Mechanism Definition and 534 Threads

In engineering, a mechanism is a device that transforms input forces and movement into a desired set of output forces and movement. Mechanisms generally consist of moving components which may include:

Gears and gear trains;
Belts and chain drives;
Cams and followers;
Linkages;
Friction devices, such as brakes or clutches;
Structural components such as a frame, fasteners, bearings, springs, or lubricants;
Various machine elements, such as splines, pins, or keys.The German scientist Franz Reuleaux defines machine as "a combination of resistant bodies so arranged that by their means the mechanical forces of nature can be compelled to do work accompanied by certain determinate motion". In this context, his use of machine is generally interpreted to mean mechanism.
The combination of force and movement defines power, and a mechanism manages power to achieve a desired set of forces and movement.
A mechanism is usually a piece of a larger process, known as a mechanical system or machine. Sometimes an entire machine may be referred to as a mechanism; examples are the steering mechanism in a car, or the winding mechanism of a wristwatch.
However, typically, a set of multiple mechanisms is called a machine.

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  1. G

    Ebola Virus Disease: Mechanism of infection

    I have looked in a lot of different websites for a explanation of the mechanism of the ebolavirus to infect our body: how it avoid our immunology system, what it exactly change from our DNA and the consequences in the body. I didn't found a clear information, can someone help me to understand ebola?
  2. C

    Mechanism that only rotates when driven from one side

    I have a geared DC motor taken from a hand drill. When I manually turn the internal motor, the drill bit rotates. This can be done in both directions. However If I try and turn the drill bit it does not rotate. What is the mechanism called that achieves this? My friend says it is a sprag...
  3. S

    Explaining Universe Expansion Through Gravity & 3D Geometry

    Hi, This is my first post and I've joined simply to see what anyone may make of the following idea. Given the relatively recent depictions of the universes 3d structure as something akin to nodes with filaments connecting them. It seemed that the expansion of the universe could be explained by...
  4. P

    Arm blade mechanism for Cosplay

    Hello everyone! I'm making a costume of a game character and I think I need some guidance regarding the mechanical aspect. I asked this question on a cosplay site, but they suggested I might get more help here. So I'm going to cosplay this character on an anime convention: As you may have...
  5. N

    Charge of the W bosons in the Higgs Mechanism

    I am confused about how the gauge boson W+ and W- get their charge under spontaneous symmetry breaking in the Higgs mechanism. Here's what I have so far: The covariant derivative for a SU(2)⊗U(1) is DμΦ = (∂μ + igWμiσi/2 + ig'Bμ)Φ where g and g' are coupling constants. SU(2) is associated...
  6. Y

    Angular Velocity and Acceleration for Elevator Mechanism

    Homework Statement In a charming 19th-century hotel, an old-style elevator is connected to a counterweight by a cable that passes over a rotating disk 3.50m in diameter (the figure (Figure 1) ). The elevator is raised and lowered by turning the disk, and the cable does not slip on the rim of...
  7. M

    Synthesis of a four bar linkage with a ternary couplar

    Hi there! Currently i am trying to design a four bar linkage for a bicycle rear shock. You can find this linkage at here http://ffden-2.phys.uaf.edu/211_fall2010.web.dir/Michael_Stanfill/VirtualPivot.html This linkage is called virtual pivot point. Critical part of this design is to achieve a...
  8. Vinay080

    Unraveling the Mystery: How Do We Sense Heat?

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  9. AryaUnderfoot

    Water Flow & Pressure: The Impact of Water Control Mechanisms on Overflow Time"

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  10. T

    Parameters for a four bar mechanism

    Homework Statement I am given a four bar mechanism and the mathematical representation of a point on the coupler I am looking for ways to determine the lengths of the linkages from this information? Homework EquationsThe Attempt at a Solution I really have no idea
  11. A

    4 in lift mechanism using a continuous servo?

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  12. R

    Is there any mechanism for learning p block reactions?

    Do we have to rote memorize it or is there mechanism so that we can learn it easily? There are some ion exchange reactions which are simple like NaCl + H2O-------> NaOH+ HCl. but for example what about this? P4 + NaOH + H2O----> ?
  13. C

    Mechanism for Phosgene Formation

    The overall reaction for the formation of phosgene from Cl2 and CO is: Cl2 + CO --> Cl2CO The mechanism is: Cl2 + M <--> 2Cl' + M Cl' + CO <--> ClCO' ClCO' + Cl2 --> Cl2CO + Cl' For this mechanism, the sum of the elementary reactions is: 2Cl2 + CO --> Cl2CO + 2Cl' However, doesn't the sum...
  14. H

    How can I create a simple latch mechanism using a roller chain for my project?

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  15. P

    What is the Mechanism of Trinitration of Phenol?

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  16. Thom Stoops

    Need Help Designing Mechanism for Automatic Spring Return

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  17. Safinaz

    Seesaw Mechanism: A Quantum Field Theory Study

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  18. S

    Oleum Fuming: Investigating the Physical Mechanism

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  19. gfd43tg

    Proposing a reaction rate mechanism

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  20. jmay4096

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  21. Q

    What is the correct mechanism for saponification?

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  22. L

    How Does d-d Transition Occur with No Free Higher Energy d-Orbitals Available?

