Electricity generating Shock absorbers
MIT has come up with an energy conserving device for vehicles. They have turned the shock absorber into a hydralic pump to power a turbine and use it to generate electricity to power the electrical system of the vehicle instead of the alternator. Seems about 1000 watts is available on the typical SUV size vehicle just from the bumps in the road. Big trucks would generate more power to drive cooling systems etc.
The idea is not new . . . 6/13/06 https://tech.groups.yahoo.com/group/ETList/message/6195 |
Pretty clever. Otherwise the energy just goes toward making the shock absorber hot, might as well recover the energy as electricity.
-BC |
That is so cool. We need more tings like this in all cars, like solar panel roofs, etc.
|
When I first read the title I had thought that the shock absorbers were using static electricity to create the charge, lol.
Good idea. Perhaps combining this system with the thermal-electric converters in the exhaust would be a great step towards removing the alternator from the automobile. Someday they will make an electric powered alternator to go a long with the electric power steering, A/C, and water pumps... Ok, sorry, j/k about the electric driven alternator. |
I have a problem with all electric accessories. The more efficient way to run the accessories is directly off the crank. This does, however, lead to inefficiencies as they are run all the time regardless of being needed or not. I would like to see accessories run off the belt but, instead of traditional pulleys, using electromagnetic torque converters like the Prius uses in its 'cvt'. If permanent magnets are used, any time the accessory is in use it's also acting as a generator. You apply more load to it to bring the accessory up to speed and as engine rpm changes the ac compressor or power steering pump can be run at a constant speed by varying the 'clutch'.
I've actually wanted to build one of these to replace the thermostatic clutch on the Durango and use it with a variable speed electric fan controller. The only problem I can see with the shock absorber generators is that it can't replace an alternator in the majority of those large vehicles. Anything used as a work truck will, in general, be subjected to long durations of idle. Heck, even my cars get that, especially at night when I need light and power from the car to work on something. |
Hmm....what about using shock absorber energy to feed hydraulic power into Gary's hydraulic hybrid pressure storage? That should be cheap and easy, probably using off-the-shelf hydraulic rams in place of shock absorbers...
|
Quote:
Plus, electric accessories are more flexible. They can be placed anywhere with regards to the drive train, and they allow continued functionality with auto-start systems. |
Yes HC it would add efficiency. My system is properly understood when you consider that no matter what you think the primary source of propulsion will be in the future (electric, hydrogen, diesel, gasoline etc), the hydraulic accumulator and in wheel regenerative drives will be the best means of applying energy to the vehicle. Another consideration with shock absorber created energy is you have no need for the electrical conversion.
Imagine what that kind of shock absorber would cost!!!!!!!! No electric hybrid will ever approach the efficiency my design will produce, once the pump efficiency has been verified. Current design are at 78 %, easily twice any hybrid electric electric vehicle. I am hoping my design will raise this to 80-85%. Thats regeneration efficiency, which means you have to go from wheel to accumulator, then back to wheel. Depending on RPM the best available bent axis pump-motors peak at 93%, at higher displacements. They suck at low displacements. The best accumulators are 99%. At low speeds I would like to see 95+% on my design. High speeds will not be necessary since wheel speeds should never exceed 1000 RPM. The competition bent axis pump drops off to about 75% at 3000 rpm which kills your highway mileage. We all know you double the engines efficiency when you operate it only in its sweet spot on the BSFC map. Storage of only max efficiency engine operation can double mileage, just like the best hypermilers can achieve, but it would be even better because although you are pulsing the engine, the vehicle speed remains constant (eliminating the exponentially higher total drag at the peak of your pulse). This is accomplished by constantly increasing the wheel-motor displacement as accumulator pressure decreases. You have the ability to apply the exact same amount of power regardless of accumulator pressure (less displacement at higher pressure, more at lower pressure-infinitely variable and controllable). The argument about the weight of the accumulator itself is also fallacious. If we spent a millionth of the money we have on battery technology, we could easily make accumulators that would have maximum pressures of 12000 PSI, almost 3 times the operating pressure of typical current designs. This requires no new technology. America's Cup Racers already use 12k PSI accumulators, the only drawback is the cost. The UPS trucks work on under 5K PSI, need 82 gallons of hydraulic fluid, but they weigh about 13 tons. In a 1 ton car that would mean you would need only 1/13 of 82 gallons. If you double the pressure, you only need 1/26th of the fluid, or about 3 gallons. You would save that same weight with your less than 4 gallon fuel tank, at least within 20 pounds. regards gary |
You have to be really careful about a lot of movement in the suspension system. If you start letting the wheels move a lot because you need the power you'll end up with very bad handling and lots of worn out suspension parts.
