REGENERATIVE SHOCK ABSORBER

Presented by:NISHANT SARASWATUSN:1DS11ME0608TH SEM,SECTION-B

Presented on:MARCH 4TH 2015

DEPARTMENT OF MECHANICAL ENGINEERINGdayananda sagar college of engineering

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

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.

WORKING OF A REGENERATIVE SHOCK ABSORBER

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.

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

DESIGN PRINCIPLE

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.

1 rack2 roller3 pinion4 planetary gears and motor5 thrust bearings6 roller clutches7 ball bearings8 bevel gears

OVERALL CIRCUIT:ORIGINAL AND SIMPLIFIED

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.

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

RESULTSthe 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.

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

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