HOME  > Low Cost Automation Tutorial  > #053 LCA Mechanism Planning Method - 2 : Glossary of Mechanisms
Low Cost Automation Tutorial

#053 LCA Mechanism Planning Method - 2 : Glossary of Mechanisms

Category : Hints on designing
August27, 2010

 In order to plan a mechanism of high reliability and low cost, it helps to be able to imagine the concept as a simple and logical motion body.

Glossary of Basic Terms of Mechanisms

TermsExplanationDescriptive
Symbols
MechanismCombination of multiple mechanical components where movement of a component results in movements of the others. 
Driver and DrivenDriver: The side with a prime mover. Input side. Solid Arrow

Solid Arrow
Driven: The "moved" side. Output side.White Arrow

White Arrow
= Explanation =
A power transmission with two spur gears is a reversible system where the gears can rotate when Driver and Driven switch places.
A worm and wheel gear combination is a non-reversible system where the worm can be the Driver side and function as a reducer transmission, but the inverse will not function.
 
Mechanical ElementAn element composing a mechanism 
PairA motion mechanism comprised of a pair (two) of mechanical elements.

= Explanation =
Categorized into two types depending on how the pair of machine elements contact.

 Low Level PairSurface Contact (sliding, rotating, screw)
SlidingShaft & Linear Bushing, Piston & Cylinder, etc.
RotationPin & Metal
ScrewBolt & Nut

High Level PaiPoint contact, Line contact pairing
Point ContactLinear motion guides used ball bearing, etc.
Line ContactLinear motion guides used roller bearing, etc.
Sliding Pair

Sliding Pair

The lower level pairs are simple mechanisms and practical. The high level pairs are suitable for high speed and accuracy motion control, though knowledge on material selection and machining accuracy are required.

MISUMI USA eCatalog