Thinking outside the box to keep
everything turning: GRW Development

  • Product layout & design
  • Calculation and Simulation
  • Certified development process

and Design

Ball Bearing Construction and Design by GRW: Innovative and Individual Solutions

At GRW we use our product catalogue and construction-kit as a basis to design all types of ball bearings. This gives you the chance to pick from a wide range of already existing products in our portfolio. If the framework and needs are clear, we can supply the parts you need within a few weeks.

More than Just the Standard in Our Portfolio: Ball Bearing Solutions by GRW

No worries – if we cannot fulfill your needs within our current product range, we will further customize our ball bearing solutions and designs in order to meet your needs. If necessary, we can also adapt the ball bearings’ assembly - We have specialized in providing you with individual ball bearing solutions that fit to your application flawlessly. Whether it be an extended inner ring, a flange on the outer ring, securing at the AC ball bearing or a completely integrated solution as a unit – we will get you the perfect product for your ball bearing application!

Modern Technology Fulfills Your Needs

Our team in the product design department designs all units with the help of modern CAE-/CAD-tools. Additionally, we make use of our GRW calculation and simulation tools. With this modern technology, we can fulfill all special requirements and make sure you get the ball bearing best suited to your needs.


GRW: Calculation and Simulation for High-Quality Ball Bearing Solutions

When designing new ball bearings we use modern CAE-/CAD-tools. Additionally, we use general bearing characteristics and service life factors of the shaft systems to predict and calculate all relevant data. Our team at GRW uses this data as a basis to optimize our designs for creating high-quality, durable ball bearing solutions. With the help of a finite-element-software, we calculate component strength, stiffness and deformation for subsequent analyses. For more extensive problems in the area of simulation, we partner with external development companies. This approach enables dynamic multiple-body simulations that will optimize the kinematics and dynamic behavior of our ball bearings in your individual application.

Possible Simulation of Ball Bearings and Shaft Systems

For ball bearings:

  1. Calculation of single ball bearings
  2. Load distribution inside of the ball bearing
  3. Service life according to ISO/TS 16281
  4. Including tilt angles and operating clearance

For shaft systems:

  1. Allows exact calculation of complete units
  2. Complex load distribution scenarios
  3. Tolerance analysis of the bearing seats
  4. Load spectrums
  5. Visualization of the complete shaft system

GRW calculations includes the following typical outcomes:

L10: nominal lifetime according to ISO 281

Lnmrh: extended modified lifetime according to ISO/S 16281 (DIN 26281

  • Service lifetime with regards to lubrication status
  • Temperature
  • Bearing seats
  • Probability of failure

Pmax: load during contact

  • <2500 MPa = “fail-safe”/no lifetime calculation
  • 2500 – 4200 MPa = lifetime calculation necessary
  • >4200 MPa = plastic deformations are to be expected

Roll and slide behavior:

  • Oil lubrication < 0,5
  • Grease lubrication <0,3

Δb_circ: ball advance

Finite-Element-Analysis of Ball Bearings and Housing Units

  • Ball bearing and component rigidity
  • Housing rigidity
  • Ball bearing deformation
  • Housing deformation
  • Rigidity calculation for ball bearing components and housings
  • Stress analysis
  • Heat transmission between components and housings (partly)
  • Preload within the system by shafts


  • Contact forces between rolling elements and trajectories
  • Kinematics of the rolling elements during touring in the bearing
  • Retainer movements and vibrations
  • Friction between all components

All results that we collect at GRW during our calculations will of course be provided to our customers in reports and in proprietary data formats or models. This is one example of how we are actively involved in the creation of your individual design. Simply include our calculation and simulation directly into your own models to benefit from our measurements.

At GRW we are constantly expanding simulation data transfer in order to assist you during development and simulation. Do you have any more questions? Feel free to contact us at GRW. We are looking forward to helping you!


Ball Bearing Testing and Simulations: How We Test Our Products

In order to provide you with the optimal high-precision ball bearing solutions, GRW puts our products through the acid test. This way we can guarantee first-class quality. We conduct many basic tests on our own test benches, some of which we developed ourselves. These will be supplemented later by further release procedures, which guarantees an optimal result for our customers. Internally, GRW ball bearing testing includes the following test options:

1. Service Life Test

The lifespan of a machine or measuring device often depends on the lifetime of the integrated ball bearings. That is why it is essential to determine the service life span of a bearing during development.

