Question

HOMEWORK PROBLEM 2 Given the driver crank length L1 = 100mm, coupler length L2 = 200 mm, and follower length 13 = 300 mm, and considering the transmission angle, find the range of values for the fixed link Lo if the linkage is to be a crank rocker. Make the design decision to limit the transmission angle to 45° 5° 135º.

Answer 1

using Law of cosines (Lo-L,) = 1 + 1.3=22 223 los min Pmin = 45 (0-100) - 200 + 30 8 - 2x 200x300 x Cos 45 Lo 312-48 mm &min L3 Lz LI Minimum transmission angle L3 L2 & man TTTTT 6 Maximum transmission angle Scanned by TapScanner

using Lo Value Cos &max = 2 2 + b} - (lothes 3 22₂ 23 2 200+ 306 (312.48 +100) 2x200x300 max = 109.54 Accepted range It man = 135 =) (LoL) 200 + 300 2% 200x300 x Cos 135 Lo 363.52 using above Lo valve Cos & min min = 206+ 308- (363.52+100) 2X200X 300 Omin 59.69 Scanned by TapScanner

312-48 <LO 36 3.5 2 Accepted range for Lo I and, 2 are Collinear When links link 3 is in limiting position considering frank-Yockey mechanisen Lo=312-48mm Maximum value of Oz Cos og = Lô + +(+22 j => 2 LoL 3 2 2 312-48 + 300 . Croot 200) 2x 312.48 X300 o'z 3 (max) = 58061 For Minimum value of 03 1 =) Cos Oz = Lot L3 (42 - L;)² 2 LOL3 Scanned by TapScanner

2 ) Cos 03 < 312-48 + 308- C200-100) 2x312-48x30 0 3 frin Jz 18.65° The range of the follower crank Can be changed by changing the of ratios link length. If transmission angle and range of motion are plotted, approach more optimum design tham hit or miss methods. we will g Scanned by TapScanner