The scope of work for the special test benches at IME strategically bridges the gap between simple standard test benches and highly complex full-system test benches. Drawing on our experience and leveraging our facilities, we are able to provide tailored test bench solutions for fundamental development challenges that involve a high degree of innovation.

Depending on the specific development objective, tests are conducted on individual components or subsystems. The level of detail regarding environmental factors (load, lubrication, temperature, etc.) is adjusted to meet the requirements of the respective project.

Our expertise encompasses the design, construction, commissioning, and operation of the test bench, as well as the processing and analysis of the measurement results.

This means that everything is possible, from short single-component tests under steady-state conditions to subsystem tests with parameter variation in highly transient endurance test cycles.

The following section presents a selection of currently available special test benches.

The test bench is used for the experimental evaluation of rolling bearings under defined operating conditions. It was specifically designed for high-speed testing, various lubrication concepts, and combined load conditions. Thanks to its modular design, different bearing types, lubricants, and load scenarios can be tested under realistic conditions.

Background

Rolling bearings are key machine components and have a significant impact on the service life, efficiency, and operational reliability of technical systems. Especially at high speeds or under complex load conditions, lubrication, temperature development, and force ratios determine bearing performance.

The test bench makes it possible to systematically analyze these relationships under controlled conditions. The bearing test bench has a modular design and allows for the targeted variation of key operating parameters such as speed, lubrication conditions, axial and radial loads, and ambient temperature.

Concept and Skills

• Drive via motor spindles (up to 36,000 rpm)
• Lubrication concepts
  • Grease-lubricated bearings
  • Oil-lubricated bearings with oil injection lubrication or oil sump
• Oil conditioning: 10 °C to 90 °C
• Housing conditioning: 0 °C to 100 °C
• Two separate units (can be operated simultaneously or individually)

2-bearing configuration: Axial force

An integrated axial force system allows defined axial loads to be applied to the test bearing.

• Dynamic axial force (pneumatic up to 1.4 kN)
• Rotating radial force (unbalance)

4-bearing configuration: Combined axial and radial forces

A separate configuration is available for realistic operating conditions, in which axial and radial forces can be applied simultaneously.

• Axial force (static via disc springs)
• Dynamic radial force (pneumatic up to 18 kN)

Research

• High-speed testing of rolling bearings
• Comparison of different lubricants
• Analysis of thermal bearing behavior
• Tests under axial and radial loads
• Independent validation of bearing and lubrication concepts
• Simulation of potential failure mechanisms

To obtain early, reliable results, we abstract the entire system and examine a representative subsystem on a specially designed test bench. This allows us to identify weak points and optimize the lubrication and cooling system before beginning costly full-scale testing.

Background

• Cooling and lubrication are critical to the service life, efficiency, and, above all, performance of modern electric motors.
• Critical points: stator winding heads, rotor laminations (temperature of the permanent magnets), rotor bearings, and radial shaft seals (RWDR).
• CFD simulations provide valuable insights, but real-world two-phase flow (oil/air) and component damage require experimental data for validation.

Concept and Capabilities

• Modular design, including faithful reproduction of housing and component geometries as well as the type of oil supply.
• Driven by motorized spindles (up to 36,000 rpm)
• Oil conditioning system:
  • Variable flow rates
  • Temperature: 10 °C to 70 °C
  • Continuous and intermittent oiling
• Determination of oil distribution via flow rate measurement at five positions

The test bench is designed to efficiently and precisely simulate specific operating conditions that can only be reproduced in isolation with great effort in larger system environments, such as electric powertrains.

Concept and Skills

To accurately simulate real-world operating conditions, the following parameters can be systematically varied on the test bench:

• Speed: 0 to 24,000 rpm (both as steady-state points and in the form of defined speed profiles)
• Pressure: Conversion of pressure differentials in the range of ± 500 mbar
• Position deviations: 
  • Setting of defined angular errors in the range of 1/100°
  • Reproducible implementation of coaxiality errors in the range of 1/100 mm
• Lubrication: Adjustable and quantifiable drip lubrication
• Temperature: Thermal conditioning of the test environment
• Test specimens: Variability in dimensions, material, and surface finish through interchangeable shafts and sealing rings