Improved structure of drum brake

Abstract

The invention provides an improved structure of a drum brake. The improved structure is used for changing the original working mode of the drum brake that a brake shoe is directly driven by a cam to expand. According to the structure, a pair of brake shoes is installed in a drum brake shell, one end of each brake shoe is provided with a semicircular arc surface, the brake shoes are installed on a rotating shaft and can rotate around the rotating shaft, and the rotating shaft is fixedly installed on the drum brake shell; the other end of each brake shoe is made into a convex tooth-shaped surface, a rack is installed between the two tooth-shaped surfaces, the rack is meshed with the pair of brake shoes and a rocker arm shaft gear, and the rocker arm shaft gear is a part of the structure of a rocker arm shaft of a brake rocker arm assembly; and when the rocker arm shaft rotates, the pair of brake shoes can be driven to do opening and closing movement, and therefore the braking function is achieved.

Description

technical field [0001] The invention belongs to the technical field of brake devices for motorcycles and electric vehicles. Background technique [0002] Drum brakes have been used as brake components on motorcycles and electric vehicles for nearly a century. Their structure generally consists of a housing, a pair of brake shoes, a brake cam, a brake rocker arm, and elastic reset elements. When braking, the brake rocker arm drives the brake cam to rotate, and the brake cam forces the brake shoe to expand and contact the housing to generate friction and then brake. After braking, rely on the elastic return element to pull the brake shoe back to its original position. During the braking process, in addition to the wear between the brake shoe and the housing, there will also be wear between the brake cam and the brake shoe, and the wear is always concentrated on several points or surfaces of the brake cam, which greatly shortens the brake life. In addition, the existing drum ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide an improved structure of the drum brake, which changes the working mode of the original drum brake which uses the cam to directly drive the expansion of the brake shoe, and effectively improves the poor braking effect of the existing drum brake, the large sliding distance of the vehicle brake, and the large braking distance of the brake cam. Disadvantages of wear and tear

Compared with the prior art, the invention adopts the innovative structural design of driving the rack with the brake rocker shaft, and then the rack drives the brake shoes to complete the brake, so that the operation of the brake mechanism is more labor-saving, and the braking torque is increased. The braking effect is better, and it also solves the problem that the original brake cam is easy to wear

Images