# Talk:Belt (mechanical)

The article originally redirected to Conveyor belt, however belts are widely used in mechanical devices and can take many forms. I've added some content and setup Flat belt, Round belt and Vee belt as redirects to here, ultimately those pages deserve content of there own. originated in china. not only known as driving belt but also belt drive and bicyle chain-drive. - Graibeard 00:29, 27 August 2005 (UTC)

## belt

the belt made of leather , cotton rubber ,nylon and steel

## pitch diameter calculation

I would like to see an article on pitch diameter calculation and on the standard types of synchronous belting along with the pitch line for each type. --Noelstalker (talk) 19:27, 4 August 2009 (UTC)Noel Stalker

## Category: Actuators

I included the article in the Actuators category, but Andy Dingley disagreed, arguing “Power transmission yes, but not significantly regarded as an actuator. Linear belt actuators are, but they're a sub-class”.

I argue that a belt drive is a very common form of linear actuator (as is a chain drive). From Sclater, N., Mechanisms and Mechanical Devices Sourcebook, 4th Edition (2007), p. 25, McGraw-Hill: "Mechanical actuators convert a motor's rotary motion into linear motion. Mechanical methods for accomplishing this include the use of leadscrews...ballscrews...worm-drive gearing, and belt, cable or chain drives." That a belt drive may not always be thought of as an actuator doesn’t make it less the case.

I welcome more discussion of the topic. —Catsquisher (talk) 16:53, 10 August 2010 (UTC)

The function of an actuator is to produce motion of some part of a mechanism, not merely to transmit power from place to place, unchanged. A ball screw is an actuator, it converts rotary motion to linear. A motor converts electrical power to rotation.
Of the articles you've categorized, those I'd dispute include:
The first three simply aren't actuators. Their function is not to generate a movement, that's merely incidental to their function of firstly replicating an existing rotation unchanged, or in the second and third cases, moving a bulk load from place to place.
Belt (mechanical) is less clear. There are indeed belt-driven actuators. The common inkjet printer head traverse is usually of this form. However Belt (mechanical) is already far too broad an article and adding this digression too would be making an over-reaching article even worse. A separate article on belt actuators would be appropriate. I admit though it is a borderline case: there are some belts, within the scope of this article, that qualify as actuators. I just don't think this article, or encyclopedia clarity is improved by adding the cat.
If you insist, by all means add Actuators to Belt (mechanical). However the others (screw conveyors?) are just plain wrong. Andy Dingley (talk) 00:34, 11 August 2010 (UTC)
Hey AD, thanks for the response. I confess that I am suffering from actuator overenthusiasm, but not quite to the extent you've spelled out. I'll get back to you when I have a moment.—Catsquisher (talk) 03:35, 11 August 2010 (UTC)
I’m not clear why you would accept belt drives as actuators, but not chain drives. For example this company makes both types of actuator. Point taken with 2 & 3. In any case, I wouldn’t insist, just wanted to discuss. If including an item in a category won’t contribute to the understanding of the article, then I would agree not to include it. Chain and belt drives are more commonly used and thought of as transmissions, so including their use as actuators may tend to confuse. I’m happy not to include in the category, unless someone else thinks they should be included. Thanks for the comments. —Catsquisher (talk) 16:07, 11 August 2010 (UTC)
Perhaps too fine a point (or just beating a dead horse), but I still think both belt and chain drive transmissions are essentially comprised of actuators. Rotation of pinion → linear motion of belt or chain → rotation of pinion, and so on. Cheers, Catsquisher (talk) 16:39, 11 August 2010 (UTC)
Belt (mechanical) is the clearest example, but the same thing applies, to a lesser extent, with Chain drive and rack and pinion.
All three of these are simple mechanisms, used for a broad range of functions and with a main function that is outside "actuators". Each of these is also used to make actuators.
The problem is that the "actuator" use is by far the secondary (not even secondary for belts & chains), so far so that it's misleading to place actuator into the lead (at least clearly so if it appears before the main function). For a belt drive, this isn't even the classic "belt drive" - the translated component is fixed to the belt and the belt can now only reciprocate, it can no longer rotate continuously. It's a development of a belt drive to turn it into an actuator, but it's so far along that it has lost connection to the ur-belt.
So I don't care too much about categorizing "belt drive" as an actuator, but this needs to be done in a way that remains clear: that the "actuator" use is a pretty minor one of a much bigger picture. Andy Dingley (talk) 23:14, 11 August 2010 (UTC)
AD, I was so ready to just let it go... My desire to include belt and chain drives, and the rack and pinion, in the category of actuator has less to do with their ultimate use or function than the fact that they are actuators. It's not a secondary aspect of those "simple mechanisms", it's the essential aspect of how those mechanisms operate. Mechanical actuators are simply mechanisms that convert between rotary and linear motion, per the reference I quoted above. That applies equally to belt drive, chain drive, and rack and pinion. Why you say the belt is the clearest example of the three remains unclear to me. What contradictory references can you cite? —Catsquisher (talk) 06:46, 12 August 2010 (UTC)
The primary use of belt and chain drives is to take rotary motion of one pulley and use it to rotate another pulley. As this is non-transformative, I don't see it as an actuator. Nor would I see a bellcrank that changed the angle of a linear push-pull motion as an actuator. If the belt drive is used to transform rotary to linear motion, then I'd agree that could be an actuator. Andy Dingley (talk) 08:46, 12 August 2010 (UTC)
Andy, you make quite a compelling argument here. I think in this case (that is the belt article) Andy's point is quite legitimate, in that when a belt is used with a sprocket and the end of the belt is used for linear translation it is no longer called a "belt drive"; instead I would think that we are just using a belt and a sprocket to create an actuator. Wizard191 (talk) 12:38, 12 August 2010 (UTC)
It's not called a belt drive (in the real world), but then neither is the Wiki article Belt (mechanical), so it's not a big problem. Really though, this whole article wants splitting and re-writing. Andy Dingley (talk) 12:44, 12 August 2010 (UTC)
What's not? A linear actuator or a rotating system? Wizard191 (talk) 13:40, 12 August 2010 (UTC)
The actuator. When we use "pulley and belt systems" to make a linear actuator, they're not called "belt drives". The "drive" connotation has implications (sourceable back 200 years) of continuous movement for power transmission. Andy Dingley (talk) 23:15, 12 August 2010 (UTC)
OK, I'm completely in agreement with that. Wizard191 (talk) 12:35, 13 August 2010 (UTC)
I think I may have found the source of disagreement. My point is an abstract one about the principle behind the operation of these devices. The discussion continues to be brought back to the “real world” question of use, which I was trying to set aside. I argued that belt and chain drives are actuators by their nature because, regardless of their ultimate use, they convert rotary motion of pinion to linear motion of belt or chain. AD argued that they are not because they function as transmissions. Transmission is their most common use (no argument from me there), but what I'm trying to get at is that the transmission occurs through actuation. AD’s is a much more concrete point than mine. In any case, if inclusion of the abstract point is more confusing than helpful (and this discussion may have proved that it is), it should remain out of the articles. —Catsquisher (talk) 17:42, 12 August 2010 (UTC)

