A method that includes monitoring a motor characteristic; and determining an actuator of a brake system has reached a retracted position after the motor characteristic has reached or exceeded a predetermined threshold.

An electric motor-driven brake apparatus has speed reduction mechanisms transmitting rotational force of an electric motor, a ball screw mechanism converting rotational force of the speed reduction mechanisms into a thrust, a piston propelled by the ball screw mechanism, and a caliper movably supporting the piston. The ball screw mechanism has a base nut non-rotatably supported relative to the caliper. The ball screw mechanism further has a push rod receiving rotational force from the speed reduction mechanisms. The push rod is movable relative to the base nut in the axial direction of the push rod. Consequently, it is possible to reduce the axial length of the cylinder portion of the caliper body, and hence possible to attain a size reduction. Accordingly, it is possible to improve the mountability of the electric motor-driven brake apparatus 1 onto vehicles.

An electromagnetic brake actuator for a vehicle. The actuator includes a motor, a casing defining an inner space containing the motor, and an electric connector leading to outside of the actuator. The actuator includes a duct in which an electric conductor is placed, which electrically connects the motor to the electric connector. The duct is configured to allow fluid to pass between the electric connector and the inner space, through the electric connector.

A rotary park lock mechanism includes a flange, a first spring, and a gear. The flange has a park pawl arranged to selectively engage a mating tooth in a transmission gear, and a locking bar pocket. The first spring is arranged to rotate the flange in a first rotational direction to engage the park pawl with the mating tooth. The gear is arranged receive a motor torque to rotate the flange in a second rotational direction, opposite the first direction, to disengage the park pawl from the mating tooth. In an example embodiment, the first spring is a clock spring. In an example embodiment, the gear is a cycloidal drive.

A brake device comprises a main braking caliper body, a brake pad part including a first brake pad and a second brake pad that are arranged at one side and another side of the main braking caliper body and have first surfaces facing each other, a main braking piston pressurizing second surfaces of the first brake pad and the second brake pad to shorten a distance between the first brake pad and the second brake pad, a parking caliper body coupled to the main braking caliper body and including a locking part caught by the second surface of the first brake pad and a parking piston installed on the parking caliper body and pressuring the second surface of the second brake pad, when the parking piston pressurizes the second brake pad, the locking part of the parking caliper body moves the first brake pad toward the second brake pad.

A brake system comprising: (a) a brake assembly including; (i) a caliper including: (1) two or more piston bores, (2) a piston located in each of the two or more piston bores, and (3) a spindle extending into each of the two or more piston bores, the spindle being rotationally movable to linearly move each of the pistons within the two or more piston bores to create a braking force; (ii) a motor gear unit in communication with each of the two or more piston bores and connected to each of the spindles extending into each of the two or more piston bores; wherein each of the spindles include threads that receive a plurality of rolling elements and when each of the spindles are rotated the two or more pistons located in each of the two or more piston bores are moved by the respective spindles to create a braking force or releasing a braking force.

An assembly that includes a parking brake system including two or more spindle/nut devices. The two or more spindle/nut devices include a high efficiency device and a low efficiency device. The high efficiency device is in communication with a first end of a brake pad, and the low efficiency device in communication with a second end of the brake pad. The high efficiency device moves the first end of the brake pad against a braking surface, and the low efficiency device moves the second end of the brake pad against the braking surface. After one or both of the ends of the brake pad are moved against the braking surface and a clamping force is created, the low efficiency device locks and prevents movement of the high efficiency device so that the clamping force is maintained.

An electromagnetic brake actuator for a vehicle. The actuator includes a motor, a casing defining an inner space containing the motor, and an electric connector leading to outside of the actuator. The actuator includes a duct in which an electric conductor is placed, which electrically connects the motor to the electric connector. The duct is configured to allow fluid to pass between the electric connector and the inner space, through the electric connector.

A ball ramp actuator assembly including a control ring, an activation ring including a first section and a second section, two circumferential plate grooves formed between the control ring and the sections of the activation ring which contain rolling elements, two clutches, a gear and an actuator. The first and second sections are splined together allowing for axial movement. The first clutch is connected to the first section of the activation ring and a second clutch is connected to the second section of the activation ring. The rotation of a section of the activation ring axially in one direction allows the corresponding plate groove to expand and apply a load to the corresponding clutch while the other section of the activation ring remains inactive and rotation in the opposite direction activates the other clutch respectively.

A brake system comprising: (a) a body assembly comprising: (i) an outboard side, (ii) an inboard side, (iii) a bridge extending between and connecting the inboard side and the outboard side, and (iv) two or more piston assemblies located entirely on the outboard side, entirely on the inboard side, or located both on the inboard side and the outboard side; and (b) an electric brake assembly comprising: (i) one or more differential assemblies in communication with the body assembly and each of the two or more piston assemblies; wherein the one or more differential assemblies provide power equally to each of the two or more piston assemblies so that each of the piston assemblies are moved axially in unison until a resistance of one of the two or more piston assemblies becomes higher than a remainder of the two or more piston assemblies and the one or more differential assemblies transfer power from the piston assembly with the higher resistance to the remainder of piston assemblies with a lower resistance so that the piston assembly with the higher resistance ceases to move and additional power is supplied to the remainder of the piston assemblies.