Mechanical Engineering Linking in Technical Objects Guiding Controls

Pages Work book p. 217 Text book p. 427

Linking in technical objects

Mechanical Engineering is… A branch of engineering that focuses on the design, production, analysis, working and improvement of technical objects with moving parts

A link allows… Two or more parts of a technical object to be held together

In mechanics, a component is… a part or fluid that performs a mechanical function

Linking is… The mechanical function performed by any component that connects different parts of a technical object

The degrees of freedom are… The set of independent movements that are possible for a given part in a technical object

Possibilities of Independent Motion

Translational Motion

Translational Motion

Translational motion From left to right From top to bottom From back to front Tx Ty Tz

Left to Right (Tx) X-Axis

Top to Bottom (Ty) Y-Axis

Back to Front (Tz) Z-Axis

Rotational Motion

Rotational Motion

Rotational Motion About the x axis About the y axis About the z axis Rx Ry Rz

X-Axis (Rx) X-Axis

Y-Axis (Ry) Y-Axis

Z-Axis (Rz) Z-Axis

Characteristics of links p. 218

1st Characteristic pair Direct Indirect

Direct Cell Phone > Case A direct link exists when two parts can hold together without requiring a linking component Cell Phone > Case

? Indirect Arm > Frame An indirect link exists when the parts require a linking component to hold them together ? Arm > Frame

2nd Characteristic pair Rigid Flexible

Rigid Base > monitor A rigid link exists when the surfaces of the linked parts or the linking component are rigid Base > monitor

Flexible Pages > spine A flexible link exists when the surface of the linked parts or the linking component can be deformed Pages > spine

3rd Characteristic pair Removable Non-removable

Removable Lid > Bottle A removable link exists when linked parts can be separated without damaging them Lid > Bottle

? Non-removable Sole > upper A non-removable link exists when separating the linked parts damages them or the linking component Sole > upper ?

4th Characteristic Pair Complete Partial

Complete link Top > bottom There is a complete link when there is no movement between linked parts Top > bottom

Toggle of the Zipper to the base Partial There is a partial link when at least one part is capable of motion with respect to the other Toggle of the Zipper to the base

Guiding Controls Work book p. 221 Text book p. 431

Guiding is… The mechanical function performed by any component that controls the motion of one or more moving parts

A Guiding Component or Control is.. A component whose mechanical function is to guide the motion of moving parts

Adhesion is… The phenomenon by which two surfaces tend to remain in contact with each other without slipping

In Mechanics, Friction is… A force that resists the slipping of one moving part over another

Lubrication is… The mechanical function performed by any component that reduces friction between two parts

Main Types of Guiding

Translational Guiding Ensures the straight translational motion of a moving part

Rotational Guiding Ensures the rotational motion of a moving part

Helical Guiding… Ensures the translational motion of a moving part while it rotates about the same axis

Homework Pp. 217-224

Activity # 2: Links Lab Goal: Study Various technical objects to determine the characteristics of the links in them

Materials Beaker tongs Petri Dish Retort Stand Overflow Can Universal Clamp C-clamp Screw Driver