Cat 631E Scrapers with retarders are used and able to haul full-heaped loads of borrow to an embankment. A push tractor
Posted: Thu May 05, 2022 11:38 am
- Cat 631e Scrapers With Retarders Are Used And Able To Haul Full Heaped Loads Of Borrow To An Embankment A Push Tractor 1 (1018.47 KiB) Viewed 27 times
- Cat 631e Scrapers With Retarders Are Used And Able To Haul Full Heaped Loads Of Borrow To An Embankment A Push Tractor 2 (1.04 MiB) Viewed 27 times
- Cat 631e Scrapers With Retarders Are Used And Able To Haul Full Heaped Loads Of Borrow To An Embankment A Push Tractor 3 (179.14 KiB) Viewed 27 times
- Cat 631e Scrapers With Retarders Are Used And Able To Haul Full Heaped Loads Of Borrow To An Embankment A Push Tractor 4 (136.75 KiB) Viewed 27 times
- Cat 631e Scrapers With Retarders Are Used And Able To Haul Full Heaped Loads Of Borrow To An Embankment A Push Tractor 5 (112.21 KiB) Viewed 27 times
a. What is the scraper cycle time? (Acceleration/Deceleration speeds shall be at 50% of the speed over the first and last 200' for road) (9pts) b. Using a 52-minute hour, how many scraper cycles per hour? (5 pts) c. How many LCY per hour is hauled per scraper? (5 pts) d. What is the production per hour if the pusher controls? (5 pts)
terial 10 and Der he , the flights rake the material upward into the bowl. The Ward with its cutting edge scraping a loose the ends of the flights are con- (Figure 8.5) oper- ribbbl pulverizing action of the flights enables a complete filling of the bowl and enhances uniform spreading at the fill location. Like a push-loaded scraper, an elevating scraper has an ejector for discharging the material. Additionally, the front portion of the bowl's floor can be retracted, and the elevator reverses to aid ejection of material. SCRAPER PERFORMANCE CHARTS Scraper manufacturers provide specifications and performance charts for their machines. These charts contain the machine specific information necessary for a scraper performance analysis under various operating conditions. Table 8.1 gives the specifications for a Caterpillar 631E single-powered axle scraper. Figures 8.8 and 8.9 present the performance charts for this particular scraper. Owners sometimes add sideboards to the bowls of their scrapers to increase the volumetric load the machine can carry. If the boards cause the volumetric load, whose specifications are given in Table 8.1, to be increased to 25.8 bcy, the weight the scraper is carrying will also increase. This scraper has a rated payload of 75,000 lb. In this sideboarding case, if the unit weight of the material being hauled is 3,000 lb/bcy, the weight of the load would be 77,400 lb (25.8 bcy x 3,000 lb/bcy). This is greater than the rated load. The effect will be a few more yards per load, but in time, maintenance costs will increase because of overloading the machine. A material having a higher unit weight would aggravate this effect. However, if the machine was operated in lightweight materials, sideboards would be a reasonable consideration. TABLE 8.1 Specifications for a Caterpillar 631E scraper Engine: flywheel power 450 Transmission: semiautomatic power shift, eight speeds Capacity of scraper: Struck 21 cy 31 cy Heaped Weight distribution: Empty Drive axle 67% Rear axle 33% Loaded Drive axle 53% Rear axle 47% 96,880 lb* Operating weight: Empty 75,000 lb Rated load: 33 mph Top speed: Loaded "Includes coolant, lubricants, full fuel tank, rollover protective system (ROPS) canopy, and operator
Construction Planning, Equipment, and Methods 30 40 Ib kg (x1000) (x1000) 150 65 120 55 100 45 35 70 25 50 20 40 15 T 10 8 Rimpull 80 100 120 160 200 lb (x1000) 90 kg (x1000) 40 50 60 70 I r 30% L 25% 20% 15% 12% 10% 8% 5/ 6% 5% 4% 3% 2% T 5 10 15 20 40 45 50 55 km/h 0 T 5 10 25 30 35 mph 1. 1st gear torque converter drive 2. 2nd gear torque converter drive 3.3rd gear direct drive 6. 6th gear direct drive 7.7th gear direct drive 4. 4th gear direct drive 8. 8th gear direct drive 5. 5th gear direct drive E Empty 43,945 kg (96,880 lb) FIGURE 8.8 Rimpull performance chart for a Caterpillar 631E scraper L Loaded 77,965 kg (171,880 lb) Reprinted courtesy of Caterpillar, Inc. = 30 20 15- 10- 5 === ----- 6 4 1 15 0 -- +-- ----- 20 L Gross weight -- -- --- 60 50 L ..... 30 L L -- سلا ===== -t Speed V 25 30 35 15 20 v - PL L 17 A 18 ps. IM CI 1024 8 11 I H- + הזיך Total resistance (grade plus rolling resistance) 55 L
55 P 30 E T 75 1 7 H 1 T 1 40 1 T T LO 1 7 1 1 T 10 15 1 I 1 El 7 100 1 L 11 | 15 11 10 H li || 20 Gross weight 150 L 50 I T 1 1 1 1 1 1 1 1 T I I 1 25 6 15 1 1 1 I 1 1 30 60 30% 1 Speed 1 I 1 T 35 + 1 I 1 175 T Chapter 8 Scrapers lb (x1000) 80 kg (x1000) 22% 70 기가 I 1 1 1 1 1 1 45 1 7 L 1 F T 1 T T T 0 5 40 r 0 30 5 20 25 E. Empty 43,945 kg (96,880 lb) L. Loaded 77,965 kg (171,880 lb) 3.3rd gear direct drive 4.4th gear direct drive 5. 5th gear direct drive 6. 6th gear direct drive 7.7th gear direct drive 8.8th gear direct drive FIGURE 8.9 Retarding performance chart for a Caterpillar 631E scraper Reprinted courtesy of Caterpillar, Inc. L LI 1 18 1 T T 1 T 50 1 16% Effective grade (grade minus rolling resistance) 10% 5% 1% 55 km/h 35 mph 233