Drum Brake Assembly Configured to Reduce Audible Noise During Braking

摘要

A drum brake assembly and method for designing the assembly are provided. The assembly includes a brake spider, a pair of brake shoes pivotally coupled to the brake spider at one end, and a pair of cam followers disposed at opposite ends of the brake shoes. The assembly further includes a camshaft having a shaft disposed along a rotational axis and a cam disposed at one end of the shaft. The cam has an inboard side proximate the shaft, an outboard side distant from the shaft and a cam surface extending between the inboard and outboard sides in engagement with the cam followers. The camshaft further includes a noise reducing mass disposed on the outboard side of the cam. The mass is configured to establish a natural frequency in the cam that differs from a natural frequency of the first and second brake shoes to reduce audible noise.

主权项

1. A drum brake assembly, comprising:
a brake spider having a central aperture configured to receive an axle extending therethrough along a center axis of the central aperture; first and second brake shoes, each of said first and second brakes shoes having a first end pivotally coupled to said brake spider; a first cam follower disposed at a second end of said first brake shoe; a second cam follower disposed at a second end of said second brake shoe; and, a camshaft having
a shaft disposed along a rotational axis;a cam disposed at one end of the shaft, the cam having an inboard side proximate said shaft and an outboard side distant from said shaft and a cam surface extending between said inboard and outboard sides in engagement with said first and second cam followers, movement of said cam causing said first and second brake shoes to move between positions of engagement and disengagement with an associated braking surface; and,a noise reducing mass disposed on said outboard side of said cam, the mass configured to establish a natural frequency in said cam that differs from a natural frequency of said first and second brake shoes by at least 200 Hz.