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Failure Bearing

A Bearing designed to fail at specific rotational speeds
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Wind turbine speeding out of control? Or something else that spins and could spin too fast? (I'm out of example ideas). Feedback loop not working and you need an absolute final solution to a runaway rotation? A bearing built with an internal structure that ejects a low-viscosity (and possibly slowly thickening, like a 2-part epoxy) at high speeds. Like a fuse protects electronic components, a fail-bearing could protect valuable assets, slowing them down gradually and then solidifying. One idea is to have fluid-filled cylinders that are hollow, filled with thickening agent and capped with a cap that has a predetermined failure point, just like CO2 bottles or SCUBA gear.
twitch, Sep 19 2017

Wind turbine overspeed failures https://youtu.be/No1Qzx1sQyc?t=40
Mentioned in my anno. What this idea is intended to prevent. Also, one of them just falls over while stopped. [notexactly, Mar 21 2019]

[link]






       // something else that spins and could spin too fast? (I'm out of example ideas). //   

       Democratic party press officers ?
8th of 7, Sep 19 2017
  

       A child's concept in a finger painting?
wjt, Sep 20 2017
  

       When bearings fail, they often lock up and blow up and break things. What you want is a clutch. Pretty old technology.
RayfordSteele, Sep 20 2017
  

       but how to put a clutch in a bearing?...
twitch, Sep 20 2017
  

       //What you want is a clutch.//   

       My first thought was a standard style clutch, excess force causes slip. The blades spin faster but the generator becomes progressively decoupled. The problem there is that the blades will spin up and self destruct, or, the clutch will quickly suffer a fricton related heat problem... quickly becoming an oxygen related fire problem. A centrifugal clutch that engages a nice robust rotary damper would be better.   

       Better still would be a centrifugal governor that feathers the blades. But then how will you sell them a new one?
bs0u0155, Sep 20 2017
  

       Easy - a dog-clutch, a spring, and a centrifugal governor. Spin the assembly too fast, and the governor releases the spring. Depending which way round the clutch is placed, either the drive is allowed to freewheel from the load, or it engages to a brake or fluid load to slow it.
8th of 7, Sep 20 2017
  

       Designing a part to do the opposite of it's intended job suggests the desired system is at fault.
wjt, Sep 21 2017
  

       Agreed. That's how we ended up with Republicans.
RayfordSteele, Sep 21 2017
  

       This idea is much more elegant than a clutch in many applications. Whenever you want to save the weight and complexity, but still have that last ditch stop.
Voice, Mar 17 2019
  

       It's like the fusible resistors used in cheap electronics, primarily for current limiting but secondarily for emergency overcurrent stopping.
notexactly, Mar 17 2019
  

       //Designing a part to do the opposite of it's intended job suggests the desired system is at fault.//   

       The key subverts the lock subverts the door subverts the wall.
Loris, Mar 19 2019
  

       ^ All parts are doing what is willed.They are doing their engineered jobs. To be pedantic, failure means to not act as wanted. This is a bearing designed not to bear under certain circumstances.
wjt, Mar 20 2019
  

       If we're just talking about wind turbines , then rotating the vanes along their axis should do the trick as it'd be the same wind speed on both sides of the blade.
not_morrison_rm, Mar 20 2019
  

       // fusible resistors used in cheap electronics //   

       Not just cheap electronics; very expensive electronjcs use them, too.   

       It seems appropriate to point out that all resistors are in fact fusible if subjected to sufficient overload. <snigger/>
8th of 7, Mar 20 2019
  

       // If we're just talking about wind turbines , then rotating the vanes along their axis should do the trick as it'd be the same wind speed on both sides of the blade. //   

       Feathering the blades? They do that. But they sometimes have overspeed failures anyway: [link]
notexactly, Mar 21 2019
  

       Has moving the blades forward been tried? -< . Less blade efficiency and balance is controlled by wind strength. Ultimately -- , shutdown.
wjt, Mar 21 2019
  

       The problem is energy dissipation. The rotating object being born has both potential and apparently external energy being applied. Stopping that requires absorbing all the energy without damage. Absorbing energy without releasing it leads to build ups of energy (usually in the form of heat) which are nearly always going to result in damage. If the object doing the absorbing is on the outside, it can radiate the energy away, but on the inside? No, what happens here is the bearing or the shaft it is bearing overheat and melt. Now you have a spinning load that is no longer born. That's worse. A clutch at the end of the shaft, or a brake outside the shaft is the way to go.
James Newton, Mar 21 2019
  

       //Designing a part to do the opposite of it's intended job suggests the desired system is at fault.//

Not so fast! Systems are designed within certain operational constraints. And part of good system design is to address failure when operating outside those constraints in order to mitigate loss or catastrophe. Mechanical fuses are planned failure points and are used widely. But I've not heard of a mechanical bearing fuse. [+]
LimpNotes, Apr 05 2019
  

       // Designing a part to do the opposite of it's intended job suggests the desired system is at fault. //   

       Easily solved by marketing it instead as a Success Bearing. When the shaft turns too fast, the bearing succeeds (at stopping it).
notexactly, Apr 05 2019
  
      
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