Link Gear

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Link Gear

 

an articulated mechanism in which two moving components—a link and a slide block—are coupled to form a sliding kinematic pair or sometimes a rotating or arc pair.

The most common plane four-link gears are divided into groups according to the type of the third moving link: crank-link, rocker-link, slide-link, or double-link. A crank-link mechanism may have rotary, rocking, or translatory link motion. Rocker mechanisms, which are derived from these types of mechanisms by limiting the angular rotation of the crank, are built with rocking links (Figure 1, a) or translatory links (Figure 1, b), are used for the transformation of motion and also as sine mechanisms (Figure 1, c) in computers.

Figure 1. Rocker-link mechanism: (a) with rocking link, (b) with translatory link, (c) sine mechanism (r sin ϕ is the displacement of the link arm upon rotation through an angle ϕ)

Slide-link mechanisms are designed to transform rocking motion into translatory motion or vice versa; they are also used as tangent mechanisms in computers. Double-link mechanisms are used in machines to provide equal angular velocities of the links with a constant angle between them. This property is used in couplings that permit displacement of the axes of the shafts. Complex multilink gears are used for various purposes—for ex-ample, in control systems for charging the cylinders of internal-combustion engines and in reversing systems of steam engines.

N. IA. NIBERG

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Radial gripping motions are achieved by incorporating a slotted link gear. Existing links cause an extreme reduction in the gripping moment if the opening angles are small; Schunk is attempting to solve this problem with the patented single-pin guide rail, which ensures a constant closing moment through the gripping range.