Hybrid vehicles

A hybrid automobile is a vehicle that uses a combination of multiple sources of energy. It could be for instance a combustion engine, electric motor and an accumulator, fuel cells, ,electro motor and an accumulator, combustion engine and flywheel etc. to name a few.

It's the combination of a combustion engine, electromotor and an accumulator that is the most wide spread and effective for LCE. That's why we are going to focus on this concept and will describe its advantages.

The effectiveness of today's combustion engines runs in a range of 30-40%. Gas (petrol) engines' effectiveness is on the bottom on the range while the diesel enginesare somewhat better. This value is mostly based on the effectiveness of the thermodynamic cycle itself which has some clear physical limitations. Therefore we cannot expect to see much of an improvement in the future. The main problem is that the current effectiveness is at its maximum and is reached only when the engine works under optimal conditions.

This effectiveness can therefore be reached only rarely under the normal working conditions and the overall effectiveness then is significantly lower. The extreme case here is an operation in idle position when the engine consumes fuel while the car doesn't perform any activity. As the combustion engine can acceptably perform only at a limited range of RPM the use of transmission is necessary.

The transmission brings another not insignificant energy loss. The number of gears is usually also limited which creates yet another reason why the engine cannot work at its optimum conditions.There are also continuous transmissions but their effectiveness is even somewhat lower.

Current electric engines' effectiveness, on the other hand, comes at around 95% and all that at a wide range of RPM and load. Ideal solution would therefore seem to be in use of electric automobiles. Unfortunately, an excessive weight and a small operating range per charge prevent usage of this system. The recharge then takes a significant amount of time making the electro mobile practically almost useless for an every day operation.

The effort to combine both of these systems resulted in a concept called Hybrid Vehicle(HEV). LCE is well suitable for mass production HEV. In fact this concept is already used for many years in Diesel-Electric Locomotives.

Linear combustion engine is suitable for serial hybrid vehicles. Combustion engine hasn't mechanical connection with wheel, but only supplies electrical power to a storage battery. In fact this concept is already used for many years in Diesel-Electric Locomotives.

One of the advantages is that there is no need for transmission as the traction motors can work effectively in a wide range of RPM. There is also no need for a differential gear when two engines are used. Another option is in use of four smaller engines one for each wheel resulting in a full-fledged four-wheel drive without a need for a complicated axle differentiation.

The greatest advantage of this system is that the combustion engine operates only at its optimal regime. The engine completely turns off when the accumulators are charged.

The picture illustrates a schema of a series hybrid vehicle.

Schema series hybrid vehicle

It is clear that the use of LCE in mass production is ideal. It can increase car's effectiveness as well as decrease its weight. More compact design then allows for a less traditional placement of the unit - for instance under the vehicle floor.