August 2008 Understanding Simple Machines Assembled by Craig TillmannCraig Tillmann from the following web sites: Inventors Toolbox: The Elements of MachinesInventors Toolbox: The Elements of Machines How Stuff Works Explore Science Beakman and Jax: Levers Delightful Machines Levers Inclined Plane Wedge Wheel and Axle Screws Gears Pulleys Cams Machine Elements Gadget Anatomy Technology Education Home Page Modified by the GA Agriculture Education Curriculum Office July 2002
August 2008 Levers Learn more about levers Water Powered Simple Machine All levers have 3 parts: the fulcrum, the load, and the effort. The fulcrum is the pivot point. When it's right in the middle of the lever, the amount of effort you push down equals the amount of load you can lift.
August 2008 Moving the Fulcrum Here the fulcrum is closer to the load. The distance from the effort end to the fulcrum is twice the distance from the fulcrum to the load. You only have to push down half as hard to lift the same weight. The trade-off is you have to push down a longer distance.
August 2008 Classes of Levers First ClassSecond ClassThird Class
August 2008 Inclined Plane Online Multimedia Activity Requires ShockwaveShockwave An inclined plane is a ramp used to reduce the effort needed to raise or lower an object over a vertical height. Examples of inclined planes: Loading ramp Stairs or wheelchair ramp Mountain road Threaded screw. Inclined Plane Clocks
August 2008 Wedge A wedge converts motion in one direction into a splitting motion that acts at right angles to the blade. Nearly all cutting machines use the wedge. A lifting machine may use a wedge to get under a load.
August 2008 Wheel and Axle A wheel or spoke is locked to a central axle so that when one is turned the other must turn. A longer motion at the edge of the wheel is converted to a shorter more powerful motion at the axle.
August 2008 Screws A screw is a central core with a thread or groove(inclined plane) wrapped around it to form a helix. While turning, a screw converts a rotary motion into a forward or backward motion. Archimedes screw
August 2008 Gears Gears are toothed or pegged wheels meshed together to transmit motion and force. The larger gear will rotate more slowly than the smaller one, but will rotate with greater force. Each gear in a series reverses the direction of rotation of the previous gear. Bevel Gear Rack and Pinion Worm Gear Learn more about Gears
August 2008 Bevel Gear Bevel Gears are Gears that mesh at an angle and change the direction rotation.
August 2008 Rack and Pinion A single gear, the pinion, meshes with a sliding toothed rack. This combination converts rotary motion to linear motion. Windshield wipers are powered by a rack and pinion gear.
August 2008 Worm Gear combination of a gear meshed with the threads of a screw. changes the direction of turning motion by ninety degrees. decreases the speed of turning from screw to gear and increase its force. Click Image for animation
August 2008 Pulley System A single pulley reverses the direction of a force. When two pulleys are connected, they permit a heavy load to be lifted with less force. The trade-off is that the end of the rope must move a greater distance than the load. Learn more about pulleys
August 2008 Pulleys in Action
August 2008 Cams A cam is a wheel with shaped bumps on it. Cams are often connected to rods, levers, or springs. gravity trip hammer
August 2008 Cams at Work A Crank Shaft changes the linear motion of the piston to a rotary motion. A Cam Shaft is connected to the Crank by gears, belts or chains. It changes rotary motion to linear motion to open and close valves.
August 2008 Other Elements of Machines Crank and RodRatchet Allows a wheel to turn in only one direction. A bar called the "pawl" is fixed above the ratchet wheel. When the crank turns, the rod is pushed back and forth. Chains and Belts Connects two separated wheels so that when one turns, the other will turn in the same direction.
August 2008 Name the simple machines that make up each device Gadget Anatomy