Interactive Powertrain: new LASME teaching tool
Worked example linking engine speed, gearbox reduction, differential reduction and wheel speeds in straight-line motion and in a turn.
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About the portal
A study guide for mechanisms
The site is maintained by Artur Henrique de Freitas Avelar, professor at UFSJ, and organizes themes that appear in the disciplines of mechanisms and machine elements: gear teeth, gear trains, planetary gear sets, cams and visualization tools.
From gear pair to complete system
Reading starts with basic quantities such as module, tooth count and pitch diameter. It then passes through simple and compound trains, which include shaft couplings, direction of rotation and train value.
This basis prepares the study of planetary and differential, in which the mobile carrier requires working with relative speeds before interpreting the absolute speed of the elements.
From the SVAJ curve to the cam profile
Articles on cams discuss followers, displacement curves, velocity, acceleration, pressure angle, base radius, and curvature. The idea is to link the law of motion to the physical profile that will be manufactured.
Recent articles
Recent publications in mechanical engineering
New portal articles on mechanisms, transmissions, gears, cams and other applied mechanical engineering topics. This area highlights the most recent texts as they are published.
Displacement curves for cam design
Selection of SVAJ curves for dwell, constant velocity, cycloidal, harmonic and eighth-degree polynomial cam motion.
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Planetary Gear Design in Engrenarium
Use of the new module to synthesize simple and compound planetary gear sets based on relations and assembly constraints.
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Ferguson's mechanical paradox: assembly in Engrenarium
History, assembly and operation of a mechanism in which three gears exhibit apparently contradictory movements.
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Allison 1000 transmission: assembly in Engrenarium
Assembly of three consecutive planetary gear sets in Engrenarium, with tooth counts, constraints, and six gear ratios.
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Ravigneaux transmission: four gears and reverse
Reading a Ravigneaux set with two sun gears, long and short planet gears, overdrive and reverse gear.
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Technical content
Articles and explanatory pages
The articles are organized as a study sequence. First come concepts of gears and gear trains; then, applications with planetary gears and differentials; finally, cams, motion curves and analytical design.
All technical articles
The index brings together texts by subject: gears and trains, planetary gears, CVT, differentials, cams and design. It helps you choose between a quick conceptual review and more in-depth reading.
Use it when you want to compare closely related topics, such as compound gear train and compound planetary gear set, or displacement curve and analytical cam design.
Open article indexGears and gear trains
Texts on nomenclature, involute profile, module, simple trains, compound trains, gear ratio, manual transmission and special gears.
These pages create the foundation for understanding more advanced applications and planetary analysis.
Start with the introductionPlanetary gears and differentials
Articles on the general case, train value, applications in automatic transmissions, compact reducers, CVT, compound planetary gear sets and differentials.
The learning path also connects to Engrenarium, which allows you to visualize how input, output, fixed element, and carrier change speed in epicyclic arrangements.
Read about the general caseCams, motion and design curves
Set of texts on nomenclature, followers, cycloidal, harmonic, polynomial curves, pressure angle, base radius and curvature.
The objective is to show how a cam profile arises from a motion specification and geometric checks.
Read basics of cams
Tools and laboratory
Software + simulators
Laboratory · UFSJ
Available projects
In addition to the articles, the site points to tools and environments linked to the study of mechanisms. Engrenarium complements planetary gear articles with interactive visualization, while LASME brings together teaching, research and development activities.
Projects
Page that gathers the Engrenarium software, Engrenarium Web and Interactive Powertrain, with links, project context and related technical articles.
LASME — Mechanical Systems Laboratory
Institutional page of the research and teaching laboratory linked to mechanisms, transmissions, software and computational tools in mechanical engineering.
Frequently asked questions
FAQ — questions about Engrenarium
Short answers to common questions, accompanied by the projects page with links to the simulator, software and related teaching tools.
What is Engrenarium and what is it for?
Engrenarium is a planetary gears web simulator with educational and technical purposes. It helps visualize epicyclic arrangements and discuss kinematic relationships between input, output, and carrier.
Do I need to install any programs to use Engrenarium?
There is a web version and a full version for Windows. The web version allows you to quickly learn about the resource; the desktop version can be used when you want to work with the tool outside of the browser.
Does the portal depend only on the simulator?
No. In addition to the simulator, there are articles on gears, compound trains, differentials, cams and motion curves. Engrenarium complements these texts when visualizing a planetary gear train helps you understand the calculation.
Who was the content written for?
The material was organized for students, teachers and professionals who need clear explanations about mechanisms, gears and teaching support resources in mechanical engineering.
How to get in touch?
Use the email available in the contact section or on the page About for questions about the technical content, tools or institutional context of the portal.
Technical reference
Glossary of terms
Objective definitions of frequent terms in the study of gears, transmissions and mechanisms.
- Module (m)
- Dimensional parameter that relates the pitch diameter to the tooth count of a gear.
- Gear ratio
- Ratio between the angular velocity of the input element and that of the output element.
- Sun gear
- Central externally toothed gear on a planetary gear train.
- Planet gear
- Element that meshes with other members of the train and can rotate around its own axis and the central axis of the assembly.
- Ring gear
- Gear with internal teeth that surrounds the planetary system.
- Planet carrier
- Structural element that supports the axes of the planet gears and rotates around the central axis of the system.
- Pressure angle
- Geometric angle associated with the transmission of force between elements in contact, relevant in gears and in cams.
- Train value
- Constant obtained with fixed carrier, used to relate speeds in epicyclic gear trains.
Publications
Translated books linked to the author's work
The books below bring together classic mechanisms, devices and movement solutions. They speak to the site's themes because they show how pairs of gears, cams, levers, and transmissions appear in real-world applications.
Translation into Portuguese
507 Mechanical Movements: Mechanisms and Devices
Translated edition with illustrated mechanisms and descriptions of operation in various applications, useful as reference material for students and those interested in movement synthesis.
Blucher Publisher, 2019
Translation into Portuguese
1800 Mechanical Movements, Devices and Components
Translated reference work with a wide variety of mechanisms, devices and classic mechanical solutions, useful for consulting alternative transmission, guidance, control, and motion conversion.
Barbudenge, 2025
Contact
Email
Contact Information
For questions about gears, cams, mechanisms, Engrenarium or teaching materials linked to UFSJ, use the contacts and links below.
Channel for questions about the simulator, published articles and mechanism topics covered on the website.