A method for performing uptower maintenance of a wind turbine in order to replace the main bearing on the turbine shaft is disclosed. Embodiments of this method to perform maintenance may include installing a rotor lock to resist rotation of the main shaft during maintenance, providing a lifting device in order to elevate the main shaft, removing the main bearing from its main bearing housing, and installing a replacement split main bearing. A crane may also be installed uptower to assist in the maintenance.

A method for repairing an at least externally coated hollow component. The direct mechanical machining of a coated component after use removes the need for a coating-removal and selective hollowing step and a selective repair of cracks, since a design adaptation leads to a component being engineered or used such that it can be used again as a result of external dimensional stipulations.

A method comprises inspecting a ceramic matrix composite component assembled in a gas turbine engine to determine an extent of damage to the ceramic matrix composite component, determining a repair technique to repair the damage to the ceramic matrix composite component based on the extent of damage to the ceramic matrix composite component, and repairing the ceramic matrix composite component using the repair technique.

A method for performing uptower maintenance of a wind turbine in order to replace the main bearing on the turbine shaft is disclosed. Embodiments of this method to perform maintenance may include installing a rotor lock to resist rotation of the main shaft during maintenance, providing a lifting device in order to elevate the main shaft, removing the main bearing from its main bearing housing, and installing a replacement split main bearing. A crane may also be installed uptower to assist in the maintenance.

A viscous clutch head may be replaced by selecting a viscous clutch head and a mount adapter. The viscous clutch head and the mount adapter may be selected from a group of universal modular fan drives and from a group of mount adapters. The mount adapter of a threaded type or a flange and bolt type may be selected. Depending on the viscous clutch head to be replaced, a fan adapter and/or a pilot adapter may also be selected from a group of fan adapters and from a group of pilot adapters. Accordingly, a range of models of viscous fan clutch systems may be replaced by using a limited number of parts. These parts may be stored on a tool cart. As different models of viscous fan clutch systems may be replaced using a limited number of parts, the in-stock inventory of replacement parts may be reduced.

Some embodiments of a fan clutch system for use in a vehicle can provide efficient access to one or more components for inspection and service even after the fan clutch system is installed in the vehicle. In particular embodiments, the fan clutch system can include a fan clutch device and a coil retainer assembly that are removably mounted to a right-angle gear box assembly in a manner that permits a technician to accessing at least one component for inspection, repair, or replacement. The coil retainer assembly may at least partially house an electromagnetic coil for selective activation. The system may further include a fan clutch device removably mounted to the drive member of the gear box assembly.

A system for enabling servicing of a rotor of a wind turbine is provided. A rotor servicing fixture attaches to a first and second rotor blade, and contacts a wind turbine tower. A clamp assembly is connected to the rotor servicing fixture, and clamps onto a third rotor blade. The clamp assembly lowers the third rotor blade from a hub and raises it back to the hub. A lifting assembly is connected to the rotor servicing fixture and the clamp assembly, and is configured for raising and lowering the third rotor blade via the clamp assembly. A slide assembly is connected to the rotor servicing fixture, and is configured to support the rotor part and to slidably move the rotor part away from or towards the wind turbine. The system enables the rotor part to be removed or replaced without requiring the rotor to be removed from the wind turbine.

A quill shaft is configured for transferring torque and accepting misalignments between a fixed gearbox and a rotatable spindle gearbox in a propulsion system of a tiltrotor aircraft, the quill shaft includes a first splined portion configured for coupling to an output gear of the fixed gearbox, and a second splined portion configured for coupling to an input gear of the spindle gearbox. The spindle gearbox includes a rotor mast associated therewith, the spindle gearbox being rotatable so that the tiltrotor aircraft can selectively operate in a helicopter mode and airplane mode.

The aircraft-engine gas turbine includes an outer sealing ring for sealing an array of rotor blades that can be attached to a housing by a clamping mechanism (80) in a friction fit, and a plurality of ring segments (20.sub.i, 20.sub.i+1), wherein a free axial path length (a.sub.f) of a sealing ring segment counter to the direction of through-flow is at least as large as an axial engagement (a.sub.1) of a rotation locking member (10) of the outer sealing ring (a.sub.f≧a.sub.1), which is free of form fit counter to the direction of through-flow, and/or an axial overhang (a.sub.2) of a radial mounting rail (23) of the outer sealing ring (a.sub.f≧a.sub.2), and/or an axial offset (a.sub.3, a.sub.4) of a sealing fin (31, 41); and/or a quotient of a specific clearance sum of the outer sealing ring attached to the housing in a friction fit.

A propulsion system for a tiltrotor aircraft includes an engine supported by the airframe and a fixed gearbox operably coupled to the engine. Inboard and outboard pedestals are supported by the airframe and positioned above the wing. A pylon assembly is rotatably coupled between the inboard and outboard pedestals. The pylon assembly includes a spindle gearbox having an input gear, a mast operably coupled to the input gear and a proprotor assembly operable to rotate with the mast. The spindle gearbox is rotatable about a conversion axis to selectively operate the tiltrotor aircraft between helicopter and airplane modes. A common shaft, rotatable about the conversion axis, is configured to transfer torque from an output gear of the fixed gearbox to an input gear of the spindle gearbox. Each of the inboard and outboard pedestals includes a spherical bearing providing a self-aligning coupling with the pylon assembly.