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(a) Name and describe the operation of any one of the mechanisms shown - Leaving Cert Engineering - Question 8 - 2011
Question 8
(a) Name and describe the operation of any one of the mechanisms shown. (i) Bevel gears. (ii) Roller bearing. (b) Explain any three of the following: (i) The adv... show full transcript
Worked Solution & Example Answer:(a) Name and describe the operation of any one of the mechanisms shown - Leaving Cert Engineering - Question 8 - 2011
Step 1
Name and describe the operation of any one of the mechanisms shown.
Answer
I will describe the operation of the roller bearing. A roller bearing allows a shaft to rotate within the bearing structure while being held in place. This significantly reduces friction, facilitating smoother motion of the rotating shaft. Roller bearings have a greater contact area compared to ball bearings, which allows them to bear larger loads and cope with radial and axial forces, making them essential in various applications, particularly in vehicles.
Step 2
Explain any three of the following: The advantages of using vee-pulley belts over flat belts;
Answer
- Greater Contact Area: Vee-pulley belts provide a larger surface area in contact with the pulley due to their unique shape, enhancing grip.
- Reduced Slip: The design of the vee-pulley minimizes the chance of the belt slipping off the pulley compared to flat belts.
- Capacity for Larger Forces: Vee-pulley belts can drive larger forces due to their improved tension and better grip.
Step 3
Explain any three of the following: Chain and sprocket;
Answer
A chain and sprocket system transmits motion from one toothed wheel to another. This arrangement is commonly used in bicycles and motor vehicles. The chain wraps around the sprockets, allowing for efficient power transfer. The positive engagement between the chain and sprockets minimizes slippage and leads to a strong connection, making it a preferred mechanism for transferring rotary motion.
Step 4
Explain any three of the following: Toggle mechanism;
Answer
The toggle mechanism employs a linkage system that clamps or holds firmly in position. It is characterized by its ability to change the direction of force effectively and maintain force even when movement is minimal. This mechanism is widely used in various applications, such as in woodworking or holding devices, due to its strength and simplicity.
Step 5
Describe, with the aid of a suitable diagram, a mechanism to control the steering of the go-kart shown.
Answer
The steering mechanism can be illustrated using a rack and pinion system. In this setup, the steering wheel connects to a column, which in turn operates a pinion gear. This pinion engages with a stationary rack. As the driver turns the steering wheel, the pinion rotates, causing the rack to move side to side. This lateral motion directly turns the front wheels, allowing the go-kart to steer left or right. This method is effective and common in many go-kart designs.