The invention relates to a disc brake, comprising a brake carrier, a brake caliper, brake shoes, and an actuating piston. The brake carrier has at least one mounting point for mounting on a vehicle. The actuating piston is displaceably accommodated on the brake caliper and is actuatable for carrying out a service brake function of the disc brake. At least one further actuating piston is provided, which in the direction of its longitudinal axis is displaceably accommodated on the brake caliper. For carrying out the service brake function, the at least two actuating pistons are actuatable, and for carrying out a parking brake function, one of the actuating pistons is actuatable. The invention further relates to a disc brake system and a parking brake system.

An electric motor-operated drive unit, in particular for a brake actuator of a motor vehicle, includes a rotor shaft rotatably mounted in a housing; and a rotor position sensor that includes a transmitter wheel arranged on the rotor shaft in a rotatably fixed manner and a sensor fixed to the housing and assigned to the transmitter wheel, where a front face of the transmitter wheel is positioned opposite, and with an axial clearance to, a housing wall section of the housing. The transmitter wheel and/or the housing wall section are/is designed in such a way that the axial clearance increases radially outward, at least in some areas.

Provided is an electric brake device including one caliper including at least two electric mechanisms each configured to apply a braking force to a vehicle and to maintain the braking force. The at least two electric mechanisms are to be driven by one drive circuit output, that is, one output from one drive circuit. In this manner, for example, even when it is required to control a large number of electric mechanisms as in a case in which the electric brake device is applied to a twin-bore caliper, the number of drive circuits for driving the electric mechanisms can be reduced, thereby being capable of reducing cost.

Disclosed is an actuator for a parking brake. In accordance with an aspect of the disclosure an actuator for a parking brake includes a motor generating power; a reduction gear portion configured to transmit the power of the motor to a parking portion implementing the parking braking of a vehicle; a locking portion configured to limit rotation of the reduction gear portion; and a housing in which the motor, the reduction gear portion, and the locking portion are accommodated; wherein the locking portion is configured to a lock gear coupled to the reduction gear portion to rotate together, a lever provided to be engaged with the lock gear through a hinge motion, an elastic member elastically supporting the lever toward the lock gear, and an electromagnet member that generates electromagnetic force when the power is applied to separate the lever from the lock gear.

Disclosed is an actuator for a parking brake. In accordance with an aspect of the disclosure an actuator for a parking brake includes a motor generating power; a reduction gear portion including a driving gear rotating in association with a drive shaft of the motor, and a sun gear coupled to the drive gear to rotate together; a housing in which the motor and the reduction gear portion are accommodated; and a locking portion configured to limit rotation of the reduction gear portion; wherein the locking portion is further configured to a pair of locking members configured to restrain and release at least a part of a rotation shaft of the sun gear, a plurality of elastic members supporting each of the locking members in a direction of the rotation shaft of the sun gear, an electromagnet member configured to separate the pair of locking members from the sun gear by generating an electromagnetic force when the power is applied.

The present disclosure relates to an electronic parking brake system including a motor actuator operated by an electric motor, wherein the electronic parking brake system further includes a motor driving circuit provided to drive the electric motor, and a controller configured to determine a temperature of the electric motor from a temperature of a brake disc during a parking operation, determine a target current based on the determined motor temperature, and control the electric motor depending on the determined target current.

An electromagnetic brake device presses a pressing plate against a brake rotor along an axis via a friction material by the electromagnetic force of an electromagnetic actuator. The electromagnetic brake device includes a support member that is disposed on the opposite side of the pressing plate to the brake rotor and that is supported by a housing so as to be displaceable along the axis and non-rotatable around the axis, and a shaft member that transmits a force in the direction along the axis between the pressing plate and the support member. An electromagnetic coil and an armature of the electromagnetic actuator are spaced apart from the pressing plate between the pressing plate and the support member, the electromagnetic coil is supported by the housing, and the armature is supported by the support member.

Disclosed is an actuator for a parking brake. In accordance with an aspect of the disclosure an actuator for a parking brake includes a motor generating power; a reduction gear portion configured to transmit the power of the motor to a parking portion implementing a parking braking of a vehicle; a housing in which the motor and the reduction gear portion are accommodated; a housing cover for closing the housing; and a locking portion configured to limit rotation of the reduction gear portion; wherein the locking portion is configured to a locking member that is provided to be movable in an axial direction of the reduction gear portion and is close contact with or spaced apart from the reduction gear portion, an elastic member elastically supporting the locking member toward the reduction gear portion, an electromagnet member configured to separate the locking member from the reduction gear portion by generating an electromagnetic force when the power is applied.

A motor gear unit for a disc brake apparatus is provided. A speed reduction mechanism is connected to a first connection portion of a motor shaft of an electric motor. A non-excited operation type brake is connected to a second connection portion of the motor shaft.

In a state where the disc brake apparatus is attached to a vehicle body, the motor shaft is disposed so as to be orientated in an upper-lower direction, and the non-excited operation type brake is disposed above the electric motor.

A method for actuating a parking brake system of a vehicle with at least three brake calipers associated with one or more axles of the vehicle is described. The method may include the following steps: providing at least one detection device for detecting the vehicle status, acquiring a value of the vehicle status with the detection device, comparing the detected value with a reference value of the vehicle status, and actuating two brake calipers of the at least three brake calipers if the detected value is lower than the reference value or actuating all the at least three brake calipers if the detected value is equal to or greater than the reference value.