I may be doing a little bit of Devil Advocate play here, but it is not strictly for the sake of play. I came here from some other articles (Chain Pump and Chain Drive), trying to decide if a Chain Pump should be considered an example of a Chain Drive or not. Then I found the discussion on the Chain Drive talk page about actuators, which might imply that if a Chain Pump is an actuator, then it might not be an example of a Chain Drive.

If a Chain Pump is an example of a Chain Drive, and per the Chain Pump article, the earliest examples date from 700 BC, then the Chain Drive article should refer to Chain Pumps as the earliest example (instead of the repeating crossbow from the 3rd Century BC).

On the other hand, if a Chain Pump is an actuator, and an actuator is not a drive, then citing the repeating crossbow as the earliest example would seem to be appropriate. (There might be other arguments to make the repeating crossbow the appropriate earliest example of a chain drive--pursuing the actuator definition is just one that came to mind.)

But, then, continue with the following...

Andy Dingley (talk) 00:34, 11 August 2010 (UTC) posted what I think is a pretty good definition of actuator:

"The function of an actuator is to produce motion of some part of a mechanism, not merely to transmit power from place to place, unchanged. A ball screw is an actuator, it converts rotary motion to linear. A motor converts electrical power to rotation."

Unfortunately, the first paragraph of the Wikipedia article on actuators doesn't seem nearly as good:

"An actuator is a type of motor for moving or controlling a mechanism or system. It is operated by a source of energy, usually in the form of an electric current, hydraulic fluid pressure or pneumatic pressure, and converts that energy into some kind of motion. An actuator is the mechanism by which an agent acts upon an environment. The agent can be either an artificial intelligence agent or any other autonomous being (human, other animal, etc.)."

I suppose these comments should be moved to other appropriate pages, among them Chain Pump, Chain Drive, and Actuator, but I thought I'd see what kind of response I get here first. --Rhkramer (talk) 17:27, 26 April 2012 (UTC)

Chain pumps aren't chain drives because they don't drive anything. Their only output is their pumping, not the rotation of the driven sprocket wheel. If this wheel had an output shaft that drove some further mechanism, then perhaps they would be. Andy Dingley (talk) 20:07, 26 April 2012 (UTC)

## FAQs

Newbie to the subject with queries

### Jargon: Idiosyncratic speed

Link leads to the idiosyncracy meme which does not explain what the term means. Please either edit the meme, sub-class it using a disambiguation page (given it's got a fistful of other meanings already) or delink it with an explanation here.