Unformatted text preview: Engineering Mechanics - Dynamics θ= 1
2 Chapter 16 θ = 90.00 rad Problem 16-7
The mechanism for a car window winder is shown in the figure. Here the handle turns the small cog
C, which rotates the spur gear S, thereby rotating the fixed-connected lever AB which raises track D in
which the window rests. The window is free to slide on the track. If the handle is wound with angular
velocity ωc, determine the speed of points A and E and the speed vw of the window at the instant θ.
s ωc = 0.5 rC = 20 mm θ = 30 deg rs = 50 mm rA = 200 mm
vC = ωc rC
s vC = 0.01 ωs = vC ωs = 0.20 rs rad
s vA = vE = ωs rA
vA = ωs rA vA = vE = 40.00 mm
s Points A and E move along circular paths. The vertical component closes the window.
vw = vA cos ( θ ) vw = 34.6 mm
s *Problem 16-8
The pinion gear A on the motor shaft is given a constant angular acceleration α. If the gears A and
B have the dimensions shown, determine the angular velocity and angular displacement of the
output shaft C, when t = t1 starting from rest. The shaft is fixed to B and turns with it.
Given: α=3 rad
2 s 399 ...
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- Spring '08
- Dynamics, Angular Acceleration, Velocity, fixed-connected lever AB