Ford pickup hydraulic hybrid (univ of idaho project)

[user removed]

Originally Posted by redpoint5

I have the same complaint about the linked video. Also, none of them show how it works. Is air compressed by the fluid to store the energy?

I don't see this as catching on for passenger vehicles, mostly because we are at the tail end of ICE in this application. With EVs becoming more popular, they will eventually eliminate even the modest mechanical complexity of hydraulics.

This seems more suited to garbage trucks and delivery vehicles as others have commented.

Does the method of energy conversion in a Nissan Leaf exclude it from having a hydraulic hybrid powertrain, or would you rather keep the friction brakes.

In fact in a battery electric configuration there would be no need to modulate the vehicle speed by restricting the energy flow to the motor since it would be done at each wheel individually and could even be intentionally imbalanced to enhance handling. All you need is on and off, replenish reserves, or off, the vehicle being driven by the accumulator.

regards
mech

[jamesqf]

Originally Posted by Old Mechanic

Does the method of energy conversion in a Nissan Leaf exclude it from having a hydraulic hybrid powertrain, or would you rather keep the friction brakes.

Just a thought: what happens with your hydraulic braking system when you have completely filled the energy storage? (Something that can easily happen in for instance mountain driving.) You have to get rid of the energy somehow...

[user removed]

Asked and answered years ago, right here. What happens to your fully charged electric car when you start going DOWN pikes peak?

You waste a lot of energy.

But like even amateur lawyers, you knew the answer before you asked the question.

regards
mech

[jamesqf]

Originally Posted by Old Mechanic

What happens to your fully charged electric car when you start going DOWN pikes peak?

You use the friction brakes, of course. But it's kinda hard to use those brakes if you no longer have them :-)

[user removed]

High pressure through a variable resitriction then to low pressure with the restriction controlling the deceleration.

regards
mech

[jamesqf]

I could be wrong, but at first glance it seems like that would have the same problem as electric braking in hybrids: it's velocity dependent, so (without a lot of added complication) braking effectiveness goes to near zero at low speeds, and wouldn't hold when parked.

[user removed]

A liquid locked hydraulic pump makes a nice parking brake, and you still need an emergency brake which is easy.

regards
mech