CN215110198U - Improved drum brake structure - Google Patents

Abstract

The invention provides an improved drum brake structure which comprises the following components: a pair of brake shoes are arranged in a drum brake shell, one end of each brake shoe is rotatably positioned in the shell, a kidney-shaped columnar brake gear driven to rotate by a brake rocker arm assembly is arranged between end gaps at the other end of each brake shoe, roller gears are respectively meshed between the kidney-shaped columnar brake gear and the end faces of the brake shoes at two sides, rotating shafts of the roller gears are arranged in kidney-shaped holes of a connecting piece and can rotate and move in the kidney-shaped holes, and the connecting piece is riveted on the pair of brake shoes by rivets. When the brake rocker arm assembly drives the kidney-shaped columnar brake gear to rotate, the kidney-shaped columnar brake gear drives the two rollers to rotate and move, and then drives the pair of brake shoes to form opening and closing movement, so that the brake device has a brake function. The abutting surface of the brake shoe abutting against the roller gear is a combination of an outward convex tooth-shaped surface and an inward concave arc surface, the outward convex tooth-shaped surface is used for being meshed with the roller gear, and the inward concave arc surface is used for being in rolling contact with the roller gear.

Description

Improved drum brake structure

Technical Field

The invention belongs to the technical field of brake devices of motorcycles and electric vehicles.

Background

Drum brakes have been used for almost a century as brake components in motorcycles and electric vehicles, and generally comprise a housing, a pair of brake shoes, a brake cam, a brake rocker arm, an elastic reset element and the like. When braking, the brake rocker arm drives the brake cam to rotate, and the brake cam forces the brake shoe to expand and contact with the shell to generate friction so as to realize braking. After braking is finished, the brake shoe is pulled back to the original position by the elastic reset element. In the braking process, except abrasion between the brake shoe and the shell, abrasion can be generated between the brake cam and the brake shoe, the abrasion is always concentrated on a plurality of points or surfaces of the brake cam, the service life of the brake cam is greatly shortened, and in addition, the existing drum brake has the defects of small braking moment, poor braking effect and large vehicle braking sliding distance. The present invention aims to improve it.

Disclosure of Invention

The invention aims to provide an improved drum brake structure, which changes the working mode that the original drum brake adopts a cam to directly drive a brake shoe to expand, and effectively overcomes the defects of poor braking effect, large vehicle braking sliding distance and easy abrasion of a brake cam of the existing drum brake. In order to solve the problems, the invention adopts the following technical scheme: the utility model provides a drum improves structure of stopping, includes shell 1, locates a pair of brake shoes 2 in the shell 1, connects elasticity resetting element 3, brake rocker arm subassembly 4, roller gear 5, connection piece 6, rivet 7 between this pair of brake shoes 2, the one end of a pair of brake shoes 2 rotates the location in shell 1, its characterized in that: the brake rocker arm component 4 is provided with a kidney-shaped columnar brake gear 41, two sides of the kidney-shaped columnar brake gear 41 are respectively meshed with a roller gear 5, the roller gears 5 are respectively abutted with a brake shoe 2, the side surfaces of a pair of brake shoes 2 close to the kidney-shaped columnar brake gear 41 are provided with concave pits 21 for mounting a connecting sheet 6, a kidney-shaped hole 62 is arranged on the connecting piece 6, the shaft 51 of the roller gear 5 is arranged in the kidney-shaped hole 62 and can rotate and move in the kidney-shaped hole 62, a round hole 61 is also arranged on the connecting piece 6, a rivet 7 is inserted into the round hole 61 to rivet the connecting piece 6 in the concave 21 of the pair of brake shoes 2, when the brake rocker arm component 4 drives the kidney-shaped columnar brake gear 41 to rotate, and then the two roller gears 5 are driven to rotate and move, and the roller gears 5 drive the pair of brake shoes 2 to form opening and closing movement, so that the brake function is achieved. Furthermore, the contact surface of the brake shoe 2 contacting the roller gear 5 is composed of an outer convex tooth-shaped surface 22 and an inner concave arc surface 23, wherein the radius of the inner concave arc surface 23 is equal to and tangent to the root circle radius of the outer convex tooth-shaped surface 22, the outer convex tooth-shaped surface 22 is used for meshing with the roller gear 5, and the inner concave arc surface 23 is used for rolling contact with the roller gear 5.

