Electronic brake system, vehicle including the same, and method of operating the same

1 . An electronic brake system comprising:

a piston provided in a caliper housing to press a pad plate;

a nut coupled to an inside of the piston to move the piston forward or backward;

a spindle configured to move the nut forward or backward by rotation and including a stepped portion formed on an outer surface thereof;

a rotation limit unit connected to or disconnected from the spindle to allow or block the rotation of the spindle; and

a drive unit configured to move the rotation limit unit to a position at which the rotation of the spindle is allowed or blocked,

wherein the rotation limit unit includes

a body surrounding an outer circumferential surface of the spindle,

a binder provided on the body to come into close contact with or be separated from the stepped portion, and

a connector provided on the body and configured to receive a driving force from the drive unit, and

wherein the connector extends from the body and moves forward and backward along with the body by the driving force,

wherein the drive unit includes a worm gear having an inner side engaged with the connector and configured to rotate so as to move the connector forward and backward.

2 . The electronic brake system of claim 1 , wherein any one of the stepped portion and the binder includes at least one first protrusion, and the other of the stepped portion and the binder includes a first groove connected to the first protrusion.

3 . The electronic brake system of claim 2 , wherein the first groove is formed to be recessed in an axial direction of the spindle.

4 . The electronic brake system of claim 1 , wherein the caliper housing includes a supporter surrounding an outer circumferential surface of the body.

5 . The electronic brake system of claim 4 , wherein

the supporter includes a second groove formed to be recessed in an axial direction of the spindle, and

the body includes a second protrusion formed to protrude from a position corresponding to the second groove.

6 . An electronic brake system comprising:

a piston provided in a caliper housing to press a pad plate;

a nut configured to move the piston forward or backward;

a spindle configured to move the nut forward or backward by rotation and including a first groove formed to be recessed in an outer surface thereof;

a rotation limit unit including a first protrusion formed to protrude from a position corresponding to the first groove to allow or block the rotation of the spindle and fixedly inserted into the first groove; and

a drive unit configured to move the rotation limit unit forward or backward to a position at which the rotation of the spindle is allowed or blocked,

wherein the rotation limit unit includes a body surrounding an outer circumferential surface of the spindle and a connector connected to the drive unit and configured to receive a driving force from the drive unit, and

wherein the connector extends from the body and moves forward and backward along with the body by the driving force,

wherein the drive unit includes a worm gear having an inner side engaged with the connector and configured to rotate so as to move the connector forward and backward.

7 . The electronic brake system of claim 6 , wherein

the spindle includes a stepped portion including the first groove and provided on an outer surface of the spindle, and

the rotation limit unit further includes

a binder including the first protrusion and provided on the body to come into close contact with or be separated from the stepped portion.

8 . The electronic brake system of claim 7 , wherein the first groove is formed to be recessed in an axial direction of the spindle.

9 . An electronic brake system comprising:

a piston provided in a caliper housing to press a pad plate;

a nut configured to move the piston forward or backward;

a spindle configured to move the nut forward or backward by rotation and including a first groove formed to be recessed in an outer surface thereof;

a rotation limit unit including a first protrusion formed to protrude from a position corresponding to the first groove to allow or block the rotation of the spindle and fixedly inserted into the first groove; and

a drive unit configured to move the rotation limit unit forward or backward to a position at which the rotation of the spindle is allowed or blocked,

wherein the rotation limit unit includes a body surrounding an outer circumferential surface of the spindle and a connector connected to the drive unit and configured to receive a driving force from the drive unit, and

wherein the connector extends from the body and moves forward and backward along with the body by the driving force,

wherein the drive unit includes:

a motor configured to generate power; and

a reduction gear connected to a rotational shaft of the motor to transmit the driving force to the rotation limit unit, and

wherein the reduction gear includes:

a worm connected to the rotational shaft of the motor; and

a worm gear having an outer side connected to the worm and an inner side connected to the connector.

10 . The electronic brake system of claim 9 , wherein

the connector has a first screw thread formed on an outer circumferential surface thereof, and

the worm gear has a second screw thread engaged with the first screw thread formed at a position corresponding to the first screw thread.

11 . The electronic brake system of claim 9 , wherein the caliper housing includes an elastic member configured to elastically support the worm gear.

12 . The electronic brake system of claim 6 , wherein the nut has a hollow in a longitudinal direction and a first screw thread, which is screw-coupled to a second screw thread formed on the spindle in a certain section in the longitudinal direction, formed on an inner circumferential surface of the hollow.

13 . The electronic brake system of claim 7 , wherein the stepped portion is formed to extend radially from the outer circumferential surface of the spindle.

14 . The electronic brake system of claim 7 , wherein

the spindle includes a spindle body connected to a motor of an actuator, and

the body surrounds an outer circumferential surface of the spindle body so that the spindle body passes through the body.

15 . A method of operating an electronic brake system, the method comprising:

in a parking mode, transmitting, by an actuator, a first driving force to a spindle so that a nut presses a piston;

transmitting, by a drive unit, a second driving force to a rotation limit unit and bringing a binder into close contact with a stepped portion; and

upon releasing the parking mode, separating the binder from the stepped portion, and releasing a state in which the nut presses the piston,

wherein, in the bringing of the binder into close contact with the stepped portion, the second driving force of the drive unit is transmitted to the rotation limit unit through a connector and a worm gear of the drive unit, the connector being connected to the drive unit and moving forward and backward by the second driving force, and the worm gear having an inner side engaged with the connector and configured to rotate so as to move the connector forward and backward.

16 . The method of claim 15 , wherein:

in the bringing of the binder into close contact with the stepped portion, a first protrusion formed on a body is inserted into a first groove formed in the binder; and

in the separating of the binder from the stepped portion, the first protrusion is released from the first groove.

17 . The method of claim 15 , wherein:

in the bringing of the binder into close contact with the stepped portion, a second protrusion formed on a body is inserted into a second groove formed in a supporter to prevent rotation of the body; and

in the separating of the binder from the stepped portion, the second protrusion is moved in a release direction in the second groove.