Gary, if you're wanting to build that system into a vehicle for testing I'd recommend a 4x4 SUV with manual hubs(or none at all like the durango). That'll make building a working prototype a heck of a lot easier and faster than in a car. Maybe a little Suzuki Samurai or something. |
Quote:
As you go over a bump, the bump pushes the piston into the cylinder, forcing hydraulic pressure into the lines, the opposite of how a common hydraulic ram is used in a jack or snowplow or backhoe. The energy is received at the accumulator. I don't know how the accumulator works, so maybe it would get complicated trying to receive the energy without making a harsh ride. |
Actually I have a Karmann Ghia. Its pretty rough so nothing lost with some sheet metal aero work. It's a 71 so the rear suspension is independent trailing arms, that dont need any axles or other powertrain parts to maintain their alignment.
I also have two diesel engines, a 600 CC 16.5 HP Kubota and a 1 liter 25 HP Yanmar. the Yanmar rotates in the right direction for adaptation to the transaxle. I would prefer to use in-wheel drives in the rear end. They could easily be installed in the existing trailing arms. I would do a significant amount of sheet metal aero work to get the CD down close to Basjoos Civic, but with smaller frontal area. I ws also thinking about some active aero, but the final configuration has not been determined yet. I was even thinking about making it a 3 wheeler with one in the rear depending on the cost of a functional in-wheel drive. Tech will have a prototype working in April, but it will not be practical for a car. Another idea would be to build a bicycle with a hydraulic drive, and energy storage. Parker hannifin has a contest with a 25k prize called the chainless challenge. Bicycles have no EPA or DOT requirements, while motorcycles have very little. Being a 1971, the car is considered an antique in VA which means it has almost no restrictions as far as inspections, etc. regards gary |
Are you trying to prove it as a viable technology for practical use or is this just something you are building for yourself?
If you are trying to prove it you'd be better off doing no aero mods at all so you can have a straight comparison with a vehicle of the same type. Then, you could take it to a proving ground and run each car individually until they use a specified amount of fuel to prove your technology. Sorry to thread jack, I try to make things as provable as possible when showing a positive effect. Your Ghia against another with a freshly rebuilt engine in it would be a good test that people will listen to. If you can't prove it and nobody can see the benefit you just have a bunch of ideas that YOU know work. That's one of the problems with Sandia National Laboratories; they invent a lot of great stuff but don't present themselves well. |
Gary - have you tried stopping and starting say from 25mph with your hybrid drive and seeing how much speed you recover from the 25mph stop energy. Repeated stops from 25mph and then back up to whatever the hydralic system can propel you will give you exactly how efficient your system is. I do know that the Prius system is pretty lossy.
As far as the shocks at MIT go it looks like they had a well made piston that had two hose fittings coming out of the center of either side of the cylinder body and I imagine some one way valving that would simply pump fluid through the shock. They claim it gave an improved ride than standard shocks and if the system failed it would still function as a standard shock would function. Wish I could remember where I saw the article . . . DUH GOOGLE !! https://web.mit.edu/newsoffice/2009/s...bers-0209.html |
Gents, I wish it was that easy. I was quoted 200k for a prototype. Tech is building a testable prototype for 2k in materials. The wife doesn't like the idea of spending 20-30% of our irreplaceable lifetime savings on my "dream".
