PROJECT MEMBERS --->
MOHIT KUMAR(97206):mohit@iitk.ac.in
DUTTATREY PARASHAR(97123):dutta@iitk.ac.in
ASHISH MOHAN(97077):amohan@iitk.ac.in
CONTENTS
Engagement of gears:
Engagement of gear asssembly with tail shaft:
The permanent magnet DC motor rotates the gear 1 at a very high speed &low torque.A high torque & low speed is required to the hand shaft which is provided by the gear train shown in right.
Speed Ratio=(Speed of hand shaft)/(Speed of motor)
=(10/35)*(18/42)*(15/45)*(10/50)
=2/245
No load Speed of hand shaft=65 rpm
No load Speed of motor=65*245/2=7962.5 rpm
For waving tail ,similarly,a gear assembly(as shown in right) is used to get a much reduced speed.
Speed ratio=(Speed of tail shaft)/(Speed of motor)
=(10/35)*(18/42)*(1/3)*(1/5)*(1/2)*(1/3)
=1/735
At the outset, motion of the "TUMBLING MONKEY" looks arbitrary though the gear assembly provides two rotary motion(one at the hand shaft & one at the tail shaft) which owes to its outer shape.
- - - - represents ground in figure
Shape of hand:-- The shape of hand is shown above.The direction of rotation of hand shaft is CCW(as indicated in figure). As one can see the first contact of the rotating arm is with its wheel to the ground to reduce the friction.otherwise,at the time of contact the normal action is quite high ,hence sliding friction will be too high to cause the required action.