[user removed]

The hydraulic hybrid power train was 78% efficient at recovering braking energy. This was a quote from Ryan Waddington at Next Energy in Detroit when I went there for a conference with Ricardo in 2006.

I had transitioned from an engine configuration to a direct in wheel drive over the summer of 2006 and Ricardo told me they were not prepared to consider the drive configuration.

Ryan suggested the best way to rapidly implement the design would be to configure it as a launch assist rear axle in a FWD car. With run flat tires or even other airless designs not capable of going flat with low RR, you could use the spare tire well as a location point for the accumulator, with it shielded with sheet metal in case of a catastrophic failure in an accident.

This would allow a currently produced vehicle to be upgraded to a launch assist option without any major redesign, or siginifiant additional manufacturing cost. No payback time period, immediate mileage benefit.

This would allow regenerative braking, but there is a critical additional benefit.

As long as your in wheel drives are truly Infinitely Variable Transmissions, you could configure the engine to go into a phase of operation where it only operated at highest BSFC while replenishing fluid pressure to the accumulator, when cruising at constant speeds with fairly light overall energy requirements. I would guess the threshold would be somewhere around 60 MPH, but if RR aero and other parasitic drag losses could be reduced overall then the 60 MPH figure would increase.

It is CRITICAL that you objectively consider this most crucial component of the system.

Understand a graph of energy demands with the 0 requirement line, where you have positive energy requirements above the line, and unnecessary losses below the line. The graph bounces all over the place, while the system I am proposing would eliminate all below the line losses and the positive requirement peaks would also disappear.

Cycling the engine only at highest BSGC would produce periods of 0 (on the line) no energy requirement, with periods of engine operation only at highest efficiency.

I have probably linked the INNAS HH BMW here several times previously, but they doubled the overall mileage using this exact operational tactic, so the benefit is documented by their efforts as well as the efforts of others.

I do NOT discount or have any reason to not consider the same power train configuration with pressure replenishment accomplished by simple applying battery power directly to an electric motor to pump hydraulic pressure to the accumulator. This would even possibly eliminate the necessity of any module to convert the battery energy to AC for the motor itself (cost $1900 for my insight)

I would imagine a Nissan leaf with a simple launch assist rear axle could possibly increase its range by 50% which would make it much more practical for many people who need that additional range.

The prototype is in the process of being designed to be built, and the motorcycle I am using to build a complete vehicle will weigh about half of the weight of its original configuration. Hopefully in a few months it will be operational. If it works as I think it will, it will refute any claims of HH being impractical due to weight penalties. INNAS has already proven that there is no weight penalty, but their design uses fixed displacement pumps which are less efficient, since fluid is constantly moving through the in wheel pump-drives.

My design would not need the transformers used in the INNAS configuration since the variable and reversible displacement in each in wheel drive allows infinite adjustment of the power applied to each wheel individually. The configuration could even be used to produce a vehicle that could corner unbelievably by apply different levels of power to each wheel completely independently of the other wheels.

regards
Mech