Author Topic: Linear Motors?  (Read 930 times)

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Offline DrabTopic starter

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Linear Motors?
« on: November 11, 2012, 07:34:15 AM »
I was having a google search for robots using linear motors, and I only found a few examples of industrial/experimental robots. Indeed, the Wiki page on linear motors doesn't mention linear motors being used for robotics at all - only monorails and railguns.

So I thought I'd find some people who know about robotics. I thought that linear motors would be perfect for replicating human or animal motion, because it's straight out linear like a muscle, rather than converting rotary motion. Plus, if one simply pulls, then two on either side of an arm can act sequentially like how muscles work. Apparently, linear motors tend not to be powerful though, and I'm not sure why.

Offline waltr

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Re: Linear Motors?
« Reply #1 on: November 11, 2012, 11:13:46 AM »
Try searching for 'linear actuators'.

Offline DrabTopic starter

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Re: Linear Motors?
« Reply #2 on: November 11, 2012, 12:30:49 PM »
Try searching for 'linear actuators'.

Well, a linear motor is a type of linear actuator, only it has linear motion to begin with rather than converting from rotary like other linear actuators. I'm looking for robots which use specifically what seem to be called linear motors, rather than the other types of linear actuator.

Offline waltr

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Re: Linear Motors?
« Reply #3 on: November 11, 2012, 02:42:20 PM »
One type of linear actuator is a motor turning a threaded shaft. A 'nut' on the threaded shaft rides in a linear guide (or housing) to push/pull. These can have considerable force.

Offline Soeren

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Re: Linear Motors?
« Reply #4 on: November 12, 2012, 08:57:09 PM »
Hi,

So I thought I'd find some people who know about robotics. I thought that linear motors would be perfect for replicating human or animal motion, because it's straight out linear like a muscle, rather than converting rotary motion. Plus, if one simply pulls, then two on either side of an arm can act sequentially like how muscles work. Apparently, linear motors tend not to be powerful though, and I'm not sure why.
Linear motors are in effect like ungeared conventional (rotational) motors - like if you cut a motor lenght-vise and ironed it flat and that's why they aren't very powerful.

The strength of linear motors is the extreme speed that can be generated, but they'd be hopeless in a robot, where torque is more important and contrary to what you may think, human muscles are very different.

If you want something that acts like human muscles, "air muscles" are the closest alternatives presently.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


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