Rotor with variable angle blades

Claim 2

A support and actuation structure for a rotatable shaft subject to high axial loads, said structure comprising: a structural frame; a first shaft rotatably supported in said frame; a first disc secured to said first shaft and having a web portion and an annular ring portion, said annular ring portion having an inner surface of revolution about the axis of said first shaft; a second disc rotatably mounted to said first shaft and having a web portion and an annular ring portion oriented toward the annular ring portion of said first disc, said latter mentioned annular ring portion having an inner surface of revolution about the axis of said first shaft; a second shaft having an enlargement on one end thereof, said enlargement including surfaces of revolution about the axis of said second shaft; means supporting the surfaces of revolution of said enlargement in contact with the inner surfaces of said annular ring portions, said contacting surfaces being further characterized by being non-concentric with each other in the plane defined by intersection of the axes of said first and second shafts; means constraining the discs and the second shaft so that the respective points of contact between said enlargement and said annular ring portions are symmetrically located with respect to the axis of said second shaft; and means for rotating said second disc relative to said first disc.

Claim 3

The structure recited in claim 1 wherein the inner surfaces of said annular ring portions are spherical surfaces having equal radii R1 and the surfaces of revolution on said enlargement are spherical surfaces having equal radii R2, R2 being smaller than R1.

Claim 4

The structure recited in claim 2 wherein the means supporting said enlargement in contact with said annular ring portions and constraining said second shaft includes an annular surface on said enlargement and a surface on each web in slidable contact therewith.

Claim 5

The structure recited in claim 3 wherein a bevel gear is attached to each web portion, said gears facing each other, and a beveled pinion is secured to said second shaft and meshes with said bevel gears, the pitch cone of said pinion being defined by revolution of the lines joining the points of contact between the spherical surfaces to the intersection of said shafts, about the axis of said second shaft, whereby said gears and pinion will provide positive synchronization of the relative motion between said discs with the corresponding rolling motion between the spherical surface of said enlargement and the inner surfaces of said annular ring portions.

Claim 6

In an axial flow apparatus having a stator and A rotor, a variable angle rotor blade system comprising at least one row of variable rotor blades peripherally disposed on said rotor with each blade having a central axis about which the blade angle may be varied, and support structure for said blades, said structure comprising: a first disc attached to said rotor and having a web portion and an annular ring portion, said annular ring portion having an inner surface of revolution about the axis of said rotor; a second disc rotatably mounted to the rotor and having a web portion and an annular ring portion oriented toward the annular ring portion of said first disc, said latter mentioned annular ring portion having an inner surface of revolution about the axis of the rotor; a blade shaft attached to the inner end of each blade, said blade shaft having an enlargement on its inner end, said enlargement including surfaces of revolution about the axis of said blade shaft which face outwardly with respect to the rotor axis; means supporting the surfaces of revolution of said enlargements in contact with the inner surfaces of said annular ring portions, said contacting surfaces being further characterized by being non-concentric with each other in the planes defined by inter-section of the central axes of said blade and said rotor; means constraining the central axis of each blade in a plane substantially normal to the rotor axis; means constraining the spacing of said discs so that the respective points of contact between each enlargement and said annular ring portions are symmetrically located with respect to the central blade axis, so that said blades will be radially supported against centrifugal loads by essentially point contact between each enlargement and each annular ring portion and relative rotation between said discs will cause said blades to rotate about their central axes with minimum friction.

Claim 7

In an axial flow apparatus having a stator and A rotor, a variable angle rotor blade system comprising at least one row of variable rotor blades peripherally disposed on said rotor with each blade having a central axis about which the blade angle may be varied, and support structure for said blades, said structure comprising: a first disc attached to said rotor and having a web portion and an annular ring portion, said annular ring portion having an inner surface of revolution about the axis of said rotor; a second disc rotatably mounted to the rotor and having a web portion and an annular ring portion oriented toward the annular ring portion of said first disc, said latter mentioned annular ring portion having an inner surface of revolution about the axis of the rotor; a blade shaft attached to the inner end of each blade, said blade shaft having an enlargement on its inner end, said enlargement including surfaces of revolution about the axis of said blade shaft which face outwardly with respect to the rotor axis; means supporting the surfaces of revolution of said enlargements in contact with the inner surfaces of said annular ring portions, said contacting surfaces being further characterized by being non-concentric with each other in the planes defined by inter-section of the central axes of said blade and said rotor; means constraining the central axis of each blade in a plane substantially normal to the rotor axis; means constraining the spacing of said discs so that the respective points of contact between each enlargement and said annular ring portions are symmetrically located with respect to the central blade axis, so that said blades will be radially supported against centrifugal loads by essentially point contact between each enlargement and each annular ring portion and relative rotation between said discs will cause said blades to rotate about their central axes with minimum friction.

