This document presents a regenerative shock absorber that can harvest energy from vehicle suspension vibrations. It discusses two types of regenerative shock absorbers - linear and rotary. It focuses on the working of a rotary type shock absorber that uses a rack and pinion mechanism along with a mechanical motion rectifier to convert linear vibration into rotational motion. This drives a generator to produce electricity. Simulations and road tests showed that such a shock absorber is feasible and can generate an average power of 15.4 Watts from a vehicle driven at 15 mph. It concludes that a rack-pinion based design with a motion rectifier provides an effective way to harness energy from vehicle suspensions.

1. REGENERATIVE SHOCK
ABSORBER
Presented by:
NISHANT SARASWAT
USN:1DS11ME060
8TH SEM,SECTION-B
Presented on:
MARCH 4TH 2015
DEPARTMENT OF MECHANICAL ENGINEERING
dayananda sagar college of engineering

2. INTRODUCTION
• WHY THE NEED??
IN UNITED STATES ALONE,70% OF THE TOTAL
OIL CONSUMPTION IS UTILISED IN
TRANSPORTATION.
USEFUL: 10-16% OF THE TOTAL FUEL ENERGY !!
IMPROVEMENT OF FUEL EFFICIENCY

4. WHAT IS A REGENERATIVE SHOCK
ABSORBER??
• The primary function of vehicle suspension is
to reduce the vibration disturbance
• Hydraulic shock absorbers dissipate the
vibration energy into waste heat
• To improve the fuel efficiency of vehicles,
regenerative shock absorbers are designed to
harvest energy from the vibration.

5. WORKING OF A REGENERATIVE SHOCK
ABSORBER

6. REG. SHOCK
ABSORBERS
LINEAR TYPE
ROTARY
TYPE
• LINEAR TYPE:
utilize the relative motion
between magnetic field and
coils to directly generate
power based on Faraday’s
law of electromagnetic
induction
• ROTARY TYPE:
The rotary shock absorbers
transfer linear motion of
suspension vibration to rotary
motion to drive permanent
magnetic dc generators.

7. ROTARY TYPE REG. SHOCK ABSORBERS
• rotary shock absorbers are capable of generating more
power and getting a larger damping coefficient for the
given space
• Convert linear vibrations to rotary via 2 mechanisms:
>ball-screw mechanism
>rack and pinion mechanism
• Ball screw mechanism yield in lower efficiency at high
frequencies of vibration
• Preferred: rack and pinion mechanism

8. DESIGN PRINCIPLE

9. ADDITION OF MMR
• MMR = MECHANICAL MOTION RECTIFIER
• Analogous to a sine wave rectifier in an electric circuit
• A “motion rectifier” is created to “commutate” oscillatory
motion
• Converts 2-directional linear movement to a 1 direction
rotary movement
• The key components of “motion rectifier” are two one-way
roller clutches that transmit rotation only in one direction
and dive the motion in two different routes
• As a result, the shaft of the motor and planetary gear will
move always in one direction.

10. 1 rack
2 roller
3 pinion
4 planetary gears and motor
5 thrust bearings
6 roller clutches
7 ball bearings
8 bevel gears

11. OVERALL CIRCUIT:ORIGINAL AND
SIMPLIFIED

12. SIMULATION
• Based on this circuit based modeling method,
simulations can be done with Simulink/MATLAB.
We see that the voltage is
smoother when the input
frequency is higher, since
the effect of the motion
inertia is larger at higher
frequencies.

13. FEASIBILITY AND PRACTICAL TESTING
• road tests were done to verify the feasibility of principle and
design.MMR shock absorber was installed on a Chevrolet
Suburban SUV to replace its left rear shock absorber

14. RESULTS
the average output power was 15.4 Watts when the vehicle was driven at 15
mph on the circle road of State University of New York at Stony Brooks.
The result gives us the most convincing evidence that the MMR shock
absorber is feasible for energy harvesting from vehicle suspensions.

15. CONCLUSLION
• A rack–pinion-based electromagnetic regenerative
shock absorber is developed and tested, which can
generate electric power from the road-induced
suspension vibration of vehicles.
• Road tests were carried out to verify the performance
of the new designed regenerative shock absorber. The
experiment results indicate that the generated voltage
reflects the road irregularities well
• Mechanical motion rectifier was adopted for enhanced
efficiency and reliability

16. REFERENCES
• Electromagnetic Energy-Harvesting Shock Absorbers: Design,
Modeling, and Road Tests by Zhongjie Li, Lei Zuo, George Luhrs,
Liangjun Lin, and Yi-xian Qin
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 62, NO. 3,
MARCH 2013
• Efatpenah K Beno JH and Nichols SP 2000 Energy requirements of a
passive and an electromechanical active suspension system Vehicle
System Dynamics 34, 437-458
• Experimental Study of Damping and Energy Regeneration
Characteristics of a Hydraulic Electromagnetic Shock Absorber by
Zhigang Fang, Xuexun Guo, Lin Xu, and Han Zhang
Hindawi Publishing Corporation Advances in Mechanical Engineering
Volume 2013, Article ID 943528, 9 pages
http://dx.doi.org/10.1155/2013/943528