Electro-hydraulic actuator for a brake

Abstract

The present invention relates to an electro-hydraulic actuator (100) for actuating a brake caliper, in particular of a disc brake of a vehicle with two or more wheels, comprising:-an electric motor (1) with a drive shaft (2); —a transformation mechanism (3) connected to the drive shaft (2) to transform a rotary motion of the drive shaft (2) into a linear translatory motion along an axial direction (X-X) of a float (4) of a hydraulic pump or brake master cylinder of said brake to pressurize a brake fluid; —a first housing (5) configured to accommodate the transformation mechanism (3) and support a second housing (6) of the electric motor (1), said transformation mechanism (3) including: —a reduction unit (7) with at least one output interface (8) and configured to demultiply the rotary motion of the drive shaft (2) and transmit it to the at least one output interface (8), —a transformation unit (10) to convert the rotary motion of the at least one output interface (8) into a translatory motion of the float (4), the transformation unit (10) comprising a rotating member (11), which is connected to the at least one output interface (8) and a thrust member (12), which is linearly translatable, wherein the rotating member (11) is mechanically coupled to the thrust member (12) so as to transform a rotation of the rotating member (11) into a linear translation of the thrust member (12) which allows a displacement in the axial direction (X-X) of the float (4), wherein the transformation unit (10) has a central axis (A) parallel to or coincident with the axial direction (X-X), the transformation unit (10) comprises a thrust cap (42) integrally connected to the thrust member (12) so that it translates linearly and integrally with the thrust member (12) between a resting configuration and a thrust configuration, wherein the thrust cap (42) is configured to contact the float (4) and transfer a thrust action to the float (4), wherein the thrust cap (42) extends in a cantilevered manner from the thrust member (12) and forms a cap cavity (43) adapted to accommodate the rotating member (11), wherein the thrust cap (42) comprises a cap side wall (44) and a cap bottom wall (45), wherein the cap side wall (44) comprises an inner side cap surface (48) radially delimiting the cap cavity (43) facing the rotating member (11) without mechanical couplings, wherein the cap bottom wall (45) comprises an inner cap bottom surface (49) axially delimiting the cap cavity (43) facing a free end (46) of the rotating member (11), wherein the cap bottom wall (45) comprises an outer cap bottom surface (50) axially opposite to the inner cap bottom surface (49) and configured to contact the float (4) and transfer a thrust action to the float (4), wherein the inner cap bottom surface (49) is tapered along said central axis (A) towards the free end (46) of the rotating member (11) and/or a central free end surface (47) of said free end (46) is tapered along said central axis (A) towards the inner cap bottom surface (49) so that the inner cap bottom surface (49) and the free end (46) contact each other only partially and about the central axis (A), wherein in the resting configuration, the inner cap bottom surface (49) is in contact with the free end (46) defining a mechanical stop of the electro-hydraulic actuator (100), and wherein in the thrust configuration, the outer cap bottom surface (50) and the float (4) are in contact, transferring an axial force from the thrust member (12) to the float (4).

Dependencies are inferred from the claim text.