Evaluate bearing performance according to supplier data with SKF calculations embedded in Romax products

Kristian Kouumdjieff,

One of the primary goals of Romax Spin, and indirectly the rest of the Romax products, is to facilitate collaboration between bearing suppliers and their customers. Both bearing suppliers and their customers use Romax and its strong bearing simulation capabilities to quickly build, analyse and share models in order to select and optimise the most appropriate bearing for a given application.

Now, in the 2021 release of the Romax software suite, we have integrated external bearing calculations provided by SKF into Romax software. This allows users to easily access SKF bearing data and calculation methods to evaluate bearing performance according to SKF’s own latest and most up to date bearing data and models. The external calculations are performed in real-time over the internet.

The results include life calculations and relevant factors, equivalent loads, lubrication details, minimum load, rolling frequencies, axial load carrying capacity for cylindrical roller bearings, reference speed, and efficiency. SKF life results are available in Romax Enduro and Romax Spin, and SKF efficiency results are available in Romax Energy.

Activating the SKF bearing calculations

Enabling the SKF bearing calculations is a fast and straightforward process. Users can enter their MySKF credentials directly into Romax software to establish the connection and to begin obtaining bearing results from SKF. If you don’t have a MySKF account, registering for one is easy and can be done by following the Register link in Romax software.

To begin, simply add a bearing from the new and updated SKF 2021 bearing catalogue to your Romax model and click Run.

A new report for SKF calculated results

There is a new dedicated report available that displays all bearing results returned by SKF. If you have Romax Spin or Romax Enduro, this report will contain the SKF bearing rating results. If you have Romax Energy, this report will contain the SKF bearing efficiency results. The power of the flexible Romax software suite also allows users to activate both sets of results together for a comprehensive overview of bearing performance to SKF’s latest calculation methods.

The bearing results from SKF are displayed, firstly in a summary table for the chosen duty cycle, followed by details for each load case in the same duty cycle.

  • Life Details
  • Dynamic Equivalent Load Details
  • Static Equivalent Load Details
  • Lubrication Details
  • Minimum Load
  • Frequencies
  • Axial Load Carrying Capacity for CRBs
  • Reference Speed
  • Efficiency

report for SKF calculated results

Capped life and duty cycle life calculation

The SKF bearing life is capped at 200,000 hours according to SKF’s guidance. When this is the case, a ‘>’ symbol will appear before the respective life value. This applies to all life results – duty cycle, load case, and results in hours and MRevs (millions of revolutions).

Capped life and duty cycle life calculation

However, for the calculation of duty cycle life, load cases with capped life values would have higher damage contributions than expected, skewing the results. Therefore, behind the scenes, the uncapped load case life values are used in order to calculate more accurate duty cycle results, and results are capped at the end.

By using the uncapped load case life values, we avoid underestimating the duty cycle life which could lead to choosing a more durable bearing than is necessary. The post-analysis capping of life results is done according to SKF’s guidance.

SKF calculations are integrated into existing Romax reports

The results from SKF are integrated into Romax’s existing reports and functions where you would usually find bearing analysis results. This makes it easy to include the SKF calculations in your existing processes and to leverage the latest SKF methods within your existing workflows.

Accessing SKF rating calculations in Romax Spin and Romax Enduro

After running static analysis for one or more load cases, the Bearing Results worksheet will be populated with the following SKF bearing calculations:

  • SKF life rating results
  • SKF static load assessment
  • SKF adjusted reference speed

Here, you can assess the durability of the bearings in the model and consider whether they are an appropriate bearing choice for the application, and compare against ISO ratings. The SKF life rating results are also integrated into the “Bearing Duty Cycle Results” and “ISO 281 and Advanced ISO/TS16281 Summary and Details” reports.

Accessing SKF rating calculations in Romax Spin and Romax Enduro

Accessing SKF efficiency calculations in Romax Energy

The bearing efficiency results from SKF are integrated with the rest of the efficiency calculations in Romax Energy and therefore affect all relevant results such as system efficiency and drive cycle calculations. Users can use the SKF calculations to identify which bearings contribute the most to the system’s overall power loss. The Load Case Full Report includes a breakdown of all losses and denotes which bearing efficiency results are calculated from the SKF cloud service.

To use SKF’s bearing calculations in Romax Energy, select the SKF bearing friction model in Analysis Settings and enable the tick-box to “use SKF external calculations on supported SKF bearings”. When enabled, the bearing efficiency results from SKF will replace the Romax results where possible

Accessing SKF efficiency calculations in Romax Energy

Using SKF bearing results in customised reporting

For users who want to create their own result reports, they can use the Customised Reporting feature. This gives users control over how durability and efficiency results from SKF are exported from Romax software. Selected SKF results are accessible within Customised Reporting for users to make their own reports with the SKF results of particular interest to them.

Using SKF bearing results in customised reporting

Using SKF bearing results in batch running and parametric study

If you use the Parametric Study feature for analysing a large number of design candidates, or if you use Batch Running to run Romax from the command line or a third-party program, you can also benefit from SKF’s bearing calculations. The SKF results are included as “targets” in Parametric Study and as “results” in Batch Running. Load case results are grouped in the new sub-section titled “SKF Rating Results”. These can be found in the respective shaft assembly > bearing > duty cycle > load case. SKF results for life, damage and safety factor are also available at the duty cycle level. With this, users can carry out complex variability and optimisation studies on their Romax models with SKF’s analysis methods.

Using SKF bearing results in batch running and parametric study 1

Using SKF bearing results in batch running and parametric study 2

Looking to the future

Advancements and trends in connected services offer exciting possibilities to make our tools more useful, especially in bearing analysis as demonstrated by this collaboration with SKF. We are looking forward to offering more capabilities in this area, ultimately bringing great benefits to end-users and bearing consumers for easier and quicker collaboration with suppliers.

You can learn more about our advanced simulation capabilities for rolling element bearings by clicking here.

Kris K

Kristian Kouumdjieff joined Romax Technology in 2015 after graduating from the University of Nottingham with a Meng degree in Mechanical Engineering. Kristian is the Product Manager of the Durability and Structural Analysis (Romax Enduro), and Bearing Design and Analysis (Romax Spin) software products.