Search results
Results From The WOW.Com Content Network
In the study of mechanisms, a four-bar linkage, also called a four-bar, is the simplest closed-chain movable linkage. It consists of four bodies, called bars or links, connected in a loop by four joints. Generally, the joints are configured so the links move in parallel planes, and the assembly is called a planar four-bar linkage. Spherical and ...
An example of a simple closed chain is the RSSR (revolute-spherical-spherical-revolute) spatial four-bar linkage. The sum of the freedom of these joints is eight, so the mobility of the linkage is two, where one of the degrees of freedom is the rotation of the coupler around the line joining the two S joints.
Link 1 (horizontal distance between ground joints): 4a Illustration of the limits. In kinematics, Chebyshev's linkage is a four-bar linkage that converts rotational motion to approximate linear motion. It was invented by the 19th-century mathematician Pafnuty Chebyshev, who studied theoretical problems in kinematic mechanisms.
A Chebyshev Translating Table Linkage, which combines together two cognate linkages: the Chebyshev Linkage and Chebyshev Lambda Linkage. In kinematics, the Chebyshev Lambda Linkage [1] is a four-bar linkage that converts rotational motion to approximate straight-line motion with approximate constant velocity. [2]
For many purposes approximate linear motion is an acceptable substitute for exact linear motion. Perhaps the best known example is the Watt four bar linkage, invented by the Scottish engineer James Watt in 1784. [3] This type of linkage is one of several types described in Watt's 28 April 1784 patent specification.
These four-bar linkages have coupler curves that have one or more regions of approximately perfect straight line motion. The exception in this list is Watt's parallel motion, which combines Watt's linkage with another four-bar linkage – the pantograph – to amplify the existing approximate straight line movement.
Link 1 (distance between ground joints): 2a. In kinematics, the Hoecken linkage (named for Karl Hoecken) [1] is a four-bar linkage that converts rotational motion to approximate straight-line motion. The Hoecken linkage is a cognate linkage of the Chebyshev linkage and Chebyshev's Lambda Mechanism. The linkage was first published in 1926. [2] [3]
Two cranks designed in this way form the desired four-bar linkage. This formulation of the mathematical synthesis of a four-bar linkage and the solution to the resulting equations is known as Burmester Theory. [3] [4] [5] The approach has been generalized to the synthesis of spherical and spatial mechanisms. [6]