Brake device
A brake device includes a brake pad, a pad propulsion part connected to the brake pad and configured to move the brake pad linearly, and a caliper body including a cylinder part on which the pad propulsion parti is accommodated. The pad propulsion part includes a conversion assembly converting rotation motion into linear motion, and a piston connected to one end of the conversion assembly, the conversion assembly is accommodated inside the cylinder part, and the piston is located outside the cylinder part.
1 . A brake device comprising:
a brake pad;
a pad propulsion part connected to the brake pad and configured to move the brake pad linearly; and
a caliper body including a cylinder part on which the pad propulsion part is accommodated,
wherein the pad propulsion part includes:
a conversion assembly converting rotation motion into linear motion; and
a piston connected to one end of the conversion assembly,
the conversion assembly is accommodated inside the cylinder part, the piston is entirely located outside the cylinder part,
one end of a moving nut is inserted into an inside of the piston and includes a first groove disposed along a circumference of the moving nut,
the piston includes a second groove at a position corresponding to the first groove on an inner surface of the piston, and
the brake device further includes a seal part having a ring shape located in a space provided by the first groove and the second groove.
2 . The brake device of claim 1 , wherein the conversion assembly includes:
a bolt screw rotating around an axis; and
the moving nut coupled to a helix of the bolt screw,
wherein the moving nut moves in a direction of the cylinder part by rotation of the bolt screw.
3 . The brake device of claim 2 , wherein a diameter of a cross section of the piston is greater than a diameter of a cross section of the cylinder part.
4 . The brake device of claim 2 , wherein a surface of the one end of the moving nut and the inner surface of the piston are spaced apart from each other by a predetermine distance.
5 . The brake device of claim 4 , wherein the predetermined distance is equal to or less than 2 mm.
6 . The brake device of claim 2 , wherein:
the cylinder part includes a third groove provided along an edge of a space;
the moving nut includes a fourth groove provided along a circumference of an outer circumferential surf ace of the moving nut;
the brake device further includes a boot sealing a space between an outer surface of the moving nut and an edge of the cylinder part from an outside; and
the boot is fixed by the third groove and the fourth groove.
7 . The brake device of claim 6 , wherein:
a cross section of the seal part is a rectangle; and
the first groove and the second groove have a shape corresponding to the cross section of the seal part.
8 . The brake device of claim 6 , wherein:
a cross section of the seal part is a circle; and
the first groove and the second groove have a shape corresponding to the cross section of the seal part.
9 . The brake device of claim 2 , wherein:
the piston is provided in plurality;
the moving nut has a portion located inside the cylinder part and includes connection parts inserted into and connected to the pistons; and
the connection parts are located outside the cylinder part.
10 . The brake device of claim 9 , wherein:
the connection parts include first grooves disposed along a circumference of the connection parts;
the pistons include second grooves at positions corresponding to the first grooves on respective inner surfaces of the pistons; and
the brake device further includes a plurality of seal parts located in a space provided by the first grooves and the second grooves.
11 . The brake device of claim 10 , wherein surfaces of the connection parts and inner surfaces of the pistons are spaced apart from each other by a predetermined distance.
12 . The brake device of claim 11 , wherein the predetermined distance is equal to or less than 2 mm.