E-Lub Tester

Introducing the world's first Dielectric Tribometer: impedance, film thickness and electrical breakdown measurement in a lubricated test bearing

The E-Lub Tester determines the ohmic resistance and capacitance of the lubricant used in a test bearing under fully variable operating conditions.

For this, a high-precision impedance measurement is used, which was developed based on flucon's EPSILON+ laboratory instrument.

Following flucon's Dual Approach, E-Lub Tester will allow you to assess the lubrication condition and the film thickness for any given operating point by means of a newly patented method.

In addition, the E-Lub Tester includes a powerful signal generator that allows you to analyze "EDM" breakdown currents and the dielectrical strength under a defined electrical load that is applied directly to the test bearing, so that the performance and discharge tendency of oils and greases can be investigated under fully variable operating conditions (lubricant temperature, speed, axial load, run time and source voltage signal).

Variable drive and axial load are applied through a Falex or Hansa four-ball tester, with the Falex Four-Ball having the advantage of full automation.

Key features

• dielectric tribometry adapter for Falex Four-Ball or Hansa VKA-110 four-ball tester
• Impedance Test Mode: measurement of the lubricant impedance in a roller bearing, determination of ohmic resistance and capacitance for each operating point
• patented Film Thickness Mode: determination of lubricating condition (boundary lubrication, mixed friction, full EHL) and h_min
• Breakdown Test Mode: measurement of electrical discharges and ohmic currents during operation, full statistical analysis (number of discharges, average power)
• test cell for representative axial ball bearings (recommended standard: FAG/SKF type 51208)
• variable operating parameters: via E-Lub Tester: lubricant temperature (automatic control), electrical load (common-mode voltage); via FBT/VKA: running time, speed, axial load (all logged in test report)
• automated or guided, semi-automated test campaigns
• includes an all-in-one PC with powerful flucon E-Lub Tester software for Windows
• auto-calibration function

 

Main components

The E-Lub Tester consists of two main components: the four-ball-adapted test cell, which contains the thrust ball test bearing as well as the impedance and temperature sensors. When inserted into the four-ball tester, this bearing pot replaces the traditional four-ball assembly.

 

 

The electronic unit in a compact 19" rack complements the composition. It includes the in-house devloped impedance meter, the signal generator and amplifier as well as a precise voltage and amperemeter for analysis of the breakdown tendency.

Optionally, this device can be obtained seperately for tests with alternative machine elements.

A Julabo Magio fluid circulator is used as a thermostat and can be connected to the test cell for automated temperature control of the bearing and its lubricant.

With the included all-in-one PC and the intuitive flucon E-Lub Tester software each test can be carried out automatically within a desired temperature range.

Background: breakdown currents in the lubrication gap

With the electrification making bigger progress every day, the electrical and dielectric properties of oils and greases used in the electric driveline are becoming more and more important. Lubricants in anti-friction bearings must have a certain specific electrical conductivity so that static charges and resulting electrical breakdowns can be minimized to prevent damage to both bearings and lubricants.

While the effects of harmful discharges in the electric drive have been documented for many years, the targeted investigation of such bearing-based spark erosion that was given the analogy of "Electric Discharge Machining (EDM) effects" has just now been made possible.

In addition to friction, electrical breakdowns occuring in rolling and ball bearings are a common phenomenon of frequency inverter-controlled drives with a capacitive coupling of different machine elements.

These discharges usually cause considerable damage to the bearing shells: sudden breakdowns with strong currents provoked by high potential discrepancies due to an insulating lubricant film will lead to pitting damage, i.e. crater and corrugation formations, but also to fluting and grayfrosting on the bearing raceway.

Furthermore, the lubricant itself will age excessively when exposed to breakdown current flow: local overtemperatures in the lubrication film will cause permanent damage to greases and oils so that the lubrication is severely affected.

A new dynamic method: Impedance measurement on lubricated bearings under real-life conditions - with laboratory-like accuracies

With flucon's E-Lub Tester it is now possible to determine the lubricant impedance and breakdown tendency directly in the bearing, under real process conditions. The proven technology of the EPSILON+ Dielectricity Meter is used for highly accurate measurement.

Intuitive software for guided and automated testing

Both the Impedance Test and the Breakdown Test of your lubricant are carried out automatically, thanks to the included software for your Windows PC. Here, various standardized and custom test modes are available.

Fields of application

The characteristic data generated with the E-Lub Tester can be used in tribological research and lubricant development as well as for the following exemplary applications, where electric discharges play an important role:

• electric motors with variable speed
• e-mobility
• gear technology
• railway technology
• wind turbines

Available now: In-house demo and service testing

On request, we can carry out measurements for you using our in-house equipment. This is, of course, possible according to the draft standard or also with individual boundary conditions suitable for you (with variable filling quantity, temperature, speed, load, applied voltage signal, running time).

Simply send in your lubricant sample and receive an extensive test report within a few work days.

Any questions about the test services by means of our E-Lub Tester? Please do not hesitate to contact us!

Technical specifications - E-Lub Tester

Compatible four-ball tester models	Falex Four-Ball, Hansa VKA-110
Obtained data	ohmic resistance, capacitance, film thickness, breakdown frequency (number & amplitude of capacitive EDM & ohmic currents)
Suitable substances	Greases and oils
Bearing type	51208 thrust ball bearing
Material - Test cell (FBT adapter)	stainless steel with PEEK housing and handle
Temperature measurement	2x Pt100 by bearing
Temperature range	20°C to 120°C
Load	2.400 N max.
Speed	6.000 rpm max. (depending on FBT)
Frequency range	100 Hz to 10 MHz
Common-Mode Voltage	60 V max. (peak-to-peak)
Connectivity	Ethernet
Power supply	110-240 V AC, 50/60 Hz
Scope of delivery	FBT-adapted test cell for 51208 bearings with sensor cable & Lemo plug, mounting mandrel & ball, 19" rack, all-in-one PC w/ "flucon E-Lub Tester" software (for Windows), Julabo Magio thermostat with insulated hoses, consumables & accessory kit for plug-and-play operation