in mechanics, device for changing rotary to back-and-forth motion. A disk is mounted off center on a shaft. One flat, open, circular end of a rod fits around the edge of the disk; the other end is usually attached to a block that slides in a slot. As the shaft rotates the block slides back and forth, carrying along whatever is attached to it, e.g., a valve. The distance between the center of the shaft and the center of the disk is the eccentricity. The so-called throw may mean either the eccentricity or the distance the block moves, which is twice the eccentricity. Cams
perform the same function as the eccentric, which designers often prefer to the crank for short motions.
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Not having the same center or center line; departing or deviating from the conventional or established norm.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
Eccentric (religion, spiritualism, and occult)
In astronomy, eccentricity refers to an elliptical orbit, specifically to the extent to which the ellipse described by a celestial body’s orbit departs from a perfect circle, expressed by the ratio of the major to the minor axis.
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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
in astronomy, an auxiliary circle in the geocentric system of the world, introduced by Hipparchus to represent the annual revolution of the sun around the earth through motion along a circle with constant angular velocity. The nonuniformity of the sun’s motion along the ecliptic was attributed to the fact
that the sun moved (uniformly) along the circumference of an eccentric, whose center C did not coincide with the earth T (see Figure 1).
a circular disk whose axis of rotation does not coincide with its geometric center. In cam mechanisms, an eccentric, acting upon a rod that moves in a straight line, communicates to the rod a harmonic motion such that the displacement of the rod is proportional to the cosine (or sine) of the eccentric’s rotation angle. In linkage, an eccentric acts as a crank, that is, as a link that makes a complete revolution around its axis of rotation. Such an application of an eccentric is efficient when the crank (its throw equal to the eccentricity of an eccentric) must be very short. Eccentrics are also used in lathe attachments to clamp details that are being machined.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
(science and technology)
Situated to one side with reference to a center.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
eccentric head and shaft
Not having the same center or center line.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
1. situated away from the centre or the axis
2. not having a common centre
3. a device for converting rotary motion to reciprocating motion
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005