Would your wife? The work being done by Tech includes all the CAD designs, which means I can hire any CAD equipped machine shop to build the pump-motor. The EPA has a funstional mule that is getting 85 MPG average with a bent axis pump. Everything becomes my property this May, unless Tech expresses interest in shared ownership. Tech has applied for a support grant that would go on for another 3 years with a final design delivered to Ann Arbor for installation in the existing EPA mule vehicle, which would allow a direct comparison of efficiency as well as the integrity of independent testing. This quest started with a 42 page document signed by 14 witnesses on August 5 2004. Maybe the present political climate is a necessary ingredient. It is truly sad to have the knowledge to fix the problem and watch my country drown in debt while I keep on plugging away. The sad thing is by addressing the real problem, one we are all familiar with, which is the potential for vast improvement in vehicle efficiency is really possible, solves a myriad of other problems at the same time. Maybe by the end of this year it will be at the next level. I sure hope so, not so much because it would make me financially secure, but because this planet may not have that much more time for people to ignore the situation. I am not a liberal or an environmnetalist by any stretch of the imagination. I just hate to see us sell ourselves out to the oil cartel, and continue destroying the environment in the process. Google Ingo Valentin to see another who has travelled the same course for over 20 years. Once you have a functional prototype the efficiency questions will be answered, but even then there will probably be some room for refinement with improvements in efficiency. Projections based on the functional prototype will be available in 2 months, but you must understand this is something that has never existed before, so it would seem unreasonable to assume you get it perfect on the first try. Think of it as the cornerstone to an already existing arch, that depends on the cornerstone to stand alone as a functional system. Your questions are valid of course, once the efficiency is confirmed, it becomes a no brainer, and the is considerable money waiting for that threshold to be met. Of course once the million dollar question is answered it will become much more expensive for any outside financier to buy any significant percentage of the rights to the design. In the present financial crisis, you can bet there is no money for anything but proven technology. This may change with the new 300 billion commitment to R&D of new vehicle technology and renewable energy sources. The other side of the coin is I am just another dreamer with a great idea looking for a handout, from the perspective of those who have seen another 100,000 great ideas that did not work. What it really boils down to is just bone headed determination, which I was genetically blessed with in abundance. regards gary |
Gary, would you be able to gather and extrapolate data from UPS' hydraulic hybrid trucks? I'm sure there must be data available, and even if it doesn't directly apply due to lower pressures or partially differing technology, I imagine that (armed with the intimate knowledge you have of the systems) it would be possible for you to make realistic extrapolations.
|
2000 LB 5 passenger car, 110 MPG city, 90 highway. 1 Liter turbo diesel engine producing 100 HP and 150 lb feet of torque. Aero CD of .25 or less.
Get the CD to .019 and the mileage would go up about 25% highway. The system would possibly double the urban mileage of pure electric vehicles. Depending on your trip distance you could always start out with a fully charged accumulator, and get a few miles on that without any outside power. Cars could have interchangeable power modules for pure electric and IC highway operation. Basic IC model would cost 10k new as a stripper, posssibly even less. Powertrain life expectency of 500k miles. To good to be believable? regards gary |
Why do you want to add a layer of complication and losses to a pure electric car when 3ph induction motors are pretty efficient across a wide range of power levels and rpm? They don't seem to NEED hypermiled, beyond reasonable conservation of momentum to prevent the losses associated with regenerative braking (which your system doesn't do 100% efficiency on either) What's the point there?
|
The regeneration efficiency of electric cars is about 35% compared to 85%.
I would think that point would be well understood. Even electric motors have a sweet spot for efficiency. Google "EPA hydraulic hybrids" if you would actually like to read and learn enough to answer your own question. regards gary |
Tesla Motors claims 85-95% efficiency for their motor, across the full range of operation loads and speeds. Now, with cheap batteries (*cough* lead acid) I can definitely see total drop to 35% or less but with good LiIon is it really that bad? And, if one adds capacitors to soak up the charge of braking, wouldn't it be much better?
I'm not trying to claim your system is bad for all applications, I'm just trying to wrap my head around why you'd want to use it with pure electric drives when 3ph induction motors driven with a VFD inverter are pretty efficient when coupled with decent batteries. |
My 85% quote is for the motor to the accumulator and back through the motor.
