N2 Fitting Machining Theory Module 14 Reduction Gearboxes

N2 FITTING & MACHINING THEORY MALUTI TVET COLLEGE LECTURER : MT MPHAGO Downloaded from hlayiso.com ITEMOHELENG CAMPUS

MODULE 14 REDUCTION GEARBOXES LO : know safety precautions to observe when working on gearboxes and explain the applications of gearboxes and reduction gearboxes. Downloaded from hlayiso.com ITEMOHELENG CAMPUS

SAFETY PRECAUTIONS WHEN WORKING WITH GEAR AND GEARBOXES.  Make sure that the power supply is disconnected before you touch a gears.  Beware of sharp edges that have been formed by teeth working against each other.  The oil used in many gearboxes often has additives to which your skin could be allergic. Downloaded from hlayiso.com ITEMOHELENG CAMPUS

GENERAL USE OF GEARBOXES.  Gearboxes are used for the purpose of altering gear ratios either to obtain more torque, to overcome inertia or more speed with lower engine revolution.  When a small driver gear, drives a gear larger than itself, we get an increase in mechanical advantage.  Reduction gearboxes use lot of energy turning shafts and bearings. Downloaded from hlayiso.com ITEMOHELENG CAMPUS

THE MAIN PARTS OF REDUCTION GEAR BOXES Reduction set 1. Input gear and shaft. 2. Driven gear. 3. Driving gear. 4. Output gear and shaft worm to worm gear wheel  Is normally a single start thread that is counted as one tooth.  It has 30 teeth and made of bronze and driving action is in one direction. Multi or double reduction gear set Downloaded from hlayiso.com ITEMOHELENG CAMPUS

THE MAIN PARTS OF REDUCTION GEAR BOXES Single reduction gearbox  Needs only two gears. One in the input shaft and one in the output shaft.  Use spur gears in slow rotating reduction gearboxes because spur gear become noisy in high speed. Helical gears are suitable for high speed. Worm gear drives  Are found in places like dividing head of a milling machine for ratios like 40:1.  They are precise with almost no backlash. Downloaded from hlayiso.com ITEMOHELENG CAMPUS

SUMMARY  Safety precautions to be observed when working with gears and gearboxes.  General use of gearboxes.  Main parts of reduction gearboxes. Downloaded from hlayiso.com ITEMOHELENG CAMPUS

ASSESSMENT Exercise 14.1 page 163 of the textbook supplied by the college. “N2 fitting & machining theory by D Meyer & AG Murdcoch.” 1 & 3. . PLEASE FEEL FREE TO CONTACT ME ON WHATTSHAP FOR ANY QUESTIONS THAT YOU MAY HAVE. MY WHATTSAPP NUMBER IS 073 215 7689 THANK YOU Downloaded from hlayiso.com ITEMOHELENG CAMPUS