2.5. Articulated rollers

Roller with articulated frame DU-62A(Fig. 2.18) is intended for layer-by-layer compaction of bulk soils and gravel-crushed stone materials. Unlike a roller with an all-frame design, where both rollers are the working body, in a roller with an articulated frame, the working body is one drive metal vibrating roller, inside which a vibration exciter is mounted. On the other axle there is a rear axle with a pair of doubled wheels, which are driven. Planetary gearboxes are built into both [eumowheels], which are fixed on the half-frame on one side, and on the other side are attached to the wheel. The rotation of the wheels is carried out by hydraulic motors flanged to the planetary gearbox. The articulated frame consists of two semi-frames, the koto-IX joint is equally located from the axes of the pneumatic wheels and the vibrating drum. This makes it possible to carry out the movement of the vibratory drum and pneumatic wheels in the wake. On a semi-frame resting on the rear axle, a power plant, a pumping station, a driver's cab and hydraulic equipment are mounted. The internal cavities of this semi-frame form two tanks: for working fluid and fuel. The front semi-frame holds the vibratory drum through shock absorbers. On the rink there is a hydrostatic drive of the vibrating drum, pneumatic wheels,

vibration exciter, vibrating drum, steering. There are three pumps in the hydraulic system of the rink. One of them serves to drive the roller, the other - to drive the vibration exciter. The third pump supplies the working fluid to the device in the form of a metering pump to reduce the force when turning the machine. The skating rink is equipped with a single cabin, in which there is a seat that can be moved in both directions and adjustable in height, a swinging steering column, levers and a control panel. To clean the metal vibrating drum, metal scrapers with rubber pads are installed.

Roller with articulated frame DU-74(Fig. 2.19) according to the design of the semi-frames, the articulation hinge, the rear axle with pneumatic wheels, the working body (vibrating drum) is similar to DU-62, DU-85. The front metal vibratory drum, which is a working body, was borrowed from the DU-85 roller. The articulated frame is formed by the rear (sub-engine) and front half-frames, as well as a hinge with vertical and horizontal axes. One of the two pumps of the hydraulic system is used to drive the undercarriage of the roller, the other pump drives the vibration exciter of the metal vibrating drum. Reversing the direction of movement of the roller occurs due to a change in the flow of the working fluid of the hydraulic pump of variable capacity. The roller is steered by a hydraulic steering circuit, which includes a pump and a hydrostatic steering mechanism that increases the turning force of the vibratory drum. The drives of the vibratory drum and dual pneumatic wheels are provided with

planetary gearboxes, each of which has a built-in brake mechanism.

The DU-85 articulated roller (Fig. 2.20) is designed for layer-by-layer compaction of pre-planned pounds of subgrade and road base layers made of gravel-sand and crushed stone materials. The rear semi-frame of the power plant and the front semi-frame of the vibratory drum are connected by an articulation joint with a vertical and horizontal axis, evenly located from the axes of the pneumatic wheels and the vibratory drum, which allows the movement of the drum and wheels next to next. The articulation joint is mounted in two lugs welded to the rear half-frame. The hub is attached to the front half-frame of the vibratory drum. The hinge body rotates relative to the hub. The rotation of the articulation hinge around the horizontal axis is necessary when the vibratory drum hits the unevenness of the compacted surface. The vertical axis of the hinge is used to rotate the roller when moving.

The power plant is made in one rigid block module, mounted on the rear half-frame at four points through compression dampers, consists of a diesel engine, a clutch and a pumping station. The pumping station, which serves to transmit torque to the hydraulic pumps, includes three pumps directly, as well as a clutch housing and a transfer gearbox attached to it with two of the three pumps to drive the roller and the vibration exciter. The skating rink has

two pneumatic wheels with built-in planetary gears mounted on one side on the rear half-frame (under-engine frame), and on the other - on the wheel disk. The tire size of both pneumatic wheels is 430...610 mm. A hydraulic motor is attached to the planetary gearbox through the flanges, which rotates the pneumatic wheels of the rear axle.

The vibratory drum is connected to the front semi-frame through two shock absorbers, it is driven by a hydraulic motor through a planetary gearbox. The vibration exciter shaft, located in the vibrating drum, is driven by a second hydraulic motor through a gear coupling. The planetary gearbox has a brake mechanism with pressure and two friction discs, controlled through pistons by the pressure of the working fluid. The articulated roller control mechanism consists of a hydrostatic steering device and control levers in the driver's cab.