Their claim is for the motor alone, which ignores the compounding of inefficiencies. 85X85x85=61.4% so your comparison is basically flawed. It also ignores the other losses in conversion of the energy from AC to DC and back, as well as other losses. As I said look at the EPA hydraulic hybrid data. Your system would need capacitors to recover the massive increase in energy in any panic stop stiuation, as well as 4 wheel drive to avoid the 14% loss calculation if you only use 2 WD. Try driving your car in heavy traffic using only the emergency brake for stopping to understand the true factual comparison. So now you electric car needs 4 whell drive, which requires 4 wheel motors, capacitors, as well as a very expensive battery, unless you use lead acid which has pitiful energy density. Don't even think about the cost of your system or its weight. Don't even think about the cycle life expectancy of your components or their replacement costs. In contrast how many ancient hydraulic machines do you see that just keep running after thousands of hours of severe duty and neglect. If they start to leak, replace a few seals and hoses and keep on abusing them for years to come. Your electric car will never be cheap, mine will cost less than you lithium battery pack, and mine will rust away to a pile af flakes before you have to replace and major powertrain components. Of course forget ever driving 500+ miles per day on a vacation, unless you buy ANOTHER car for road trips. Mine can do either easily, so youy can do fine with one car. They have built hybrid SUV's. The EPA has built a Ford Expedition that gets 40 MPG with their bulky system. Imagine where they would be if they had spend the 20+ billion that has been spent on battery research over the last two decades. Quite the contrary, your proposed system is not good for any application, while mine is good for EVERY application. Accumulators can store 65 HP seconds per kilo in weight. That means I can recover all the energy in a 60-0 braking event in a package that weighs a hundred pounds, reapply that same energy at 85 % efficiency for blistering acceleration, hundreds of thousand of times without replacing anything. The future of short range electric vehicles in any metropolitan area will be a lot of dead batteries and cars stranded on the side of the road. When you run that battery dead it will have to be replace much earlier than its normal several thousand cycle lifespan, and compared to replacing an engine the bill will require you to take a second mortgage out on your house. regards gary |
And your hydraulic electric hybrid wont have to use batteries? Am I missing something? What will be it's primary energy source if not a big battery? And where's that 14% loss for 2wd come from?? Last I checked, 4wd was worse due to more moving components and weight.
One hundred pounds? That seems awfully light compared to anything hydraulic I've ever seen, if you want to talk about hydraulics in use now. I've looked at accumulators and they all seem large, heavy, expensive, and with minimal energy storage capability. (Kinda like older batteries?) At least, the ones available for purchase by Joe Consumer like me. I guess I'm just going to have to see your system when you build it. Not that I wish you failure, it would be a grand machine if you pull it off... Good luck! :D Dale |
The early Porsche 911 series had a self leveling option built by BOGE where the action of the front suspension supplied a volume of oil to give a self leveling to the front of the car where the luggage was.
The claim was a better ride and handling but the option cost and the repair and replacment costs meant the item was not commonly specified. Pete. |
RIDE, you inspired me to do some further research of my own into the world of hydraulics, and I found a few interesting things...
I found a 10 gallon, 3000psi (1500psi when nearly empty) 150lb accumulator (seems common) for about $900, and if I did my math right that works out to around 160 watt hours, or 780 HP-seconds. For a 2000lb car, like maybe a CRX with this added, that works out to enough energy to accelerate you from 0-40mph (My most common in-city scenario) 4 times WITHOUT regenerating any of it upon braking. While the accumulator wont get you more than a mile or so, it obviously can output vast amounts of power for a short period of time, way moreso than a hybrid-sized battery pack. Now, if you have 100 miles worth of LiIon or some other decent battery tech onboard, you already have a couple hundred HP of potential electrical energy to tap (and a reasonable recharge rate/efficiency hopefully) so I'm still not 100% sure it's worth it for that, but for a hybrid app it looks SWEET. That said, it also looks like it'd cost me a few grand to outfit anything like this onto a car of my own, even using off the shelf components.... but oh so tempting... |
Dale think of the accumulator as a energy demand dampner. Long term storage is unnecessary. You would want enough accumulator storage to get from 0-60 once. Accumulators are very ancient tech. The Americas cup racers use 12,000 PSI accumulators, and carbon fiber will bring the weight down even further, without making them exorbitantly expensive.
