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friction machine
KRL
The Ducom KRL Shear Stability Tester is used to determine an oil's resistance to viscosity loss due to shear.
Kinematic viscosity loss is tested in accordance with CEC L-45-A-99, where the test oil is sheared using a tapered roller bearing block. This test method is applicable, for example, to the development of hydraulic oils that can reduce the cost per ton of excavation in the mining industry.
The Ducom KRL Shear Stability Tester complies with CEC procedure L-45-A-99. Load range from 500 to 5000 N, speed range from 150 to 1500 rpm and lubricant temperature range from room to 60 °C.
Figure 1. Ducom KRL shear stability tester.
Tapered roller bearing
Application- Analysis of the quality of hydraulic and transmission oils used in mining and construction equipment.
- Screening of polymers used as viscosity index improvers (VIIs) in oils
- Development of predictive models using both friction torque and loss of kinematic viscosity of oils.
How the system worksThe Ducom KRL shear stability tester can be equipped with a manual or pneumatic loading system. The applied load is measured by a load cell (located under the bearing pad). The bearing block (Fig. 2) is placed above the cushion. It contains a shear element consisting of a tapered roller bearing immersed in the test fluid. The bearing is loaded by a rotating spindle driven by a motor. The test fluid is heated by a pair of heating elements underneath the bearing block.
Rice. 2. Ducom KRL shear stability tester in section.
A closed loop temperature control system is used to maintain the set temperature (60°C) during shearing. It includes a k-type thermocouple (Figure 3), a heat exchanger, a recirculating water tank, and a variable frequency drive pump. Cold water is pumped and circulated in the bearing block. A heat exchanger is used to remove heat from hot water to the external environment. With this system, the temperature during shearing is maintained between 59°C and 61°C.
Fig 3. Ducom KRL bearing block assembled with thermocouple and water circulation system
Fig 4. Ducom KRL bearing block assembled with extended lever and load sensor
SpecificationsParameter Meaning Speed 0 - 1,500 rpm Normal load 500 - 5,000 N Friction force 0 - 100 N Temperature From room temperature to 60 °C Amount of oil tested 40 ml Tapered roller bearing SKF 32008X INSTRUMENT CONTROL AND DATA COLLECTIONThe Ducom KRL Shear Stability Tester is controlled by LabVIEW based WinDucom software (Figure 5), which also collects and displays data on load, frictional torque, coefficient of friction, velocity, fluid temperature and test duration. The resulting data can be presented in several ways: sample test graphs can be printed, results from different tests can be overlaid for comparative viewing, and data can be exported to Excel.
Figure 5. WinDucom software window for KRL.
Bearing block filled with gear oil
Bearing block with connectors for water recirculation system
How to quantify aging?According to the Beer-Lambert law, the concentration of attenuating substances is related to absorption. If the concentration of attenuating (absorbing) substances increases, absorption increases in the same ratio. The peak around 1750 cm-1 corresponds to C = 0. Combining both peaks results in a ratio of 1.68 between the original synthetic oil after the KRL shift and the new sample. This indicates that the concentration of absorbent material (C = 0) in the shifted oil has increased by almost 70% compared to new oil.
Changes in tribological and physical parameters of sample RL 209 - fresh, aged in KRL and aged in an oven. Each parameter is presented as a percentage of the value corresponding to the new oil for that parameter. Molecular weight (Mn) was determined using gel permeation chromatography (GPC), and decomposition temperature (onset temperature) was determined using thermogravimetric analysis (TGA).
DIGITAL MODULEMOOHA is a digital lab assistant with powerful features that can help keep your instrument in top condition and your test data safe and easily accessible. Its automatic logging and reporting features ensure reliable data protection from unauthorized access. Find out more at www.ducom.com/digital
Figure 6. Several features are available in MOOHA WEB software: performance analytics, device management, data history (digital log), spare parts and much more.
