Education of the republic of uzbekistan tashkent state technical university named after islam karimov

№3/2021 year. 
Technical science and innovation
234 
0

and the theoretical foundations of functional relationships between the physical and 
geometric characteristics of the wheel and the rail. I. Quoted by Naumov. It is the maximum 
value of attachment 
max
S
at normal force R given as, the magnitude of the stresses in the body of 
the wheel and rail corresponding to the limit of material strength. In this case 
P
S
max
0


(2) 
Research [11] has shown that in order to increase the value of, 
0

it is necessary to 
expand the contact surface area. This can be achieved by increasing the diameter of the wheel 
circumference, the radius of the surface of the rail head, with a special profile of the bandage, as 
well as increasing the strength limit of wheel bandages and rails, making materials with large 
Poisson's ratio and much lower elastic modulus. 
Experimental studies conducted in the laboratory [12], as well as traction tests in the use 
of locomotives [13] confirmed the findings and patterns. 
0

the value is reduced by contamination of the rails with mineral dust and oil stains, 
contamination of contaminated rails with dew or light rain, as well as under the influence of melt 
moisture under the wheels. On the contrary, heavy rains wash away impurities, restores the high 
value of 
0

. 
0

the maximum value of reaches 0.5 according to experimental data [14]. 
0

In order to stabilize the value, it is necessary to use fine quartz sand with a minimum 
amount of moist soil (not more than 1%) and pour it in a continuous stream under the wheels on 
difficult sections of the road and in adverse weather conditions. It is much easier to automate 
such sand transmission by using a shatter relay or by pressing a special button by the machinist. 
Quartz sand removes dirt and the oxide film that covers it from the surface of the wheel 
roll, thereby increasing the actual contact area. 
In this case 
0

should not be confused with the calculated coupling coefficient, which 
depends on the speed in the rules of traction calculations for the operation of trains. 
Fundamental studies have been conducted to study the traction characteristics of mainline 
locomotives [15 - 16]. From these studies, for us N. N. The scientific work done by Menshutin 
[16] is of great importance. Nominal load on rails from VL22 series experimental locomotive 
wheel pair
т
P
22
0

and the diameter of the wheel equals
22
,
1

d
.
The tests were performed 
with both conical and cylindrical bandages, both with and without sand. The experimental rail 
track had a number of different sections. The slip frequency was measured using induction 
sensors. One of the sensors is mounted on the axle, which develops the torque of the engine 
wheel pair, while the other is mounted on the axle with the engine off (standard). The measuring 
coils of both sensors were connected to a vibrator. When the slip was formed, similar vibrations 
were generated in the recording film. The ratio of the sliding speed to the rolling speed was 
found based on the distance between the nodes in the film and between the marks of the standard 
wheel turns 
v
u


. 

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