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.

A method for creating a tapered spiral welded conical structure where the overall shape of the cone is first graphically slit axially and unwrapped, and then a series of construction arcs and lines are created to form the edge lines of a strip that can then be wrapped (rolled) to form a tapered conical structure. The edges of the spirally wound strip can be welded together, and a very large conical structure can thus be achieved. Various construction options are presented from a constant width strip to strip made from straight segments. Equations are given for the formation of the strips to enable those skilled in the art of spiral welded tubing to practice the invention.

A rotor for use in an aircraft engine, that has been repaired by (a) welding together a first portion of a damaged blade of the rotor and a second portion of metal to form a weld nugget, (b) compressively stressing the weld nugget throughout its volume, and (c) heat treating the compressively stressed weld nugget to recrystallize metal therein.

A method of reassembling a gas turbine engine including steps to support a core engine on a core stand and support a fan case on a fan stand that includes a base frame coupled a fan case frame by a hinge. The fan case frame is arranged to (i) rotate about an axis of the hinge between abutting the base frame and being perpendicular to the base frame, and (ii) tilt about a yaw axis perpendicular to the hinge, which is located in a plane of the fan case frame. The method includes rotating and tilting the fan case frame to align the fan case and core engine, translating at least one of the core engine and the fan case into axial abutment, coupling the fan case and the core engine to reassemble the gas turbine engine, and decoupling the fan case from the fan stand.

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.

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.1+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.fa.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.fa.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 .Iadd.and pi is at least as large as a difference between a maximum outer diameter of the outer sealing ring and a minimum inner diameter of the flow channel inlet of the housing.Iaddend..

An adjustable blade outer air seal apparatus includes a case that extends circumferentially around an axis, a support ring non-rigidly mounted to the case on spring connections radially inwards of the case, whereby the support ring floats with respect to the case, and at least one blade outer air seal segment that is radially adjustable relative to the support ring.

A repair system for a gearbox of a wind turbine includes for removably coupling to the first portion of the gearbox housing of the gearbox. The lifting apparatus is adapted for lifting the first portion of the gearbox housing relative to the second portion gearbox housing. The repair system also includes at least one gearbox housing support member for mounting to the second portion of the gearbox housing. The at least one gearbox housing support member provides a support surface for the first portion of the gearbox housing during a repair procedure of the gearbox. The support surface is offset from the second portion of the gearbox housing.

A method of repairing a damaged spar cap of a wind turbine blade of a wind turbine, the damaged spar cap including carbon fiber-reinforced plastic and the method having the steps of: removing a damaged carbon fiber-reinforced plastic part from the damaged spar cap to obtain a corresponding recess in the damaged spar cap, applying an adhesive to the recess, and fitting at least one patch including carbon fiber-reinforced plastic into the recess, is provided.