Hi all. Im working on a diy project for a super charger. I need to purchase some high speed bearings capable of 80,000+ rpm. I know SKF make super precision anguler ball bearing for this but I am clueless of where to actually purchase these! I gotten a headache searching for days now. Or if anyone can think of a low cost solution thats already available? These must be a mechanical bearing of some sort, not oil, air or manetic. I know they are found in nummerous apliances and power tools. Myonic make ball bearings for the new turbos, but is there a budget way of getting my hands on something like this for a small load?
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Where to Buy High Speed Ball Bearings 80000+ rpm 1
- Thread starter mamba76
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exactly what i imagined. If I blag a linkedIn profile maybe they will just give me some for a prototype lol
So back to square one. Anything I could salvage from a product already in use, bit early for the latest dysons 104krpm motors to be scrapped!
So back to square one. Anything I could salvage from a product already in use, bit early for the latest dysons 104krpm motors to be scrapped!
". . . but I am clueless of where to actually purchase these! I gotten a headache searching for days now."
My mistake. I'm sorry. I thought you were asking where you can purchase the bearings. I didn't realize your actual question was "Anyone want to make some calls for me and get some prices on what I'm looking for?" Seems like so many people are lost without their cell phones while never actually using the phone.
My mistake. I'm sorry. I thought you were asking where you can purchase the bearings. I didn't realize your actual question was "Anyone want to make some calls for me and get some prices on what I'm looking for?" Seems like so many people are lost without their cell phones while never actually using the phone.
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Thanks for getting the ball rolling (so to speak) 3DDave and understanding my hastly written question..
This ones cheap, must be bigger than it looks in the picture!
This ones cheap, must be bigger than it looks in the picture!
BrianPetersen
Mechanical
The price of bearings goes down as they get smaller, down to a certain theshold, then it starts going up again.
Minor investigation found this:
And this:
And this:
It's pretty apparent that these are tailored to the application and are not built-up from standard bearings. The inner and outer races of both bearings are one part.
Minor investigation found this:
And this:
And this:
It's pretty apparent that these are tailored to the application and are not built-up from standard bearings. The inner and outer races of both bearings are one part.
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Thanks Brian thats some helpful stuff will re read in more detail just out of interest. Its amazing how the turbo bearings hold up behind the turbine at temps of 900 degrees so oil cooling is a must. The amount of R&D put in to overcoming this problem is on top of just the R&D for a 'cold' bearing which just needs to withstand the centrifugal forces hence Im sure thats reflected in the price and would be over kill for my application. My design really is simple and will put together a CAD drawing to share at some point but essentially its a new machined spindle that accepts a bearing at each end with a V pulley between the two. The compressor wheel will be attached to one end. I cant remember what load limit for the SKF bearing I see was but having the pulley between the two instead of a one end will double the tension I can put on a poly V belt, I dont think axial load will be an issue. Then its balancing (youtube may have helped with this). Im trying to do this on a budget (£100 or less) I have the turbo but without the bearings its a non start.
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clear as mud mate
maybe dyson use magnetic or air bearings, i dont know. At the end of the day its just a f!*kin bearing, for my purpose it no other job but to withstand high centrifugal forces. ie I dont want it breaking apart causing pieces of compressor wheel to fly into my engine. I can see ultra high speed bearings becoming more and more in demand in the future. Dyson and e-turbos being a good example.
maybe dyson use magnetic or air bearings, i dont know. At the end of the day its just a f!*kin bearing, for my purpose it no other job but to withstand high centrifugal forces. ie I dont want it breaking apart causing pieces of compressor wheel to fly into my engine. I can see ultra high speed bearings becoming more and more in demand in the future. Dyson and e-turbos being a good example.
BrianPetersen
Mechanical
The turbocharger bearings will not have significant side-pull loadings in their original application (e.g. the type of loading that would happen if you drove it with a belt). Speaking of which, a belt that drives to 80,000 - 100,000 rpm would be challenging on its own.
I own a vehicle that has a centrifugal supercharger. A chain-and-sprocket drive an intermediate shaft at fairly close to engine crankshaft speed, then that intermediate shaft drives a set of planetary gears in a speed-increaser configuration to drive the centrifugal compressor such that the high-speed shaft has as little side loading as possible. Hydrodynamic bearings on that shaft - not ball bearings.
