Mechanical Engineering- Old technologies & Present day applications

1. Simple Mechanisms & Highly interesting Simple applications –
By Muralidhar Ekambaram
CEO, Adeptus Servo- Mechatronics Private Limited

2. “Certainly when I thought of the hetero structure laser, I did not intend to
invent CD Players. I could not have anticipated the tremendous impact of
fiber optic communications. The person who come up with applications
thinks differently than the scientist who lays the foundation” – Herbert
Kroemer, Nobel Laureate
The above validates the importance of Application Engineering in any
field of science

3. Applications – Four Square method of testing transmission
components – Using Mainly Mechanisms/ Transmissions and
Electromagnetic devices of yesteryears
• Mechanically close looping Power with introducing torque thru
differential transmission & a Electromagnetic torquer
• Power to simulate load conditions= only losses in the mech. Loop
i.e approx. 40% of testing power
• Static and dynamic – variable speed@variable torque tests are
possible

4. Applications – Back to back regenerative method of testing transmission
components – Present day
• Electronically close looping Power with introducing torque thru back to back
coupling of transmission elements & an Electronic regenerative Load
simulating Dynamometer
• Power to simulate load conditions= only losses in the electrical Loop and
transmissions of approx. 30% of testing power
• Static and dynamic – variable speed @ variable torque tests are possible

5. Applications – Mechanical Engineering
• Planetary screws backlash free linear movements
Works on Sun-Planetary differential transmission –
For smooth back lash free, high efficiency
rotation to linear movement conversion

6. Cycloidal transmissions

7. Applications- Cycloidal transmissions
Advantages and disadvantages :
• High efficiencies
• Ultra high ratios per stage – Very low speed belt/ chain conveyors
• Compactness especially like aero space applications
• Inline Coaxial transmissions – Ease of machine designs
• Differential transmissions Like for centrifuges
• Zero backlash and high torque capacity.
• High vibration and increased wear on the exterior teeth of the cycloidal disk, as well as
component bearings due to the eccentric nature of the drive, if the cycloidal disk is not
balanced by a second disk or a counterweight.

8. Planetary gear/ Epicycloidal transmissions
Spur Planetary Helical Planetary
Applications that demand :
• High efficiencies
• Ultra high ratios
• Compactness
• Ease of installation
• Inline Coaxial transmissions
• High torque transmissions
• Differential transmissions

9. • Horizontal Centrifuge – Liquid – solids separator – By control of
differential speed between bowl & screw through braking
• Operated in differential speed mode
Special Applications – Planetary Gear boxes
• Machine – Crystallizer in Sugar Industry
• Objective – Power saving – From typical 15 HP to 3 HP
• Ratios – Usually of the order of 400: 1 to 30000:1
• Vertcal & horizontal equipment applications
• Equipment – Level control screw jacks
• Application – Critical container automatic leveling - Defence
• Prime mover – Servo motor
• Transmissions & Screw - Planetary

10. Applications – Horizontal Centrifuge – Decanter
Planetary/ Epicyclodal gear differential transmissions

11. Applications – Horizontal Centrifuge – Decanter
construction

12. How the Decanter Process Works
• The slurry is inserted into the centrifuge through a connecting pipe and onto a conveyor.
• Utilizing an internal feed compartment, the conveyor ushers the slurry through a nozzle into
the bowl area.
• The bowl rotates at high speeds to induce gravitational forces.
• The differential speed between bowl and screw convey the solids out of centrifuge
• High speed rotation separates the solid material from the liquid in a matter of seconds.
• The conveyor delivers the solid material upwards where it is discharged through a nozzle.
• The solid material removed, the purified liquid is released from a separate output.
Applications – Horizontal Centrifuge – Decanter

13. Applications – Horizontal Centrifuge – Decanter …. Contd…
Special notes on controls
• For achieving variable differential between bowl and screw, initially Pneumatic/Eddy current
brakes were used on the second input of the differential gear box (Epicycloidal/ Cycloidal). By
varying torque through closed loop Electro- Pneumatic/ Magnetic actuations based on
speeds feed back, the differential speed used to be controlled
• In one type of Decanter, the controls used to be in Positive feed back. That is if error is
positive actuation increases and vice versa
• Subsequently, Eddy current with 4 quadrant control was used for precise control of
differential
• Presently the second input is controlled through 4 Quadrant AC drive for dead on control of
differential

14. 1.The centrifugal force required for sedimentation of the solids
2.The clarification area necessary to “capture” the solids
3.The differential speed required to transport the solids out of the decanter
4.The hydrodynamic design, which determines the exact parameters for the turbulence
5.The design of the conveyor and beach sections, which are important for efficient solids
transportation.
Applications – Horizontal Centrifuge – Decanter ……….contd……
For designing a decanter centrifuge for a particular application, very specific design
considerations to be carried out:
• the pitch of the conveyor
• feed zone design
• beach angle
• bowl surface
• abrasion and wear resistance
• materials of construction

15. Applications – Automatic Levelling systems for mobile shelters –
Servo motorized Screw jacks with automation

16. Typical servo motorized screw jack for Auto Levelling systems
• Auto Levelling based on 2 axes
inclinometer feedback
• Actuations are by AC/DC Servo motors in
position control based on feed back from
absolute encoders pitch of the conveyor
•All the four actuators are either
individually controlled / in synchronism
• System ruggedized to suit harshest
ambience
•Controllability within 0.5 degrees or even
better in 2 axes
• PLC based system with remote
communication capability
• The transmissions are either worm/
bevel planetary/ bevel helical/ planetary
• The jacuators either Trapezoidal / V
threaded / Planetary screws depending on
application.

17. Four bar Linkage Mechanism in Papermaking in Roll to Sheeting lines
in a Paper Mill – Converting House

18. CONCLUSION
• Mechanical technologies and Mechatronics has extraordinarily large boundaries of
applications
• It is more oriented to Applied sciences, Sourcing and Integration with Cost engineering
• It is successful with concentrated perception, observation, knowledge management as
well as reverse engineering and systematic project & integration management
• Applied Mathematics & Physics play very vital role