Impact of Return Spring Positioning on Brake Drag Forces and Gaps

This study investigates the impact of return spring positioning on brake drag forces and brake gaps in an S-Cam brake assembly. A detailed analysis reveals that the offset placement of the shoe return spring leads to a shoe tilting phenomenon, resulting in uneven brake gaps. This misalignment reduces the clearance on the dust cover side, increasing drag forces and adversely affecting brake performance, fuel efficiency, and liner wear. To address this issue, an optimized design is proposed, that effectively eliminates tilting, restores uniform brake gaps, and significantly reduces drag forces. Validation through dynamometer testing confirms the effectiveness of the revised spring placement in minimizing brake drag and improving system efficiency. By optimizing return spring positioning, the study highlights improvements in braking efficiency, extended brake liner life, and enhanced durability of the braking system. The findings underscore the importance of precise spring placement in S-Cam brake assemblies, offering valuable insights for engineers and designers focused on brake system optimization. Furthermore, the study contributes to a broader understanding of how minor design modifications can mitigate parasitic losses in braking systems. This research provides a framework for developing more efficient brake assemblies, ultimately supporting improved vehicle performance, reduced maintenance costs, and better fuel economy. The insights gained from this analysis can guide future advancements in commercial vehicle brake systems, promoting enhanced reliability and sustainability in the automotive industry.