Is there such thing as a bearing that provides resistance?

Question

I'm designing something that requires a wheel that will not rotate freely, but have a certain amount of consistant resistance over the course of thousands of rotations. Is there such a thing?

Answer 1

Well, no, not really...generally that would be bad. Generates heat, leads to smearing and flaking and premature bearing failure. You can over-tighten an angular contact bearing to get that effect (sort of) but that is a bad thing! Need more info about your application.

Answer 2

If you need only a little resistance a fan might work; it will perform consistently with very little change due to wear. Similarly, a member in water might be useful.

Sliding friction tends to vary over time as the materials wear down.

Answer 3

A bearing with resistance?  Sounds nasty to me.

Forget it.  Use a brake instead.

Answer 4

a bearing is designed to provide very low friction. Otherwise it would overheat and melt down.

As the other answer suggests, a water paddle is one solution, but the water will heat up and evaporate. A DC generator with a power resistor as a load is another possibility. a brake of some sort is a possibility, like the disk brake on an auto, but you will have to provide cooling and the pads will wear.

The "feel" of the resistance will vary with each type, and that may be important to you.

Answer 5

Virtually all bearings have some friction, while in air bearings it is negligible, in others it can sometimes be significant. It would help to have a better idea what "a certain amount of consistent resistance" is.

A grease packed double sealed ball bearing can have a fair amount of resistance.

There are magnetic hysteresis or eddy current brakes that can be used. Perhaps you have seen the demonstration of dropping a strong magnet down a copper tube? if falls much slower than one might expect. The same principal, or the different, but structurally similar hysteresis brake,  can be used with a disk  or cup for rotary motion. As there is no mechanical contact it can last for millions of rotations. (one supplier in "sources" below)

There are very viscous fluids used in some devices for that purpose, but I don't really know anything about them other than that they exist.

One thing I do know about,  is that excessively preloading a roller bearing to get a resistance is a bad idea. I used to work on a piece of equipment where a rather expensive part had to be replaced every few months because the manufacturer did just that, I presume when the part was originally designed it was designed to turn freely, but in use it was found that turning too freely was a problem,  apparently rather than redesigning the part, they just cranked down on the preload until they got the resistance they needed, then called the part a "consumable item" so they didn't have to replace it under warranty. The preload actually did work well at first, the part has a smooth fairly constant resistance - for a while - but then the bearings failed quite prematurely, and, of course, it was a weird bearing we couldn't find anywhere so we had to buy the whole part.