Apparatus for indicating the pitch of turbofan blades
First Claim
1. Apparatus for indicating change in pitch of variable pitch blades, the pitch being changed in response to a relative displacement between at least two members, each member being movable with respect to a frame of reference, said apparatus comprising:
- detecting means for providing signals indicating respective displacements of said members with respect to said frame of reference; and
processing means, responsive to said signals from said detecting means, for determining relative displacement between said members, said relative displacement being indicative of the change in blade pitch.
1 Assignment
0 Petitions
Accused Products
Abstract
Apparatus indicates changes in blade pitch of variable pitch blades by detecting relative displacements of first and second members of a blade pitch actuator. The members are selectively displaced to change the pitch of the blades. The apparatus includes sensors which provide output signals to a microprocessor, which determines displacement of each member with respect to a frame of reference. The microprocessor takes the difference between the displacements of the two members to determine the relative displacement, which is indicative of a change in blade pitch.
43 Citations
15 Claims
-
1. Apparatus for indicating change in pitch of variable pitch blades, the pitch being changed in response to a relative displacement between at least two members, each member being movable with respect to a frame of reference, said apparatus comprising:
-
detecting means for providing signals indicating respective displacements of said members with respect to said frame of reference; and processing means, responsive to said signals from said detecting means, for determining relative displacement between said members, said relative displacement being indicative of the change in blade pitch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. Apparatus for indicating a change in pitch of variable pitch blades, the pitch being changed by differential means, responsive to first and second control shafts, for coupling a fan shaft to said blades, said blades being adjusted in one direction when said first control shaft is rotated relative to said second control shaft, said blades being turned in an opposite direction when said second control shaft is rotated relative to said first control shaft, said apparatus comprising:
-
first sensing means, responsive to the rotation of said first control shaft, for indicating a first displacement of said first control shaft with respect to a frame of reference; second sensing means, responsive to the rotation of said second control shaft, for indicating a first displacement of said second control shaft with respect to a frame of reference; and processing means, responsive to outputs of said first and second sensing means, for taking the difference of said first and second displacements, whereby said difference is indicative of the change in blade pitch.
-
-
15. Apparatus for indicating the angular displacement of a member with respect to a frame of reference, comprising:
-
coding means, secured to said m ember, having an alternating pattern of first and second zones, each said zone having a width As; first and second sensor means, secured to said frame and arranged in phase quadrature, for sensing said first zones on said code wheel, said first and second sensor means providing sensor signals which indicate said first zones within a resolution error Ar; sampling means, responsive to said first and second sensors, for sampling said sensor signals at a maximum period ta of;
space="preserve" listing-type="equation">Ta=(As-Ar)/Nwhere N is angular speed of said coding means; and processing means, responsive to said sampling means, for processing said sampled sensor signals into said angular displacement.
-
Specification