Mechanisms Animations and Technology Notes

This section of the D&RMT package contains:

• Mechanisms animations
• Technology exercises
• Design exercises
• Design analysis exercises

The animations cover:

• types of motion

• levers: Class 1, Class 2, Class 3, bell crank lever

• linkages

• pulleys and belts:

  • used to transmit motion and torque 

  • change speed of rotation

  • stepped cone pulleys

  • pulley belts used to transport products

  • pulley belts used as bandsaws

  • pulleys used for lifting and hauling

• chain and sprocket drive

• chain parts

• Gears:

  • spur gears

  • gear train

  • bevel gears

  • worm gear

  • rack and pinion

• cams, rotary and linear, cam followers

• ratchet and pawl

• crank mechanisms

• crank and slider

• application of screw mechanisms:

  • for clamping

  • to control movement

  • for lifting

• ball screws

• couplings

  • flanged

  • split

  • flexible

  • universal joint

• friction used to oppose motion:

  • brakes

  • clamps

  • grips / knurling

• reducing friction by the use of lubricants and bearings

• lubrication

• bearings:

  • bush

  • ball bearing

  • roller bearing

• mechanisms used on a bicycle.

View a sample of the mechanisms animations

Mechanisms Technology Exercises

This section, on the full version CD, contains mechanisms exercises that include:

Belt And Pulley Mechanism On A Drilling Machine

A drill chuck fitted to the spindle of a drilling machine should be capable of rotating at a variety of appropriate speeds for the sizes of twist drills being used and the material being drilled. A table of approximate speeds is given below.

The drilling machine spindle is connected to the electric motor by a V-belt running between two sets of pulleys called stepped cone pulleys. The speed of the driven pulley can altered by changing the position of the V-belt. 

In this example, the electric motor runs at a velocity of 2300 RPM. The pulley sizes are as shown on the diagram.

1. Draw a diagram of a pillar drill and label the INPUT device, the CONTROL device and the OUTPUT device.
2. Work out the output spindle speeds when the belt is fitted on each of the four possible positions on the stepped cone pulleys.
3. Draw the diagram of the stepped cone pulleys. Label the most appropriate belt positions for drill sizes between 3mm and 12mm when drilling mild steel, brass and aluminium. 

Mechanisms Design Exercises

This section, on the full version CD, contains design exercises in a mechanisms context, that include:

Design a method of hauling building materials onto high buildings.

In this design exercise, you will need to apply your knowledge of windlass mechanisms, pulleys, ratchet and pawl mechanisms, gear trains, electric motors and feed back in a system.

Bricks, mortar and roofing tiles regularly have to be hauled high onto buildings on a building site.  Use notes and sketches to illustrate your designs for the following: 

1. a system of hauling building materials up a building using a block and tackle arrangement;
2. a system of hauling building materials up a building using a windlass and a gear train arrangement; 
3. a system of hauling building materials up a building using an electric motor, where feedback is built into the system so that the electric motor will stop when the materials are at the required height. 
   

Your designs should show clearly the mechanical systems used and how all the components of the system are held together. You should describe any risks involved in using each system and how the hazards could be minimised.