Now downsize the engine (IC) initially but let someone like Gale Banks make it have a high power output. Lets say a 200 HP 2 liter turbo diesel design. To this add an true aerodynamic body like the Mercedes Bionic style based on the Box Fish, with a CD of .19. Its inportant to understand that a single 60-0 braking event wastes the fuel that could carry you 7 tenths of a mile at a steady speed of 50-60 MPH. With my in wheel drive that only weighs the same as normal braking components, you have 4 wheel regeneration. The 4 wheel drive component is essential for 4 wheel brakes. It's not that I have any preference for 4 WD, but 4 wheel brakes are critical. In most circumstances you would never use the 4 wheel capability, except for braking events. There is no weight penalty if you understand that the system consists of the accumulator and the in wheel drives. You no longer need a transmission, drive axles, differential, brakes, or any other components related to any of those systems. Acceleration merely changes the stroke of the in wheel drives which changes their displacement depending of the acceleration desired. Braking merely reserses the process. The system will work equally well with any power source. By that I mean it could be electric or fuel consuming. Right now lithium batteries are the next "great white hope" of those who beleive electric cars are the future. Others believe hydrogen fuel cells are the future. Honda has committed a lot of money in that direction. others believe Homogenous Charge compression engines are the future. The fact is that any of the three examples would work fine in the design we are discussing. By removing the peak loads from the engine, you can run the engine only in it's sweet spot and double its efficiency. Design the engine for the application and efficiency goes even higher. The IC engine configuration would cycle the engine to maintain accumulator pressure levels, adn the engines load during it's operation would be only at its ideal brake specific fuel consumption. We should all know by now that is the essence of hypermiling, and the economy gains are dramatic. Last point, the design I am promoting, of which my in wheel drive is only the cornerstone somponent of an already existing system, makes the car capable of "pulse and glide" because that operational tactic is an essentail component of the system. The difference is now the engine can pulse, but the vehicle speed remains the same. The advantages of pulse and glide without anyone around you knowing it is even happening. Think of it as "stealth pulse and glide" your car does it automatically without any effort on the part of the driver. Even inefficient drivers would see little difference in mileage, harder stops and starts would only accumulate and supply the energy in less time. All future energy consuming power sources, hydrogen, biofuel, electric, gasoline. diesel. would compete on a level playing field using the same powertrain platform, with operation strategies optimalized for the specific application. The current lithium battery packs that would be necessary for 100 mile ranges cost as much as the whole vehicle I am describing with a simple small 4 cylinder engine. Your 10 gallon accumulator would shrink in size by a factor of 4 if the operational pressure was 12,000 instead of 3000, thats 2.5 gallons of fluid. A good compromise would be 6000 and a 5 gallon accumulator, that could be incorporated into the stricture of the vehicle, like and integral accumulator crossmember that supported the suspension and engine in a small FWD vehicle. This is real stuff, and it will happen soon I hope. I appreciate that fact that you have looked at the concept because it is not easy to explain so that people can understand it. My design could also be used in a bicycle. Parker hannefil has be sponsoring a contest called the Chainless Challenge for hydraulic drive bicycles. I actually think a small motor in an aero bike, with human power backup, may be the best intitial pathway to success. Everyone here should make the effort to understand this better. if a man can pedal an airplane 42 miles, imagine what he could do if he could glide and pulse the airplane with short term high capacity lightweight storage. That was done decades ago. Check out the Gossamer Albatross, Condor, and Penquin. Those are the Human powered airplanes that flew the courses to win the Kremer Prize. The Condor is in the Smithsonian Air and Space Museum. The other 2 flew the English channel, and the mythological route of Icarus in the mediterranean that was 42 miles over water. regards gary |
Here is the battery of the future.
Google "NASA flywheel battery" My design could use a battery of this type, IF it could be designed to work in an automotive environment. The design could also use a flywheel for storage instead of a conventional battery or accumulator. regards gary |
Re: Electricity generating Shock absorbers
sorry for making this thread become a zombie but....
what if you could use the power of the shocks to help power the engine kind of like a turbo compound engine(uses a turbine of the front of the crank to help turn the engine i think it can net 50 hp) so it can help the engine. |
Re: Electricity generating Shock absorbers
Holy crap, how rough are the roads there?!? :eek:
|
Re: Electricity generating Shock absorbers
Quote:
|
Re: Electricity generating Shock absorbers
Quote:
|
| All times are GMT -8. The time now is 01:13 PM. |
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.