**Conflict of interest**

(scuffing), we used the well-known Dowson and Higginson formulas to determine the lubricating layer parameter (λ) [44, 45] and the criterion C developed by us at the values of the coefficient K = 2.7 and the exponent e = 0.336 in formula (3). Dependences of the fields of deviations of the values of these criteria on the gear

*Dependences of the fields of deviations of the temperature criterion (θ, 1) of H. block, criterion (SF, 2) of G. Niman and Saitzinger and offered criterion (C, 3) of destruction of the third body, on the gear wheels circular*

*Dependences of the fields of deviations of the values of λ parameter (1) and criterion C of destruction of the third*

*Tribology in Materials and Manufacturing - Wear, Friction and Lubrication*

As it is seen from the graphs, deviations of the criterion C of destruction of the third body developed by us, are small and constant, while deviations of the param-

**Figure 16** shows the results of similar calculations using the C criterion with the values of the coefficient K = 1.55 and the exponent e = 0.29 in formula (3) and the formulas of H. Block [47] and Niemann G. and Saitzinger K. [48]. The studies were carried out on gear drive test bench FZG for transmissions A, L, N 141, 142, 143,

It is seen from the graphs that deviations of the offered criterion C of destruction of the third body little differ from the unit in the whole range of variation of the circular velocity, while deviations of other criteria significantly differ from the unit

tribological properties of the third body, degree of its destruction, disposition of the surfaces to seizure etc. The researches have shown that the continuous or

• Tribological properties of the interacting surfaces mainly depend on

eter λ and its values increase with increase of the gear wheels velocity.

wheels circular velocity are shown in **Figure 15**.

*body (2) developed by us, on the gear wheels circular velocity.*

and they increase with increase of the circular velocity.

201, 202, and 203 with lubricant k1.

**5. Conclusions**

**146**

**Figure 15.**

**Figure 16.**

*velocity.*

The authors declare no conflict of interest.