This testing is often carried out directly within the end application, where the exact operational conditions can be reproduced. GRW also relies on its own endurance test benches to support customer testing in an earlier development phase and to accelerate development:

Endurance test bench "ORAKEL" (2nd and 3rd generation)

A long lifespan is particularly important for medical-grade hand pieces, which largely contribute to maintaining the health of patients. We use our endurance test benches to test the service life of ball bearings in dental hand pieces and contra-angle hand pieces. These endurance tests monitor and measure both the speed and applied load over the running time. The test bench is developed in-house by GRW and is also available for customer use.

Endurance and functional test rig for spindle bearings

We also have a special test rig to determine the service life of spindle bearings. This test takes place in a GRW original machine tool spindle. In addition, the operating data are also recorded.

2. Dynamic Structural Analysis and Noise Testing

Many associate the whir of a dentist's drill with discomfort and pain. Therefore, making the running noise of the bearing as inaudible as possible is crucial in such applications. In order to adapt our ball bearings to these requirements and to reduce the noise as much as possible, noise measurements and analysis are essential. If the bearings are used, for example in space applications, identifying and addressing high levels of vibration plays an important role. That is why GRW uses various testing and analysis options for ball bearing testing in relation to noise and dynamic structure analysis:

Noise check:

We have the option of performing advanced noise measurements and analyses on components in a noise-reduced environment. We measure airborne and structure-borne noise on the running component. Then the measurements can be appropriately evaluated for noise level or vibration analysis.

Dynamic structural analyses:

Using a laser vibrometer, we record and evaluate the vibrations of a component on three axis. This non-contact measurement method makes it possible, for example, to excite and measure components on a shaker test rig. If necessary, we can identify resonance ranges or verify constructive dampening measures. Afterwards, we can evaluate the measured signals accordingly.

3. Environmental Simulation Tests

Whether it be in medical technology, the aerospace industry or in mechanical engineering - our ball bearing solutions are often used under special and extreme conditions. From extreme temperatures to aggressive substances such as acids or superheated steam – a successful ball bearing must withstand all of these influences. To combat these external influences, GRW has expanded its ball bearing design and testing, developing a reputable know-how over the years. Several test benches are available to subject our products to extreme environmental and operating conditions:



Climatic chamber:

On this test device, we can expose the bearings to freezing cold temperatures of up to -94°F (-70 ° C) and scorching heat of up to +356°F (+180 °C). Additionally, within a range, we can control the humidity within the chamber. Static temperature changing tests and friction torque tests are also possible under varying temperatures and humidity.

Steam sterilization:

In our laboratory we have two different devices for steam sterilization. With these, we are able to simulate the sterilization of bearings in medical devices or tools. The cycles and temperatures can be varied and partially automated.

Condition and Failure Analysis of Rolling Bearings

A visual assessment of the components during and after the ball bearing test is particularly important. The condition of the bearing components gives clear indications of:

  • the conditions during and after the endurance run
  • the course of wear
  • the condition of the lubricant
  • the possible reason for failure


This is why the use of modern, state of the art equipment is essential for the analysis of test runs:

Optical microscopes with digital image capturing:

Our product development department has several stereo microscopes with digital image capturing in order to assess, document and quantify damage or running conditions.

Digital 3D microscope with measuring function:

We use high-resolution 3D microscopes to be able to record surface structures three-dimensionally and measure them geometrically. These are a supplement to the optical microscopes and enable a more precise measurement.

The test rig examples mentioned above serve as the foundation of our testing field. For further testing, we also rely on a large number of mobile measuring devices to determine temperature, speed, pressure, load and other measurable variables. We also provide the option of building smaller, more accessible test benches that can be assembled in a short amount of time.


You are looking for further information? Simply address our experts. They are happy to help you with questions concerning our ball bearings. Our engineering-team will gladly answer your technical questions regarding our ball bearings and the application of our products as quick as possible.