Page 440 - Analysis and Design of Machine Elements

Analysis and Design of Machine Elements
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Design Problems
1 Design a compression spring with closed and ground ends using hard-drawn wire.
The deflection is to be 60 mm when the force is 80 N and to close solid when the force
is 100 N. The spring must fit inside a 40 mm diameter hole. Loading is essentially
static.

2 A value spring operates under a variable load, with one end fixed and one end hinged.
The spring is needed to resist a dynamic load that varies from 200 to 1000 N while
the end deflection varies from 5 to 25 mm. The outer diameter of spring is less than
5
40 mm and the life is 10 . Design the helical compression spring.
3 Design a helical extension spring. The spring has a length of 100 mm at the load of
150 N and a length of 125 mm at the load of 400 N. The outside diameter is 30 mm
and allow 0.5 coil extra for hook flexibility.

4 Design a torsion spring with an initial torque of T = 2000 N mm and a maximum
1
∘
torque of T = 8000 N mm. The minimum angular deflection is = 10 and the
2 1
∘
maximum angular deflection is = 40 . The spring is to be installed in a steadily
2
operating machine.
CAD Problems

1 Write a flow chart for spring design process to complete the Example Problem 14.1.

2 Develop a program to implement a user interface similar to Figure P14.2 and com-
plete the Example Problem 14.1.

Figure P14.2 Illustration for CAD Problem 2.