1 A six-speed RWD MT is shown in the figure. The following data are given in...

       

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1 A six-speed RWD MT is shown in the figure. The following data are given in the gear design: Input gears: Ni = 26, Nc = 29, normal diametral pitch: 12, normal pressure angle: 20%; helical angle: 25°, tooth length: 0.95 inch. First speed: N10/Nlc = 41/13, normal diametral pitch: 12, normal pressure angle: 20°, helical angle: 25°. Sixth speed: N60/N6c = 21/34, normal diametral pitch: 12, normal pressure angle: 20°, helical angle: 25°. 5-6 Synch. 1-2 Synch. Rev. synch. Input shaft Ni N60 HH HE No Nec N30 HE N3c N40 N20 H HH N4c N2c N10 HH Vehicle data: Front axle weight: 1900 lb Center of gravity height: 14 in. Air drag coefficient: 0.30 Tire radius: 11.0 in Mass factor: 1.0 H Nro HEH Nri Nic Nrc Output shaft Counter shaft 3-4 Synch. All the gears on the counter shaft are right handed. The transmission efficiency is 0.98 and the final drive efficiency is 0.97. a) The input gears Ni and Nc are designed as standard gears. Determine the con- tact ratio. b) The tooth thickness of gear N1c is designed to be 20% larger than the standard tooth thickness. Determine the tooth thickness of gears Nic and N10. c) The vehicle is running in 6th gear at a speed of 65 miles on a 1% slope and with an acceleration of 2 ft/s². Determine the gear forces on the counter shafts, and the resultant thrust on the bearing on the counter shaft. You must show the direction of each gear force and the thrust. d) An optional 6th gear ratio of 0.7215 is to be made available for the transmission by redesigning the six gears N60 and N6c only. The redesigned 6th gears must be standard helical gears with normal diametral pitch equal to 12 and normal pres- sure angle equal to 20°. The number of teeth N6c must be kept the same at 34. Determine the helical angle of the resigned 6th gears. Rear axle weight: 1500 lb Wheel base: 108 in. Frontal projected area: 21 sq. ft Roll resistance coefficient: 0.02 Final drive ratio 3.21 1 A six-speed RWD MT is shown in the figure. The following data are given in the gear design: Input gears: Ni = 26, Nc = 29, normal diametral pitch: 12, normal pressure angle: 20%; helical angle: 25°, tooth length: 0.95 inch. First speed: N10/Nlc = 41/13, normal diametral pitch: 12, normal pressure angle: 20°, helical angle: 25°. Sixth speed: N60/N6c = 21/34, normal diametral pitch: 12, normal pressure angle: 20°, helical angle: 25°. 5-6 Synch. 1-2 Synch. Rev. synch. Input shaft Ni N60 HH HE No Nec N30 HE N3c N40 N20 H HH N4c N2c N10 HH Vehicle data: Front axle weight: 1900 lb Center of gravity height: 14 in. Air drag coefficient: 0.30 Tire radius: 11.0 in Mass factor: 1.0 H Nro HEH Nri Nic Nrc Output shaft Counter shaft 3-4 Synch. All the gears on the counter shaft are right handed. The transmission efficiency is 0.98 and the final drive efficiency is 0.97. a) The input gears Ni and Nc are designed as standard gears. Determine the con- tact ratio. b) The tooth thickness of gear N1c is designed to be 20% larger than the standard tooth thickness. Determine the tooth thickness of gears Nic and N10. c) The vehicle is running in 6th gear at a speed of 65 miles on a 1% slope and with an acceleration of 2 ft/s². Determine the gear forces on the counter shafts, and the resultant thrust on the bearing on the counter shaft. You must show the direction of each gear force and the thrust. d) An optional 6th gear ratio of 0.7215 is to be made available for the transmission by redesigning the six gears N60 and N6c only. The redesigned 6th gears must be standard helical gears with normal diametral pitch equal to 12 and normal pres- sure angle equal to 20°. The number of teeth N6c must be kept the same at 34. Determine the helical angle of the resigned 6th gears. Rear axle weight: 1500 lb Wheel base: 108 in. Frontal projected area: 21 sq. ft Roll resistance coefficient: 0.02 Final drive ratio 3.21

Answer rating: 100% (QA)

a Contact ratio for standard gears with module m1p and pressure angle 20 is 125 Given data p12 20 Th... View the full answer