Actuating mechanism and brake assembly

An actuating mechanism, comprising a screw actuator having a screw and a nut threadably coupled together, an electric drive for driving one of said screw and said nut axially relative to the other and comprising a stator and a rotor, a sleeve assembly including a generally cylindrical sleeve interposed between said rotor and said nut and supporting said rotor for rotation relative to said sleeve, said rotor being connected to one of said screw or said nut for rotating said screw or said nut, said screw actuator being at least partly mounted within said sleeve and being arranged to bear against a portion of said sleeve assembly to transmit axial thrust to said sleeve assembly, and by that transmission, to place said sleeve in tension, and said sleeve assembly cooperating with an abutment to transmit the axial thrust to said abutment, wherein said rotor is connected to said screw or said nut by a gear mechanism, wherein said gear mechanism is a reduction gear mechanism which facilitates a reduction in the speed of rotation between said rotor and said screw or said nut, wherein said gear mechanism comprises a transmission member which extends from one axial end of said rotor, so that said transmission member rotates with said rotor, said transmission member being configured to extend about a first end of said sleeve, and to extend to within said sleeve, to form or support an input gear of said mechanism, said input gear being rotatable with said transmission member, said gear mechanism further comprises a stationary gear provided on the radially inner surface of said sleeve in a region of said first end of said sleeve, so that said stationary gear is fixed against rotation relative to said sleeve, and a plurality of planet gears are disposed between and in toothed engagement with each of said input and said stationary gears, said input gear being rotatable relative to said stationary gear, said gear mechanism further including an output gear which is in toothed engagement with said planetary gears, said output gear being rotatable relative to said stationary gear at a reduction compared to said input gear, said output gear being in fixed connection with said screw or said nut so that rotation of said output gear causes rotation of said screw or said nut.

An actuating mechanism, comprising a screw actuator having a screw and a nut threadably coupled together, an electric drive for driving one of said screw and said nut axially relative to the other and comprising a stator and a rotor, a sleeve assembly including a generally cylindrical sleeve interposed between said rotor and said nut and supporting said rotor for rotation relative to said sleeve, said rotor being connected to one of said screw or said nut for rotating said screw or said nut, said screw actuator being at least partly mounted within said sleeve and being arranged to bear against a portion of said sleeve assembly to transmit axial thrust to said sleeve assembly, and by that transmission, to place said sleeve in tension, and said sleeve assembly cooperating with an abutment to transmit the axial thrust to said abutment, wherein said rotor is connected to said screw or said nut by a gear mechanism, wherein said gear mechanism comprises an input gear, an output gear, planet gears disposed between and in meshing engagement with said input and output gears, and a stationary gear which is fixed against rotation and which is in meshing engagement with said planet gears, said rotor being arranged to drive said input gear, said input gear being arranged to drive said output gear through said planet gears, said output gear being operable to drive said screw or said nut, and wherein said rotor extends axially over said gear mechanism and radially into engagement with said input gear.

A disc brake caliper including a housing having a bridge section which in use, bridges a disc brake rotor, a finger section depending from a distal end of said bridge section, generally perpendicularly therefrom and arranged to support a first brake pad in facing relationship with said disc brake rotor, said housing defining a cavity within which an actuating mechanism is disposed, and which is operable to displace a second brake pad into engagement with an opposite face of said rotor, said actuating mechanism including a screw actuator having a screw and a nut threadably coupled together, an electric drive for driving one of said screw and said nut axially relative to the other and including a stator and a rotor, said stator being fixed to the housing, a sleeve assembly including a generally cylindrical sleeve interposed between said rotor and said nut and supporting said rotor for rotation relative to said sleeve, said rotor being connected to one of said screw or said nut for rotating said screw or said nut, said screw actuator being at least partly mounted within said sleeve and being arranged to bear against a portion of said sleeve assembly to transmit axial thrust to said sleeve assembly, and by that transmission, to place said sleeve in tension, and said sleeve assembly cooperating with an abutment of said housing to transmit the axial thrust to said abutment, wherein said abutment of said housing is a flange which extends radially inwardly into said cavity and a pair of projections extend from said sleeve radially outwardly to engage said housing flange on each of axially opposite sides thereof, to fix said sleeve relative to said housing, a further projection extends from said sleeve radially inwardly for engagement with said screw actuator for transmission of axial thrust to said sleeve assembly, said axial thrust being transmitted to said abutment through one of said pair of projections.