CC BY
36
Section 7. Technical sciences
Rustamov Rakhmatali Muradovich, The research scientific institute of mechanization and electrification of agriculture, Republic of Uzbekistan, Ph. D. technics, senior scientific employee E-mail: ax_stajyor@mail.ru
Research on the status of single-channel systems of the grains harvesting combines
Abstract: As it is specified that Poisson and steady flows of customers demand are delivered to the Corporate technical service (FTS) system by inoperable (faulty) grains harvesting combines; with an increase in production capacity of combine harvesters to the 2000-2500 operating hours and it is required more and more mobile workshops.
Keywords: grains harvesting combine, the corporate technical service system, mobile workshop, the average number of customers demand, waiting time, standing time of one customer demand in the system.
In effort to organize the corporate technical service (CTS) to the grains harvesting combines of model Case in Uzbekistan JV «UzCaseservice» is founded and it has regional service centers. Those centers are equipped with mobile workshops (servicing maintenance devices), that implement service and maintenance works, including troubleshooting cases occurred with harvesting combines.
As a rule, in the harvesting season the 8-10 units of grain harvesting combines are maintained by a single mobile workshop that means a single-channeled CTS is formed (as shown in Fig. 1).
q = q0¥ =(1 ,
where y = X/ / — a device load factor;
q0 = 1 -y — the expectance in system idleness. When the production capacity of combine harvesters has reached 2000-2500 operating hours the customer demands with number K (K> 1) and the expectancy qk = (1 began to reach
to the system and it resulted in a change in the system status.
In this case the average number of customers demand in the system [2; 3].
i(i) 1 -y
The average number of customers demand, standing in a turn:
L =
¥
1 -¥
Average waiting time of a single unit:
W
W = ' (1 -W)v
(2)
(3)
Fig. 1. The status scheme of a single-channeled CTS system without a turn
We have found that from the harvesting combines Poisson and steady flow demands are delivered to the system with \ intensity, and they are serviced by a workshop mechanical with average intensity of When the harvesting combines had a production capacity of 500-1500 operating hours, certain expectations with respect to the system status were found as following: S0 status — during t time there was no demand delivered from a customer and during At time they were not received; that is all N harvesting combines are in working condition for operating the device is free; S1 state — during t me time one demand is received (number of working combines N-1), during t time it was served, and the device is no longer received. The standing expectation of one (K = 1) demand [1] in the system.
W = ■
In the event if the average servicing time is added to the average waiting time tserv = 1/ /, then can be obtained the average time of staying of a single unit in the system:
1_
HO-V). (4)
As it is considered after made analysis (1)- (4), when y = 0 or X = 0, that mean in case if the intensity of units is equal to zero (all
the machines are good operation) L = Lq = W = 0; W = — = t
q q H .
In case if tserv = 2,16 hours; X = 0,3 unit/hour; ^ = 0,462 servicing/hour can be obtained the following: y= 0,649 ; i = 1,85 « 2,0; Lq = 1,19 « 1,0; Wq = 4 hours; W = 6 hours. From above it is obvious that W > Wq > tserv. Afterwards in order to ensure normal functioning of CTS need to increase the number of mobile workshops.
References:
1.
Ivchenko G. I., Kashtanov V. A., Kovalenko I. N. The Theories of Теория mass servicing: Study book for the universities. - M.: Higher School, 1982. - 256 p.
2. Common technical reference book. - М.: Machinery, 1971. - 464 p.
3. Akulinchev V. M., Kudryavtsev V. A., Koreshkov A. N. Mathematical methods in rail roads operations. - M.: Transport, 1981. - 223 p.
