Efficiency of Gear Transmissions With Flexibly Connected Gears Subjected to Axial Vibrations

The axial vibrational motion of one of the engaged gears increases the mechanical efficiency of a gear system by reducing the frictional resistance in the plane of gear rotation. The purpose of this investigation was to determine the effect of axial vibrations on the frictional losses in gear systems which are operated under the conditions of boundary lubrication. Two basic cases were investigated: the case when all four gears were rigidly connected to the shaft, and the case in which two of the four gears in the drive were mounted to the shaft in such a manner that they had a certain degree of freedom in the axial direction. In the second case, the relative axial displacement between the engaged gears may be smaller than the amplitude of the shaft vibrations, and the effect of the axial vibrations on the frictional losses in a gear system may be reduced. The influence of the following factors upon the efficiency of the gear train were investigated: the magnitude of the force transmitted by the train, the weight of the flexibly connected gears with the masses attached to them, the frequency of the axial vibration of the shaft, and the amplitude of this vibration.