Golovatyj I. V. Substantiation of rational parametres and development of brake system for storage electric locomotive ARP10-900

One of the main processes productions of mining enterprise is moving of minerals. Miner transport posesses an exclusive role in mining. Electric locomotive is the important part of transport. It is economic and productivity [1]. The Brake mechanism is responsible knot, which creates artificial resistance to electric locomotive movement.

Relevance of topic. Goals and objectives

Meaning of brake devices is increasing due to the intensification of production, the increase in the moving mass, velocity and frequency of braking. In a short period of time braking device must convert in heat a large amount of mechanical energy and transfer this heat into environment without reducing the efficiency of the device or machine in general. The main directions of improving the reliability and efficiency of the braking devices are constructive improvement of the mechanical part and the drive of the brakes and the creation of new varieties of construction, development and application of new materials with improved friction properties. In connection with the increase of coal production is increasing the load on electric locomotive. This requires a fundamentally new design of braking systems, which provide the necessary braking torque in small dimensions [2].

The scientific significance of the topic lies in the choice of rational parameters of the braking system that provides high braking torque in small dimensions.

The practical value of the work - developed disc brake and the drive to it is able to replace in electric locomotive ARP-10 shoe brake with mechanical drive. Dimensions of disc brake is less than shoe brake, drive of disk brake working faster than mechanical.

The aim of this work: the choice and determination of the parameters of the braking system of electric locomotive ARP10-900 for improve reliability, reduce the size of brake devices, the speed of operation, avoiding wear tires wheels.

To achieve this goal, the following main tasks:
- select the most appropriate executive mechanism for braking;
- choice of friction materials;
- choice of governance and the drive of the executive mechanism;
- calculation of braking devices;
- thermal calculation of the friction material.

A review of research on topic of scientific work

Candidate of Technical Sciences Monya A.G. develops effective braking devices and systems in Ukraine. His works are: "Substantiation and the choice of rational parameters of disc brake mine locomotive", where was designed disc brake for mine locomotive, "Mathematical modeling braking of mine locomotive disc brakes, creating a pulsating brake torque". Doctor of Technical Sciences A. A. Rengevich developed new braking system for electric locomotive [3].

Overview and analysis of braking devices

Classification of brakes: shoe brakes-working element in the form of blocks, interacting with the outer or inner surface of the brake drum, belt brakes- with a working element in the form of a flexible tape, interacting with a brake drum, disc brakes- with a working element in the form of entire disks or individual segment blocks, conical brakes- with a working element in the form of a cone; rail brakes- with a working element that interacts with the plane of the rail, which moves the machine, or with a special surface [2]. Based on the design parameters, I preliminary selected multi-brake for service braking, and parking.

Analysis of friction materials and pre-selection for the friction pair

Based on values of average coefficient of friction, the stability coefficient of friction, linear wear, the maximum temperature (taking the average operating conditions) [4], I have tentatively chosen the friction material MKV-50A, disc, made of cast iron CHNMH. The average coefficient of friction in a pair of 0.35.
This choice of materials is preliminary, final decision on the selection of materials should be taken following the thermal calculation.

Definition of braking torque and calculation of disc brake

For electric locomotive ARP10-900 required brake torque on one axis, when braking device is located on the second gear shaft (between the wheel pair and a pair of motor shaft) is

where P - adhesion weight electric lokomotive, kN; ψ - coefficient of adhesion to rails; D_к - diameter of wheel, m; U_4,5 - gear ratio; η_п - efficiency of transfer. Braking torque disc brake is

where N - axial force, N; φ - friction coefficient; z - number of pairs surfaces of friction; r_cp - radius of friction force, m. Nominal contact area:

Proposed construction of braking device (developed in accordance with [2], [5], [6], [7], [8], [9], [10]):

Picture 1 - Braking device: I - no braking, II - service braking, III - parking brake, 1 - disks that are recorded from the rotational motion of the shell 2 - disks, rotating with the brake shaft, 3 - spring for the parking brake.

Determination of stopping distance

The expressions for the determination of the stopping distance depending on pressure applied to pistons multidisk brake:

where P - adhesion weight electric lokomotive, kN; Q - weight trains (loaded or empty), kN; ω - resistance of movement (loaded or empty wagons), N/kN; i - slope of rail track, V - speed by beginning of braking, km/h; l_т - stopping distance, m; S - total area of pistons in the brake cylinders, m²; B - braking force, N; η_мех - mechanical coefficient, which takes into account the loss of power to friction between piston and cylinder; Р_р - pressure in hydraulic system, Pa. Maximum pressure in the hydraulic system will be

Based on formulas presented above, has built a schedule change in stopping distance depending on the pressure in the hydraulic system.

Conclusions

1. The analysis of friction materials. As a result, for the friction pair is selected: the friction material- sintered iron MKV-50A, disc, made of cast iron CHNMH.

2. Multi disk brake installed on the second shaft of gearbox and braking torque is equal M_т2=1192 Nm, number of pairs surfaces of friction are 4.

4. The expressions for determining the stopping distance depending on pressure applied to pistons of multi disk brake.

Literature

1. Волотковский С.А. Рудничная электровозная тяга. – М.: Недра, 1981. - 278 c.

2. Александров М. П. Тормозные устройства: Справочник. – М.: Машиностроение, 1985. – 312 с.

3. Ренгевич А. А., Салов В.А. Разработка усиленной тормозной системы и её размещения на рудничных электровозах // Горный журнал, 1985. – №6. – с. 7

4. Федорченко И.М., Крячек В. М., Панаиоти И. И. Современные фрикционные материалы. – Изд. «Наукова думка», 1975. – 335 с.

5. http://protect.gost.ru/document.aspx?control=7&id=150986 Сайт "Федерального агенства по техническому ругулированию и метрологии". ГОСТ 1139-80. - "Соединения шлицевые прямобочные. Размеры и допуски".

6. http://protect.gost.ru/document.aspx?control=7&id=141886 Сайт "Федерального агенства по техническому ругулированию и метрологии". ГОСТ 13773-86. - "Пружины винтовые цилиндрические сжатия II класса, разряда 4 из стали круглого сечения. Основные параметры витков".

8. http://protect.gost.ru/document.aspx?control=7&id=134284 Сайт "Федерального агенства по техническому ругулированию и метрологии". ГОСТ 1786-95. - "Накладки фрикционные. Общие технические требования".

9. Хебда М., Чичинадзе А. В. Справочник по триботехнике - т. 3, М.: Машиностроение, 1992. - 730 с.

10. ГОСТ 12.2.112-86. - "Система стандартов безопасности труда. Транспорт рудничный электровозный. Общие требования безопасности к подвижному составу".

Golovatyj Il'ya Vladimirovich

Faculty Electromechanics and automatics

Chair Mining-factory transport and Logistics

Speciality: Electromechanical equipment of power-consuming industries

Theme of master's work:

"Substantiation of rational parametres and development of brake system for storage electric locomotive ARP10-900"

Scientific adviser: Chebanenko Konstantin Ivanovich

Summary of research and developments

Introduction