Talk:Gear train

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where can i find information on a simple gear with an idler?

Revisions to this article
Gear trains are important. I have pulled together subsections of other articles that discuss the analysis of gear trains. This means there is some duplication, but I believe it is necessary because these topics are linked and this helps both to be more easily understood. Prof McCarthy (talk) 05:23, 27 July 2011 (UTC)

I removed the stub template. It no longer seems appropriate to consider this article to be a stub. Prof McCarthy (talk) 00:07, 30 October 2011 (UTC)

Angular Velocity
Linear and angular displacement and velocity are vector quantities. Consistent treatment as such, with the adoption and use of appropriate sign conventions in physics and engineering, is essential for consistent technical expression and comprehension.

In this article, the lack of a negative sign in the first equation in this section [ https://en.wikipedia.org/wiki/Gear_train#Mechanical_advantage ] and, at present, most subsequent equations on this page involving $$\omega$$, $$v$$, and $$r$$, invalidates it's correctness and applicability to consequent, subordinate or related wikipedia articles.

A particularly good example of this problem is the dependent understanding and analysis of an epicyclic gear train. [ https://en.wikipedia.org/wiki/Epicyclic_gearing#Gear_ratio_of_reversed_epicyclic_gearing ] and [ https://en.wikipedia.org/wiki/Epicyclic_gearing#Fixed_carrier_train_ratio ]

This article's explanation and mathematical analysis of the motions, absolutely depends upon, and uses, signed angular velocities. I'm actually a little surprised (I suspected sabotage actually) by the lack of signing in this article, or any explanation as to why direction of rotation was not codified in the mathematical expressions, in light of it's importance.

May I propose we edit this article by either:

1a/ Adding negative signs to one side of equations. [A distinguishing property of simple gear trains is that 'negative inverse' ratio equalities will result from the analysis of gear trains with an even number of gears >= 2*, whereas 'positive inverse' equalities result for trains with an odd number of gears >=3, and, for pulley and chain drives with any number of pulleys and chains >=2 [the trivial case of one gear/sprocket/pulley is ignored]].

1b/ Adding or modifying the explanatory text

[I'm new to Tex (hours) - apologies for this inelegant attempt] Eg:


 * $$ \begin{align}

&v = r_\text{A} \omega_\text{A} = -\,r_\text{B} \omega_\text{B} \\

=> &\frac{\omega_\text{A}}{\omega_\text{B}} = -\,\frac{r_\text{B}}{r_\text{A}} \\

&p = \frac{2 \pi \vert r_\text{A}\vert}{N_\text{A}} = \frac{2 \pi \vert

r_\text{B}\vert}{N_\text{B}} \\

=> &\left\vert{\frac{r_\text{B}}{r_\text{A}}}\right\vert = \frac{N_\text{B}}{N_\text{A}} \\

&\frac{\omega_\text{A}}{\omega_\text{B}} = -\,\left\vert\frac{r_\text{B}}{r_\text{A}}\right\vert

= -\,\frac{N_\text{B}}{N_\text{A}}

\end{align} $$

Or: 2/ Rewrite the equations as vector cross products (as the center to pitch point, $$r$$'s are vectors, as are $$v$$'s at that point, and too the $$\omega$$'s).

[I apologize; I do not yet know enough Tex, nor wikipedia's expectations for vector mathematics and algebra for articles of this rank.]

As such, I am very much in need of, and would greatly appreciate the input and assistance of others, who - like me - am drawn to improving technical articles, like this, so that first and foremost, the conventions of physics and mathematics [our primordial models] are always used, but where not (historical; brevity; common practise, etc) mention is at least made of the underlying assumptions.

I do realize the kinematics here, and in the linked articles is both simplified and condensed - it is not a full 3D translation and rotation analysis and does not need to be. 2D and 'as simple and brief as possible' fits my thinking for a technical article of this rank. Your thoughts? Alternative approaches? Ideas? Many Thanks. 100kWhr (talk) 17:38, 16 October 2017 (UTC)

Efficiency?
It would be really helpful if some kind of figures could be given for the mechanical efficiency of a typical real-world gearbox in both directions. In particular, a step-down gearbox might be 95% efficient for each stage - but what about a step-up gearbox?

Technology
Give at least 3 mechanism that include gear trains internally? 197.90.149.173 (talk) 17:05, 15 May 2022 (UTC)

Maths for grade 8s
￼how to resolve maths 41.150.212.186 (talk) 20:29, 30 April 2023 (UTC)

Gear train is an antiquated term. Gear set, or gearbox more common today.
We ought to consider renaming this article, per WP:COMMONNAME. Gear train is an antiquated term; was in more common use in the 1800s and early 1900s when, you guessed it, "trains" and railroads were such an important part of industrialization worldwide. Gear set, or gearbox (when the gears are located in a "box" and the box contains only gears, lubricants, etc.) are much more common today. Gear set seems to be most common in automotive and industrial use. I'm less familiar with the terminology of other fields, but it seems rather clear that "gear train" is outdated now. N2e (talk) 23:36, 11 February 2024 (UTC)