On the nature of changes in static forces of scraper winches

Abstract

As is known, the following resistances act during the movement of a loaded scraper: 1. resistance to movement of the material captured by the scraper, 2. resistance to movement of the scraper itself, 3. resistance to movement of the ropes, 4. resistance in the blocks and from the rigidity of the ropes, 5. resistance to scooping up the scraped material. During the movement of an empty scraper, only resistances (2), (3) and (4) act, resistances (1) and (5) are equal to zero. However, the pattern of change in the resistance to movement of the material captured by the scraper (hereinafter designated z₁) and the resistance to scooping up the scraped material (hereinafter designated z₅) during filling the scraper has not been studied in essence. Meanwhile, knowledge of this pattern is highly desirable from the point of view of overloading the scraper winch engine and, consequently, a more theoretically justified choice of the power of this engine. Based on existing data on the operation of scraper installations, in particular, on the existing coefficients friction and the values ​​of the specific work of scooping, below we offer the following interpretation of the pattern of change during filling of the scraper of the two types of resistance indicated above.