DESCRIPTION AND PURPOSE
The Caterpillar D7R is a 15th traction class (medium category) mining bulldozer. When developing the series, the manufacturer took into account the possibility of operation in harsh climatic conditions. As a result, the power plant, transmission and cabin have been significantly redesigned. The resulting model has become optimal for use by consumers from Russia and post-Soviet countries. The bulldozer has retained the qualities characteristic of other Caterpillar products (structural strength, high productivity, reliability), additionally receiving a number of advanced solutions.
The main purpose of the Caterpillar D7R is to work with soil categories 1-3. The equipment is used for laying roads in forests, moving earth over short distances, arranging passage along highways, developing holes, ditches and canals. Design features allow the bulldozer to quickly perform large volumes of work. In this case, the machine demonstrates maximum efficiency.
The Caterpillar D7R model range is presented in 3 versions:
- STD – standard version;
- XR – modification with a modified chassis system with an extended tracked part, providing better balance and maneuverability;
- LGP is a wide-tracked variation designed to work in marshy areas.
TECHNICAL SPECIFICATIONS Caterpillar D7R
Dimensions (STD/XR/LGP):
- bulldozer length with towing device – 4736/4736/4736 mm;
- axle width – 2876/2876/3396 mm;
- width without trunnions with standard shoe – 2541/2541/3143 mm;
- height according to the OROPS design – 3290/3290/3370 mm;
- height according to the EROPS design – 3280/3280/3360 mm;
- height along the exhaust pipe – 3244/3244/3325 mm;
- ground clearance - 634/634/713.4 mm.
Bulldozer weight parameters (STD/XR/LGP):
- operating weight – 24962/25441/27101 kg;
- transport weight – 20288/25441/22380 kg.
Caterpillar D7R is equipped with a hemispherical blade, which has 2 modifications. One is used for the STD and XR models - 7SU, the other for the LGP version - 7SU LGP.
Blade parameters (7SU/7SU LGP):
- width along the side edges – 3693/4545 mm;
- height – 1524/1343 mm;
- maximum digging depth – 527/668 mm;
- maximum lifting height – 1145/1153 mm;
- maximum skew – 799/686 mm;
- weight without hydraulic equipment controls – 3593/3732 kg;
- capacity – 6.86/5.98 cubic meters.
A parallelogram adjustable ripper is available as a rear attachment (for all modifications):
- number of racks – 3;
- total width – 2210 mm;
- maximum lifting height – 757 mm;
- maximum depth – 748 mm;
- maximum breakout force – 176.6 kN;
- maximum penetration force – 85 kN;
- Tilt adjustment with ripper lowered (forward/reverse) – 15/10 degrees;
- weight with 3 racks – 3337 kg.
Capacity of filling containers:
- fuel tank – 479 l;
- cooling system – 73 l;
- hydraulic tank – 54 l.
Cat D7 Bulldozer: New Features and Features
The new Cat D7 dozer, with an operating weight of 29,776 kg, replaces the current Cat D7R dozer. Its design has been completely updated to increase productivity and increase the amount of material moved per hour (by 11%). The Cat D7 has a new cab and a new 265 hp diesel engine, paired with a smooth-shifting Cat D7 4-speed automatic transmission. Operators do not need to change gears - just select the driving speed. The operator's compartment features a highly adjustable air-suspended seat and an 8-inch instrument panel with a clear overview of functions and settings for operation and maintenance. You can separately order a Premium cab with fully adjustable armrests and a convenient touch screen (10-inch diagonal) with an operator interface and a rear view camera.
A heavier frame like the Cat D8, a reinforced undercarriage and a new road wheel frame improve durability. The fuel system has also been modernized. Cat D7 blade capacity increased by 10%. The dozer is equipped with Cat Link telematics, Cat Grade with 3D to automate blade movement for both precision grading and high-productivity dozing operations, and ARO with Control - an option for grade control that includes auxiliary functions that work in background mode. Four LED lights are available as standard; versions with six or 12 lights can be ordered separately.
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ENGINE
The Caterpillar D7R is equipped with a proprietary Cat C9 ACERT 4-stroke diesel engine. The unit is suitable for use in areas with poor fuel quality. A special coating of the spray needle allows you to work with fuels with high sulfur content. Due to this, the service life of the unit increases.
