Position Analysis of a Non Grashofian Slider Rocker RRRP Mechanism
Schematic Diagram of a 4 Bar RRRP Linkage
The 4 bar RRRP mechanism is another basic mechanism in studies on kinematics. It is also widely used in various forms because of the relative simplicity of design and manufacture. Like RRRR linkages, Grashof's criteria is used to distinguish between 4 bar linkages with one prismatic joint, depending on the rotatability of the links In brief, if l is the shorter of the crank and the coupler and L the longer of the two, and e is the offset, then the following cases arise
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l + e < L : Grashofian linkage
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l + e < L, shortest link s is the ground link. : Inverted Slider Crank (RRPR)
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l + e < L , shortest link is the coupler : Inverted Slider Rocker (RRPR)
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l + e < L , shortest link is crank : Slider Crank (RRRP)
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l + e < L , shortest link is coupler : Slider Rocker (RRRP)
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l + e > L : Non Grashofian linkage
For a more detailed introduction to Grashof criteria for linkages with one prismatic joint see the animated guide that follows. If undisturbed , the animation will proceed at a predetermined pace. You can either click on the animation itself to move from step to step as per your convenience. Alternatively you can use the controls at the bottom of the animation to see it at your own pace.
In a Non Grashofian Slider Rocker the input link (link 2) CANNOT rotate through a full circle.Like the slider, there exists limits on the range of motion for the input link (link 2) as well. However unlike the Grashofian slider rocker, here there are no two distinct modes of motion. In a Grashofian slider rocker, depending on the mode of assembly, the same set of links will tracea differenrt coupler curve for each of the two modes. But a Non Grashofian slider rocker, irrespective of mode of assembly will tracea the same coupler curve. Check the Demo tab to see the comparison.