Experimental and numerical investigations on rolling element bearing thermal behaviour

Abstract

In the present study, some measurements have been conducted on a dedicated test rig to investigate rolling element bearing thermal behaviour. This test rig makes possible the determination of the tested rolling element bearing power losses through the resistive torque measurement. Some thermocouples are located on fixed parts of the system (housing, rolling element bearing outer ring) and others on rotating parts (rolling element bearing inner ring and shaft) via a telemetry system. A deep groove ball bearing, whose pitch diameter is equal to 85 mm, has been tested under oil jet lubrication for different operating conditions. Measurements of the penetration ratio, defined as the proportion of oil actually entering the rolling element bearing versus the oil injected, have also been conducted. An extended thermal network of the test rig has been established to enable a closer understanding of the rolling element bearing inner thermal behaviour. Based upon the first principle of thermodynamics for transient conditions, the studied system is divided into lumped elements at uniform temperature connected by thermal resistances which account for conduction, radiation and convection. Convection within the rolling element bearing depends on the amount of oil in the oil–air mixture known as the volume fraction. At specific test conditions, the developed model found good agreements with experiences for a given oil volume fraction of 15%. This value of volume fraction leads to an adapted formula for volume fraction in the case of jet lubrication which includes the measured penetration ratio.

Power Losses of Oil-Jet Lubricated Ball Bearings With Limited Applied Load: Part 2—Experiments and Model Validation

“…The parameter must therefore be modified according to the REB geometry and size. Similar experimental work has been done by Brossier [22], comparing two REBs of different dimensions but with the same operating conditions. Once more the value must be adjusted to REB dimension.…”

“…As it has been said previously, value is given in tables from Harris depending on both the type of lubrication and the type of REB. However, previous studies found this value should be modified in order to predict power losses [22]. In the present study, needs to be determined for According to the experimental results presented earlier, the average power losses ratio between REB#1 and #2 is equal to 2.45.…”

“…Nevertheless, these temperatures can be estimated using a thermal network, discretising REB in several isothermal nodes, connected by thermal resistances, as performed for REB in previous works [10,12,22]. A combined model with power losses and thermal aspects provides better accuracy and more information.…”

“…A REB test rig, originally developed by Niel et al [21] and used by Brossier et al [22] to study REB thermal behavior (Figure 1), has been used to measure REB power losses under different operating conditions. A detailed presentation is available in [21] and [22]. The test rig has been designed to test a wide variety of REBs.…”

Thermal characteristics and distribution rule of lubrication film of full ceramic ball bearing under different service condition

“…The Harris/Palmgren formula is selected as the basic model to predict the friction torque of full ceramic ball bearing. The resistance torque value, temperature value and oil flow rate are measured by the test bench, and the iterative algorithm is set to find the optimal parameters suitable for calculating the friction torque (Brossier et al , 2021). These parameters are reported in Table 1: …”