GB778336A - Improvements in or relating to the cooling of brakes - Google Patents

Abstract

778,336. Cooling brakes; disc wheels. SOC. D'INVENTIONS AERONAUTIQUES ET MECANIQUES, S.I.A.M. May 23, 1955 [May 24, 1954], No. 14849/55. [Classes 103 (1) and 144 (1). In a cooling device for brakes, two annular chambers are mounted on a fixed portion of a wheel assembly, each chamber having at least one wall in a plane perpendicular to the axis of rotation of the wheel, one or more brake discs being mounted for rotational movement with the wheel so as to be capable of frictional engagement with one of the walls of each chamber, a substance of high calorific capacity in each of the chambers, and means to produce relative axial displacement between the two chambers and the brake disc or discs so as to apply or release the brake. In the embodiment illustrated in Fig. 1, a disc brake comprises a hollow annular chamber 7a rigidly secured to the non-rotatable wheel hub 6 and provided with a chromium plated friction surface 9a, a brake disc 3 carrying friction linings 4a, 4b which are either in the form of a continuous ring or in the form of a series of pads, and rotatable and axially moveable on splines with the wheel 1, and a second hollow annular chamber 7b which is permitted axial movement on fixed hub 6. The hollow annular chambers 7a and 7b are filled with liquids or metals having high specific heats such as sodium, bismuth, water or glycol &c. The brake is energised by means of a series of hydraulic actuator units 11, hydraulic pressure being supplied via conduit 14 in the fixed piston 12 of each actuator unit to supply fluid under pressure into chambers 16 to move the annular chamber 7b in the direction of the arrow f to bring the friction surface 9b of chamber 7b into frictional contact with friction lining 4b secured to brake disc 3 to move the brake disc into frictional contact with braking surface 9a on fixed chamber 7a. To prevent excessive pressures developing during braking action when water is used as the coolant, chambers 7a and 7b are not completely filled and any excess steam pressure may be released by relief valves 19a, 19b. Alternative arrangements are illustrated in Figs. 3 and 4 wherein in the case of the disc brake shown in Fig. 3 the brake disc is formed as the central web 21 of wheel 1 having friction linings 4a and 4b secured thereto and annular chambers 7a, 7b being forced inwardly in direction of arrows # when a plurality of opposed hydraulic actuator units are pressurized. In the construction illustrated in Fig. 4 the wheel is formed as a hollow body made up of two half shells 1a, 1b assembled together by means of bolts 23 and forming two discs 1a, 1b carrying friction linings 4a, 4b. When conduits 24, 25, 26a, 26b, are pressurized, annular chambers 7a and 7b are forced axially outwardly into frictional contact with friction linings 4a, 4b to effect braking of the wheel. Specification 652,436 is referred to.