1. Motion Transmission Systems 1. the mechanical fxn of relaying motion from 1 part to another without altering the nature of the motion 2. a set of components that perform the fxn of transmitting motion

2. Characteristics of Motion Transmission Systems All the systems transmit rotational motion. 1) The direction of rotation is sometimes identical throughout and sometimes different e.g. clockwise versus counterclockwise. 2) Reversing the sys may not always be possible.

3. 5 Systems 1) Gear Trains 2) Chain and Sprocket 3) Worm and Worm Gear 4) Friction Gear 5) Belt and Pulley

4. Gear Trains 1) Direction alternates from 1 gear to next. 2) Reversible.

5. Elements to consider when building a Gear Train At least 2 gears. Used to transmit motion btw 2 or more closely positioned parts. All teeth must be identical = same shape and spacing. Straight Gears when axes are parallel. Bevelled Gears when axes are perpendicular. The higher the number of teeth/the larger the diameter = the slower the speed.

6. Gear Train Animation http://www.youtube.com/watch?v=CgXCFw39 Gkw&feature=player_detailpage

7. Chain and Sprocket Systems Identical rotation for sprockets touching same side of chain. The 2 or more gears DO NOT mesh; they are connected by a chain. Used to transmit motion btw distant parts. The teeth on the sprockets must be identical. The chain links mesh with the sprocket teeth. Frequent lubrication necessary. The smaller a sprocket the faster it turns.

8. Chain and Sprocket http://www.youtube.com/watch?v=_GVq9O9mF Cs&feature=player_detailpage

9. Worm and Worm Gear Direction of Rotation varies with the threads on the worm screw shaft. Not reversible! Single worm (endless screw) whose rotational motion is transmitted to one or more worm gears. The groove of the worm must fit the gear teeth. The driver is the worm.

10. Worm and Worm Gear Animation http://www.youtube.com/watch?v=mNI0TwHK Ni4&feature=player_detailpage

11. Friction Gear Systems Direction alternates from 1 gear to next. Reversible. No teeth. Friction btw gears. Closely placed parts. More economical and less complicated. Less efficient because gears can slip. Straight, Bevelled and Spherical gears.

12. Belt and Pulley Systems Identical direction for pulleys touching on the same side of the belt. Toothless gears are referred to as pulleys connected by a belt. Btw 2 or more distant parts. Pulleys must contain a smooth groove where the belt can fit. The belt must adhere to the pulley to avoid slipping. The smaller the pulley the faster it turns.

13. Belt and Pulley Systems http://www.youtube.com/watch?v=OqrsEUVNA Js&feature=player_detailpage