1. BASIC MECHANICAL FUNCTIONS
CHAPTER 12: PART 3
BASIC MECHANICAL FUNCTIONS
A technical object’s COMPONENTS are the parts or fluids that have a mechanical function.
A BASIC MECHANICAL FUNCTION is the role played by a component or a group of components in the function or assembly of a technical object.
1 – GUIDING FUNCTION
2 – LINKING FUNCTION

2. 1 – GUIDING FUNCTION
GUIDING is the basic mechanical function of any component that controls the motion of one or several parts.
A GUIDE is a component that has the basic mechanical function of guiding.
1 – ROTATIONAL GUIDE allows only rotational motion
2 – TRANSLATIONAL GUIDE allows side to side (up and down) motion

3. 2 – LINKING FUNCTION
A LINK helps connect two or more parts of a technical object.
LINKING is the basic mechanical function provided by any component that links and object’s parts.
A LINKING COMPONENT is one that has the basic mechanical function of linking.

4. LINKING CHARACTERISTICS
1 – DIRECT / INDIRECT no linking component vs. linking component (screw) EX. lid and container / shelves and wall 2 – RIGID / FLEXIBLE will not deform vs. deforming EX. hammer head and shank / tire and wheel 3 – REMOVABLE / NON-REMOVABLE seperation (no damage) vs. no seperation (damage) EX. nuts & bolts / glue or grout 4 – COMPLETE / PARTIAL no movement between parts vs. atleast one part can move EX. skate blade & plate / clothespin

5. PRINCIPAL TYPES OF LINKS
FIXED LINKS
ROTATING LINKS
SLIDING LINKS
SLIDING-ROTATING LINKS
SPHERICAL LINKS
HELICAL LINKS
With the exception of FIXED LINK, one of the two linked parts always guides the other. The motion performed by the guided part determines the link type.

6. FIXED LINK FIXED LINK: there is no movement between parts
Example: Remote control devices have parts that snap into place and don’t allow parts to move.

7. ROTATING LINK
ROTATING LINK: the guided part can undergo rotational motion around one axis.
Examples: Laptops and pliers, in order to open and close, rotate on a part that allows for limited movement on one axis.

8. SLIDING LINK
SLIDING LINK: the guided part can undergo translational motion on one axis.
Examples: Sliding doors move translational to open and close along a bracket that parts attach to together.

9. SLIDING-ROTATIONAL LINK
SLIDING-ROTATIONAL LINK: the guided part can undergo rotational and translational motion on the same axis.
Examples: Billboards use both a rotating and sliding motion to move their advertisements. Car companies use them to manufacture their cars on an assembly line.

10. SPHERICAL LINK
SPHERICAL LINK: the guided part can undergo rotational motion in many different directions.
Examples: Joysticks from video games can motion in all direction.

11. HELICAL LINK HELICAL LINK: the guided part can undergo helical motion.
Examples: Water taps move in their parts to open and close their valve in an helical fashion.