The grader (motor grader).
Grader – towed or self-propelled wheeled machine with an adjustable blade, positioned between front and rear wheels, which cuts, moves and spreads the material usually for the purpose of profiling.
Other road construction equipment: paver, bulldozer, grader, scraper
Grader (eng. grader, from the English. grade – to level, flatten) is a trailer or self-propelled machineequipped with working body – adjustable blade knife is intended for planning and profiling areas and slopes, leveling layer of soil and other grounds, displacement of soil, snow or loose construction materials.
Grader – special road-building machinery (machine), able to perform various earthworks, construction, road construction and transport operations.
Grader – mining and transporting the machine, equipped knife working on the blade, which is placed within the wheel base.
Depending on the form of a suspension distinguish between ordinary grader and the grader.
Grader – self-propelled wheeled machine with an adjustable blade, positioned between front and rear wheels, which cuts, moves and distributes material usually for the purpose of profiling.
Conventional grader is trailed or semi-trailed machine, fixed to the underlying transport the machine, the tractor or other technique.
The work of the grader is carried out at a low speed – up to 3-4. 5 km/h.
The main parts of the grader are basic wheeled machine and the main working equipment – blade, and auxiliary (optional) working equipment – cirkovic, Ripper, snowplough and front blade, dozer blade, swept blade, otkazniki, extenders, etc.
The blade is the main working body of the grader, which distinguishes it from other types of road construction equipment. The blade is a rectangular sheet having a certain bending radius. The blade can be set to different angles in the horizontal and vertical planes relative to the longitudinal axis of the base transport machines, a also be taken out and pushed to the side. It can ascend, descend and rotate in horizontal and vertical planes.
Dumps all types of graders are fitted with mechanisms with hydraulic or mechanical actuator for lifting-lowering of the blade, bends in two planes, the distortions in the transverse plane, tilt forward and backward in the course. The blade is fastened to the traction machine with rotary mechanism and the traction frame.
Along the bottom and side edges of the blade are attached to the blades, respectively referred to as the lower knife and side knife.
Cirkovic accessories in the form of a frame with removable teeth (7-11 teeth) for loosening soil, digging road surface during the road repairs. Cirkovic can be installed ahead of the front wheels of the grader or between the front and rear wheels.
Ripper – additional equipment, comprising a frame, connected through brackets from the rear part of the base of the machine, and provided with one or more teeth. Loosening equipment is not just for the graders, but in many cases also on bulldozers and tractors.
Snowplough – a structure placed ahead of the front wheels and is intended for moving snow in the transverse direction due to the plowing action of the blade. The plow can be odnodolnym and duchatellier.
Front dozer – blade, usually having a curved surface, is placed ahead of the front wheels and designed for raking and pushing of the material, usually in the forward direction.
Motor grader is also equipped with automatic leveling system to expedite business operations and obtaining surfaces with strictly defined parameters.
The graders can be equipped with a remote control system.
Graders klassificeret chassis equipment, performance, design, type of control system working bodies, etc. parameters.
Chassis equipment graders klassificeret on:
– trailer and semi-trailer,
– self – propelled motor graders. The graders are able to move on their own.
Performance (depending on total weight, power of engine and size of the dump) graders are divided into the following classes:
– easy graders. Equipped with blades with a length of 2500-3000 mm, motor power up to 80 kW. Have a mass of not more than 9 tonnes;
– middle graders. Equipped with blades of length 3000-3500 mm, motor power up to 130 kW. Have a mass of not more than 13 tons;
– heavy graders. Equipped with blades with a length of 3500-4000 mm., engine power to 185 kW. Have a mass of not more than 19 tons;
– heavy graders. Equipped with engine capacity of 185 kW and have a lot more than 19 tons.
Depending on the operating power of the motor graders are classified into classes:
class 100 with operating power of the engine to 88.2 kW (120 HP),
class 140 having an operating power of the engine within the range of 88.9 to 117.6 kW (or from 121 to 160 HP),
class 180, with operational capacity engine in the range of 118.4 to 147,0 kW (or from 161 to 200 HP),
class 250, having the service capacity of the engine from 147,8 or above (or from 201 HP and above).
Type of control working bodies distinguish graders with mechanical and hydraulic control.
The number of wheels of the undercarriage distinguish between four-wheeled and six-wheeled graders.
The number of engines are single-engine and twin-engine graders.
The location of the motor graders are divided into:
– graders, a front – engine,
– motor grader with a rear-mounted engine.
The steering system distinguish graders:
– with front steering wheels,
– with front and rear steered wheels,
– with front steering wheels and rear swivel truck,
– with front steering wheels and articulated frame
– with articulated frame having two vertical hinge.
The drive system stroke secrete graders:
– with two leading wheels,
– with four driving wheels,
– with six driving wheels.
The main quality parameters of the grader include the following indicators:
operating motor power
– operating weight,
– the length of the blade,
– height of blade,
– maximum speed for the gear
– specific fuel consumption of the engine,
– oil consumption in the engine and transmission of motor grader,
– achieved parameters of precision planning,
specific ground pressure,
– the opacity of exhaust gases of motor grader,
– vibration operator’s seat,
– emissions of harmful substances with exhaust gases from the exhaust system of the motor grader,
– the sound level at the operator’s workplace,
– the average operational complexity of every shift maintenance,
– specific total operational complexity of the planned technical services,
– 80% of the resource before the first overhaul and limit state criteria,
– the average time to failure.
– planning and profiling areas, excavation and other paintings
– layout and profiling of the surface and side slopes of mounds and recesses to impart the necessary transverse and longitudinal gradients,
– layer-by-layer alignment of ground and other grounds
– cut ditches,
– the construction of low embankments,
– installation of gutters and side ditches,
– earth moving, snow or loose construction materials,
– cleaning of roads and plazas from snow,
the crust canvas or curb,
– sweep slopes,
– cleaning of ditches and ditches.
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