Electro-mechanical brake

1 . An electro-mechanical brake provided with a pair of brake pads disposed at both sides of a disc, the electro-mechanical brake comprising:

a driving motor;

a first rotating part assembled with a rotating shaft of the driving motor;

a second rotating part driven while connected to the first rotating part through a driving transmission member;

a nut driving part rotationally driven while connected to the second rotating part so that power is directly or indirectly transmitted to the second rotating part; and

a screw driving part which is installed inside and engaged with the nut driving part and driven forward or backward according to a rotation direction of the nut driving part so that a piston pushes the brake pads to come into close contact with the disc through a member,

wherein one end of the screw driving part is assembled with the member,

the other end of the screw driving part passes through the driving transmission member and is disposed between the first rotating part and the second rotating part to move forward or backward,

a driving gear is fixedly installed on an outer surface of the nut driving part or the screw driving part, and

a pinion to be engaged with the driving gear is installed on a lower portion of the second rotating part,

wherein a bearing member, including a thrust bearing and a radial bearing, is disposed on the outer surface of the nut driving part to reduce rotational friction with a body of a housing,

wherein a jaw portion is formed on the body of the housing,

wherein, when a vertical toward the piston is defined as a lower direction and a direction opposite to the lower direction is defined as an upper direction:

the nut driving part includes a thrust bearing lower member integrally formed with and radially protruding from the nut driving part, and

the thrust bearing includes a thrust bearing upper member and a plurality of thrust bearing rollers arranged between the thrust bearing upper member and the thrust bearing lower member,

an upper surface of the thrust bearing upper member being fixedly in contact with a lower surface of the jaw portion of the body of the housing.

2 . An electro-mechanical brake provided with a pair of brake pads disposed at both sides of a disc, the electro-mechanical brake comprising:

a driving motor;

a first rotating part assembled with a rotating shaft of the driving motor;

a second rotating part driven while connected to the first rotating part through a driving transmission member;

a screw driving part disposed radially inside the nut driving part and rotationally driven while being connected to the second rotating part so that power is transmitted to the second rotating part; and

a nut driving part surrounding the screw driving part, installed outside and engaged with the screw driving part so as to move forward or backward without rotation according to a rotation direction of the screw driving part so that a piston pushes the brake pads to come into close contact with the disc,

wherein one end of the nut driving part is assembled with the piston,

the other end of the nut driving part passes through the driving transmission member and is disposed between the first rotating part and the second rotating part to move forward or backward,

a driving gear is fixedly installed on an outer surface of the nut driving part or the screw driving part, and

a pinion engaged with the driving gear is fixedly installed on a lower portion of the second rotating part.

3 . The electro-mechanical brake of claim 1 , wherein the first rotating part and the second rotating part are positioned coplanar with each other.

4 . The electro-mechanical brake of claim 1 , wherein a diameter of the first rotating part is smaller than a diameter of the second rotating part.

5 . The electro-mechanical brake of claim 3 , wherein the driving transmission member connecting the first rotating part and the second rotating part includes a belt or chain.

6 . The electro-mechanical brake of claim 1 , wherein a diameter of the driving gear is greater than or equal to a diameter of the second rotating part.

7 . The electro-mechanical brake of claim 1 , further comprising a tensioner which provides a tension to the driving transmission member.

8 . The electro-mechanical brake of claim 1 , wherein each of the nut driving part and the screw driving part includes a ball nut and a ball screw.

9 . The electro-mechanical brake of claim 1 , wherein the driving motor is driven according to an electrical signal generated by a brake pedal.

10 . The electro-mechanical brake of claim 1 ,

wherein the nut driving part includes a radial bearing inner ring integrally formed with and radially protruding from the nut driving part,

the radial bearing includes a radial bearing outer ring and a plurality of radial bearing rollers arranged between the radial bearing inner ring and the radial bearing outer ring,

an outer circumferential surface of the radial bearing outer ring being fixedly in contact with an inner surface of the jaw portion of the body of the housing;

the thrust bearing lower member being disposed upper side than the radial bearing inner ring.

11 . The electro-mechanical brake of claim 10 , wherein the thrust bearing lower member is disposed vertically adjacent to and directly above the radial bearing inner ring with a gap therebetween.

12 . The electro-mechanical brake of claim 11 ,

wherein a protruding length of the thrust bearing lower member from the nut driving part is greater than a protruding length of the radial bearing inner ring from the nut driving part.

13 . The electro-mechanical brake of claim 1 ,

wherein the pinion is engaged with the driving gear with a tooth connection without a belt connecting the pinion and the driving gear.

14 . An electro-mechanical brake provided with a pair of brake pads disposed at both sides of a disc, the electro-mechanical brake comprising:

a driving motor;

a first rotating part assembled with a rotating shaft of the driving motor;

a second rotating part driven while connected to the first rotating part through a driving transmission member;

a nut driving part rotationally driven while connected to the second rotating part so that power is transmitted to the second rotating part; and

a screw driving part installed inside and engaged with the nut driving part and driven forward or backward according to a rotation direction of the nut driving part so that a piston pushes the brake pads to come into close contact with the disc,

wherein one end of the screw driving part is assembled with the piston,

the other end of the screw driving part passes through the driving transmission member and is disposed between the first rotating part and the second rotating part to move forward or backward,

a printed circuit board (PCB) is disposed parallel to the driving transmission member, and

a through hole through which the screw driving part or the nut driving part passes is formed in the PCB,

wherein a bearing member, including a thrust bearing and a radial bearing, is disposed on an outer surface of the nut driving part to reduce rotational friction with a body of a housing,

wherein a jaw portion is formed on the body of the housing,

wherein, when a vertical toward the piston is defined as a lower direction and a direction opposite to the lower direction is defined as an upper direction:

the nut driving part includes a thrust bearing lower member integrally formed with and radially protruding from the nut driving part, and

the thrust bearing includes a thrust bearing upper member and a plurality of thrust bearing rollers arranged between the thrust bearing upper member and the thrust bearing lower member,

an upper surface of the thrust bearing upper member being fixedly in contact with a lower surface of the jaw portion of the body of the housing.

15 . The electro-mechanical brake of claim 14 , wherein the first rotating part and the second rotating part are positioned coplanar with each other.

16 . The electro-mechanical brake of claim 14 , wherein a diameter of the first rotating part is smaller than a diameter of the second rotating part.

17 . The electro-mechanical brake of claim 14 , further comprising a tensioner which provides a tension to the driving transmission member.

18 . An electro-mechanical brake provided with a pair of brake pads disposed at both sides of a disc, the electro-mechanical brake comprising:

a driving motor;

a first rotating part assembled with a rotating shaft of the driving motor;

a second rotating part driven while connected to the first rotating part through a driving transmission member;

a screw driving part disposed radially inside the nut driving part and rotationally driven while being connected to the second rotating part so that power is transmitted to the second rotating part; and

a nut driving part surrounding the screw driving part installed outside and engaged with the screw driving part and driven-so as to move forward or backward without rotation according to a rotation direction of the screw driving part so that the piston pushes the brake pads to come into close contact with the disc,

wherein one end of the nut driving part is assembled with the piston,

the other and of the nut driving part passes through the driving transmission member and is disposed between the first rotating part and the second rotating part to move forward or backward,

a printed circuit board (PCB) is disposed parallel to the driving transmission member, and

a through hole through which the screw driving part or the nut driving part passes is formed in the PCB.