomeric bearing (60) and a cylindrical elastomeric bearing (48). Certain of the elastomeric bearing assemblies connect the carrier to one of the rotating members while the remaining elastomeric bearing assemblies connect the other rotating member to the carrier. The axis of symmetry (67) of the carrier always bisects the angle of misalignment between the two rotating shafts or members to assure that a constant velocity joint is achieved.

Abstract: The subsurface position of a blowing well with respect to an adjacent relief well is determined by detecting at a plurality of axially and tangentially spaced locations in the relief well acoustic waves emanating from a subsurface location of the blowing well. The distance between the wells is calculated on the basis of the difference in times of arrival of the waves at said axially spaced locations. The radial direction of the blowing well relative to the relief well is determined by measuring the acoustic intensity resulting from the waves at each of said tangentially spaced locations.

Abstract: This invention relates to helicopter rotors and more particularly to rotor mounting involving a composite fiber-reinforced unitary yoke with resilient inplane restraints.

Abstract: A helicopter having a main rotor lift unit includes a plurality of pendulus mass units (44, 46) mounted to oscillate in a plane perpendicular to the chord plane of the rotor blade (10). The mass units (44, 46) are connected to a rotatable shaft (28) which passes through or adjacent the blade grip (12) for each blade (10). Hubshear vibrations generated parallel to the axis of the rotor mast (18) are damped by the oscillating mass units (44, 46) which are tuned to minimize the vibrations transmitted from the lift unit to the fuselage.

Abstract: A helicopter having a multiblade main rotor lift unit includes a plurality of pendulus mass units (48,60) mounted to oscillate in the plane of the rotor. The mass units (48,60) are connected to a rotatable shaft (24) which passes through a blade grip (14) for each blade (16). Vibrations generated in the plane of the rotor system are damped by the oscillating pendulums (22) which are tuned to minimize the vibrations in the lift unit.