An improved rotor for a helicopter comprises a yoke at the inner end of each arm engaging the rotor hub by way of a spherical abutment

Rotor for rotating wing type aircraft

An elastomeric bearing for a helicopter rotor in which the laminates of the bearing are shaped and positioned so that the center of hydrostatic pressure generated in each elastomer laminate and the cross-sectional center of gravity of each metal laminate are in alignment so that the integrated load vectors reacted through the metal and elastomer laminates of the bearing in imparting blade centrifugal loads to the hub therethrough are substantially in alignment to thereby prevent the creating of eccentric internal moments and hence avoid life reducing bending and hoop stresses in the metal laminates and unnecessarily high hydrostatic pressures in the elastomer laminates.

Elastomeric bearing for helicopter rotor

A helicopter rotor hub assembly (10) in which a blade grip (30) extends inboard of a yoke (14) and transfers centrifugal forces to the yoke (14) through a spherical elastomeric bearing (38). Pitch change of the grip (30) and blade (32) is accommodated by the spherical elastomeric bearing (38) which also acts as the pivot point for lead-lag motion of the blade (32) and grip (30). A lead-lag damper (22) is located inboard of the elastomeric bearing (38) and is connected between one end of the grip (30) spaced away from the lead-lag pivot and the yoke (14) for damping the lead-lag motion between the grip (30) and yoke (14).

Soft inplane helicopter rotor

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.

Constant velocity elastomeric bearing joint

A rotor blade retention system connects an elongated rotor blade to a rotor hub that is rotatable about its central axis The connected rotor blade normally extends generally radially from the hub and is rotatable with the hub The retention system includes at least three laminated elastomeric bearings connected together in serial compression load transmitting relationship Each laminated bearing includes a plurality of alternating and bonded together layers of elastomeric material and substantially inextensible material The layers of each of the serially interconnected bearings are at least partially inclined relative to the longitudinal axis of the rotor blade In section taken radially of the longitudinal axis of the blade, at least a portion of each layer of each bearing projects longitudinally toward an end of the rotor blade Preferably, only one of the serially interconnected bearings is rigidly connected to the rotor blade The rotor blade is spaced radially, relative to its longitudinal axis, from at least all portions of the retention system other than the bearing to which the blade is rigidly connected

Rotor blade retention system

An elastomeric rotor mounting structure for a helicopter blade is provided. In the mounting, a blade grip is coupled to a yoke structure by means of radial-thrust elastomeric bearings and the yoke structure is connected to the rotor hub. The elastomeric bearings simplify the rotor design and eliminate the need for bearing lubrication.

Castle Hugh Fagan

Papers

Elastomeric rotor blade mount