ELECTRIC PARKING BRAKE MOTOR GEAR UNIT

id041200300400


Purpose/Function

•  The electric parking brake motor unit operates the built-in motor to press out the disc pads using the torque increased by the gear reduction to maintain the rear disc plate in a clamped condition. When the electric parking brake is released, the motor rotates in the opposite direction.

Construction

•  The electric parking brake motor gear unit is located on the rear brake caliper.
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•  The electric parking brake motor gear unit is built into the motor and the planetary gear.
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Operation


When operating electric parking brake

1.  When motor operation current flows from the electric parking brake control module, the electric parking brake motor gear unit operates the built-in motor.

2.  The motor speed/torque is transmitted to the spindle by decelerating the speed using the built-in planetary gear and increasing the torque.

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3.  When the spindle rotates, the ball and ramp moves to the brake piston side and it contacts the brake piston.

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4.  The contacted ball and ramp moves the brake piston to the disc pad side and the brake piston is pressed against the disc pad.

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5.  The disc pads are pressed against the rear disc plate and the rear disc plate is held engaged.

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When releasing electric parking brake

1.  When motor operation current flows from the electric parking brake control module, the electric parking brake motor gear unit operates the built-in motor.

2.  The motor rotates in the opposite direction of the electric parking brake operation.

3.  The motor speed/torque is transmitted to the spindle by decelerating the speed using the built-in planetary gear and increasing the torque.

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4.  When the spindle rotates, the ball and ramp moves to the motor side and separates from the brake piston.

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5.  The brake piston separates from the disc pad by the piston seal force to release the engaged the rear disc plate.

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Fail-safe

•  Not applicable.