I own a vehicle that has a centrifugal supercharger. A chain-and-sprocket drive an intermediate shaft at fairly close to engine crankshaft speed, then that intermediate shaft drives a set of planetary gears in a speed-increaser configuration to drive the centrifugal compressor such that the high-speed shaft has as little side loading as possible. Hydrodynamic bearings on that shaft - not ball bearings.
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Hmm side load, been thinking about that most of the night. I thought a large sprocket would produce lower load than a belt but surely any unequal load would unbalance a balanced shaft even tho the bearings have a radial force limit. Planatary gears with oil film bearings is probably the only way to go, Kawasaki H2 has the same setup. How about a bigger compressor & housing at lower speed? What sort of speed limit for a side load biased design?
Is the speed increaser to limit acceleration stresses on the compressor shaft or to do with tuning air flow to the engine? Is yours petrol? Mines a 3.0lt diesel audi ASB engine already mapped to 289 on a dyno. It has a wee bit of black smoke at higher rpm which tells me theres wasted power there due to lack of air. When I learnt more about superchargers on diesels and realized you can achieve boost on idle Im like Fuk yeah! It will be all down to controlling the boost which there are numerous ways to achieve that (Im thinking independent controlled maps, rasberry PI, solenoid, pwm servo, emergency mechanical pop off valve, etc). Probably have to look at the drivers wish and fuel maps on my ecu at some point too as having that much air available at that rpm was never in the tuners mind.
Is the speed increaser to limit acceleration stresses on the compressor shaft or to do with tuning air flow to the engine? Is yours petrol? Mines a 3.0lt diesel audi ASB engine already mapped to 289 on a dyno. It has a wee bit of black smoke at higher rpm which tells me theres wasted power there due to lack of air. When I learnt more about superchargers on diesels and realized you can achieve boost on idle Im like Fuk yeah! It will be all down to controlling the boost which there are numerous ways to achieve that (Im thinking independent controlled maps, rasberry PI, solenoid, pwm servo, emergency mechanical pop off valve, etc). Probably have to look at the drivers wish and fuel maps on my ecu at some point too as having that much air available at that rpm was never in the tuners mind.
BrianPetersen
Mechanical
Mine is a Kawasaki H2 ...
Re "superchargers can produce boost down to idle" That is only true of a positive-displacement supercharger (Roots, screw-type, VW G-lader, etc). It is absolutely not true of a centrifugal supercharger, which is if anything even worse off than a turbocharger in this respect. At least with a turbocharger you can size the turbine so that it drives the compressor into its good operating speed range somewhere in the mid-range of engine revs, and either wastegate or use variable vane angles to keep it from overspeeding at high engine revs. With a centrifugal supercharger, no can do, it is locked in proportion to engine revs, and remember, the natural characteristic of a centrifugal pump is for the pressure it produces to go up with the square of revs.
In the case of the H2, the centrifugal supercharger has been very carefully matched to the engine. It is small and fast-spinning to get good boost in the mid-range, and the flow through it is intentionally choking at high engine revs to contain the boost pressure at high revs. It doesn't produce much boost down low ... but the cam timing of the engine has been selected so that the engine itself naturally makes lots of torque down low; that also chokes off at higher revs but that's when the supercharger stuffs more air into it.
I know it's possible to speed up the supercharger drive of the H2, but it's very easy to get in trouble that way, and I've not done it.
Re "superchargers can produce boost down to idle" That is only true of a positive-displacement supercharger (Roots, screw-type, VW G-lader, etc). It is absolutely not true of a centrifugal supercharger, which is if anything even worse off than a turbocharger in this respect. At least with a turbocharger you can size the turbine so that it drives the compressor into its good operating speed range somewhere in the mid-range of engine revs, and either wastegate or use variable vane angles to keep it from overspeeding at high engine revs. With a centrifugal supercharger, no can do, it is locked in proportion to engine revs, and remember, the natural characteristic of a centrifugal pump is for the pressure it produces to go up with the square of revs.
In the case of the H2, the centrifugal supercharger has been very carefully matched to the engine. It is small and fast-spinning to get good boost in the mid-range, and the flow through it is intentionally choking at high engine revs to contain the boost pressure at high revs. It doesn't produce much boost down low ... but the cam timing of the engine has been selected so that the engine itself naturally makes lots of torque down low; that also chokes off at higher revs but that's when the supercharger stuffs more air into it.
I know it's possible to speed up the supercharger drive of the H2, but it's very easy to get in trouble that way, and I've not done it.
