PSI - Issue 13

Filip Miletić et al. / Procedia Structural Integrity 13 (2018) 1644 – 1650 Author name / Structural Integrity Procedia 00 (2018) 000–000

1647

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methodology and the circular movement of the excavator to the left and to the right, in relation to the axis, is divided into four segments. Techical characteristics of excavator SRs – 2000.32/5 are shown in table 1.

Table 1. Basic technical characteristics of excavator SRs – 2000.32/5

Surface mine Tamnava – West field – Excavator SRs – 2000.32/5

Installed engine power for rotor drive Volume of a bucket with a ring space

2 x 670

[kW]

2000

[lit]

Number of buckets

20 30 12

kom.

The speed of the upper construction The diameter of the rotor wheel

[m/min]

[m] [V]

Motor voltage

6000

Peripheral speed of the rotor wheel

2,7

[m/s]

Specific cutting force

1000

[N/cm]

4. Comparative overview of the obtained measurement results As mentioned earlier, in order to compare the results obtained, two measurements were made on the rotor excavator SRs – 2000.32/5. The first measurement was performed in the middle of May, when the wearing of cutting elements was about 30%. After excavator left the overhaul, a second measurement was performed with new cutting elements. The goal of re measurement is to determine the dependence of the worn cutting elements with specific energy consumption, apropos specific resistant of material to dig. Determined micro-technological parameters of the block in measurements with weared cutting elements the others are the same for the new measurement, in order to compare the results obtained. The following tables show the methodology for determining the specific energy consumption and the specific resistance of the digging material for the rotor drive. In table 2 are presented result of weared cutting elements and in table 3. for new cutting elements, when excavator left the overhaul. It is clearly noticeable the impact of weared cutting elements when talking about the electricity that the excavator takes from the transformer. In the case of weared cutting elements, the average value of the electricity is 124 A, while in the case of new cutting elements this value is drastically lower and is 113 A. It is similar to the specific resistance of digging material, which is 592 N / cm for weared cutting elements, and for new 538 N / cm.

300 350 400 450 500 550 600 650 700 750 800 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 [N/cm] Number of measurement Comparative view of maximum resistance to digging for weared and new cutting elements kLmax weared cutting elements kLmax new cutting elements

Figure 2. Results of measuring the maximum consumption of the energy