Friction loss of bearings under dynamic load is often measured by motoring on an actual engine. Motoring, however, is not capable of reproducing the bearing load during the firing.
The authors developed a dynamic load simulating machine, which applies variable load corresponding to one engine load cycle by means of a hydraulic pressure controlled with servo valves.
Friction loss and the shaft center locus were measured under the static load and the dynamic load simulating to the main bearing load of V-engine. The variation was studied while changing various dimensions of a bearing such as clearance, bearing length, revolution speed, shaft diameter, and presence of a circumferential groove.
By comparing the test results with theoretical values, good agreement in the basic tendency was obtained.