Brake actuator for aircraft wheel hydraulic brake

Patent metadata

Field	Value
Publication number	US-2016169309-A1
Application number	US-201514945660-A
Country	US
Kind code	A1
Filing date	Nov 19, 2015
Priority date	Dec 12, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

The invention relates to a brake actuator for an aircraft hydraulic brake, which is intended to be added into one of the cavities of a brake ring, the actuator comprising a liner ( 1 ) designed to be housed sealingly in the cavity of the ring, a piston ( 3 ) mounted to slide sealingly in the liner along an axis of sliding (X) so as to apply a braking force on friction pads when a fluid is introduced under pressure into the cavity, and having a determined operational travel, a wear compensation device ( 10 ) which defines a position to which the piston retreats into the liner by means of a mobile stop ( 11 ) that can be moved forward by the piston as a braking force is applied, and an elastic return member ( 16 ) returning the piston towards the retracted position bearing against the mobile stop. According to the invention, the mobile stop is reduced to a friction member rubbing against the liner, such that one of the faces of the friction member serves as a stop defining the retracted position of the piston, and the other of the faces serves as a support for the elastic return member, the elastic member having, when compressed, a sufficient increase in force in order to be able to push back the mobile stop in the event that the piston is not in contact with the friction pads while its operational travel is already exhausted.

First claim

1 . Brake actuator for an aircraft hydraulic brake, which is intended to be added into one of the cavities of a brake ring, the actuator comprising
a liner ( 1 ) designed to be housed sealingly in the cavity of the ring; a piston ( 3 ) mounted to slide sealingly in the liner along an axis of sliding (X) so as to apply a braking force on friction pads when a fluid is introduced under pressure into the cavity, and having a determined operational travel; a wear compensation device ( 10 ) which defines a position to which the piston retreats into the liner by means of a mobile stop ( 13 ) that can be moved forward by the piston as a braking force is applied; an elastic return member ( 16 ) returning the piston towards the retracted position bearing against the mobile stop;
characterized in that the mobile stop is reduced to a friction member ( 13 ) rubbing against the liner, such that one of the faces of the friction member serves as a stop defining the retracted position of the piston, and the other of the faces serves as a support for the elastic return member, the elastic member having, when compressed, a sufficient increase in force in order to be able to push back the mobile stop in the event that the piston is not in contact with the friction pads while its operational travel is already exhausted.

2 . Brake actuator according to claim 1 , in which the elastic member is a helical spring ( 16 ) whose coils meet during application of the braking force if an operational travel of the piston is exhausted before the latter touches the friction pads.

3 . Brake actuator according to claim 1 , in which the piston has a proximal end ( 4 ) that is closed and fluidtight.

Assignees

• Messier Bugatti Dowty

Inventors

• Robin Jean-Baptiste
• Lucienne Robin

Classifications

• B64C25/44

  Actuating mechanisms · CPC title

• F16D2125/06

  Pistons · CPC title

• F16D65/48

  with eccentric or helical body · CPC title

• F16D2121/02

  Fluid pressure · CPC title

• F16D65/44

  by means of direct linear adjustment · CPC title