A method for assembling a gas turbine engine includes providing a high pressure turbine, providing a low-pressure turbine inner rotor that includes a first plurality of turbine blade rows configured to rotate in a first direction, providing a low-pressure turbine outer rotor that includes a second plurality of turbine blade rows configured to rotate in a second direction that is opposite the first direction, and coupling a plurality of bearings between the outer rotor and a turbine mid-frame between the high pressure turbine and at least one of the inner and outer rotors such that the plurality of bearings support a forward end of the outer rotor.

Counter-rotating gas turbine engine and method of assembling same

A bearing damper includes: (a) an annular sleeve (42) having spaced-apart grooves (44, 46) formed in a radially-facing surface therein; (b) an annular bearing race (24) received in the sleeve (42); and (c) a resilient seal ring (54, 154) disposed in each of the grooves (44, 46), wherein the seal rings (54, 154) cooperate with the sleeve (42) and a radially-facing surface of the bearing race (24) to define a closed annular gap, and further wherein the seal rings (54, 154) are sized so as to urge the bearing race (24) towards a coaxial position relative to the sleeve (42).

Bearing damper with spring seal

A method of transmitting power among a plurality of shafts in a turbine engine is disclosed herein as well as a turbine engine for practicing the method. The turbine engine includes a compressor section having a low pressure portion and a high pressure portion. The turbine engine also includes a turbine section spaced from the compressor section along a centerline axis. The turbine section includes a low pressure portion and a high pressure portion. The turbine engine also includes a low pressure shaft extending between the low pressure portion of the compressor section and the low pressure portion of the turbine section. The turbine engine also includes a high pressure shaft extending between the high pressure portion of the compressor section and the high pressure portion of the turbine section. The turbine engine also includes a tower shaft operably engaged with both of the low pressure shaft and the high pressure shaft. The tower shaft can impart initial rotation to the high pressure shaft and the low pressure shaft can transmit power through the tower shaft after initial rotation has been imparted to the high pressure shaft.

Power transmission among shafts in a turbine engine

A device for controlling pitch of fan blades of a turboprop including at least one set of adjustable-pitch fan blades secured to rotate with a rotary ring mechanically connected to a turbine rotor, each blade of the set being coupled for pitch adjustment to a synchronization ring. The device includes a rolling bearing including an inner cage slidably mounted on a turbine casing and connected to the rod of an actuator, and an outer cage that is mechanically connected to the synchronization ring by a plurality of connection arms connected to the actuator rod and hinge-mounted on the synchronization ring such that actuating the actuator causes the synchronization ring to move in turning about the longitudinal axis.

Device for controlling the pitch of fan blades of a turboprop

Controllable pitch blade non-ducted propeller for a jet engine, comprising a rotor member comprising radial housing for mounting blade support plates, each plate being attached in a ring centered and guided in rotation in a housing of the rotor member and comprising external toothing engaged and locked in internal toothing of the ring, to withstand the centrifugal forces to which the propeller blades are subjected in operation.

Controllable pitch blade non-ducted propeller for jet engine

An actuation system which includes apparatus for transferring control signals for varying the blade pitch from a non-rotating member to a rotating member of a gas turbine engine is described. In one embodiment, the engine includes a main disk containing a row of blades, and the disk is coupled to a main shaft which rotates about the engine axis. An actuating disk, or cone, rotates with the main disk, and the torque required to rotate the actuating cone is transmitted through ball splines attached to the main shaft. The ball splines allow transmission of torque between the disk and the cone and at the same time enable the disk and the cone to move axially relative to each other without binding. The actuating cone is supported at one end by the ball splines and at its other end by ball thrust bearings. The ball thrust bearings are pre-loaded to enable the bearings to withstand axial loads in opposite directions. The outer races of the bearings are supported by a ring, and the ring is connected to an actuator through a connecting cone. In addition to the actuating system, a blade support system is provided wherein the load of the blade is transferred from a blade "button" head to the main disk through a load transfer ring, a bearing inner race support, and a thrust bearing. A nut retains a crank of the actuating system on the blade spindle. To rotate the blade about its radial axis, the ring is moved axially by the actuator. Such axial movement of the ring imparts axial motion to the rotating actuating cone, which rotates a crank attached to the blade. The thrust bearings allow the actuating cone to rotate about the centerline of the actuator and to move axially when actuated.

Actuation system for a gas turbine rotor blade

A blade retention system which allows a blade to be rotated about a blade stack axis by utilizing a cover, an anti-rotational key, and strap is described. The substantially cylindrical cover rotatably couples to a rotor disk opening using a thrust bearing. The cover includes a dovetail-load slot for receiving a rotor blade dovetail key. The anti-rotation key is positioned between the dovetail key and the dovetail-load slot to secured the blade to the cover. The strap holds the key in place and is clamped between the cover and the control mechanism.

August H. Kramer

Papers

Actuation system for a gas turbine rotor blade

Blade retention system for a variable rotor blade