US 4,591,313 A · Propeller pitch control system and apparatus

Abstract

A plurality of propeller blades are mounted to an axially elongated tubular propeller hub (H1). Each blade is rotatable in position about a radial axis. An electromechanical linear actuator (A1) is housed within the hub for rotating the blades to change their pitch. The actuator includes a rod member (R1) fixed in position relative to the hub, a casing (C1) which can extend and retract relative to the rod member, a rotary electric motor (M1), and a planetary screw drive (SD1). The screw drive (SD1) drivingly interconnects the electric motor (M1) with the casing (C1) for causing the casing to move axially in response to operation of the motor. The actuator (A1) is connected to the propeller (P1) by a linkage (L1) so that movement of the casing causes the propellers to change their pitch. A second actuator (A2) may be housed within the hub (H1) and connected to the first actuator (A1) for providing redundancy in the event of failure of the first actuator.

Claims30

Dependent claims

An adjustable pitch propeller, comprising:

an axially elongated tubular hub having a center axis;
a plurality of propeller blades mounted on said hub, each for rotation in position about a radial axis;
an electromechanical linear actuator housed within said hub, said actuator having a longitudinal axis coinciding with the axis of the hub, said actuator including:
a rod member which is fixed in position relative to said hub, a casing which is extendible and retractable axially relative to said rod member, a rotary electric motor within said casing, said motor including a rotor, and, planetary screw drive transmission means within said casing drivingly interconnecting said rotor and said casing, for causing said casing to move axially relative to said rod member in response to operation of said motor;
mechanical drive means interconnecting said casing and said propellers, for causing the propellers to rotate in position in response to axial movement of said casing;
and
compression spring means for maintaining an axial loading on the planetary screw drive transmission means in an amount sufficient to prevent slippage within the planetary screw drive transmission.

4 more elements

An apparatus for adjusting the pitch of a propeller, the apparatus being housed within a propeller hub that rotates about a center axis, said apparatus comprising:

a generally cylindrical rod member;
a generally tubular cylindrical casing, closely surrounding said rod member in concentric relationship therewith, with an annular-shaped cylindrical space being defined between an inner surface of said casing and an outer surface of said rod member;
a planetary screw drive transmission means drivingly interconnecting said rod member and said casing, said planetary screw drive transmission means being positioned in said annular-shaped space;
and
an electric motor drive means drivingly connected to said planetary screw drive transmission means to cause said planetary screw drive transmission means to extend or retract said casing relative to said rod member, said motor drive means being positioned in said annular-shaped space, and wherein said rod member and casing are connected between said propeller and said hub so that extension or retraction of said casing relative to said rod member causes an adjustment in propeller pitch.

2 more elements

An electromechanical actuator connected between a support and a member to be moved relative to said support, said actuator comprising:

a generally cylindrical rod member;
a generally tubular cylindrical casing, closely surrounding said rod member in concentric relationship therewith, with an annular-shaped cylindrical space being defined between an inner surface of said casing and an outer surface of said rod member;
a planetary screw drive transmission means drivingly connecting said rod member and said casing, said planetary screw drive transmission means being positioned in said annular-shaped space;
an electric motor drive means drivingly connected to said planetary screw drive transmission means to cause said planetary screw drive transmission means to extend or retract said casing relative to said rod member, said motor drive means being positioned in said annular-shaped space, and wherein said rod member and casing are connected between said support and said member to be moved in a manner so that extension or retraction of said casing relative to said rod member causes movement of said member;
and
compression spring means for applying an axial loading on said planetary screw drive transmission means.

3 more elements

Dependencies are inferred from the claim text.

Propeller pitch control system and apparatus

Life of this patent

Propeller pitch control system and apparatus

Life of this patent

Abstract

Claims30