Brake apparatus for vehicle
A brake apparatus for a vehicle may include: a drive unit configured to generate a rotational force in forward and reverse directions, a piston unit configured to be moved forward and backward in conjunction with the rotational force generated from the drive unit, a transfer gear unit configured to transfer the rotational force generated from the drive unit to the piston unit, a parking gear unit configured to be rotated together with the transfer gear unit, a locking unit arranged in a manner that faces the parking gear unit, fastened to the parking gear unit when braking for parking is performed, thereby limiting a rotation of the parking gear unit and an unlocking unit separating the parking gear unit and the locking unit from each other when the rotational force is generated in the reverse direction from the drive unit.
1 . A brake apparatus for a vehicle, comprising:
a drive unit configured to generate a rotational force in a first rotational direction or a second rotational direction opposite to the first rotational direction;
a piston unit configured to move forward or backward in response to receiving the rotational force from the drive unit;
a transfer gear unit configured to transfer, to the piston unit, the rotational force from the drive unit;
a parking gear unit configured to rotate along with the transfer gear unit, the parking gear unit including a parking protrusion;
a locking unit facing the parking gear unit and including a parking drive unit and a locking member, the parking drive unit being configured to move the locking member into engagement with the parking protrusions of the parking gear unit to limit a rotation of the parking gear unit; and
an unlocking unit configured to enable the locking member of the locking unit to be moved apart from the parking protrusion of the parking gear unit in response to the rotational force being generated in the second rotational direction from the drive unit,
wherein:
the parking drive unit is configured to slidably move in a direction parallel to the reciprocal axis of the locking rod, and
the unlocking unit is connected to the parking drive unit and configured to longitudinally expand or contract to selectively press the parking drive unit toward the parking gear unit.
2 . The brake apparatus of claim 1 , wherein:
the drive unit comprises a first output shaft, and
the parking gear unit comprises:
a parking gear body coupled to the first output shaft of the drive unit and configured to rotate in response to receiving the rotational force from the drive unit; and
a plurality of parking protrusions radially protruding from a circumferential surface of the parking gear body and spaced apart from each other.
3 . The brake apparatus of claim 2 , wherein the parking gear body and the first output shaft are coaxial.
4 . The brake apparatus of claim 2 , wherein the locking unit comprises:
a screw member configured to rotate in response to receiving the rotational force from the parking drive unit;
a locking rod configured to reciprocate along a reciprocal axis parallel to a rotational axis of the parking gear body in response to rotation of the screw member; and
wherein the locking member extends from the locking rod and is configured to selectively engage the parking protrusion in response to reciprocation of the locking rod.
5 . The brake apparatus of claim 4 , wherein the locking unit further comprises a stopper configured to selectively contact the locking rod to limit rotation of the locking rod.
6 . The brake apparatus of claim 1 , wherein, in response to receiving the rotational force in the second rotational direction from the drive unit, the unlocking unit is configured to contract and move the parking drive unit away from the parking gear unit.
7 . The brake apparatus of claim 1 , wherein the piston unit comprises:
a ball screw configured to rotate in response to rotating of the transfer gear unit;
a ball nut connected to the ball screw and configured to reciprocate along a rotational axis of the ball screw; and
one or more balls disposed between and in contact with the ball screw and the ball nut.