ELECTRICALLY ACTUATABLE OPERATING UNIT FOR A MOTOR VEHICLE BRAKE, BRAKE BOOSTER HAVING SUCH AN ELECTRICALLY ACTUATABLE OPERATING UNIT, AND MOTOR VEHICLE BRAKE SYSTEM HAVING SUCH A BRAKE BOOSTER

An electrically actuatable operating unit (106) for a motor vehicle brake comprises a housing body (122) which is arranged so as to be displaceable in a braking direction for operation of the motor vehicle brake, a recess (150) formed in the housing body (122), wherein the recess (150) is delimited at one longitudinal end by a contact shoulder (172), a through-opening (158) delimited by the contact shoulder (172), an operating member (124) which is arranged in the recess (150) so as to be displaceable for operation of the motor vehicle brake and projects through the through-opening (158) of the contact shoulder (172), wherein the operating member (124) can be arranged in a force-transmitting manner between a brake pedal and the motor vehicle brake (400). The operating unit (106) further comprises a return spring (126) which is arranged in the recess (150) and is configured to move the operating member (124) relative to the housing body (122) away from the contact shoulder (172), and a sleeve element (180) which circumferentially surrounds a portion of the operating member (124) at least partially and is held in contact with the contact shoulder (172) by the return spring (126), and wherein the sleeve element (180) projects into the through-opening (158) in such a manner that it is arranged between the operating member (124) and an inner circumferential surface of the contact shoulder (172) that delimits the through-opening (158).