L Liebherr PR 754 – bulldozer construction the German company Liebherr. Recent years, the brand’s lineup was marked by the global update. Earlier in the composition of caterpillar models, 1 special and 5 basic machines with a capacity of 77-276 kW, the fourth generation was expanded to 6 basic machines with a power range 86-310 kW. New line made the technique of medium and heavy class. One of the products of the last generation was the model of the Liebherr PR 754 L.
The new machine retained the main feature – the hydrostatic transmission. Bulldozers brand still manned engine of its own production. Thus in terms of economy, performance and comfort have been significantly improved.
Liebherr PR 754 L has impressive dimensions that defines its scope. The model is rarely used in the city. The main direction of the movement and leveling of the ground. Dumps large amounts of allow the bulldozer to handle any tasks in no time.
Liebherr PR 754 L is used to perform the following operations:
- various road construction works;
- excavation in the mining industry;
- transportation on short distances large amounts of soil and materials;
- preparing sites for construction;
- leveling, demolition of small buildings;
- digging and backfilling of trenches, pits, pits.
Modifications and features
The range of Liebherr PR 754 series consists of 2 models, differing by the type of the wheelbase:
- Liebherr PR 754 L – modification with a standard base;
- Liebherr PR 754 LGP – crawler upgraded part. The large surface area of contact with the ground provides better maneuverability and allows you to work in marshy and damp areas.
Characteristics Liebherr PR 754 L:
- easy maintenance (minimum expenses for diagnostics and service);
- the engine of own production with a large capacity and high efficiency;
- excellent maneuverability. Due to the hydrostatic drive bulldozer performs the rotation in a limited space, and the operator securely controls the blade and the cultivator regardless of the speed;
- increased efficiency in operations by loosening materials;
- protection against damage when operating on uneven areas. Flat and sturdy bottom with additional reinforcement contributes to the increase of reliability;
- high speeds and minimum slip in all conditions;
- long service life of the undercarriage. Reliability is achieved through the use of proven elements.
- length (with blade without blade) – 6448/4875 mm;
- width – 3145 mm;
- height 3630 mm;
- tracks – 3174 mm;
- ground clearance – 630 mm;
- gauge 560/610/660/710 mm.
Operating weight of equipment depending on the configuration varies from 35000 to 40800 kilograms. Specific surface pressure is 100 kPa, the maximum pulling force of 530 kN. For a sufficiently large weight of the Liebherr PR 754 L remains a highly mobile machine: the speed of movement in any direction can reach 11 km/h.
Volume filling of containers:
- tank – 240 l;
- cooling system – 74 L.
Bulldozer working blade with the following parameters:
- width – 4030-4325 mm;
- height – 1650 mm;
- capacity – 8,9-11,7 cubic meters;
- maximum lift height – 1400 mm;
- the ultimate depth – 570 mm.
The device and operating features
Frame box-section and the addition of separate elements forms the basis of a bulldozer Liebherr PR 754 L. Design, proven reliable on previous generations, practically does not give failures even at long high loads.
Chassis model is standard and is built on the basis of semi-rigid suspension. Node swing frames undercarriage bogies and final drive are separated from each other. Mount the rollers to the frames of trucks hard. Ring gears have wheels made integral with multiple segments and bolt-on to the hub. Support rollers and track rollers are filled with special grease for entire service life. For caterpillars provided for the detachable locking links and lubricates the joints. For Liebherr PR 754 crawler L part used with the following elements:
- number of carrier rollers (each side) – 7;
- the number of chain links (each side) – 44;
- the number of segments stars – 5.
Liebherr PR 754 L is equipped with hydrostatic transmission with stepless speed adjustment. For bulldozer there are 2 front and 2 reverse speeds, gear ranges can be changed through the buttons located on the joystick control. The speed is maintained without interruption of power flow and transmission shift. The hydrostatic transmission has a high reliability, which is achieved due to the absence of several elements: a friction clutch pivot, torque Converter, differential control and transmission.Basic hydraulic motors and pumps are practically wear-free and have great life. Another feature of the system is the Litronic technology, which automatically adjusts tractive force and speed with the constantly changing load.
The bulldozer installed electronic limited-slip brakes. Multi-disc Parking brake are activated automatically when the neutral position of the joystick control. The lack of freewheel provides maximum handling and safety even on slopes. When the speed drops to zero is the auto Parking brake.
Hydraulic system Liebherr PR 754 L made the type of “open loop”. It is carried out through adjustment of the power at the required loads. The system comprises a valve with multiple partitions, hydraulic, axial piston pump and filter with a magnetic core. The power supply is 261 l/min, max pressure 260 bar. Implement control is via a single joystick.
For Liebherr PR 754 L a wider range of additional devices:
1. Prednisnoe equipment:
- universal blade;
- semi-u blade.
2. Sydneyuse equipment:
- single-shank Ripper;
- the multi-wheel cultivator;
- the counterweight;
- the towing device.
On Liebherr PR 754 L used homoveratrylamine cabin, in the shape of a hexagon and mounted on elastic shock absorbers. Special Jack allows the cab to swing 40 degrees to the rear to access the elements. Built-in protection system FOPS and ROPS protect the driver from falling objects and overturning of equipment. The operator’s chair has broad regulatory and depreciation opportunities and armrest with 3 positions. Ventilation, creating overpressure in the cabin, sliding Windows and a liquid heater provides optimum temperature.Special tinted Windows reduces the load on the driver. For convenience, also includes a socket for 12 In the pad for the feet and glove box.
Control of main machine functions is performed using 2 joysticks built into the armrests of the chairs. The left joystick is used to select the speed, maneuvering and motion control, the right to work with attachments. Analog-to-digital control panel with automatic mechanism for monitoring of key parameters allows the operator to monitor the status of equipment.
Inspection and repair of Liebherr PR 754 L greatly simplified. Grouped service points and easy access. Most of the elements designed for long service life.
The main driving force of a bulldozer Liebherr PR 754 L is the diesel engine of own production Liebherr D 946 L A6. The motor has inline cylinders, direct injection, liquid cooling, turbocharging and electronic injection system. The level of exhaust emissions, the power plant meets the requirements CARB Tier 3 and Stage IIIA.
Regardless of motion speed, the motor operates at a single frequency, lower rpm provides better combustion of fuel. This achieves a balance between traction and speed.
As the injection system uses technology PLD (pump-pipe-injector), supplemented by electronic control. Lubrication system pressure operates effectively on surfaces with an inclination angle up to 45 degrees. For bulldozer use a traditional cooling system with a combined heat sink (section charge air, coolant section).
Specifications engine Liebherr D 946 L A6:
- the working volume of 12 l;
- rated power — 250(340) kW (HP);
- rated speed is 1600 rpm;
- number of cylinders – 6;
- fuel tank capacity – 650 l