Claim 8

The system recited in claim 5 wherein the means supporting each enlargement in contact with said annular ring portion and constraining said central blade axis includes an annular surface on each said enlargement normal to the blade axis and facing the rotor axis, and a surface on each said web in slidable contact with said annular surface.

Claim 9

The system recited in claim 6 wherein a bevel gear is attached to each web portion, said gears facing each other, and a beveled pinion is secured to each blade shaft and meshes with said bevel gears, the pitch cone of said pinion being defined by revolution of the lines joining the points of contact between said contacting surfaces and the intersection of the central blade axes and rotor axis, about the central axis of said blade whereby said gears and pinion will provide positive synchronization of the relative motion between said discs with the corresponding rolling motion between the surface of revolution of said enlargement and the inner surface of said annular ring portions.

Claim 10

The system recited in claim 7 wherein said surfaces of revolution are spherical.

Claim 11

The system recited in claim 7 wherein the means securing said pinion to said blade shaft comprises: a surface formed on the end of said blade shaft; a seat formed on a first face of said pinion and mated with said surface; a recess formed in the second face of said pinion opposite said first face, said recess including at least two female splines; a center hole defined through said pinion; an adapter extending through said center hole and secured to said blade shaft, said adapter comprising two webs having male splines at their ends engaged with said female splines, said adapter additionally holding said surface and said seat in contact with each other, said webs being nominally located in a direction parallel with the axis of said rotor and being further characterized by flexibility adequate to isolate said meshed pinion and gears from loading caused by lateral vibration or misalignment of said blade shaft; a pair of lugs on the inner end of said blade Shaft and radially spaced from the axis thereof in planes nominally normal to the axis of said rotor; and a pair of slots in said pinion mated with said lugs.

Claim 12

The system recited in claim 5 including actuating means for rotating said second disc relative to said first disc wherein said actuating means include at least one fluid powered actuator having a range of positions from one end stop to another end stop.

Claim 13

The system recited in claim 10 wherein said actuation structure further includes centrifugal balance means responsive to the rotation of said rotor for urging the blades to and maintaining the blades at the nearest end stop upon disengagement of the actuation force.

Claim 14

The system recited in claim 11 wherein said balance means comprises: a first annular support member secured to said second disc; a second annular support member secured to said rotor shaft; a plurality of links pinned to said first annular support member for rotation with respect thereto and secured to said second annular support member for limited radial sliding motion and rotation with respect thereto; said links further including a mass of material for generating centrifugal force located at their inner ends.

Claim 15

The system recited in claim 5 wherein the central axis about which the blade angle may be varied is in close proximity to the intersection of the leading edge of the blade with the blade tip and the locus of incremental centers of gravity for the incremental blade sections which lie in planes orthogonal to the central blade axis is arranged so that the centrifugal forces acting on all points on the locus balance about the central blade axis to cause no bending moment at the point of blade attachment to the rotor.

Claim 16

In an axial flow apparatus having a stator and a rotor, a variable angle rotor blade system comprising at least one row of variable rotor blades peripherally disposed on said rotor and support and actuation structure for said blades, said structure comprising: a support member movably disposed on said rotor; actuating means for moving said supporting member relative to said rotor; connecting means for transmitting movement of said support member relative to said rotor into blade angle orientation; and balance means having a second support member secured to said rotor shaft and spaced radially inward of said first support member together with a plurality of links each of which is rotatably attached to said first and second support members wherein one of the rotatable attachments of each link is adapted for limited radial sliding motion with respect to the support members and each link includes a mass of material for generating a centrifugal force for urging the blades to a stable position thereby insuring a stable flow through the blades upon disengagement of actuator force.

Claim 17

In an axial flow apparatus having a stator and a rotor, a variable angle rotor blade system comprising at least one row of variable rotor blades peripherally disposed on said rotor and support and actuation structure for said blades, said structure comprising: a support member movably disposed on said rotor; actuating means for moving said supporting member relative to said rotor; connecting means for transmitting movement of said support member relative to said rotor into blade angle orientation; and balance means having a second support member secured to said rotor shaft and spaced radially inward of said first support member together with a plurality of links each of which is rotatably attached to said first and second support members wherein one of the rotatable attachments of each link is adapted for limited radial sliding motion with respect to the support members and each link includes a mass of material for generating a centrifugal force for urging the blades to a stable position thereby insuring a stable flow through the blades upon disengagement of actuator force.

Claim 18

The axial flow apparatus of claim 14 wherein the second support member is an annulus having a plurality of radially oriented elongated slider tracks around its periphery and the inner radial end of each link is rotatably pinned to a slide which slidably engages a slider track to provide said limited radial sliding motion.