When the rear axle is equipped with four pneumatic wheels with tires measuring 320 ... 508 mm, the roller receives the index DU-84.

Roller with articulated frame DU-85-1(Fig. 2.21) is unified in terms of components and assembly units with the analogue model DU-85. Modification DU-85-1 is obtained when a removable cam bandage is installed on a smooth metal roller. The use of a working body with a removable cam bandage allows the use of a roller for compaction of clay and other

cohesive soils of the roadway. Mounting and dismantling of the bandage can be carried out directly at the site of the ice rink. Before installing the bandage, it is necessary to remove the legs from the smooth roller and the pipe of the wetting system, and muffle the ru-z going to this pipe. The connection of two sections is even carried out by 10 studs and 20 mounting nuts with a cap that prevents dirt from entering the thread. After fixing the bandage, it is necessary to install new ribs designed to clean the intercam space. The design of the front half-frame provides for the possibility of attaching bulldozer equipment to it. Technical characteristics of articulated rollers are given in Table. 2.5.

Self-propelled road rollers are classified according to the type of working body, the principle of operation, the method of movement, the number of axles and the number of rollers.

According to the type of working body, rollers with smooth rollers, cam, lattice, pneumatic and combined are distinguished.

The first type of roller is characterized by the fact that the roller shells have a smooth working surface. In the second type of rollers, rows of cams are rigidly fixed on the roller shells. The stress on the contact surface of the cams with the ground is several times greater than the stress under the roller with smooth rollers. Therefore, during the first pass, when the soil is still loose, the cams are completely immersed in it and, as a result, the roller of the roller also enters into contact with the soil. During subsequent passes of the roller, the dipping of the cams into the soil is reduced due to its compaction. The cam rollers are effective only when compacting loose cohesive soils . The thickness of the compacted layer does not exceed 22-30 cm.

At the lattice road roller, the drum shell is made in the form of a lattice composed of cast metal elements. Such rollers are used to compact both cohesive and non-cohesive cloddy soils that contain solids. The latter are crushed by the roller grate, which significantly improves the quality of compaction.

Pneumatic rollers, in contrast to rollers with smooth rollers, allow for a long time to apply a load to the compacted material. When passing along the compacted surface, due to the deformation of the pneumatic wheel, a stress arises on the area of ​​its contact with the compacted material, the duration of which is measured in tenths of a second.

During this time, the load has time to spread into the depth of the compacted layer and cause irreversible deformations in it. Pneumatic road rollers with a wheel load of about 5 tons can compact the layers of the earth bed (except for sand and clay) and layers of pavement up to 30 cm thick.

Suret 2- Classification of road rollers by type of working body

The combined skating rink is equipped with the working bodies characteristic of road skating rinks of various type. The most common are rollers with pneumatic wheels and a vibrating drum, which provide the greatest versatility of the machine in terms of compaction of various materials - from loam and asphalt mix to coarse materials and sands.

As well as pneumatic wheeled rollers, combined ones have special high-pressure tires. Tires provide compaction of the material at the surface, and the vibratory drum - at a depth exceeding the zone of action of the tires. The smooth-surfaced roller creates a flat surface of the compacted material, which is required in the construction of pavements.

The working bodies of the rollers are divided into driving and driven ones. Torque is transmitted to the leading working bodies from the internal combustion engine. The driven working bodies of self-propelled road rollers are guides and, as a rule, serve to turn the machine.

According to the principle of operation, road rollers are divided into static and vibration.

A static road roller compacts under the action of gravity when the working body rolls over the material, and a vibrating one compacts due to gravity and periodic oscillations of one or more working bodies.

To create vibration, as a rule, an unbalanced vibration exciter is built into the drum, driven by the roller transmission. The use of vibration makes it possible to reduce by 1.5-3 times the number of passes of the roller along one track, increase the thickness of the compacted layer (in some cases up to 1.5 m or more), and also compact coarse-grained materials.

According to the method of movement, rollers are divided into trailed, semi-trailed and self-propelled. In a trailed roller, its mass is completely transferred to the compacted material, and in a semi-trailer, part of its mass is transferred to the tractor through the coupling device. With such rollers, pneumatic wheeled tractors and tractors are used.

Self-propelled rollers include an engine, a power train and a propeller.

According to the number of axles, rollers are divided into single-axle, two-axle and three-axle.

According to the number of rollers, one-roller, two-roller and three-roller are distinguished.

