An electromechanical actuator for use in a hydraulic braking circuit of a vehicle comprising: an electric motor having a stator and a rotor, and a linear actuator that is located within the motor, in which: the stator is located within a housing having a first end and a second end, the rotor is located inside the housing and comprises an elongate rotor body having a bore passing from one end of the rotor body to the other, the bore being enlarged over a first portion of the rotor body located towards the first end of the motor, and being of reduced size over a second portion of the rotor body located towards the second end of the motor, the linear actuator comprising an elongate shaft that is located within the bore in the rotor body, the shaft having a screw part at one end carrying an external thread that extends along a portion of the shaft that is located within the enlarged portion of the bore in the rotor body, and a fixing part at the other end of the shaft that is a tightly located into the bore of the second portion of the rotor body to prevent radial movement of the shaft relative to the rotor body, the linear actuator further comprising a drive nut that surrounds the screw part of the shaft and is located at least in a retracted position inside the enlarged bore of the first portion of the rotor body, the drive nut having an internal thread and being connected to the screw part through a set of balls that engage the threads (21, 22) of the drive nut and screw part, the rotor body being secured relative to the stator by a bearing assembly that is fixed to the second portion of the rotor body, the other end of the rotor body being otherwise unsupported and overhung from the bearing assembly, in which the bearing assembly has an annular inner race that is secured to the second portion of the rotor body, an annular outer race that is secured to the housing, and a plurality of bearings located between the inner race and the outer race, characterized in that the bearing assembly comprises a four point contact bearing and in that the elongate shaft has a tapered outer portion that engages a complementary tapered inner portion of the bore of the second portion of the rotor body. the stator is located within a housing having a first end and a second end, the rotor is located inside the housing and comprises an elongate rotor body having a bore passing from one end of the rotor body to the other, the bore being enlarged over a first portion of the rotor body located towards the first end of the motor, and being of reduced size over a second portion of the rotor body located towards the second end of the motor, the linear actuator comprising an elongate shaft that is located within the bore in the rotor body, the shaft having a screw part at one end carrying an external thread that extends along a portion of the shaft that is located within the enlarged portion of the bore in the rotor body, and a fixing part at the other end of the shaft that is a tightly located into the bore of the second portion of the rotor body to prevent radial movement of the shaft relative to the rotor body, the linear actuator further comprising a drive nut that surrounds the screw part of the shaft and is located at least in a retracted position inside the enlarged bore of the first portion of the rotor body, the drive nut having an internal thread and being connected to the screw part through a set of balls that engage the threads (21, 22) of the drive nut and screw part, the rotor body being secured relative to the stator by a bearing assembly that is fixed to the second portion of the rotor body, the other end of the rotor body being otherwise unsupported and overhung from the bearing assembly, in which the bearing assembly has an annular inner race that is secured to the second portion of the rotor body, an annular outer race that is secured to the housing, and a plurality of bearings located between the inner race and the outer race, characterized in that the bearing assembly comprises a four point contact bearing and in that the elongate shaft has a tapered outer portion that engages a complementary tapered inner portion of the bore of the second portion of the rotor body.