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user removed · 08-31-2012, 07:50 AM

My design which is covered by US patent #7677208 is for an in wheel variable displacement hydraulic pump-motor that does exactly what you describe in your post.
It is covered in several threads on this site since I joined in 2008.

The principle is to incorporate pulse and glide into the vehicle. Engine operation is separated from the vehicles speed, allowing the engine to operate in the range of absolutely best efficiency while maintaining a constant vehicle speed.

In wheel drives have an advantage over any other type. The reason is hydraulic drives suffer efficiency losses at higher RPM. Placing the drive in the wheel reduces the RPM. This allows the drive to keep speeds below 1000 RPM where efficiency is highest.

The infinitely variable ratios of the variable displacement drive mean that as pressure drops in the accumulator the precise amount of power may still be applied to the wheels until the pressure has reached the minimum required, at which point the engine starts and replenishes the pressure. This means the stroke position in the drive is constantly changing, as pressure drops the stroke increases. As pressure rises when the engine is running the stroke position decreases. All during the cycle the power applied to the wheels remains constant, providing a constant speed, even though the pressure is constantly changing. You are pulsing the accumulator instead of the vehicle itself, storing energy in the accumulator, versus conventional P&G where energy is stored in the speed of the vehicle itself.

If you search through the thread I have posted here over the last 4 years there is plenty of information. If you have a question please do not hesitate to ask.

regards
Mech

08-31-2012, 07:50 AM	#2 (permalink)
user removed Master EcoModder Join Date: Sep 2009 Posts: 5,927 Thanks: 877 Thanked 2,024 Times in 1,304 Posts	My design which is covered by US patent #7677208 is for an in wheel variable displacement hydraulic pump-motor that does exactly what you describe in your post. It is covered in several threads on this site since I joined in 2008. The principle is to incorporate pulse and glide into the vehicle. Engine operation is separated from the vehicles speed, allowing the engine to operate in the range of absolutely best efficiency while maintaining a constant vehicle speed. In wheel drives have an advantage over any other type. The reason is hydraulic drives suffer efficiency losses at higher RPM. Placing the drive in the wheel reduces the RPM. This allows the drive to keep speeds below 1000 RPM where efficiency is highest. The infinitely variable ratios of the variable displacement drive mean that as pressure drops in the accumulator the precise amount of power may still be applied to the wheels until the pressure has reached the minimum required, at which point the engine starts and replenishes the pressure. This means the stroke position in the drive is constantly changing, as pressure drops the stroke increases. As pressure rises when the engine is running the stroke position decreases. All during the cycle the power applied to the wheels remains constant, providing a constant speed, even though the pressure is constantly changing. You are pulsing the accumulator instead of the vehicle itself, storing energy in the accumulator, versus conventional P&G where energy is stored in the speed of the vehicle itself. If you search through the thread I have posted here over the last 4 years there is plenty of information. If you have a question please do not hesitate to ask. regards Mech Last edited by user removed; 09-04-2012 at 08:32 PM..