What’s a Motion Transmission System? Def: A system that passes on the same type of motion from one part of the system to the other part. Translational motion at the beginning to translational motion at the end Rotational motion at the beginning to rotational motion at the end

Motion Transmission Systems

Some vocabulary to know Most basic Driver component which begins the motion Driven component which receives the motion Reversibility is the ability for a system to operate by swapping the roles of the driver and driven.

Motion Transmission 1: Gear Trains Contains at least two gears that mesh together. The size of the teeth must be constant. The gears can be spurred (parallel) or bevelled (perpendicular) to one another. The bigger the gear, the slower its rotation. The smaller the gear, the faster its rotation. When the driver turns clockwise, the driven turns __________________.

The gear ratio (or speed ratio) is a number that tells you the relative speed of each gear. If the gear ratio > 1, the driver will ______________. If the gear ratio < 1, the driver will ______________.

Questions 1 2 3

Motion Transmission System 2: Chain and Sprocket This system involves gears that are not touching one another. They are connected by an intermediate, known as a chain. The speed ratio works the same way as it does for the gear train system.

Motion Transmission System 2: Chain and Sprocket Is the system reversible? If gear A turns clockwise…

Motion Transmission System 2: Chain and Sprocket Specific details about chain and sprocket systems: The teeth on the sprockets (gears) must be identical and must mesh with the chain. The system requires constant ______________.

Motion Transmission System 3: Worm and Gear Consists of one endless screw and at least one gear. For each full rotation of the worm, the gear turns: ________________

Motion Transmission System 3: Worm and Gear Is this system reversible? Explain.

Motion Transmission System 4: Friction Gears Like Gear Trains, but with no teeth. Also, they are less efficient because they can slip.

Friction Gear System

Belt and Pulley System Like a Chain and Sprocket, but without teeth. It does not need to be lubricated, but it can slip.

Gear Train Chain and Sprocket Series of interlocking gears Sprockets (gears) surrounded by a chain

Worm and Worm Gear Friction Gear System Worm (screw) which turns a worm gear Friction Gear System Like a gear train, but without teeth

Belt and Pulley System Like a Chain and Sprocket, but without teeth. It does not need to be lubricated, but it can slip.

Speed Changes in Motion Transmission Systems

Speed Changes in the Remaining Systems The speed varies with the number of teeth/diameter of the gears If motion is transmitted from a large gear to a small gear, speed increases If motion is transmitted from a small gear to a large gear, speed decreases If motion is transmitted to gears of equal size, no speed change occurs

Motion Transformation Systems

Motion Transformation Systems Definition: Relaying a motion from one part of the system to another, while changing its form Translational motion to Rotational motion Rotational motion to Translational motion

Rack and Pinion Contains a rack (straight bar with teeth) and a pinion (gear). This system is reversible While building a rack and pinion you must ensure that: The teeth on both the rack and pinion must be identical The system requires frequent lubrification More teeth on pinion = slower rotation Uses: Car stirring mechanism

Motion Transformation 1 – Rack and Pinion This involves a gear (pinion) and a straight toothed piece of material (rack), that is sort of like an unrolled gear. When the pinion turns (rotational), it moves the rack back and forth (translational)

Where do we have Rack and Pinions?

Cam and Follower Rotational motion changed to translation motion Aspects of the cam and follower: The system is NOT reversible (you can’t push down on the cam to turn the follower). The follower must be guided in its translational motion. The shape of the cam affects the movement of the follower. A spring is needed to keep the follower in contact with the cam

Cam and Follower Uses Toys

Cam and Follower Uses Water Powered Mill

Motion Transformation 2 – Cam and Follower

Slider-Crank Rotational motion from the crank is changed into translational motion at the slider This system is reversible This is the mechanisms used in pistons

Slider-Crank Uses Trains-wheels

Screw Gear Systems (2 Types) Contains a nut and a screw. This system is not reversible Initial Motion: Rotational Final Motion: Translational Type 1: The Screw is the driver (nut is the driven) Type 2: The Nut is the driver (screw is the driven)

Screw Gear Systems: Type 1 Use: Car Jack The Screw is turned, which allows for translational motion of the jack to rise

Screw Gear Systems: Type 2 Use: Monkey Wrench It’s the nut that does the initial rotational movement

Gear Train Chain and Sprocket Series of interlocking gears Sprockets (gears) surrounded by a chain

Worm and Worm Gear Friction Gear System Worm (screw) which turns a worm gear Friction Gear System Like a gear train, but without teeth

Belt and Pulley System Like a Chain and Sprocket, but without teeth. It does not need to be lubricated, but it can slip.

Rack and Pinion Screw Gear (Two types) Nut and a screw Rack (bar) and Pinion (gear) Screw Gear (Two types) Nut and a screw

Slider-Crank Mechanism Cam and Follower Cam (circular component) and follower (red stick) Slider-Crank Mechanism Crank (rotational component) Slider (moving rod)