Expense management of transmission spare parts

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Expense management of transmission spare parts taking into account their quality for rolling stock To cite this article: S V Bulatov 2018 J. Phys.: Conf. Ser. 1118 012011

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International Conference “Complex equipment of quality control laboratories” IOP Publishing doi:10.1088/1742-6596/1118/1/012011 IOP Conf. Series: Journal of Physics: Conf. Series 1118 (2018) 012011

Expense management of transmission spare parts taking into account their quality for rolling stock S V Bulatov1 1

Orenburg State University, 13, Victory ave., Orenburg, 460048, Russia

E-mail: [email protected] Abstract. The technique used in the article allows one to fix a specific value of the level of defectiveness. The experiment showed that the efficiency of using high-quality spare parts amounted to an average of 32.5 thousand rubles per year, and the number of defective spare parts in recent years has decreased significantly (≈ 30 %).

1. Introduction The rolling stock needs a repair as a result of the natural wear (certain details and units were run out) and as a result of the unforeseen circumstances (roadway covering quality, rejects presence in spare parts, etc.) [1,4,7,9-11]. One of the maintenance conditions in operating state of the rolling stock is not only the competent carrying out of scheduled and repair work [2,5,8], but also the use of high-quality spare parts. However, buying spare parts is impossible without being sure completely of their quality. Therefore, the quality control of new spare parts is an obligatory task of the enterprises. 2. Method of forecasting The condition of the continuous control expediency in comparison with the acceptance of products lot without controlling [3,6]: 𝐶𝑘 𝑁 ≤ 𝐶𝑞 𝑀,

(1)

where Сk – the cost of the detail (unit) control; N – the volume of the accepted lot; Сq – the expenses (damage) cost from the admission of the rejected detail (unit); M – the number of the rejected details (units) in a lot. The condition of the selective control expediency in comparison with the continuous control: 𝐶𝑘 𝑛 + 𝐶𝑞 𝑀𝑃 < 𝐶𝑘 𝑁,

(2)

where P – the acceptance probability by the results of the selective control of a lot with the rejected details (units). The hit probability of k defective products in n selection:

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1

International Conference “Complex equipment of quality control laboratories” IOP Publishing doi:10.1088/1742-6596/1118/1/012011 IOP Conf. Series: Journal of Physics: Conf. Series 1118 (2018) 012011 𝑛!

𝑃𝑛𝑘 = 𝐶𝑛𝑘 𝑞𝑘 𝑝𝑛−1 = 𝑘!(𝑛−𝑘)! 𝑞 𝑘 (1 − 𝑞)𝑛−𝑘 .

(3)

3. Experimental research 164 KAMAZ-6520 trucks which are in operation of Orenburg motor transport enterprises (MTP) were investigated. The experiment was carried out from January 2012 to December 2017. There were 14152 current repairs during the experiment. 13365 replacements of units and sets elements have been made during the tests. The researches have allowed one to reveal characteristic for the movement in mountain conditions, the refusals distribution features of transmission units and sets details taking into account the possible rejects in spare parts (clutch release yokes, pinions, universal shafts, crosspieces, etc.) (figures 1 – 3).

Figure 1. A crack in a clutch release yoke.

Figure 2. Wear of engine gearbox pinions.

Figure 3. Crosspiece of gimbal gear. Thus, the structurization of refusals types of KAMAZ-6520 units and sets was made on the basis of the conducted researches of the operational reliability: – the refusals connected with wear make – 67 %;

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– different types of fatigue and strength failures – 23 %; – the quality of the installed spare parts – 7 %; – other reason – 3 %. The exact diagnosing system of the current mechanical condition of the transmission units and sets details and also the check of new spare parts on rejects presence is in general necessary for the increase in service life and reliability of the rolling stock. It is offered to carry out the operating condition diagnostics of transmission units, their standard sizes, and the admissible shaft beat should be conducted by means of the special equipment (figures 4 – 7).

Figure 4. Diagnostics of reduction gear.

Figure 5. Micrometer.

Figure 6. Device for shaft beat measurement.

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Figure 7. Calliper. 4. Conclusion The revealed shortcomings have shown a tendency to decreasing the number of rejects in the purchased spare parts (figure 8) and allow one to reduce time for the installation of the rejected spare parts and to achieve an economic effect for 30,5 thousand rubles per year.

Figure 8. The level of transmission spare parts deficiency of KAMAZ trucks by years, %. The prognostication allows one to draw the demand schedule for the transmission spare parts of KAMAZ-6520 for three months (figure 9).

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Figure 9. The demand schedule for the transmission spare parts of KAMAZ-6520. The received results will lead to cost cutting on mechanical services and repair and also on the purchase of spare parts, i.e. will provide the technical and economic efficiency. References [1] Kuznetsov E S 2004 Technical operation of cars (Moskow: Transport) [2] Fastovtsev G V 1989 The Organization of maintenance and repair of cars (Moskow: Transport) [3] Gise R 1991 Modern concept of complex management of circulating material resources Motor transport enterprise 3 105-107 [4] Gordon M 1994 Logistics (M: Transport) [5] Boutellier R 2006 Strategy and organization of supply (M: KIA center) [6] Lukinsky V S, Berezhnoy V I, Berezhnaya E V 2004 Logistics of road transport (Moskow: Finance and statistics) [7] Berezhnaya E V 1994 Forecasting on the basis of time series (Stavropol: SGTU) [8] Schonberger R 1988 Japanese methods of management of production (M: Economics) [9] Bulatov S V, Filatov M I 2017 Management of the expense of spare parts taking into account their quality at the passenger motor transport enterprise Intellect. Innovations. Investment 11 47-51 [10] Bulatov S V 2018 Requirement definition of passenger motor transport enterprises for spare parts by method of short-term combined forecasting Journal of Physics: Conference Series (Electronic Materials vol 1015) ed E Schöll (UK: Institute of Physics and IOP Publishing Limited) 052004 [11] Fomina E V, Kozhukhova N I, Sverguzova S V, Fomin A E 2018 Application of mathematical model methods for optimization tasks in construction materials technology Journal of Physics: Conference Series (Electronic Materials vol 1015) ed E Schöll (UK: Institute of Physics and IOP Publishing Limited) 052015

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