A regenerative shock absorber is a type of

shock absorber A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most sh ...

that converts parasitic intermittent

linear motion Linear motion, also called rectilinear motion, is one-dimensional motion along a straight line, and can therefore be described mathematically using only one spatial dimension. The linear motion can be of two types: uniform linear motion, with co ...

and

vibration Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic function, periodic, such as the motion of a pendulum ...

into useful

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...

, such as

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

. Conventional shock absorbers simply dissipate this energy as

heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is al ...

. When used in an

electric vehicle An electric vehicle (EV) is a vehicle that uses one or more electric motors for propulsion. It can be powered by a collector system, with electricity from extravehicular sources, or it can be powered autonomously by a battery (sometimes cha ...

hybrid electric vehicle A hybrid electric vehicle (HEV) is a type of hybrid vehicle that combines a conventional internal combustion engine (ICE) system with an electric propulsion system ( hybrid vehicle drivetrain). The presence of the electric powertrain is intende ...

the electricity generated by the shock absorber can be diverted to its powertrain to increase battery life. In non-electric vehicles the electricity can be used to power accessories such as

air conditioning Air conditioning, often abbreviated as A/C or AC, is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as 'comfort cooling') and in some cases also strictly controlling ...

. Several different systems have been developed recently, though they are still in stages of development and not installed on production vehicles.

Electromagnetic

A patent for such a device was filed in 2005. This type of system uses a

linear motor A linear motor is an electric motor that has had its stator and rotor "unrolled", thus, instead of producing a torque (rotation), it produces a linear force along its length. However, linear motors are not necessarily straight. Characteristicall ...

/generator consisting of a stack of

permanent magnet A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, ...

s and coils to generate electricity. This system was further developed at

Tufts University Tufts University is a private research university on the border of Medford and Somerville, Massachusetts. It was founded in 1852 as Tufts College by Christian universalists who sought to provide a nonsectarian institution of higher learning. ...

and has been licensed to Electric Truck, LLC. Preliminary data suggests 20% to 70% of the energy normally lost in the suspension can be recaptured with this system. A system developed at

Swinburne University of Technology Swinburne University of Technology (often simply called Swinburne) is a public research university based in Melbourne, Australia. It was founded in 1908 as the Eastern Suburbs Technical College by George Swinburne to serve those without access ...

used DC electromagnetic machines as damping elements to generate energy for storage in conventional batteries. This system utilized a device based on similar principles to a 'step-up' (boost) DC-DC converter. The design offered the ability to optimize the

energy conversion efficiency Energy conversion efficiency (''η'') is the ratio between the useful output of an energy conversion machine and the input, in energy terms. The input, as well as the useful output may be chemical, electric power, mechanical work, light (radia ...

of the system and also allow the ability to control the damping coefficient of the damper, such that the system could act as a semi-active damper.

Hydraulic

A system developed at

MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...

uses

hydraulic Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counter ...

pistons to force fluid through a

turbine A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating e ...

coupled to a

generator Generator may refer to: * Signal generator, electronic devices that generate repeating or non-repeating electronic signals * Electric generator, a device that converts mechanical energy to electrical energy. * Generator (circuit theory), an eleme ...

. The system is controlled by active electronics which optimize damping, which the inventors claim also results in a smoother ride compared to a conventional suspension. They calculate that a large company like

Walmart Walmart Inc. (; formerly Wal-Mart Stores, Inc.) is an American multinational retail corporation that operates a chain of hypermarkets (also called supercenters), discount department stores, and grocery stores from the United States, headquarter ...

could save $13 million annually by converting their trucks. Another system has been developed by a team at

New York State University The State University of New York (SUNY, , ) is a system of public colleges and universities in the State of New York. It is one of the largest comprehensive system of universities, colleges, and community colleges in the United States. Led by c ...

References

External links

US Government study
Auto parts Energy recovery {{automotive-part-stub

Electromagnetic

Hydraulic

See also

References

External links