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 11:28 am
Cat 631E Scrapers with retarders are used and able to haul full
heaped loads of borrow to an embankment. A push tractor is used to
facilitate scraper loading. The road to the fill is 1,600 ft long
at 8% grade followed by another 1,500 ft run at 5% grade. The rad
has an RR of 80lbs/ton.
Pusher contact time= .85 min
Dump time= .37 min
Turn times at fill= .21 min
turn times at pit= .3 min
the weight the scraper is carrying will also increase. given in Table 8.1, to be 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 67% Drive axle Rear axle 33% Loaded 53% Drive axle 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
growth curve (Figure 8.11) is typical for push loaded scrapers, consequently average load time of 0.85 min. The load- rolling resis- 100 80 1.0 1.2 1.4 0.0 0.2 0.4 0.8 0.6 Loading time, minutes FIGURE 8.11 A typical load-growth curve for scraper loading Possible payload, percent 60 40 20 0
lb (x1000) 150 120 100 70 50 40 30 20 15 10 Rimpull 5 ▬ T T kg (x1000) 65 55 45 35 25 20 15 10 8 + 2 I |||| I 30 L I I M T " |||| 18 15 I I ||ال 40 I 20 1 I Gross weight 80 50 60 I ↓ 0 5 10 15 20 0 5 10 1. 1st gear torque converter drive i T |||| +++ |||| 30 I I T |||| I Speed T ! L 40 100 120 1 + TI |||| |||| LINNE 160 200 lb (x1000) 90 kg (x1000) 50 60 70 T - די 25 30 35 40 45 50 15 20 25 30 6. 6th gear direct drive JL. T 30% 25% 20% 15% 12% 10% 8% 6% 5% 4% 3% 2% 55 km/h 35 mph Total resistance (grade plus rolling resistance)
2. 2nd gear torque converter drive 3. 3rd gear direct drive 4. 4th gear direct drive 5. 5th gear direct drive FIGURE 8.8 Rimpull performance chart for a Caterpillar 631E scraper Reprinted courtesy of Caterpillar, Inc. Gross weight 55 75 100 150 175 50 0 30 5 10 40 z 15 20 25 30 60 30% 7. 7th gear direct drive 8. 8th gear direct drive E Empty 43,945 kg (96,880 lb) L Loaded 77,965 kg (171,880 lb) lb (x1000) 80 kg (x1000) 22% 16% 35 40 70 45 00 50 10% 5% 1% 55 km/h Effective grade (grade minus rolling resistance)
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.
heaped loads of borrow to an embankment. A push tractor is used to
facilitate scraper loading. The road to the fill is 1,600 ft long
at 8% grade followed by another 1,500 ft run at 5% grade. The rad
has an RR of 80lbs/ton.
Pusher contact time= .85 min
Dump time= .37 min
Turn times at fill= .21 min
turn times at pit= .3 min
- Cat 631e Scrapers With Retarders Are Used And Able To Haul Full Heaped Loads Of Borrow To An Embankment A Push Tractor 1 (479.47 KiB) Viewed 36 times
growth curve (Figure 8.11) is typical for push loaded scrapers, consequently average load time of 0.85 min. The load- rolling resis- 100 80 1.0 1.2 1.4 0.0 0.2 0.4 0.8 0.6 Loading time, minutes FIGURE 8.11 A typical load-growth curve for scraper loading Possible payload, percent 60 40 20 0
lb (x1000) 150 120 100 70 50 40 30 20 15 10 Rimpull 5 ▬ T T kg (x1000) 65 55 45 35 25 20 15 10 8 + 2 I |||| I 30 L I I M T " |||| 18 15 I I ||ال 40 I 20 1 I Gross weight 80 50 60 I ↓ 0 5 10 15 20 0 5 10 1. 1st gear torque converter drive i T |||| +++ |||| 30 I I T |||| I Speed T ! L 40 100 120 1 + TI |||| |||| LINNE 160 200 lb (x1000) 90 kg (x1000) 50 60 70 T - די 25 30 35 40 45 50 15 20 25 30 6. 6th gear direct drive JL. T 30% 25% 20% 15% 12% 10% 8% 6% 5% 4% 3% 2% 55 km/h 35 mph Total resistance (grade plus rolling resistance)
2. 2nd gear torque converter drive 3. 3rd gear direct drive 4. 4th gear direct drive 5. 5th gear direct drive FIGURE 8.8 Rimpull performance chart for a Caterpillar 631E scraper Reprinted courtesy of Caterpillar, Inc. Gross weight 55 75 100 150 175 50 0 30 5 10 40 z 15 20 25 30 60 30% 7. 7th gear direct drive 8. 8th gear direct drive E Empty 43,945 kg (96,880 lb) L Loaded 77,965 kg (171,880 lb) lb (x1000) 80 kg (x1000) 22% 16% 35 40 70 45 00 50 10% 5% 1% 55 km/h Effective grade (grade minus rolling resistance)
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.