Variable pitch fan blade system
AssigneeUnited Technologies Corporation
InventorLESLIE CHARLES KURZ
Life of this patent
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Abstract
A gas turbine engine may have a blade receiver for holding a fan blade, wherein the blade receiver is rotatable about a radial axis of the gas turbine engine. The gas turbine engine may also include a variable pitch mechanism comprising an actuation arm. The gas turbine engine may also include a splined index ring disposed between the actuation arm of the variable pitch mechanism and the blade receiver. The splined index ring may include an outer spline and an inner spline.
Claims20
A variable pitch fan blade system comprising:
- a blade receiver for holding a fan blade, wherein the blade receiver is rotatable about a radial axis of the gas turbine engine;
- a variable pitch mechanism comprising an actuation arm;
- and
- a splined index ring disposed between the actuation arm of the variable pitch mechanism and the blade receiver.
A gas turbine engine comprising:
- a fan hub rotatable about an engine central longitudinal axis of the gas turbine engine;
- a blade receiver for holding a fan blade, the blade receiver rotatably coupled to the fan hub and rotatable about a radial axis of the gas turbine engine;
- a spring element disposed between the fan hub and the blade receiver, the spring element being biased to exert a radially outward force against the blade receiver;
- a segmented annular retaining ring in direct engagement with the blade receiver, disposed around the radial axis, and disposed between the fan hub and the blade receiver, the segmented annular retaining ring configured to limit radially outward movement of the blade receiver to prevent the blade receiver from decoupling and disengaging from the fan hub, wherein the segmented annular retaining ring comprises a plurality of circumferential segments;
- a variable pitch mechanism comprising an actuation arm, wherein the segmented annular retaining ring is in direct engagement with the actuation arm of the variable pitch mechanism;
- and
- a splined index ring directly coupled between the actuation arm of the variable pitch mechanism and the blade receiver, wherein the splined index ring comprises an outer spline and an inner spline, wherein the blade receiver comprises a first ring spline engaging one of the outer spline and the inner spline and the actuation arm comprises a second ring spline engaging the other of the outer spline and the inner spline.
A method for adjusting an incidence angle of a fan blade, the fan blade being held by a blade receiver and the blade receiver being rotatable about a radial axis of a gas turbine engine, wherein a splined index ring is disposed between the blade receiver and an actuation arm of a variable pitch mechanism, the method comprising:
- disengaging the blade receiver from the splined index ring;
- after disengaging the blade receiver from the splined index ring, rotating the blade receiver relative to the splined index ring about the radial axis in a first direction;
- after rotating the blade receiver, re-engaging the blade receiver to the splined index ring;
- disengaging the splined index ring from the actuation arm of the variable pitch mechanism;
- after disengaging the splined index ring from the actuation arm, rotating the splined index ring relative to the actuation arm about the radial axis in a second direction opposite the first direction;
- and
- after rotating the splined index ring, re-engaging the splined index ring with the actuation arm.
Dependencies are inferred from the claim text.