The engine uses ACERT technology, through which the fuel supply is electronically controlled. The engine cooling system includes an ATAAC system, a radiator and a hydraulic oil cooler. The air supply system contains a charge air intercooler, which ensures more efficient operation of the unit. Maximum performance of the power plant is achieved through the presence of multiple injections. The engine operates efficiently at altitudes up to 2286 m.
Cat C9 ACERT motor specifications:
- working volume – 8.8 l;
- rated power – 204 (274) kW (hp);
- speed – 1900 rpm;
- cylinder diameter – 112 mm.
DEVICE
The supporting structure of the bulldozer is a frame with a reinforced front cross member. In this case, the rolling axis of the equipment runs along the entire length of the frame, entering the frame of the rollers, due to which loads are evenly distributed across the zones of the machine structure. Diagonal struts are not used on bogie frames. The Caterpillar D7R has a modular design that simplifies maintenance.
The bulldozer undercarriage is equipped with a front element with a raised sprocket. The proven design features a low center of gravity for increased machine stability. The undercarriage uses reinforced caterpillar tracks. The edges of adjacent shoes are located so that they overlap each other, due to which the service life of the tracked part is increased.
Chassis specifications (STD/XR/LGP):
- track width - 1981/1981/2235 mm;
- standard shoe width – 560/560/914 mm;
- number of shoes (on one side) – 40/41/43;
- length of the track contact surface with the ground – 2870/3048/3175 mm;
- contact area of the caterpillar track with the ground – 3.21/3.41/5.81 sq.m;
- ground pressure – 76.32/73.22/45.70 kPa;
- lug height – 71/71/71 mm.
The Caterpillar D7R is equipped with a planetary gearbox with mechanical power shift. A special feature of the transmission is a torque divider, which allows the force to be distributed between the working parts and the chassis. Differential steering control significantly improves maneuvering capabilities by reducing work cycles. One handle is used to change speed and direction. When turning, the speed of one of the tracks increases and the speed of the other track decreases at the same time.
Travel speed range (forward/reverse):
- 1st gear – 0-3.52/0-4.54 km/h;
- 2nd gear – 0-6.10/0-7.85 km/h;
- 3rd gear – 0-10.54/0-13.58 km/h.
The Caterpillar D7R hydraulic system is load-sensing and responds quickly to operating conditions. The optimal power is selected automatically.
The bulldozer is equipped with a large cabin mounted on insulating supports. The noise level in the cabin does not exceed 83 dB. The operator's workplace is based on a Comfort seat with an offset of 15 degrees. This feature improves visibility. The chair has wide armrests and several settings. The microclimate in the cabin is maintained by ventilation and air conditioning systems.
D7R
Operator's cabin
The D7R bulldozer features a pressurized cab mounted on insulating mounts to reduce noise and vibration. Large solid windows provide good visibility in all directions. This improves productivity and safety on the job site. The Comfort Series seat can be moved up to 15° for improved visibility. The seat is fully adjustable and has armrests for comfort when working on steep slopes. The indicators and hazard warning lamps on the instrument panel are clearly visible even in direct sunlight. The Caterpillar Monitoring System display provides operators and service technicians with easy access to operating parameters and maintenance information. The system provides parameter monitoring and three levels of warnings. Due to this, the operator receives complete information about the machine without being distracted from the work. The heating and air conditioning vents distribute air flow evenly into the cabin. The cabin is equipped with electrical wiring for connecting a 12 or 24 V radio, as well as two speakers and an antenna. There is space above the windshield for installing radio equipment.
Blade and ripper controls
All D7R controls are effortless to use and ergonomically designed for easy operation. For added convenience and increased precision, the blade and ripper controls are hydraulically servo driven. When AccuGrade™ is activated, the blade is controlled using electro-hydraulic control. When switching to manual mode, the blade is controlled by the hydraulic control loop.
Engine speed rocker switch
Selecting low or high idle speed is done with one press of the rocker switch. Using the decelerator pedal, the operator can control engine speed when the rocker switch is in the high idle position. The operator can also adjust the engine speed to any value between low and high idle speeds. To do this, hold down the throttle switch for 3 seconds and simultaneously use the decelerator pedal to adjust the speed.
Steering and shift control system
A single lever is used to change the direction of travel and gears. The control handle provides greater precision when working in confined spaces near buildings, marker posts and other machinery. Differential steering control provides the most precise modulation in the industry.
Attachment lock switch
The attachment lockout valve prevents unintentional activation of hydraulic attachments, increasing safety.
