Air Hybrid Drive 

     Project Status; New R&D project.                                               

This Air Hybrid Drive system is powered by Compressed air and an internal combustion engine.

The air cylinder is recharged whenever the cars brakes are applied (regenerative braking) by the dual air motors attached to the rear wheels. The stored free energy (compressed air) is released to assist in launching the vehicle from a standing start. No batteries required.


This hybrid design is referred to as "through the road" as there is no mechanical connection between the standard front drive axle and the rear air driven axle.


For those that doubt this hybrid configuration, Borg Warner have successfully produce an electric "through-the-road" hybrid system. Click on the link below for more information.  




Air Hybrid versus Hydraulic Hybrid

Hydraulic Hybrid Car

A good example of a sophisticated "hydraulic hybrid system" in cars, is the newly launched hybrid car concept developed by an EU consortium,  PSA Peugeot Citroen and Bosch hydraulics. Despite their misleading name of "Hybrid Air" it is a typical hydraulic hybrid system.

The hybrid driving elements form part of a complex hydro-mechanical transmission, stored energy created from "regenerative braking" is collected in a high pressure hydraulic accumulator, this oil is drawn from the  low-pressure accumulator or  reservoir. These hydraulic accumulators are commonly used in hydraulics systems. The accumulators are charged with nitrogen, not compressed air as advertised. Congratulations to them, for a job well done, in producing an outstanding hydraulic hybrid car design.



Air Hybrid Car

A true "Air Hybrid" only requires a single storage tank, as atmospheric air is drawn on to replenish the compressed air tank, see image below.

Air hybrids use air motors, not hydraulic motors and pumps and compressed air to produce the hybrid drive system. 

The below image is one of our new projects that we hope to have completed by the end of 2014. 


The power density is much less for the compressed air hybrid system than the hydraulic hybrid system, so performance of an air hybrid will never match that of the hydraulic hybrid system. On the up side, the Air Hybrid is much cheaper to manufacture and has a significant weight advantage in being much lighter. We expect a 40% reduction in fuel consumption for city driving cycles from our prototype over a standard vehicle. 

Also in development is a version, with a single air motor being incorporated in the trans-axle. This integrated trans-axle design would benefit from the torque multiplying effect of the transmission.

Pneumatic (AIR) drive components depicted in these images consist of 2, air powered wheel hub motors (blue), a high pressure air cylinder (grey) and a control block (red) 


The Mechatronic Control Unit (MCU) is the electronic module that controls all parameters of the vehicles driving cycle. It is an autonomous unit that operates independently of the vehicles existing electronics. 

Expressions of interest are sought from companies wanting to be an early adopter of this emerging technology



Cliff Hall.