# Rotary motion mechanisms

### What should we know to be able to solve these exercises of pulleys?

### Exercise pulleys 01

a) Calculate the gear ratio of this friction system

b) If the drive wheel moves at 30 rpm, at what velocity and in wich direcction will the driven wheel move?

### Exercise pulleys 02

a) Calculate the diameter of the drive wheel in the system in the diagram if it rotates at 70 rpm and the output wheel rotates at 560 rmp.

b) What is the gear ratio? What does it means?

### Exercise gear 01

a) Calculate the gear ratio of this gear system.

b) A what velocity does the drive wheel rotate if the output wheel rotates at 60 rpm?

In which direction do the wheels rotate?

### Exercise pulleys 03

An engine moves the wheel 1 at 900 rpm

- Calculate the velocity of the wheel 2
- Calculate the gear ratio of this system

### Exercise pulleys 05

An engine rotates at 100 rpm whith a wheel of 40 mm in its axle, joined with a belt to a pulley of 10 mm.

- Draw the system of pulleys. Indicate wich one is the drive wheel and the output wheel
- What is the gear ratio?
- What is the velocity of the output wheel

### Gear train

Calculate the velocity of the output of the gear system in the diagram

Write down the rotation direction of the wheels 2,3 and 4 given that the wheel 1 rotates in a clockwise direction.

### Pulley train

Calculate the velocity of the output wheel given that the diameter of the large wheels is 30 cm and that of the small wheels 5 cm.

The pulley 1 rotates at 150 rpm.