BrianPetersen
Mechanical
Another small thing. Boost pressure regulation. With a turbocharger, you can spill some of the exhaust flow (thus essentially slowing down the compressor and thus regulating the boost pressure) and it doesn't really hurt the efficiency much, because you are throwing away energy that you would have thrown away down the exhaust pipe anyhow. If you are doing ANYthing to regulate boost pressure of a supercharger by spilling boost pressure that you have generated using mechanical crankshaft power, it will be an efficiency-killer and put more heat into the system.
The H2 has a blow-off valve, but it only opens if the throttle is abruptly shut at higher revs to avoid having the compressor operate in the surge regime (and it only blows off just enough to keep the compressor out of surge under shut-throttle coast-down conditions). It is absolutely not used for primary boost pressure regulation - that is done purely through tailoring the characteristics of the turbocompressor to the engine. Remember, you can't overspeed (overboost) a mechanically-driven supercharger the way you can a turbocharger.
Petrol consumption on the H2 is kept tolerable because when you are puttering around slowly on it (and "slow" means anything below 200 km/h, it's all relative), the engine is at lower revs, not generating much boost, and the compressor is therefore not consuming much shaft power. Otherwise ... it will pass everything except a petrol station. At best, it uses more petrol than my car does. It is very easy, although potentially license-busting, to make it use more petrol than my van.
The H2 has a blow-off valve, but it only opens if the throttle is abruptly shut at higher revs to avoid having the compressor operate in the surge regime (and it only blows off just enough to keep the compressor out of surge under shut-throttle coast-down conditions). It is absolutely not used for primary boost pressure regulation - that is done purely through tailoring the characteristics of the turbocompressor to the engine. Remember, you can't overspeed (overboost) a mechanically-driven supercharger the way you can a turbocharger.
Petrol consumption on the H2 is kept tolerable because when you are puttering around slowly on it (and "slow" means anything below 200 km/h, it's all relative), the engine is at lower revs, not generating much boost, and the compressor is therefore not consuming much shaft power. Otherwise ... it will pass everything except a petrol station. At best, it uses more petrol than my car does. It is very easy, although potentially license-busting, to make it use more petrol than my van.
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one big difference here tho Brian is its diesel. You can put as much air as you like through a diesel engine it will only produce heat relevent to the fuel the map makes available to burn. It doesn't matter if you run a bottle of nitrous at idle with 50 psi boost it wont produce any more heat / power until you add more fuel. My engine and lots of other diesels don't need stoic control for combustion as we rely on smoke maps for polution control. I probably wouldn't run 10 psi at idle anyway but its possible. If you have a large compressor and gearing to achieve it great I have 10 psi at idle, as you say centrifugal speed squares with rpm like a turbo and unlike a PDS system.
So say at 2000 crank rpm I'd have way too much boost from here on up to redline, but its simple pressure control and relieve. This could be made to work upstream or downstream of the Maf too as there no such thing as a lean diesel.
Id have to put theis thread to Bobby Singh on the particulars as he's the expert on these engines. I just need some help / knowledge of certain engineering methods mainly.
ps at this point I realise ball bearings may not be ideal, but there must be something that uses fluid bearings that could be salvaged from scrap. Hard disk drives use them. Should have posted this under steam punk heading lol
So say at 2000 crank rpm I'd have way too much boost from here on up to redline, but its simple pressure control and relieve. This could be made to work upstream or downstream of the Maf too as there no such thing as a lean diesel.
Id have to put theis thread to Bobby Singh on the particulars as he's the expert on these engines. I just need some help / knowledge of certain engineering methods mainly.
ps at this point I realise ball bearings may not be ideal, but there must be something that uses fluid bearings that could be salvaged from scrap. Hard disk drives use them. Should have posted this under steam punk heading lol
BrianPetersen
Mechanical
It will "work" but expending significant shaft power to compress too much air and then throwing it away out a bypass/vent/pressure-relief valve wastes a lot of it ... and because the engine is unthrottled, it will be trying to do that all the time. Yes it can "work" but it will be wasteful.
If you are using the vehicle for tractor-pulling or drag racing or some such thing, perhaps it doesn't matter.
If you're stuck in traffic, or puttering along at 60 km/h following a speed limit, it will cost you.
The OEMs know about superchargers, and their relative advantages and disadvantages.
If you are using the vehicle for tractor-pulling or drag racing or some such thing, perhaps it doesn't matter.
If you're stuck in traffic, or puttering along at 60 km/h following a speed limit, it will cost you.
