US 12,291,321 B2
Propeller blade pitch change actuation system
Thibaut Marger, Beduer (FR); and Romain Bouloc, Saint-Félix (FR)
Assigned to RATIER-FIGEAC SAS, Figeac (FR)
Filed by Ratier-Figeac SAS, Figeac (FR)
Filed on Nov. 16, 2022, as Appl. No. 17/988,325.
Claims priority of application No. 21290076 (EP), filed on Nov. 22, 2021.
Prior Publication US 2023/0159155 A1, May 25, 2023
Int. Cl. B64C 11/38 (2006.01); B64C 27/64 (2006.01)
CPC B64C 11/38 (2013.01) [B64C 27/64 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A pitch change actuation system for varying a propeller blade pitch, the pitch change actuation system comprising:
an actuator body defining an interior volume; and
a chamber separator located within the interior volume of the actuator body and dividing the interior volume into a first chamber and a second chamber, the two chambers being fluidly separated by the chamber separator;
wherein the first and second chambers are configured to receive hydraulic fluid;
wherein the actuator body is configured to translate relative to the chamber separator in response to a difference in hydraulic pressure between the first chamber and second chamber; and
wherein the translation of the actuator body is configured to effect a change in propeller blade pitch;
the pitch change actuation system further comprising:
a transfer tube, wherein the transfer tube is coupled to the actuator body; and
a shaft extending axially from the chamber separator and wherein the actuator body is configured to translate with respect to the shaft;
wherein the actuator body is slidably mounted on the shaft such that the actuator body may slidably translate along the shaft with respect to the chamber separator;
wherein a portion of the transfer tube is received within the actuator body;
wherein the transfer tube is configured to provide hydraulic fluid to the first and second chambers;
wherein the actuator body comprises a fluid passageway that extends from the transfer tube to the first or second chamber such that the transfer tube and the first or second chamber are in fluid communication.