Gear tooth design

Gear tooth design


  • An Advanced Approach to Optimal Gear Design
  • Gear Tooth Profile
  • Gears generally have an involute curve tooth profile. There are other types of gear profiles, but they are mainly utilized in specialty applications such as cycloidal gears in clocks and watches.

    This involute curve helps the gears transmit power smoothly during the rolling action. The curve is produced by wrapping a string around a cylinder, the base circle, and as it is unwrapped from this cylinder traces the involute curve. The base circle of the involute curve is also important because it helps to determine the pressure angle of the gear, another fundamental of gear design. The contact point of the gear and pinion goes along the involute curves of the gears.

    The involute gear tooth profile also helps with smooth rotation even with variations in the center distances between the gear and the pinion. The tangent line of the base circle of the gear and the base circle of the pinion form the line of action for the gear set.

    The tooth thickness, diametral pitch and pressure angle all go into determining the gear tooth profile. These factors are determined by the desired contact ratio between mating parts of the gear. The gear tooth profile also varies by the number of teeth on the gear such that the larger the amount of teeth the straighter the profile of the gear eventually forming what is called a rack gear.

    An advantage to making a rack form is strength obtained through the rack form. Many gear manufacturing firms also have the ability to determine the gear profile from the geometry of the hobs that is used to generate the teeth on a gear. While this method is able to generate the profile of the gear, the firm would still need some supplementary dimensions in order to accurately reverse engineer said part.

    Marples Gears specializes in high precision fine pitch gear manufacture up to Q13 quality standard on our gear products that we custom manufacture in house. At Marples Gears, we also use software in order to analysis the gear tooth profile of your part. While we are not certified to design gears through ASD, but we can consult on the best method of manufacturing of your gears. Marples Gears also has the ability to reverse engineer as gear through the method discuss above and through the analysis of the original gear.

    For a custom engineer reviewed quote email info marplesgearsinc.

    By Steve Bush 4th March Involute gears, and how not to get frustrated when designing them Some spare time recently got used-up designing a pair of involute gears — which, it transpires, is easy in principle, once certain almost-impossible-to-obtain facts have been gathered.

    There are several guides on the web, but some important bits of information seem habitually to be missed out. They are easily calculated. By convention: gear teeth stick out one modulus above the pitch circle there are variations. If the base circle ends up part-way up the teeth, the profile of the teeth inside the base circle is a simple radius Here are two I made earlier and created too in DesignSpark Mechanical And here are some useful resources: The best diy gear information source, of all the many many videos, websites and documents that I read to design my gear pair, this presentation was far clearer than the rest, and had extra information.

    CAD package Fusion will draw gears for you — so you might want to stop reading here, and download that instead. Also, there are two that will design gears for you. Woodgears is an excellent on-line gear generator website which is very flexible frankly, amazingly flexible and has this excellent associated video. The author, Matthias Wandel, will also sell you a programme to run on your Windows computer. Gear generator is an on-line gear generator websites by Abel that is easy to use, and you can download CAD files from it for a small payment.

    However, it does not provide a format that DesignSpark Mechanical can directly import. Now for some other useful gear facts if you are to diy: Involute is a type of shape, very important to most gears, and easily drawn. To mesh properly, involute gears only need two things in common: modulus and pressure angle. This does not mean that they will have the same shaped teeth. In fact, if they are different diameters, to mesh perfectly they will have different shaped teeth.

    Based on this last item, here are a bunch of things where, unless you are really lucky, you will have to trade-off at least one to get a working gear pair: centre-to-centre distance.

    An Advanced Approach to Optimal Gear Design

    The contact point of the gear and pinion goes along the involute curves of the gears. The involute gear tooth profile also helps with smooth rotation even with variations in the center distances between the gear and the pinion. The tangent line of the base circle of the gear and the base circle of the pinion form the line of action for the gear set.

    The tooth thickness, diametral pitch and pressure angle all go into determining the gear tooth profile. These factors are determined by the desired contact ratio between mating parts of the gear. The gear tooth profile also varies by the number of teeth on the gear such that the larger the amount of teeth the straighter the profile of the gear eventually forming what is called a rack gear.

    Woodgears is an excellent on-line gear generator website which is very flexible frankly, amazingly flexible and has this excellent associated video. The author, Matthias Wandel, will also sell you a programme to run on your Windows computer. Gear generator is an on-line gear generator websites by Abel that is easy to use, and you can download CAD files from it for a small payment. However, it does not provide a format that DesignSpark Mechanical can directly import.

    Gear Tooth Profile

    Now for some other useful gear facts if you are to diy: Involute is a type of shape, very important to most gears, and easily drawn. It is evident that the design according to the AGD method is performed automatically—that is, with the help of a computer. Similar to uniting the design methods, their implementing program systems can be integrated here, with each of them becoming the module subsystem of the integrated CAD-system. Conclusion This paper describes a new approach to the process of involute spur and helical gear design, assembling the advantages of two new methods, which occurred not long ago and are now being developed intensively—that is, the method of Direct Gear Design DGD and of Dynamic Blocking Contours DBC.

    Practical implementation of the new method allows: 1 to look at the process of computer-aided design of involute spur and helical gears in a new way, enriching considerably its contents and results; 2 to create on its base new generation gears with considerably better characteristics and with the possibility of their application in new mechanisms and machines.

    References 1 F. Kapelevich, R. Kapelevich, Y. Groman, Selection of gear correction, Vestnik mashinostroeniya, 2, 4—15, in Russian. Goldfarb, A. Tkachev, Designing involute spur and helical gears. Bolotovskiy, V. Bezrukov, O.


    thoughts on “Gear tooth design

    1. In my opinion, it is an interesting question, I will take part in discussion. I know, that together we can come to a right answer.

    Leave a Reply

    Your email address will not be published. Required fields are marked *