CBC AUTOMOTIVE RK DRIVE SHAFTSand UNIVERSAL JOINTS Chapter 6 Page 119 Classroom Manual
OBJECTIVES CBC AUTOMOTIVE RK • Describe purpose and construction of common RWD drive shafts. • Describe purpose and construction of common universal joint designs. • Importance of driveshaft balance. • Explain natural speed variation. • Describe the canceling universal joint angles.
INTRODUCTION CBC AUTOMOTIVE RK • Drive shaft - transfers power from trans to differential. • Drive shaft is made from seamless steel tubing with yokes at each end. • Some vehicles use two piece drive shafts. • Four-wheel-drive use two drive shafts. • Some axle shafts are made like drive shafts.
DRIVE SHAFT CONSTRUCTION CBC AUTOMOTIVE RK • Typical universal joint and yokes.
Page 121 DRIVE SHAFT CONSTRUCTION CBC AUTOMOTIVE RK • As the differential travels up and down U-joint angle changes. • The distance between trans and differential also changes. • U-joints permit change in angle. • Slip yoke allows change in length. • Drive shafts have a natural tendency to vibrate.
MOVEMENT CBC AUTOMOTIVE RK
Page 122 Types of Drive Shafts CBC AUTOMOTIVE RK • Hotchkiss - External shaft and U-joints. • Can be either one or two piece. • Torque tube - drive shaft is enclosed. • Ridged shaft. • Torque tube - • Flexible shaft.
Page 124 UNIVERSAL JOINTS CBC AUTOMOTIVE RK • U-joints are crosses between two Y-shaped yokes. • Because U-joints transfer power at an angle they DO NOT rotate at a constant velocity nor are they vibration free.
CBC AUTOMOTIVE RK
Page 125 SPEED VARIATIONS CBC AUTOMOTIVE RK • Input and output speeds are the same. • But the drive shaft itself speeds up and slows down every 90 degrees.
Page 127 PHASING of U - JOINTS CBC AUTOMOTIVE RK • To provide for this canceling effect, drive shafts should have at least two U-joints and their angles must be slight and equal to each other. • Speed fluctuations can be canceled if the driven yoke has the same point of rotation, or same plane , as the driving yoke.
Page 128 CANCELING ANGLES CBC AUTOMOTIVE RK • Vibrations can be reduced by canceling angles.
Page 128 TYPES of U - JOINTS CBC AUTOMOTIVE RK • Single universal joint retained by either an inside or outside snap ring. • Spicer - outside snap ring • Mechanics or Detroit - inside snap ring • Universal joints held in the yoke by U-bolts or lock plates. CBC AUTOMOTIVE RK
Page 130 DOUBLE CARDAN Coupled Universal Joint CBC AUTOMOTIVE RK • Total operating angle is divided equally between the two joints. • Because the two joints operate at the same angle, fluctuations are canceled out. • Double Cardan is classified as a constant velocity joint.
Page 132 MAINTENANCE CBC AUTOMOTIVE RK • Factory joints do not have grease fittings. • Replacement joints need servicing. • Dirt and other buildup on the shaft will affect its balance.