Diomin, R.

Kovtanetz, M.

Kravchenko, K.

Nozhenko, V.

Prosvirova, O.

eEast-UkrNUIR (Electronic Volodymyr Dahl East Ukrainian National University Institutional Repository)

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Globalization of scientific and educational space. Innovations of transport.
Problems, experience, prospects.
DETERMINING THE PARAMETERS OF AN IMPROVED
RAILWAY BRAKE EQUIPMENT
Kovtanetz M., Kravchenko K., Prosvirova O., Diomin R., Nozhenko V.
Volodymyr Dahl East Ukrainian National University
High speed train discs must be capable of absorbing large amounts
of heat in emergency brake applications from maximum speed. Heat dissi-
pation during braking is low and therefore it is crucial to ensure low initial
brake temperatures.
This can only be achieved with good cooling characteristics, since
brake mass must be kept to a minimum to ensure low unsprung mass. It
must also be taken into consideration that emergency braking from maxi-
mum speed is relatively rare, however the brake system must be capable of
performing this duty without excessive thermal loading.
Ventilated brake discs are commonly employed for their good cool-
ing qualities, however this type of brake disc can generate substantial pump-
ing losses when rotating at high speed. The effects are very serious because
a high number of discs (usually 4 discs per axle) rotating at high speed (up
to 2000 min-I) require very high levels of power, just for disc rotation.
56  _________________________________________________________
Globalization of scientific and educational space. Innovations of transport.
Problems, experience, prospects.
This has resulted in the development of numerous 'low loss' ventilat-
ed disc designs and the use of solid discs. Obviously, a very fine balance of
low pumping losses and good cooling characteristics are necessary to satisfy
braking and power consumption requirements for all vehicle routes.
The basis of the proposed technical solution the task of increasing
the efficiency of the method of braking of the locomotive and equipment for
its implementation through effective use of compressed air, which is dis-
charged from the brake cylinder, and the cooling of the brake pad and the
working surface of the disk, the categorization of products galling to contact
"brake pad and brake disc".
The basis of the model the task of increasing the efficiency of the
method of braking of the locomotive and equipment for its implementation
through effective use of compressed air, which is discharged from the brake
cylinder, and the cooling of the brake lining and the working surface of the
disk, the categorization of products galling to contact "brake lining and
brake disc".
Suggested ventilated disc brake for which reasonably desegment the
task of increasing the efficiency of the method of braking of the locomotive
and equipment for its implementation through effective use of compressed
air,  which  is  discharged  from  the  brake  cylinder,  and  the  cooling  of  the
brake pad and the working surface of the disk, the categorization of prod-
ucts galling to contact "brake pad and brake disc".
Justified quantification of factors affecting the process of supplying
compressed air between the brake disc and the brake pads during braking
and the dynamics of their actions.
Consequently, the use of the proposed design will allow:
- effective use of compressed air which is discharged from the brake
cylinders,
- cooling the area of frictional contact of the brake pad and brake
disc", using the compressed, cooled air into the holes of the brake pads,
- improving braking performance and reduce the intensity of wear of
the brake pads due to the timely disposal, the frictional wear of the zone,
- increasing the level of traffic safety of trains by increasing the reli-
ability of the braking.
The coefficient of heat transfer by radiation is given depends on the
degree of tone color scheme (dark, light) radiating surface of pad, of the ab-
solute temperature of the pad and the ambient temperature. In a modified
construction of the pad coefficient of heat transfer by radiation is not con-
sidered, because it does not significantly affect the wear pads because orga-
nized weak heat removal from the zone of friction of the wheel roll surface
and overlay in the environment.
____________________________________________________________57
Globalization of scientific and educational space. Innovations of transport.
Problems, experience, prospects.
The heat transfer coefficient by convection is calculated according to
the criteria of Reynolds and Prandle.
The presence of grooves in the proposed design of pads reduces the
intensity of wear, especially at high speeds, through the stabilization of the
temperature regime at the expense of increasing the efficiency of heat re-
moval from the zone of friction in the environment. During braking, the
cold air that is blown under the cover, heats up and goes effectively in the
environment. As a consequence, there is an increase, which reduces the av-
erage temperature of the friction of the working surface of the pad, thereby
increasing the time to reach the maximum temperature at which there is de-
struction of the projections of the actual contact. In the overlay model when
increasing the initial speed of braking of the intensity of the heat increases.
References:
1. Kocevski A. N. The calculation of the internal fluid flows in channels with
using software FlowVision // Bulletin of Sumy state University. – Sumy, 2004. –
№ 2 (61). – P. 25-36.
2.  Kocevski A. N., Pope V. G. a Modern approach to the modeling and
computation of fluid flows in centrifugal hydraulic machines // Bulletin of Sumy
state University. – Sumy, 2003. – № 13 (59). – P. 195-210.
3. Cebeci,  T.,  Smith  A.  M.  O.,  Analysis  of  Turbulent  Boundary  Layers.  –
Academic Press, New York, 1984.
4. Prikhodko, A. A., D. A. Semin Technical Aeromechanics: a Training manual. –
Lugansk: Publishing house of the East Ukrainian NAT. the University of the ei.
V. Dahl, 2002. – 170 p.


Determining the parameters of an improved railway brake equipment

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Determining the parameters of an improved railway brake equipment

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