Drawings

Fig. 1 and fig. 2 are schematic structural diagrams of the present invention, in which fig. 1 is a housing, fig. 2 is a pair of brake shoes, fig. 3 is an elastic reset element, fig. 4 is a brake rocker arm assembly, fig. 5 is a roller gear, fig. 6 is a connecting sheet, fig. 7 is a rivet, fig. 21 is a pit for installing the connecting sheet on the brake shoes, fig. 22 is a convex tooth-shaped surface meshed with the roller gear on the brake shoes, fig. 23 is a concave arc surface in rolling contact with the roller gear on the brake shoes, and fig. 41 is a part of the brake rocker arm assembly: the waist-shaped columnar brake gear 51 is a rotating shaft of the roller gear, 61 is a mounting round hole of the connecting piece, and 62 is a waist-shaped hole of the connecting piece.

The specific implementation mode is as follows:

the technical solution of the present invention will be described more fully below with reference to the following embodiments of the present invention, but the described embodiments are only a part of the present invention, that is, the present invention includes, but is not limited to, the embodiments. The following description of the exemplary embodiment(s) is merely illustrative and is not intended to limit the invention, its application, or uses. All other similar embodiments obtained by a person skilled in the art without making creative efforts based on the embodiments in the present application do not belong to the new inventions outside the present invention.

Examples

As shown in fig. 1 and 2, a pair of brake shoes 2 are mounted in a housing 1, an elastic reset element 3 is connected between the brake shoes 2, one end of each brake shoe 2 is rotatably positioned in the housing 1, a kidney-shaped columnar brake gear 41 driven by a brake rocker arm assembly 4 is arranged between end gaps of the other end of each brake shoe 2, a roller gear 5 is respectively engaged between the kidney-shaped columnar brake gear 41 and the end surfaces of the brake shoes 2 on two sides, a connecting piece 6 is fixedly connected in a pit 21 of each brake shoe 2 by a rivet 7, and a shaft 51 of the roller gear 5 is mounted in a kidney-shaped hole 62 of the connecting piece 6 and can rotate and move in the kidney-shaped hole. When the brake rocker arm assembly 4 drives the kidney-shaped columnar brake gear 41 to rotate, the kidney-shaped columnar brake gear 41 drives the two roller gears 5 to rotate and move, and the roller gears 5 drive the pair of brake shoes 2 to form opening and closing movement, so that the brake function is achieved. Furthermore, the contact surface of the brake shoe 2 contacting the roller gear 5 is composed of an outer convex tooth-shaped surface 22 and an inner concave arc surface 23, wherein the radius of the inner concave arc surface 23 is equal to and tangent to the root circle radius of the outer convex tooth-shaped surface 22, the outer convex tooth-shaped surface 22 is used for meshing with the roller gear 5, and the inner concave arc surface 23 is used for rolling contact with the roller gear 5.

Advantageous effects

The invention has the advantages that the gear meshing mechanism replaces the original cam structure, so that the brake mechanism is more labor-saving in operation, the brake torque is increased, the brake effect is better, and the problem that the original brake cam is easy to wear is solved.

Claims (2)

1. The utility model provides an improved structure is stopped to drum, includes shell (1), locates a pair of brake shoes (2) in shell (1), connects elasticity resetting element (3), brake rocker arm subassembly (4), roller gear (5), connection piece (6), rivet (7) between this pair of brake shoes (2), the one end of a pair of brake shoes (2) is rotated and is positioned in shell (1), its characterized in that: the brake rocker arm component (4) is provided with a kidney-shaped columnar brake gear (41), two sides of the kidney-shaped columnar brake gear (41) are respectively meshed with a roller gear (5), the roller gears (5) are respectively abutted against a brake shoe (2), a pair of brake shoes (2) are provided with pits (21) on the side surfaces close to the kidney-shaped columnar brake gear (41) for mounting a connecting sheet (6), a kidney-shaped hole (62) is arranged on the connecting sheet (6), a shaft (51) of the roller gear (5) is mounted in the kidney-shaped hole (62) and can rotate and move in the kidney-shaped hole (62), the connecting sheet (6) is also provided with a round hole (61), a rivet (7) penetrates into the round hole (61) to rivet the connecting sheet (6) in the pits (21) of the pair of brake shoes (2), when the brake rocker arm component (4) drives the kidney-shaped columnar brake gear (41) to rotate, and then the two roller gears (5) are driven to rotate and move, and the roller gears (5) drive the pair of brake shoes (2) to form opening and closing movement, so that the brake function is achieved.

2. The improved drum brake structure according to claim 1, characterized in that: the brake shoe plate (2) abutting surface abutting against the roller gear (5) is composed of a convex tooth surface (22) and a concave arc surface (23), wherein the radius of the concave arc surface (23) is equal to and tangent to the tooth root radius of the convex tooth surface (22), the convex tooth surface (22) is used for being meshed with the roller gear (5), and the concave arc surface (23) is used for being in rolling contact with the roller gear (5).

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