Name:___________________________
Activity 2.2.2a Mechanical
Gears Review
Read each question carefully and place your answer in the appropriate space.
Examine the picture of the VEX model below and then answer the first three
questions.
1. Name the type of movement used as an input
____________________________.
2. The output movement has been changed to
__________________ movement.
3. We call this mechanism a
_______________________________.
4. In the belt drive mechanism, what happens when the belt is crossed instead of
open?_________________________________________________________
5. In a mechanism, when the input goes from a small gear to an output which is a
larger gear, the speed will ________________ (increase, decrease). When this
happens, the amount of torque will ____________________ (increase,
decrease).
6. When a big gear turns a small one, the output provides more
_____________________ but less _________________ than the input.
7. Which of the following mechanisms moved slower, the worm and wheel or the
rack and pinion? _____________________________________
8. Which mechanism transmits rotary motion to reciprocating? _______________
9. The advantage of using a chain drive over a belt drive is
______________________________________________________________.
10. The advantage of using a belt drive over a chain drive is
______________________________________________________________.
11. The purpose of an idler gear is to ___________________________________.
Use the formula below to determine the answers to questions 12 and 13.
Distance moved by rack = number of input turns X pitch X number of teeth on the gear
Problem: A rack with a pitch of 4 mm is used with a 20-tooth gear.
12. How far will the rack move when the input is given one turn?
________________________
13. How many turns will be needed to move the rack a distance of 240 mm?
________________
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PLTW Gateway – Automation and Robotics VEX Activity 2.2.2a Mechanical Gears Review – Page 1