PSI - Issue 59

Victor Aulin et al. / Procedia Structural Integrity 59 (2024) 428–435 Victor Aulin et al./ Structural Integrity Procedia 00 (2019) 000 – 000

433

6

start the generator 4.

Fig. 6. Block diagram of the device for determining the relative time of existence of continuous oil layers and dissipative secondary structures; 1 - power source, 2 - resistor, 3 - comparator, 4 - generator, 5 - frequency meter, 6 - tribo coupling of parts, *- friction parameters have been measured according to standard methods. The comparison level is selected in such a way that generator 4 is started only when the tribocoupler resistance of the samples (parts) is higher than 1-2 Ohms. Frequency meter 5 counts the number of pulses x n , which are generated during the set countdown time ref t . The time of existence of continuous oil layers or (and) dissipative secondary structures that separate the triboconjugation of samples (parts) is determined as:

n

f n

i    1

r x

(2)

t

t



re

ren

where r f - pulse generation frequency, Hz . he relative time of existence of continuous oil layers and DSS is determined from the equation (1):

(3)

.

Setting the countdown time MHz, it has been obtained that in the presence %), which separate the tribocoupler of of continuous oil layers and dissipative secondary structures ( samples (parts), the number of pulses is counted by a frequency counter . Thus, the measured quantity and will be the relative time of existence of dissipative secondary structures and oil layers expressed as a percentage. Other relationships between parameters are also possible ref t and r f . So at and 10  r f MHz, to receive ξ у percentages, the readings of the frequency meter 5 must be divided by 10, thus achieving the possibility of continuous monitoring of the processes of formation, destruction and restoration of oil layers and dissipative secondary structures, both in the tribo coupling run-in mode and during normal friction and wear. The electrical diagram of the device for determining the relative time of existence of continuous oil layers and dissipative secondary structures is shown in Fig. 7. In the scheme, to increase the sensitivity, a DC amplifier is additionally introduced on the operational amplifier А 1, and the comparison level is set by a potentiometer R6. The generator for starting is made in the form of a quartz generator on a logic chip D1 and an electronic key, the output of which is connected to the devices for registration. To display the magnitude ξ in digital form, a digital frequency meter has been used. μs and frequency