# Mechanisms (05AOCEDM)

**Coefficient :**2**Hourly Volume:**63h (including 36h supervised)- Labo : 36h supervised (and 6h unsupervised)
- Out-of-schedule personal work : 21h

### AATs Lists

## Description

- Reading technical plans (overall plans, definition) Mechanical connections Rotational guidance (plain bearings, bearings, mounting and lifespan of bearings) Translational guidance (parallel keys, splined shafts with parallel sides)
- Power transmission (power, torque, efficiency, transmission ratio) Straight tooth gears
- ISO tolerance systems Functional rating
- Illustrations by industrial applications CAD work (CATIA software)

## Learning Outcomes AAv (AAv)

EDM

AAv1 [heures: 3, A1, C2, F1, F2] (2D/3D Vision): Situation: at the end of the course, the student must be able to represent a system in 3D from its orthogonal projection in 2D and vice versa

- complete an incomplete definition drawing
- extract a part in 2D from a 2D assembly drawing
- produce an isometric view of a part or system freehand

AAv2 [heures: 11, A3, C2, G2] (kinematic modeling): Situation: At the end of the course, from a given mechanical system (2D overall drawing or 3D CAD model) the student must be capable of producing a kinematic diagram of the system while respecting the standards for representing elementary mechanical connections.

- standardized and respected representation
- solids are clearly identified
- the standardized connections chosen correspond to the relative movements of the solids in contact.
- the spatial arrangement of the connections corresponds to the real system
- entry and exit movements are clearly highlighted

AAv3 [heures: 7, A3, C2, G2] (functional specification): At the end of the course, from a given mechanical system (2D overall drawing or 3D CAD model), the student will be able to define the dimensional and geometric specifications necessary to guarantee a given mechanical functionality, while respecting the associated standards:

- determine and report, on a definition drawing, the dimensional specifications. In particular, determine the operating clearances (axial and radial) on the overall drawing, trace the chains of dimensions and calculate the tolerances of the functional dimensions.
- recognize and justify geometric and surface finish specifications

AAv4 [heures: 7, C1, C2] (power transmission): At the end of the course, from a given mechanical system (2D overall drawing or 3D CAD model), the student will be able to analyze a synchronous power transmission, in particular:

- analyze an existing synchronous power transmission (by obstacle: toothed belt, gear, screw/nut), in particular define the input/output law, identify the force transmission chain, calculate the torques and powers involved)

AAv5 [heures: 7, C1, C2] (guidance): At the end of the course, from a given mechanical system (2D overall drawing or 3D CAD model), the student will be able to analyze a guidance solution, in particular:

- analyze existing guidance (mounting of bearings, bearing, slide, etc.) determine the positioning and force transmission chains.

AAv6 [heures: 7, C2, G2] (assembly techniques): At the end of the course, from a given mechanical system (2D overall drawing or 3D CAD model), the student will be able to design the assembly of the elements of a mechanical system:

- analyze the assembly techniques in a given system, in particular: determine the positioning and tightening of the parts, construct the assembly graph and analyze the chosen sealing solutions

CAO

AAv7 [heures: 11, B3, D1, D2] : The student will be able to model a part using mechanical CAD software.

- Situation :
- From a definition drawing of a part.
- Halfway through the session.

- Targeted learning outcomes: In particular, he will know:
- Choose the position of the part reference frame in order to facilitate its design.
- Use the material creation or removal functions in an order that respects functional tolerancing and facilitates future modifications.
- Create iso-constrained sketches.
- Use only functional dimensions for modeling.
- Use specialized features like fillets, chamfers, threads and patterns, etc.
- Arrange the tree structure to make it easier to understand and modify the part.

- Situation :
AAv8 [heures: 5, B3, D1, D2] : The student will be able to model an assembly using mechanical CAD software.

- Situation :
- Based on an overall drawing of a mechanical system and CAD models of the constituent parts.
- At the end of the session.

- Targeted learning outcomes: In particular, he will know:
- Choose a grouping of parts by subassemblies functional
- Assign all assembly constraints to guarantee the positioning and mobility of the parts.
- Improve the ergonomics of the tree structure and the model to facilitate its understanding and future modifications.

- Situation :
AAv9 [heures: 5, F1, G2] : The student will be able to generate one or more 2D drawings using mechanical CAD software.

- Situation :
- From a given CAD model (assembly or part).
- At the end of the session.

- Targeted learning outcomes: In particular, he will know:
- Choose a consistent format, scale and orientation for each layer
- Choose the types of views and their arrangements to remove any ambiguity on the geometry.
- Respect industrial design standards
- Check compliance with clearances to guarantee the functionality of the assembly
- Represent dimensional, geometric and surface condition clearances, adjustments and dimensions.
- Generate system bill of materials.
- Edit the drawing using different file formats.

- Situation :

## Assessment methods

Average of several short continuous assessment evaluations

## Key Words

Connections, guides, gears, functional play, drawing

## Prerequisites

Knowledge of conventions specific to industrial design.

## Resources

Guide to industrial science and technology IT resources: CATIA software