Depending on how long the piston rod is, stresses can be calculated differently.
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The connecting rod connects to the opposite end of the beam to the piston rod, and then to the flywheel.
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Perhaps a piston rod, some gears, a pendulum, or whatever.
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To the end of the piston rod was attached a cord passing over two pulleys and a weight hung down from the cord's end.
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The piston is a disc or cylinder, and the piston rod transfers the force it develops to the object to be moved.
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Stroke length for this design is not limited, however, the piston rod is more vulnerable to buckling and bending.
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The piston rod protrudes from the top of the cylinder and has fixed to it a cross-head which runs in slides attached to, and rising from, the cylinder top.
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Bramah had designed a hydraulic press, but was having problems sealing both the piston and the piston rod where it fitted into the cylinder.
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As the piston rod moved backwards and forwards in a straight line, its linear motion would be converted into circular motion by the gear wheel.