There is disclosed an aircraft engine having: an engine shaft; a first transmission shaft in driving engagement with the engine shaft and a second transmission shaft concentric with the first transmission shaft and in driving engagement with the first transmission shaft, the second transmission shaft drivingly engageable to an engine accessory, the first and second transmission shafts rotatable about an axis; and at least two axially spaced apart annular ring seals disposed radially between the first and second transmission shafts, the at least two annular ring seals biased against both of the first and second transmission shafts.

A damped primary drive sprocket system is provided that may be directly driven by a motorcycle engine and may be arranged in a primary drive connecting the motorcycle engine to a motorcycle transmission. The damped primary drive sprocket system may include damper segments such as discrete isolator bushings arranged in leading and trailing slot chambers, on opposite sides of a lug within a slot of a coupling system that connects a hub to a sprocket within the damped primary drive sprocket system. The slot chambers may be circular in cross-sectional perimeter shape so and the isolator bushings may be cylindrical and fit snugly in the slot chambers in a manner that damps slight rotational clocking movements of the hub and sprocket with respect to each other during firing pulses of the motorcycle engine.

A damped primary drive sprocket system is provided that may be directly driven by a motorcycle engine and may be arranged in a primary drive connecting the motorcycle engine to a motorcycle transmission. The damped primary drive sprocket system may include damper segments such as discrete isolator bushings arranged in leading and trailing slot chambers, on opposite sides of a lug within a slot of a coupling system that connects a hub to a sprocket within the damped primary drive sprocket system. The slot chambers may be circular in cross-sectional perimeter shape so and the isolator bushings may be cylindrical and fit snugly in the slot chambers in a manner that damps slight rotational clocking movements of the hub and sprocket with respect to each other during firing pulses of the motorcycle engine.

A joint device is provided for connecting two shaft sections. The joint device comprises at least one joint, at least one elastic damping arrangement which provides mechanical decoupling of the at least one joint and is coupled to the at least one joint in a torque transmitting manner, the elastic damping arrangement having at least one fiber package which is at least partially embedded in an elastic material, the at least one damping arrangement being arranged with the at least one joint in such a manner that at least the at least one joint and the at least one damping arrangement are arranged coincident at least in the rest state of the joint device.

A joint device is provided for connecting two shaft sections. The joint device comprises at least one joint, at least one elastic damping arrangement which provides mechanical decoupling of the at least one joint and is coupled to the at least one joint in a torque transmitting manner, the elastic damping arrangement having at least one fiber package which is at least partially embedded in an elastic material, the at least one damping arrangement being arranged with the at least one joint in such a manner that at least the at least one joint and the at least one damping arrangement are arranged coincident at least in the rest state of the joint device.

A coupling for attaching a pair of longitudinally aligned rotatable shafts. It has a pair of circular hubs having a bore through a central axis. A shaft is fixed within each bore. A circular power ring is positioned between the hubs. Either the hubs or the power ring have circular apertures through and spaced around each hub and a hollow bushing positioned in each circular aperture. The other of the hubs or the power ring has mating coupling pins extending outwardly mounted within a corresponding one of the hollow bushings. Preferably an end of the coupling pins mating with the bushings have a generally truncated spherical, bulbous configuration with an outside diameter about 5% to about 25% greater than an outside diameter of its opposite end. Preferably elastically deformable, solid cylindrical spacers are attached to, and projecting between each circular hub and the circular power ring.

A coupling for attaching a pair of longitudinally aligned rotatable shafts. It has a pair of circular hubs having a bore through a central axis. A shaft is fixed within each bore. A circular power ring is positioned between the hubs. Either the hubs or the power ring have circular apertures through and spaced around each hub and a hollow bushing positioned in each circular aperture. The other of the hubs or the power ring has mating coupling pins extending outwardly mounted within a corresponding one of the hollow bushings. Preferably an end of the coupling pins mating with the bushings have a generally truncated spherical, bulbous configuration with an outside diameter about 5% to about 25% greater than an outside diameter of its opposite end. Preferably elastically deformable, solid cylindrical spacers are attached to, and projecting between each circular hub and the circular power ring.

A coupling system for a machine assembly and a base is provided. The machine assembly includes a frame and a gib key extending outwardly from the frame. The coupling system includes at least one u-bracket configured to couple to the gib key such that said at least one u-bracket cooperates with the gib key to define a tenon pin opening. The at least one u-bracket is sized and shaped to be received in a clearance fit in a key channel defined in the base. The coupling system also includes a tenon pin sized and shaped to be received in the tenon pin opening such that the tenon pin couples the base to the gib key, and such that forces exerted on the received tenon pin parallel to a first direction are substantially in tension between the machine assembly and the base.

A coupling system for a machine assembly and a base is provided. The machine assembly includes a frame and a gib key extending outwardly from the frame. The coupling system includes at least one u-bracket configured to couple to the gib key such that said at least one u-bracket cooperates with the gib key to define a tenon pin opening. The at least one u-bracket is sized and shaped to be received in a clearance fit in a key channel defined in the base. The coupling system also includes a tenon pin sized and shaped to be received in the tenon pin opening such that the tenon pin couples the base to the gib key, and such that forces exerted on the received tenon pin parallel to a first direction are substantially in tension between the machine assembly and the base.

A clutch apparatus or system for a vehicle drive train for transmitting torque between the vehicle's engine and gear change gearbox. Three interoperative clutch members are provided in the apparatus. The three clutch members cooperate with at least two clutch plates, a pressure-receiving plate, a clutch pressure plate, a plurality of clutch pressure springs, and a setting device, which is provided between the second clutch member and the third clutch member, for setting a back torque between the third clutch member and the first clutch member by an axial displacement of the third clutch member relative to the second clutch member. An engagement device is provided between the second clutch member and the third clutch member for accomplishing a releasable engagement position, between the second clutch member and the third clutch member, as a function of the rotational angular velocity of the third clutch member.