Determination of the Thickness of Lubricating Films when Testing the Gear Train Materials of Printing Equipment

The article considers the upgraded device to determine the thickness of lubricating films when testing the gear materials. The content of modernization of such a device includes apart from the connected in series the rolling samples of ammeter, rheostat, battery and switch as well as the voltmeter samples connected in parallel with the additional the rigid conductive plate and two voltmeters connected by ones of their ends between themselves and the rigid conductive plate and by the other ones with the individual samples. The modernization of the device due to the use of two additional voltmeters in it provides an opportunity to determine the thickness of the self-generating organic film on the working surface of each roller sample by individually measuring the drop in electrical voltage in a normal glow discharge mode. The tests were carried out using roller samples of improved steel 45 with a hardness of 255 НВ, a diameter of 50 mm, a roughness of working surfaces of 0.35 microns, a load of radial compressive force at the contact stresses of compression of 500 MPa, lubrication with a lubricant material ‘Industrialne 45’ and the temperature of its heating in the bath to 70° C. When measuring the values of electric voltage drop through a roller sample, a constant current of 1.5 A. The mentioned above device in addition to the determining the oil film thickness and the total thickness of boundary lubricating films on the working surfaces of both roller samples provides also the possibility of determining on the working surface of each sample separately. This enhances significantly its functional capacity for physical simulation of work conditions for closed gear trains of the printing equipment.