The OEMs know about superchargers, and their relative advantages and disadvantages.
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I thought about that but I dont believe the work required(in bhp) will be that high. The final drive shaft, compressor wheel & pulley / coupling would weigh no more than 130g or less, the complicated maths come with the air resistance (54/43 compressor) and then run that in 2 atmopheres boost (3 absolute), Im sure someone on here could work this out, Ill do this another time, then compare that to say the bulk of an alternator (mines 180amp) if you try turning one by hand you'll know how heavy it is. I suspect the final work required to turn the compressor at full boost will still be less than an alternator, although the alternator has inertia???
As long as there is always more air than the fuel requires there shouldn't be any fluctuations in performance.
The key to this setup is boost control, I mean by the micro second, there actuators and large bore needle valve that can cope with precise small air bleed to wide open air dump very quickly. Using data from the existing map and speed sensors, with some programmable device could control this. Another method Im toying with is a magnetic coupling on the final drive instead of pulley, planet or spur gear, hell possibly magnetic reluctance gear but Iv heard eddy currents are a problem at very high speed. I put this question to a wind turbine company which uses this tech, Ill let you know what they say.
Iv been reccommended these by a bearing company as the best they can offer. They say upto 84krpm, Iv found data elsewhere that say 67krpm. They are marketing these for skateboards! lmao. I like to know what anyone thinks-
As long as there is always more air than the fuel requires there shouldn't be any fluctuations in performance.
The key to this setup is boost control, I mean by the micro second, there actuators and large bore needle valve that can cope with precise small air bleed to wide open air dump very quickly. Using data from the existing map and speed sensors, with some programmable device could control this. Another method Im toying with is a magnetic coupling on the final drive instead of pulley, planet or spur gear, hell possibly magnetic reluctance gear but Iv heard eddy currents are a problem at very high speed. I put this question to a wind turbine company which uses this tech, Ill let you know what they say.
Iv been reccommended these by a bearing company as the best they can offer. They say upto 84krpm, Iv found data elsewhere that say 67krpm. They are marketing these for skateboards! lmao. I like to know what anyone thinks-
You can calculate the compressor power requirement easily as long as you can plot the operating point on the map (or know the isentropic efficiency at your operating point). Simply calculate the isentropic compressor power and divide by the efficiency.
je suis charlie
je suis charlie
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- #19
Hi, unfortunately BorgWarner never published a compressor map for this turbo (BV50) but i can assimilate with a similar size turbo. First I want to see if I can solve the basic mechanical issues. One step at a time I guess but will defo post my findings on here when I get to it.
BrianPetersen
Mechanical
Start with this:
If you have a 3 litre 4 stroke engine turning at (let's say) 1500 rpm unthrottled, it's going to use 1.5 litres per rev x 1500 rpm = 2250 litres per minute (ballpark, order-of-magnitude) multiply by volumetric efficiency, multiply by compressor pressure ratio, divide by compressor temperature ratio. That calculator unfortunately wants old English units, but 2250 litres per minute is about 80 cfm. If you are wanting a compressor pressure ratio of 2 and you have perfect intercooling, that's going to be 160 cfm (remember, this calculator is wanting the volume of the compressor intake air) and it calculates 8 horsepower and that's assuming 100% efficiency throughout, so it's going to be worse.
Back off to a pressure ratio of 1.5 (so 120 cfm and 22 psia discharge pressure) and it becomes 3.3 horsepower. It will be higher due to various inefficiencies.
That's still enough to put a dent in your gas mileage.
If you have a 3 litre 4 stroke engine turning at (let's say) 1500 rpm unthrottled, it's going to use 1.5 litres per rev x 1500 rpm = 2250 litres per minute (ballpark, order-of-magnitude) multiply by volumetric efficiency, multiply by compressor pressure ratio, divide by compressor temperature ratio. That calculator unfortunately wants old English units, but 2250 litres per minute is about 80 cfm. If you are wanting a compressor pressure ratio of 2 and you have perfect intercooling, that's going to be 160 cfm (remember, this calculator is wanting the volume of the compressor intake air) and it calculates 8 horsepower and that's assuming 100% efficiency throughout, so it's going to be worse.
Back off to a pressure ratio of 1.5 (so 120 cfm and 22 psia discharge pressure) and it becomes 3.3 horsepower. It will be higher due to various inefficiencies.
That's still enough to put a dent in your gas mileage.
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