225
CHAPTER 9
SPUR GEAR DESIGN
Forces on Spur Gear Teeth
226
Problem 1 Pressure angle = 20 degrees
Chapter 9 Power = 7.5 hp
pinion speed = 1750 rpm
Given data teeth in pinion = 20
teeth in gear = 72
diametral pitch = 12
RESULTS:
a. Gear speed = 486.1 rpm
b. VR = mG = 3.600
Problem 2 Pressure angle = 20 degrees
Chapter 9 Power = 50 hp
pinion speed = 1150 rpm
Given data teeth in pinion = 18
teeth in gear = 68
diametral pitch = 5
RESULTS:
a. Gear speed = 304.4 rpm
b. VR = mG = 3.778
Forces on Spur Gear Teeth
Forces on Spur Gear Teeth
227
Problem 3 Pressure angle = 20 degrees
Chapter 9 Power = 0.75 hp
pinion speed = 3450 rpm
Given data teeth in pinion = 24
teeth in gear = 110
diametral pitch = 24
RESULTS:
a. Gear speed = 752.7 rpm
Problem 4 Pressure angle = 25 degrees
Chapter 9 Power = 7.5 hp
pinion speed = 1750 rpm
Given data teeth in pinion = 20
teeth in gear = 72
diametral pitch = 12
RESULTS:
a. Gear speed = 486.1 rpm
Forces on Spur Gear Teeth
228
Problem 5 Pressure angle = 25 degrees
Chapter 9 Power = 50 hp
pinion speed = 1150 rpm
Given data teeth in pinion = 18
teeth in gear = 68
diametral pitch = 5
RESULTS:
a. Gear speed = 304.4 rpm
Problem 6 Pressure angle = 25 degrees
Chapter 9 Power = 0.75 hp
pinion speed = 3450 rpm
Given data teeth in pinion = 24
teeth in gear = 110
diametral pitch = 24
RESULTS:
a. Gear speed = 752.7 rpm
Forces on Spur Gear Teeth
Given: PdnA
NANBNCND
PBPCPD
a. Pitch diameter of each gear
D = N Pd
b. Center distance for each mesh
c. Rotational speed of each shaft
VR1nAnBNBNAVR2nBnCNCNB
d. Torque in each shaft T P n
230
e. Tangential force on the teeth of each gear P
D n Wt
Gear Quality
For Problems 14 16:
231
Gear Materials
233
234
BLUE
235
parts of complete problem
solutions,
237
238
239
240
[For Problems 60 to 83, single sample solutions are shown for each set of data.]
