Tham khảo tài liệu 'sổ tay tiêu chuẩn thiết kế máy p36', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | __CHAPTER 30_ CLUTCHES AND BRAKES John R. Zimmerman . Professor of Mechanical and Aerospace Engineering University of Delaware Newark Delaware TYPES USES ADVANTAGES AND CHARACTERISTICS TORQUE AND ENERGY CONSIDERATIONS I TEMPERATURE CONSIDERATIONS FRICTION MATERIALS TORQUE AND FORCE ANALYSIS OF RIM CLUTCHES AND BRAKES BAND AND CONE BRAKES AND CLUTCHES I DISK CLUTCHES AND BRAKES I ELECTROMAGNETIC TYPES I ACTUATION PROBLEMS REFERENCES SUGGESTED READING GLOSSARY OF SYMBOLS a Vehicle deceleration ft s2 m s2 a Location of shoe pivot in m a Lever arm for larger band force in m A Area in2 m2 b Percentage of grade b Width of band shoe or web in m c Lever arm for smaller band force in m C Center of pressure C Specific heat Btu lbm F J kg C d Inside disk diameter in m D Outside disk diameter in m D Pitch diameter of gear in m Dmax Maximum roll diameter in m e Radius to center of circular brake pad in m E Total energy dissipated ft lb or Btu J f Coefficient of friction f Ventilation factor STANDARD HANDBOOK OF MACHINE DESIGN F Actuating force lb N Fd Prime-mover factor F Actuating force on leading shoe lb N Fl Load factor F Normal force lb N Fs Starting factor F Tension force on web lb N F Actuating force on trailing shoe lb N g Local acceleration of gravity ft s2 m s2 gc Gravitational constant Ibm ft lb s2 1 kg m N s2 h Overall heat transfer coefficient Btu in2 s F W m2 C hc Convection heat transfer coefficient Btu in2 s F W m2 C hr Radiation heat transfer coefficient Btu in2 s F W m2 C Hm Average rate of heat dissipation lb ft s or Btu s W I Mass moment of inertia lb in s2 kg m2 IL Mass moment of inertia on load side lb in s2 kg m2 1P Mass moment of inertia on prime-mover side lb in s2 kg m2 Ks Service factor Moment arm of actuating force drum brake length of actuating lever in a band brake in m m Mass Ibm kg Ma Moment of actuating force .
