Basic Mechanical Functions

Mechanical Function: The role that any part plays inside an object is defined as its ‘mechanical function’. Four simple mechanical functions are –Guidance –Linking –Lubricating –Sealing

Guidance: Guidance and the links between prevent certain motions that would negatively affect the way the machine works. Guidance is the function of a part that directs another part along a specific path. Guidance dictates whether the motion is either rotational (wheel and axle) or translational (sliding drawer)

Motion: An object, totally independent from any other object has 6 degrees of motion freedom, - translation along 3 axis, and rotation around the same three axis. Guidance: 2 translations and 2 rotations around 3 different axis result in 12 different potential motions.

Lubrication: Lubrication is the function of a substance that reduces friction. Lubrication can be done by liquids (oil), semi-liquids (grease) or solids (graphite)

Lubrication: Choosing materials that facilitate motion reduces friction For example: choosing nylon or teflon Shape of an object can also reduce friction. For example – bearings and rollers

Sealing: A seal is a part whose function is to prevent a fluid (liquid or gas) from escaping its container. A seal between 2 parts may be obtained by a simple contact between them, but more often by the insertion of a compressible (squishy) material.

See “Links- Types” and “Links- Characteristics” PowerPoint presentations Basic Mechanical Functions Linking function: