A revolution in the speed of gearbox concept creation and analysis

The Concept Modeller module (RomaxDesigner and RomaxWIND module option S14-1) revolutionises the speed with which complex gearbox models can be created, functionally analysed and exported to CAD for packaging analysis. Typical gearbox design projects are evaluating 50+ conceptual layouts to decide on around 5 to take forward for detailed development and analysis.

The high speed user interface and concept analysis features are designed for use by engineers that are not necessarily transmission experts. The simulation models created can, however, be seamlessly transferred into RomaxDesigner/RomaxWIND for further detailed specification and analysis at the high accuracy levels required for optimisation by experts.

Key features:

• A simple 4 step process - Create > Visualise > Analyse > Export
• “Stick diagram” modelling of a transmission, easier than pen-and-paper
• Fast drag & drop manipulation of the layout to adjust the design in minutes
• Powerflow path analysis for each transmission ratio, speed and torque
• Tooth passing frequency analysis to provide early indications of likely NVH performance
• Gear sizing analysis to determine packaging requirements
• Export to CAD for packaging analysis
• Creates model for further detailed analysis in RomaxDesigner/RomaxWIND

Gearbox Concept Analysis  in a simple 4 step process

Create > Visualise > Analyse > Export

Toolboxes of pre-defined standard components:

Fast drag & drop manipulation:

 

Gearbox Concept Analysis

Create > Visualise > Analyse > Export

Easy visualisation in 2D and 3D views:

Cut plane visualisation:

Cut plane visualisation is a powerful feature that unobstructed representation of particular paths by simple by drawing a line on a 2D view.

 

Gearbox Concept Analysis

Create > Visualise > Analyse > Export

Model abstraction levels:

The concept modeller module works at loading gear and concept gear levels of abstraction as defined by Romax in the diagram below:

 

Load cases

Load cases are automatically defined by clicking through the powerflow path or by selecting engaged clutches or brakes in a table format.

 

Speed ratio

For each of the powerflow conditions the speed and torque ratios are calculated and displayed along with the engaged clutches.

 

Gear sizing

Four different gear sizing calculation methods are provided. These are based on the fundamental torque/centre; distance/face; and width/ratio relationships that are expressed in the gear durability calculations of ISO 6336

 

Centre distance

Based on the actual applied torque, the recommended centre distances (or ring gear diameter in the case of planetary gear sets) are provided

 

Safety factor

A recommended centre distance is calculated for each gear set and the safety factor in relation to the actual centre distance.

 

Concept gear tooth numbers

Two semi-automatic methods are provide for converting gear sets defined as loading gears into concept gear sets which include gear tooth numbers.

 

Clutch pack capacity

A basic torque capacity calculation is provided for clutch packs

 

NVH analysis

When gear sets have been defined at concept gear abstraction levels and powerflow conditions specified, tooth passing frequencies can be calculated to give early indication of potential noise and vibration (NVH) issues.

Gearbox Concept Analysis

Create > Visualise > Analyse > Export

System packaging export to CAD

System packaging export to CAD allows a complete gearbox design to be exported as one component in STEP or IGES CAD format files. Standard CAD package tools can then be used to assess the overall dimensions of the design and ensure that system packaging requirements are satisfied from early in the design process.

Export/Import to RomaxDesigner/RomaxWind

The system models create by the concept modeller module can be directly imported into RomaxDesigner/RomaxWIND where further modelling details can be added without re-entry of previous data. It is also possible to automatically extract concept level abstraction models from detailed RomaxDesigner/RomaxWIND models and load them into the concept modeller module.