Complex Mechanical Function System: set of components that share the same function Complex mechanical function: role played by set of components in transferring motion inside a technical object

Example: Crankset of a Bike A bicycle is a system of simple machines. It is made up of different components that work together. All systems contain: 1. Driver: receives power to set system in motion (sprocket of crankset) 2. Driven: receives the motion and transmits it to another part (crankset to wheel) 3. Intermediate (may contain or not) transfers motion between driver and driven

Mechanical Systems When simple machines are combined, a MECHANICAL SYSTEM is formed When the same type of motion is transmitted from one component to another without changing form, we call it MOTION TRANSMISSION. When the type of motion changes from one component in a system to another, we call it MOTION TRANSFORMATION.

Motion transmission Chain & sprocket

Motion Transmission Chain and sprocket Connects components that are far away from one another. gears don’t mesh together; connected with a chain (or sprocket) Advantages Chain meshes prevents slip Great force aplied Disadvantages Constant lubrication Limited speed

Motion Transmission Belt & pulley

Motion Transmission Belt and pulley system(far apart) When building a belt and pulley system, you must ensure: Pulleys must contain a groove where the belt can fit The belt must adhere to the pulleys The smaller the pulley the faster it turns Adv.- no lubrication, high speed Disadv.- belt may slip or break

Motion Transmission Gears

Motion Transmission Gear trains Contains(nearby parts) at least two gears that meet and mesh together Advantages Motion constant, Tiny spaces, high speed Disadvan. Precision, noisy, may need lubrication

Motion Transmission Friction wheels

Motion Transmission 4. Friction gear systems (nearby parts) Similar to gear trains yet less efficient (friction gears slip). Larger the gear the slower the rotation Adv.- easy to build, not noisy Disadv.- wheels might slide over

5. Worm and worm gear Transmits rotational motion to non-parallel part (close together) Teeth of worm slide into groove of worm gear thread Adv.- doesn’t loosen when gear releases adjusts precisely Disadv.- hard to build, wears out

Motion Transformation Recall: When the type of motion is changed from one component to another in a mechanical system, the motion has transformed.

Motion Transformation Systems 1. Slider- Crank System

Motion Transmission This is the mechanisms used in pistons

Motion Transformation Rack & Pinion

Motion Transformation 2. Rack and Pinion Contains a rack (straight bar with teeth) and a pinion (gear) While building a rack and pinion you must ensure that: The teeth on the rack and on the pinion must be identical The system requires frequent lubrification The greater the number of teeth on the pinion the slower the rotation

Motion Transformation 3. Cam & Follower

Motion Transformation Cam and Follower Rotational motion changed to translation motion When building a cam and follower, you must ensure that: The follower must be guided in its translational motion The shape of the cam determines how the follower will move A device such as a return spring is usually necessary to keep the follower in continual contact with the cam.

Motion Transformation 4. Screw Gear System: 4. Screw Gear System: