connecting rod(redirected from Main rod)
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connecting rod[kə′nekt·iŋ ‚räd]
a link in a plane mechanism that is connected to other moving links by means of rotating kinematic pairs and that describes a complex two-dimensional motion.
Connecting rods are an important component in widely used crank-slide mechanisms, which convert the reciprocal motion of a slide (the piston) into the rotary motion of a crank (the crankshaft), or vice versa. In piston engines, compressors, and pumps, the connecting rod generally has an H-shaped cross section; the end connected to the piston (the small, or piston end) is not detachable, and the big end, connected to the crankshaft, is demountable to allow assembly of the mechanism.
In forging and press equipment, the connecting rod end is sometimes of a special design that allows acceptance of high loads in a single direction; connecting rods of both constant and variable length are also used to control the position of a slide. The length of the connecting rod may be varied by means of a rod, the threaded end of which is screwed into the body of the connecting rod and the other (spherical) end of which forms a spherical kinematic pair with the slide.
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