Electro-mechanical brake system and method for operating same
Provided is an electro-mechanical brake system and a method of operating the same including: a pair of pad plates disposed on both sides of a disk rotating together with a wheel; a piston configured to allow the pad plates to come in close contact with or to be separated from the disk; a first motor and a second motor configured to operate independently from each other and provide the piston with power; a first gear configured to decelerate power of the first motor and transmit the decelerated power; a second gear configured to convert power of the second motor into a translational motion and apply pressure to or release pressure on the piston while in contact with the piston, the second gear including a guide part slantly formed on a portion that comes in contact with the piston; and a connecting part connecting the first gear and the second gear to each other to allow the first gear and the second gear to rotate together with each other, the connecting part configured to couple the first gear and the second gear such that the second gear is slidable with respect to the first gear.
1. An electro-mechanical brake system comprising:
a pair of pad plates disposed on both sides of a disk rotating together with a wheel;
a piston configured to allow the pad plates to come in close contact with or to be separated from the disk;
a first motor and a second motor configured to operate independently from each other and provide the piston with power;
a first gear configured to decelerate power of the first motor and transmit the decelerated power;
a second gear configured to convert power of the second motor into a translational motion and apply pressure to or release pressure on the piston while in contact with the piston, the second gear including a guide part slantly formed on a portion of the second gear that comes in contact with the piston; and
a connecting part connecting the first gear and the second gear to each other to allow the first gear and the second gear to rotate together with each other, the connecting part configured to couple the first gear and the second gear such that the second gear is slidable with respect to the first gear.
2. The electro-mechanical brake system of claim 1 , wherein the connecting part includes a plurality of connection holes passing through an upper side and a lower side of the first gear and a plurality of connection pins provided to be slidably coupled to the plurality of connection holes.
3. The electro-mechanical brake system of claim 1 , wherein the guide part includes a first surface protruding forward with a slope such that a force to press the piston is gradually increased during a rotation of the second gear and a second surface obliquely depressed rearward such that the force, passing through the first surface, to press the piston is released.
4. The electro-mechanical brake system of claim 1 , further comprising a belt part configured to transmit power output through a drive shaft of the first motor to the first gear.
5. The electro-mechanical brake system of claim 1 , wherein the second gear is provided with a nut part that allows the second gear to move forward and backward according to a rotation of a spindle for outputting power of the second motor.
6. The electro-mechanical brake system of claim 3 , wherein a plurality of the guide parts are consecutively provided along a circumferential direction on a front surface of the second gear.
7. The electro-mechanical brake system of claim 6 , wherein the guide part is provided to come in contact with a rear portion of the piston.
8. The electro-mechanical brake system of claim 7 , wherein the piston includes a rotating ball supported at the rear end thereof to enable free rotation.
9. The electro-mechanical brake system of claim 5 , wherein the nut part is formed in a hollow cylinder shape and connected to the second motor by passing through the first gear.
10. The electro-mechanical brake system of claim 1 , further comprising a control part configured to detect whether the first motor and the second motor operate, and control the operation of the first motor and the second motor.
11. A method of operating the electro-mechanical brake system of claim 10 , wherein the guide part is provided as a plurality of guide parts consecutively provided along a circumferential direction of the second gear, and by the first gear and the second gear rotating together with each other according to operation of the first motor, repeatedly applies pressure to and releases pressure on the piston.
12. The method of claim 11 , wherein the second gear is configured to, when the second motor rotates in one direction, slidably advance to press the piston, and when the second motor rotates in an opposite direction, slidably retreat to release the pressure of the piston.
13. The method of claim 12 , wherein in a first mode to implement an anti-lock brake system (ABS), the control part is configured to control to drive the first motor while the second motor is prevented from being driven.
14. The method of claim 12 , wherein in a second mode to stop a vehicle, the controller is configured to control to rotate the second motor in the one direction.
15. The method of claim 12 , wherein in a third mode to implement an emergency braking, the control part is configured to control the first motor to drive in a direction that the piston is pressed by the guide part and control the second motor to rotate in the one direction.