PROBLEM 6.159
The gears D and G are rigidly attached
to shafts that are held by frictionless
bearings. If r
D
90 mm and r
G
30
mm, determine (a) the couple
M0
that
must be applied for equilibrium, (b) the
reactions at A and B.
PROBLEM 6.159 (Continued)
PROBLEM 6.160
In the planetary gear system shown, the radius of the central gear A is
a 18 mm, the radius of each planetary gear is b, and the radius of the
outer gear E is (a 2b). A clockwise couple of magnitude M
A
10 N m
is applied to the central gear A and a counterclockwise couple of
magnitude M
S
50 N m is applied to the spider BCD. If the system is
to be in equilibrium, determine (a) the required radius b of the
planetary gears, (b) the magnitude M
E
of the couple that must be
applied to the outer gear E.
PROBLEM 6.161*
Two shafts AC and CF, which lie in the vertical xy plane, are connected by a universal joint at C. The
bearings at B and D do not exert any axial force. A couple of magnitude 500 lb in. (clockwise when
viewed from the positive x-axis) is applied to shaft CF at F. At a time when the arm of the crosspiece
attached to shaft CF is horizontal, determine (a) the magnitude of the couple that must be applied to shaft
AC at A to maintain equilibrium, (b) the reactions at B, D, and E. (Hint: The sum of the couples exerted
on the crosspiece must be zero.)
PROBLEM 6.161* (Continued)
PROBLEM 6.162*
Solve Problem 6.161 assuming that the arm of the crosspiece attached to shaft CF is vertical.
PROBLEM 6.161
Two shafts AC and CF, which lie in the vertical xy plane, are connected by a universal
joint at C. The bearings at B and D do not exert any axial force. A couple of magnitude 500 lb · in.
(clockwise when viewed from the positive x-axis) is applied to shaft CF at F. At a time when the arm of
the crosspiece attached to shaft CF is horizontal, determine (a) the magnitude of the couple that must be
applied to shaft AC at A to maintain equilibrium, (b) the reactions at B, D, and E. (Hint: The sum of the
couples exerted on the crosspiece must be zero.)
Ayz
PROBLEM 6.162* (Continued)
PROBLEM 6.163*
The large mechanical tongs shown are used to grab and lift a
thick 7500-kg steel slab HJ. Knowing that slipping does not
occur between the tong grips and the slab at H and J, determine
the components of all forces acting on member EFH. (Hint:
Consider the symmetry of the tongs to establish relationships
between the components of the force acting at E on EFH and the
components of the force acting at D on DGJ.)
xy
PROBLEM 6.163* (Continued)
PROBLEM 6.163* (Continued)
x
y