Fans

Claim 2

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a non-rotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the rotative subassembly also including a spinner which encloses the forward part of the hub structure.

Claim 3

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a non-rotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the rotative subassembly also including a spinner which encloses the forward part of the hub structure.

Claim 4

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a non-rotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the rotative subassembly also including a spinner which encloses the forward part of the hub structure.

Claim 5

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a non-rotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the fan blading being of variable pitch with the pitch adjustable under the control of a servo-system housed, at least in part, within the hub structure.

Claim 6

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a non-rotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the fan blading being of variable pitch with the pitch adjustable under the control of a servo-system housed, at least in part, within the hub structure.

Claim 7

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, with a fan of tiered form having an inner tier of blading adapted to charge the engine compressor and an outer tier of blading to charge a by-pass duct, constructed as a unitary assembly which can be fitted and removed as such and comprising a nonrotative portion including the by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the inner tier of blading being of fixed pitch and the outer tier of fan blading being of variable pitch with the pitch adjustable under the control of a servo-system housed, at least in part, within the hub structure.

Claim 8

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, with a fan of tiered form having an inner tier of blading adapted to charge the engine compressor and an outer tier of blading to charge a by-pass duct, constructed as a unitary assembly which can be fitted and removed as such and comprising a nonrotative portion including the by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the inner tier of blading being of fixed pitch and the outer tier of fan blading being of variable pitch with the pitch adjustable under the control of a servo-system housed, at least in part, within the hub structure.

Claim 9

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a nonrotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported withIn the nonrotative by-pass duct, the fan blading being variable in pitch angle to provide positive pitch, zero or near zero pitch, negative pitch and a feathered position in order to provide complete control of the air flow along the duct with the pitch adjustable under the control of a servo-system housed, at least in part, within the hub structure.

Claim 10

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a nonrotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported withIn the nonrotative by-pass duct, the fan blading being variable in pitch angle to provide positive pitch, zero or near zero pitch, negative pitch and a feathered position in order to provide complete control of the air flow along the duct with the pitch adjustable under the control of a servo-system housed, at least in part, within the hub structure.

Claim 11

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprises a non-rotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the fan assembly being adapted for bolting up to the main engine assembly so as to pick up a drive for the rotative subassembly from the main engine shaft.

Claim 12

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprises a non-rotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the fan assembly being adapted for bolting up to the main engine assembly so as to pick up a drive for the rotative subassembly from the main engine shaft.

Claim 13

A fan assembly according to claim 5, wherein the fan blading is arranged in a single stage.

Claim 14

A fan assembly according to claim 5, wherein the by-pass duct is supported by a main body of said non-rotative portion through a ring of stator blading positioned downstream of the fan blading, which main body is adapted for bolting to the front of the main engine assembly and also supports the rotative sub-assembly.

Claim 15

A fan assembly according to claim 5, and gearing to drive the rotative subassembly, said gearing being housed within the fan assembly.

Claim 16

A fan assembly according to claim 8, wherein said gearing is reduction gearing.

Claim 17

A fan assembly according to claim 8, wherein said gearing is housed within the nonrotative portion of the fan assembly.

Claim 18

A gas turbine engine embodying a fan assembly according to claim 10, wherein the duct portion of the fan assembly provides the complete by-pass duct of the engine.

Claim 19

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a nonrotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the fan assembly being adapted for bolting up to the main engine assembly so as to pick up a drive for the rotative subassembly from a reduction gear box embodied in the engine assembly.

Claim 20

A fan assembly for attachment to the front of a main gas turbine engine assembly to provide an engine of the ducted-fan by-pass type, constructed as a unitary assembly which can be fitted and removed as such and comprising a nonrotative portion including a by-pass duct, and a rotative subassembly supported in bearings by the nonrotative portion and including a hub structure and fan blading positioned and rotatably supported within the nonrotative by-pass duct, the fan assembly being adapted for bolting up to the main engine assembly so as to pick up a drive for the rotative subassembly from a reduction gear box embodied in the engine assembly.