Electro-mechanical brake

1. An electro-mechanical brake (EMB) comprising:

a driving unit configured to generate rotational force by power selectively applied as a user operates a brake pedal;

a differential gear unit connected to the driving unit and including a first shaft and a second shaft disposed to be aligned to form rotational shafts and rotate in the same direction by rotational force from the driving unit;

a first pad disposed on one side of a brake disk;

a second pad disposed on the other side of the disk;

a first braking unit connected to the first shaft in one end thereof and connected to the first pad in the other end thereof and configured to enable the first pad to be brought into contact with one side of the disk according to a rotation of the first shaft to generate braking force; and

a second braking unit connected to the second shaft in one end thereof and connected to the second pad in the other end thereof and configured to enable the second pad to be brought into contact with the other side of the disk according to a rotation of the second shaft to generate braking force,

wherein the first braking unit moves in a first plane and the second braking unit moves in a second plane different from the first plane,

wherein the first braking unit is disposed in a direction parallel to the first shaft and varied in length in a length direction of the first shaft according to a rotation of the first shaft,

wherein the second braking unit is disposed in a direction parallel to the second shaft and varied in length in a length direction of the second shaft according to a rotation of the second shaft,

wherein the first braking unit, with a length increasing, moves the first pad in the direction toward the disk, and the second braking unit, with a length decreasing, moves the second pad in the direction toward the disk.

2. The electro-mechanical brake of claim 1 , wherein the driving unit is configured as a driving motor having a driving gear coupled to a rotational shaft.

3. The electro-mechanical brake of claim 2 , wherein the differential gear unit comprises:

a ring gear rotated in mesh with the driving gear;

a differential case coupled to one side of the ring gear and rotated together with the ring gear;

the first shaft penetrating through the differential case;

the second shaft penetrating through the ring gear and aligned with the first shaft;

a pair of side gears disposed to face each other and coupled to one end of the first shaft and the other end of the second shaft, respectively, within the differential case; and

a pair of differential pinions engaged with the pair of side gears perpendicularly and disposed to face each other within the differential case.

4. The electro-mechanical brake of claim 3 , further comprising a first driven gear coupled to one end of the second shaft.

5. The electro-mechanical brake of claim 3 , wherein when the driving motor rotates, the first shaft and the second shaft are rotated in the same direction according to rotations of the ring gear and the differential case.

6. The electro-mechanical brake of claim 1 , wherein the first braking unit comprises:

a first screw unit connected to the first shaft in one end thereof and having a thread formed on an outer circumferential surface of the other end thereof; and

a first nut unit screw-coupled to the first screw unit and connected to the first pad,

wherein the first pad coupled to the first nut unit linearly moves in a direction toward the disk according to a rotation of the first screw unit by the first shaft.

7. The electro-mechanical brake of claim 1 , wherein the second braking unit comprises:

a second driven gear engaged with the first driven gear coupled to the second shaft so as to be connected to the second shaft;

a second screw unit coupled to the second driven gear in one end thereof and having a thread formed on an outer circumferential surface of the other end thereof; and

a second nut unit screw-coupled to the second screw unit and connected to the second pad by a caliper,

wherein the second pad coupled to the second nut unit linearly moves in a direction toward the disk according to a rotation of the second screw unit by the second shaft.

8. The electro-mechanical brake of claim 1 , wherein the first pad and the second pad are simultaneously be brought into contact with the disk according to operations of the first braking unit and the second braking unit based on a rotation of the differential gear unit.

9. The electro-mechanical brake of claim 2 , wherein the first pad and the second pad are simultaneously be brought into contact with the disk according to operations of the first braking unit and the second braking unit based on a rotation of the differential gear unit.

10. The electro-mechanical brake of claim 1 , wherein the first pad and the second pad are simultaneously be brought into contact with the disk according to operations of the first braking unit and the second braking unit based on a rotation of the differential gear unit.

11. The electro-mechanical brake of claim 7 , wherein the threads of the first screw unit and the second screw unit are formed in the same direction.

12. The electro-mechanical brake of claim 7 , wherein a direction change gear is disposed between the first driven gear and the second driven gear, and the threads of the first screw unit and the second screw unit are formed in the opposite directions.