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  23. C

    Coriolis Acceleration of a Mechanism

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  24. Z

    Kinematics of pantograph device

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  25. L

    Need mechanism for connect from handle to controlled object (please see pic)

    Please see the above picture, I need a mechanism to connect handle to a controlled object below. While the handle moves from a to b (~10cm) the object needs to move from c to d (about 25 - 30 cm) and when handle moves back from b to a, the object needs to moves back from d to c. They are both...
  26. M

    Explaining the mechanism of a reaction and drawing its Energy diagram

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  27. J

    What is the best method for designing a trigger system for a ball launcher?

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  28. enorbet

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  29. T

    Does the Higgs Mechanism Influence Gravity in the Same Way for All Particles?

    I understand that Higgs mechanism “gives” mass to particles in QM sense. My first question is, why it also gives mass in GR sense, bending space-time? Of course, I don’t expect an answer now as it is definitely a TOE/Quantum gravity territory. However, let me rephrase my question in a narrower...
  30. B

    How Can a Sensor Accurately Control Inflation to 2 PSI?

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  31. gauss44

    Why doesn't this reaction use an E2 mechanism?

    tert-butyl bromide + MeOK in MeOH -----> I would think that MeOK would dissociate in solution making it MeO- which would be strong enough to yank a proton off tert-butyl bromide and initiate an E2 reaction. Where am I going wrong? PS - I am a tutor who hasn't done organic chemistry for a...
  32. spacecadet11

    Exploring the Mechanism of the Higgs Boson and Its Potential Control

    Hello. Since the Higgs Boson is responsible for giving sub-atomic particles mass..or any particles there mass..is there a present understanding of the mechanism by which the field actually does this? And if there is...is there any artificial way of controlling it? My thinking is that if you...
  33. agnishom

    Does the Higgs mechanism explain the equivalence of gravitiational and

    I am not well versed in the idea of Higgs mechanism. However, I was wondering if it does explain the problem of equivalence of gravitational and inertial mass. Also, what is the modern accepted definition of mass?
  34. jmex

    Airfoil Mechanism: Exploring Lift & Drag Forces, Angle of Lift & VAWT

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  35. S

    Retraction Mechanism for threaded nut

    Hi, I have been trying to find all the retraction mechanisms possible to bring the nut back on the threaded shaft when it comes forward. Constraint is geometry. Between the back of nut and the face of the threaded shaft, space is max. 6 mm. also, the nut moves only 2 mm forward on shaft...
  36. T

    Mechanism of Intake Pumping Losses

    I'm a mechanic and I'm debating the exact mechanism of the so called "pumping losses" or "pumping work" of conventionally throttled 4 stroke spark ignition engines. We know that EGR is employed to reduce intake pumping losses and actually increases engine efficiency for slightly better fuel...
  37. B

    Crystal Radios - Understanding The Tuning Mechanism

    Hello, I bought an electronics kit for my 12 year old brother (and perhaps a little for myself too...) for building a crystal radio. I would like to understand what's going on when I tune the radio, so that I can explain it to him. It's a simple setup, where changing the position of a...
  38. R

    Does steam deaeration involve Henry's Law?

    On many boiler feed-water systems there are deaerators which essentially sparge steam through the water. Why does steam deaerate water? Is this simply a temperature effect on gas solubility? Or something else?
  39. J

    Why was confirming Higgs mechanism worth it?

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  40. Dotini

    Solar Wind Modulates Lightning - Mechanism Unknown

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  41. B

    Neutron Stabilization mechanism?

    If a neutron is unstable outside the nucleus, then what makes it stable within the nucleus? Does the binding of particles together somehow make them stable? Neutrons decay via the weak force, but are bound in the nucleus by the strong force. Does the strong force inhibit the weak force...
  42. Kkangliu

    How could Einstein's theory contradict to the quantum mechanism?

    We all know that Einstein's theory apply to the big universe, and quantum mechanism apply to the nanoscopic scale, and both theory work perfectly in it's realm, but how could two theory contradict each other?
  43. S

    Mechanism of benzene nucleophilicity activation

    I have some questions how various substituents are transfering benzene conjugated (π) electrons (i.e. activating/deactivating). As usual, no chemist provides an explanation. 1)As I see, the first important thing when forming a carbocation during electrophilic aromatic substitution is to find...
  44. M

    Missing technique used to find acceleration of a 4-bar mechanism?

    Hi there! There is a technique that is being used by my lecturer for mechanisms course at uni and i could not understand how this technique is manipulated.I wish i would know this methods name but no chance!. This technique is being used to find normal acceleration of link in 4-bar...
  45. A

    The 'mechanism' of length contraction

    Let's suppose that we have a rod which is 2 meters long in its rest frame. Its rest length can be defined as a set of points which do not occupy the same place, measured in a frame which is at rest with the rod as a whole. Now if we travel relative to the rod, it gets length contracted, I...
  46. P

    Analytical kinematics of a 6-bar mechanism

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  47. P

    The Higgs field (mechanism) is the cause of fictitious forces?

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  48. ChrisVer

    Initiating mechanism of supernovae

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  49. H

    Launching Mechanism: Design & Build for 400 Gram Projectiles

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  50. D

    Energy production mechanism using capillary action

    We know that water rises in a glass capillary owing to the surface tension phenomenon. If we make an arrangement as shown in the attachment, (read Water instead of mercury in the attachment, I got confused there) & do the following procedure. The valve at the bottom is open, & the one at the top...
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