Rotorcraft including variable blade torsional angle mechanism

Patent metadata

Field	Value
Publication number	US-2021047031-A1
Application number	US-202016898458-A
Country	US
Kind code	A1
Filing date	Jun 11, 2020
Priority date	Dec 14, 2017
Publication date	Feb 18, 2021
Grant date	—

Abstract

A rotor craft changes a torsional angle of a blade by driving an actuator. The rotor craft includes a plurality of torsion applying mechanisms that each twist a proximal end portion of a corresponding blade relative to a distal end portion of the corresponding blade about a center axis A of the blade. Each blade includes a spar having a proximal end portion connected to a hub and a skin in which the spar is inserted, such that a distal end portion of the skin and a distal end portion of the spar are connected to each other, and such that other portions of the skin than the distal end portion are rotatable relative to the spar about a center axis of the spar. The hub includes a hub body mounted to a main rotor shaft, and a hub arm that connects the spar to the hub body.

First claim

1 . A rotor craft, comprising:
a rotor shaft; a plurality of blades that rotate about the rotor shaft; a hub that couples the plurality of blades to the rotor shaft; and a plurality of torsion applying mechanisms, each torsion applying mechanism of the plurality of torsion applying mechanisms twisting a proximal end portion of a corresponding blade of the plurality of blades relative to a distal end portion of the corresponding blade about a center axis of the blade, wherein each blade of the plurality of blades includes:
a spar constituted by a long shaft-shaped structural member, the spar including a proximal end portion that is connected to the hub; and
a skin in which the spar is inserted, such that a distal end portion of the skin and a distal end portion of the spar are connected to each other, and such that portions of the skin other than the distal end portion are rotatable relative to the spar about a center axis of the spar, and
the hub includes:
a hub body mounted to the rotor shaft; and
a hub arm that connects the spar to the hub body.

2 . The rotor craft according to claim 1 , further comprising a pitch-changing mechanism, which changes a pitch of each blade of the plurality of blades, and the pitch-changing mechanism including:
a swash plate; and a plurality of pitch links having a first end connected to the swash plate and a second end connected to the hub arm.

3 . The rotor craft according to claim 1 , wherein each of the torsion applying mechanisms includes an actuator that applies rotating force about the center axis of the spar to a proximal end portion of the skin, the actuator being provided on the hub arm.

4 . The rotor craft according to claim 1 , wherein each of the torsion applying mechanisms includes an actuator that applies rotating force about the center axis of the spar to a proximal end portion of the skin, the actuator being provided at a position different from the hub arm.

5 . The rotor craft according to claim 1 , wherein each of the torsion applying mechanisms includes a second swash plate that applies rotating force about the center axis of the spar to a proximal end portion of the skin.

6 . The rotor craft according to claim 3 , wherein each of the torsion applying mechanisms further includes an arm that connects between the actuator and a leading edge portion or a trailing edge portion of the proximal end portion of the skin.

7 . The rotor craft according to claim 5 , wherein each of the torsion applying mechanisms includes an arm that connects between the second swash plate and a leading edge portion or a trailing edge portion of the proximal end portion of the skin.

8 . The rotor craft according to claim 1 , wherein
at least a partial segment of the spar in a longitudinal direction of the spar forms a flattened cross-sectional shape, such that a dimension of the cross-sectional shape in a forward-rearward direction is greater than a dimension of the cross-sectional shape in an upward-downward direction, and at least a portion of the skin, the portion being different from the distal end portion, is rotatably supported on the spar via a bearing.

9 . The rotor craft according to claim 1 , wherein from a specific position in a longitudinal direction of the spar toward the distal end portion of the spar, a dimension of the cross-sectional shape in a forward-rearward direction and/or a dimension of the cross-sectional shape in an upward-downward direction increases gradually.

10 . A rotor craft, comprising:
a rotor shaft; a plurality of blades that rotate about the rotor shaft; a hub that couples the plurality of blades to the rotor shaft; and a plurality of actuators, each actuator of the plurality of actuators twisting a proximal end portion of a corresponding blade of the plurality of blades relative to a distal end portion of the corresponding blade about a center axis of the blade, wherein each blade of the plurality of blades includes:
a spar having a long shaft-shape, the spar including a proximal end portion that is connected to the hub; and
a skin in which the spar is inserted, such that a distal end portion of the skin and a distal end portion of the spar are connected to each other, and such that portions of the skin other than the distal end portion are rotatable relative to the spar about a center axis of the spar, and
the hub includes:
a hub body mounted to the rotor shaft; and
a hub arm that connects the spar to the hub body.

11 . The rotor craft according to claim 10 , further comprising a pitch-changing device, which changes a pitch of each blade of the plurality of blades, and the pitch-changing device including:
a swash plate; and a plurality of pitch links having a first end connected to the swash plate and a second end connected to the hub arm.

12 . The rotor craft according to claim 10 , wherein each of the actuators includes a rotary actuator that applies rotating force about the center axis of the spar to a proximal end portion of the skin, the actuator being provided on the hub arm.

13 . The rotor craft according to claim 10 , wherein
each of the actuators is provided at a position different from the hub arm, and each of the actuators applies a rotating force about the center axis of the spar to a proximal end portion of the skin.

14 . The rotor craft according to claim 10 , wherein each of the actuators includes a second swash plate that applies rotating force about the center axis of the spar to a proximal end portion of the skin.

15 . The rotor craft according to claim 12 , wherein each of the actuators further includes an arm that connects between the actuator and a leading edge portion or a trailing edge portion of the proximal end portion of the skin.

16 . The rotor craft according to claim 13 , wherein each of the actuators further includes an arm that connects between the actuator and a leading edge portion or a trailing edge portion of the proximal end portion of the skin.

17 . The rotor craft according to claim 14 , wherein each of the actuators includes an arm that connects between the second swash plate and a leading edge portion or a trailing edge portion of the proximal end portion of the skin.

18 . The rotor craft according to claim 10 , wherein
at least a partial segment of the spar in a longitudinal direction of the spar forms a flattened cross-sectional shape, such that a dimension of the cross-sectional shape in a forward-rearward direction is greater than a dimension of the cross-sectional shape in an upward-downward direction, and at least a portion of the skin, the portion being different from the distal end portion, is rotatably supported on the spar via a bearing.

19 . The rotor craft according to claim 10 , wherein from a specific position in a longitudinal direction of the spar toward the distal end portion of the spar, a dimension of the cross-sectional shape in a forward-rearward direction and/or a dimension of the cross-sectional shape in an upward-downward direction increases gradually.

20 . An assembly for a rotor craft, the assembly comprising:
a rotor shaft; a hub that couples the rotor shaft to a plurality of blades of the rotor craft; and a plurality of actuators, each actuator of the plurality of actuators twisting a proximal end portion of a corresponding blade of the plurality of blades relative to a distal end portion of the corresponding blade about a center axis of the blade, wherein each blade of the plurality of blades includes:
a spar having a

Assignees

• Kawasaki Heavy Ind Ltd

Inventors

• Hayashida Atsushi
• Wakatsuki Tadashi

Classifications

• B64U80/86

  Land vehicles · CPC title

• B64C27/605 Primary

  including swash plate, spider or cam mechanisms · CPC title

• B64C27/473 Primary

  Constructional features · CPC title

• B64C11/32

  mechanical · CPC title

• B64C11/06

  for variable-pitch blades · CPC title