1. Vallejo High Engineering Academy Jack Gillespie 2010

2. Gear Ratios Vallejo High Engineering Academy Jack Gillespie 2010

3. Key Questions How do gears work? What is the Law of Gearing? How can Gear Ratios be used to design machines? Vallejo High Engineering Academy Jack Gillespie 2010

4. Overview Vallejo High Engineering Academy Jack Gillespie 2010 Gears can be used to change direction of motion Gears can be used to increase speed while reducing power (torque) Gears can be used to reduce speed while increasing power (torque)

5. Examples of gears More example needed hear Vallejo High Engineering Academy Jack Gillespie 2010

6. What three reasons do we use gears? Vallejo High Engineering Academy Jack Gillespie 2010

7. What are the variables? Teeth – Each sized gear has a particular # of teeth. How many does each size have? Turns – Each gear turns an exact amount of times, which we can count. How many times does each one turn? Vallejo High Engineering Academy Jack Gillespie 2010

8. Mathematical Relationship (Input gear turns x Input gear teeth) = (Output gear turns x Output gear teeth) Make the equation easier to use by substituting 1.Let N i = # of turns of the Input gear 2.Let T i = # of teeth of the Input gear 3.Let N o = # of turns of the Output gear 4.Let T o = # of turns of the Output gear 5.N i x T i = N o x T o

9. The Law of Gearing N i x T i = N o x T o Can we write it another way? Vallejo High Engineering Academy Jack Gillespie 2010