GRADE 9 Pre-technical TOOLS AND PRODUCTION – DRIVING TOOLS Notes
Pre-Technical: Tools and Production — Driving Tools
Subtopic: Driving Tools
Target: Kenyan learners (age 14). Simple notes, examples, safety and a short activity.
1. What are Driving Tools?
Driving tools are parts or tools in machines that pass motion or power from one part to another. They help make machines work by moving shafts, wheels, pumps, mills and other parts.
2. Common Types (with simple pictures)
Belt and Pulley
A flexible belt (rubber or leather) loops over two pulleys. When one pulley (driver) turns, it moves the belt and turns the other (driven).
- Used in maize (posho) mills, water pumps and some small factories.
- Good for smooth, low-noise drive and different pulley sizes (speed change).
Chain and Sprocket
A metal chain fits over toothed wheels (sprockets). Common on bicycles and motorcycles (boda-boda).
- Strong and good for high loads.
- Needs regular oiling to avoid rust.
Gears
Gears are toothed wheels that mesh together. They can change direction, speed and torque. Example: gearboxes in motor vehicles and some mills.
Couplings, Shafts and Universal Joints
- Couplings join two shafts so power passes between them.
- Shafts carry rotation from one machine part to another.
- Universal (U-) joints allow power transmission when shafts are at an angle (common in tractors and some farm machines).
3. Uses in Kenya — easy examples
- Bicycle: chain and sprocket — how you pedal and the wheel turns.
- Boda-boda and motorcycles: chain drive or sometimes shaft drive.
- Posho mill (maize mill): often uses belt and pulley from the motor to the grinding stones.
- Water pumps for small farms: belt or direct-coupled to engine or motor.
- Tractor implements: shafts, couplings and universal joints transfer power to ploughs and pumps.
4. Advantages and Disadvantages (short)
- Easy to change speed (pulleys/gears).
- Can transmit high power (chains, gears).
- Simple to fit and replace (belts).
- Belts can slip or wear out.
- Chains need oiling and can stretch.
- Gears are noisy and need accurate fitting.
5. Safety and Maintenance
- Always switch off and unplug machines before checking belts, chains or gears.
- Keep guards in place — never remove a cover while the machine runs.
- Oil chain regularly to stop rust and reduce wear.
- Check for loose bolts and worn teeth; replace parts that are damaged.
- Use correct tools and ask a trained person when unsure.
6. Quick Classroom Activity (5–10 minutes)
Find three items around your home or school (bicycle, pump, posho mill or generator). Identify which driving tool they use (belt, chain or gear). Draw a simple label showing driver and driven parts.
7. Short Quiz (answer in your notebook)
- Name two advantages of chain drives.
- Why should you oil a bicycle chain?
- Give one example of a machine in Kenya that uses belt drives.
End of notes — remember: driving tools are the hidden helpers that make many machines run. Spot them next time you ride a bicycle or visit a posho mill!