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A mechanism is an arrangement of parts assembled to work as a whole Function: transmits or transforms outside force that puts it in motion
The role played by a component in a technical system is called a mechanical function.
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A link connects, fastens, or puts together two or more components of a technical object.
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A direct link means that 2 parts connect to one another WITHOUT a 3rd linking component. An indirect link means that there is a linking component (welding,glue, nail, screw, bolt, etc.) holding the 2 components together.
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The rigid link cannot be bent or deformed The elastic/flexible link can be stretched, bent or deformed
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What’s the difference from the point of view of destruction? The non-removable link cannot be removed without wrecking what’s linked
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In a partial link at least one part is capable of motion with respect to the other A complete link has no movement between linked parts (both parts moving together)
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Direct, rigid, removable, partial
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indirect, flexible, removable, complete
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a technical object, linking limits the possibility of independent motion of one part in relation to another. Ex. A complete link totally restricts motion between the parts while a partial link, the amount of motion is only partially restricted.
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Two degrees of freedom
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A guiding control or component is a component whose function is to force (guide) the motion of the moving parts forces the parts to follow a specific path Also prevents unwanted motion
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Translational Guiding: guides the object in a straight back and forth, side to side or up and down motion Translation guiding is usually characterized by groves or walls that guides the motion
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Rotational guiding: moves object in a circular motion Rotational guiding is characterized by cylindrical objects that guide the motion
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Helical Guiding: guides an object in a back and forth motion as it rotates about the same axis Helical guides are usually characterized by the threads that guide motion
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2 surfaces stay in contact without slipping Holds 2 parts together
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1) The nature of materials in contact.
Rubber & asphalt vs. Steel & asphalt. 2) The presence of a lubricant.
Oil on the road will make tires slip. 3) Temperature.
The warmer the weather, the better the adhesion.
4) The state of the surfaces in contact.
The rougher the surface, the better the adhesion.
5) The perpendicular FORCE exerted by one surface on another.
More force, better adhesion.
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FORCE that resists slipping Increases with adhesion A moving part in a technical object is usually guided by another part which could cause parts to slip over each other. However, adhesion tends to make these parts hold together creating a force which resists the slipping motion - FRICTION.
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Polishing also reduces friction
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