Method and apparatus for adjusting the pitch of a fan blade
AssigneeEmerson Electric Co.
InventorFrank E. Cahill
Life of this patent
Estimating the term…
Abstract
A variable pitch fan blade assembly includes a hub, a pitch-adjusting assembly, a fan blade, and an actuator. The pitch-adjusting assembly includes a first element rotatable on a first axis and a second element rotatable on a second axis. The first element presents an elongated pitch pin. The second element defines an elongated pitch slot receiving the pitch pin. The fan blade is coupled to one of the elements for rotation therewith. The actuator is coupled to the other of the elements for rotation therewith. When the actuator rotates the element to which it is coupled, the element to which the fan blade is coupled is rotated via the pin/slot arrangement, thereby adjusting the pitch of the fan blade.
Claims39
A pitch adjusting assembly for varying the pitch of a fan blade coupled to a hub, said hub rotatable on a hub axis, said fan blade rotatable relative to the hub on a blade axis, said pitch adjusting assembly comprising:
- a first element rotatable on a first element axis and presenting an elongated pin;
- and
- a second element rotatable on a second element axis and defining an elongated slot,
- said pin movable about the first element axis and said slot movable about the second element axis,
- said element axes being at least substantially perpendicular to one another,
- said pin extending at least substantially parallel to one of the axes,
- said slot elongated at least substantially parallel to the other of the axes,
- said slot receiving the pin at a location offset from both of the axes.
A variable pitch fan blade assembly comprising:
- a rotatable hub;
- a pitch-adjusting assembly supported by the hub,
- said pitch adjusting assembly including a first element rotatable relative to the hub on a first axis and a second element rotatable relative to the hub on a second axis,
- said first element presenting an elongated pitch pin,
- said second element defining an elongated pitch slot for receiving the pitch pin so that rotation of one of the elements causes rotation of the other of the elements;
- said pin extending at least substantially parallel to one of the axes,
- said slot elongated at least substantially parallel to the other of the axes,
- a fan blade coupled to one of the elements;
- and
- an actuator coupled to the other of the elements,
- said actuator coupled to the hub for rotation therewith,
- said actuator at least partially rotatable relative to the hub on one of the first or second axes.
A variable pitch fan blade assembly comprising:
- a hub adapted for rotation on a hub axis, said hub having a housing and a pitch wheel disposed within the housing, said housing adapted to rotate on the hub axis, said pitch wheel adapted to rotate relative to the housing on a pitch wheel axis, said pitch wheel presenting an outer radial surface defining a slot;
- and
- a fan blade pivotally coupled to the hub, said fan blade adapted to rotate with the housing around the hub axis, said fan blade further adapted to rotate relative to the housing on a blade axis which is at least substantially perpendicular to the hub axis, said fan blade presenting a protruding pitch pin offset relative to the blade axis, said pitch pin extending at least substantially parallel to the blade axis, said pitch pin received in the slot in the pitch wheel,
- said fan blade being rotated on the blade axis when said pitch wheel is rotated relative to the housing, thereby adjusting the pitch of the fan blade.
A method of simultaneously varying the pitch of a plurality of fan blades using an actuator, said method comprising the steps of:
- (a) coupling a fan blade to a first element rotatable on a first axis;
- (b) coupling an actuator to a second element rotatable on a second axis;
- (c) inserting an elongated pin presented by one of the elements and extending at least substantially parallel to one of the axes into an elongated slot presented by the other of the elements;
- (d) positioning the first and second elements so that the first and second axes are at least substantially perpendicular to one another;
- and
- (e) actuating the actuator to rotate the second element and thereby cause rotation of the blade.
Dependencies are inferred from the claim text.