Bad time to drop a turbo!

[ArtMech]

You're right guys. Probably it was Nissan corporation (correct me if I'm still wrong), which in about the mid '90ths has designed the turbocharger with the ball bearings first. But as I know from the history, it was an issue of vibration, durability and correct lubrication of these bearings, although the spec advantage was on the side of ball bearings. That's why the possible solution at that time was to use wet bearing (or floating sleeve, if it might be called a bearing). I had much dealing with them.

But I was too strict writing "I don't know any bearing, which could not vibrate at such conditions", because I didn't take into account last decade's technical development in this area.

The following link probably gives an answer to our discussion (I hope ):
APS Ball Bearing Turbocharger

I would stress on the statement from the part of an article of that link "Why Twin Ball Bearing?":
"In order to achieve crisp turbocharger response, a number of advances in turbocharger design have been utilized over the past decade. Primarily through the use of modern metals/ceramics in order to reduce the mass of the rotating assembly. However, significant gains have been made by reducing the friction of the rotating assembly - and this has meant a departure from traditional turbocharger designs."

What do You think the turbochargers of most tractor owners are like - sleeve or ball type?

I didn't know the ball bearings are actively implemented to the today's turbochargers. That's my fault :confused3:

 

[SPYDERLK]

The problem I see with ball bearings [other than huge G forces] is that they wear out. ... Unlike the hydrodynamic bearing that can last many lifetimes because there is no contact.
larry

 

[Redneck in training]

The problem I see with ball bearings [other than huge G forces] is that they wear out. ... Unlike the hydrodynamic bearing that can last many lifetimes because there is no contact.
larry

Large turbines, motors and compressors use "tilt pad bearings" like this one

TurboCare - Tilt Pad Bearing
or this one
John Crane - Orion - Bearings - Tilting Pad Journal Bearings

they might last years of continous operation because the shaft never touches the bearing.

 

[KWentling]

Wow. I've worked as a machinist in electric motor repair shops for the last 30 years and that is the first I've heard of the tilt pad bearings. Worked with a lot of conventional babbit bearings in motors up to 6500 HP. Looks like a great idea. Most bearing failure I've seen are misalignment (hot spots), loss of oil, or oil contamination.

Kim

 

[SPYDERLK]

Large turbines, motors and compressors use "tilt pad bearings" like this one

TurboCare - Tilt Pad Bearing
or this one
John Crane - Orion - Bearings - Tilting Pad Journal Bearings

they might last years of continous operation because the shaft never touches the bearing.

Continuous op they will outlast the assembler and his children.
larry

 

[mostly_gas]

I would think rolling element bearings would fly apart at turbo speeds -- even with ceramic balls to limit mass. Are you sure that isnt superchargers that use the ball bearings? The hydrodynamic plain bearing/~bushing seems the way to go for 100K turbo speeds.
larry

The machine shop I worked at had a vertical machining center with a spindle that capable of 18,000 RPM and bearings. It also had coolant (800 psi) through the spindle that was used on a regular basis. they average about 3000(mostly no operator) hours a year on the machine, usually above 12K spindle speed. Average tool weight was bout 25-30 pounds and is used to mill hardened tool steel.