In two-axle double-drum rollers, the rollers are located one after the other, which ensures uniform compaction across the entire width of the compacted strip formed during the passage of the roller. The width of both rollers is usually the same.

Two-axle three-roller rollers are equipped with two narrow driving rear rollers and a wide driven roller.

Widely spaced drive rollers provide good lateral stability of the roller.

In addition, large-diameter drive rollers extend beyond the dimensions of the roller and make it possible to easily overcome the resistance to movement, come close to walls, high curbs and other obstacles. The rollers of these rollers are located in such a way that the rear rollers overlap by 100-120 mm the track of the front roller.

Three-axle three-roller rollers are used for the final finishing of asphalt concrete pavements and for leveling the compacted pavement. These rollers are equipped with three rollers of the same width, two of which are driven guides. The roller suspension design allows redistributing the mass of the roller along the axles depending on the unevenness of the compacted surface. All protrusions on the surface are rolled with increased pressure and leveled.

A two-axle three-roller static roller consists of a frame, a guide and two driving rollers, an engine, a transmission, a driver's workplace with control mechanisms, lighting devices, cleaning scrapers and a wetting system for the working surface of the rollers.

The frame serves as a supporting structure on which all assembly units of the rink are mounted. The engine is mounted on support brackets and frames by front brackets and a rear support fixed to the flywheel housing.

The gearbox has one bracket on each side, with which the gearbox, like the engine, is mounted on brackets and frames.

Suret 3- Two-axle three-drum static roller

1,6 - rollers, 2 - cleaning scraper, 3 - lighting devices, 4 - control mechanisms, 5 - driver's workplace, 7 - frame, 8 - fork

The engine and gearbox are attached to the frame brackets with bolts and nuts. The gearbox connected to the gearbox by a cardan shaft is installed at the rear of the frame.

With the front support legs, the gearbox is bolted to brackets welded to the sidewalls of the frame. The rear bearings of the gearbox are semi-axle cages mounted in the frame brackets and tightened with bolts.

Two driving and one guide rollers serve as the working bodies of the roller. The diameter of the driving roller is 1.6 times greater than the diameter of the guide roller, and the width is 2 times less.

Widely spaced drive rollers provide good lateral stability of the roller. The main compaction is carried out by the rear driving rollers, which account for 2/3 of the mass of the roller. After the passage of the roller from the rear rollers, a trace remains in the form of two narrow strips. The strip formed in the middle is compacted in the next two passes of the roller.

The rollers of the rink are shells rolled from sheet metal and welded along the generatrix. To obtain a rolling surface without traces from the edges of the rollers, rounded chamfers 15-18 mm wide are made on the outer edges of their shells. Discs are welded into the shells from the ends, to which cast hubs are welded. Roller bearings are installed in them, which serve as supports for the axis. The internal cavity of the rollers is filled with ballast through the holes in the disks, closed by covers, to increase the mass of the roller and the pressure on the compacted material. Water, dry or wet sand is used as ballast.

To the inner disk of the drive roller, the gear rim of the final final drive of the roller is attached with studs and nuts. The common axis of the driving rollers is fixed with locking screws in the frame brackets. Tapered roller bearings are bolted through an end washer.

The guide roller consists of two identical sections mounted on one common axle. The sections can be freely rotated independently of one another, which facilitates the rotation of the roller and prevents shifting of the compacted material. The gap between the ends of the sections of the guide roller does not exceed 3mm. The fixed axis of the roller is held by bolts in pins connected to the frame. The frame is pivotally connected by a fork, which achieves the rotation of the roller in a vertical plane at an angle of up to 35. The axes of the hinged attachment of the fork and the fork itself coincide with the longitudinal plane of the roller. The upper part of the fork ends with a kingpin, with which the fork is installed in the seat of the roller frame with the help of two tapered roller bearings. Part of the king pin protrudes above the socket. At its splined end there is a lever for turning the roller.

Consider the kinematic scheme of a two-axle three-roller static roller. The torque from the crankshaft of the engine through the coupling is transmitted to the drive rolls through a power transmission, consisting of a hydromechanical gearbox, a cardan shaft, a gearbox with a differential and gear final drives to drive the drive rolls.

Multi-plate friction clutches for forward and reverse, mounted on the input shaft of the gearbox, are used to quickly and smoothly change the direction of the roller (reverse). The smoothness of the beginning of the movement of the roller in any direction is necessary to eliminate slippage of the drive rollers and obtain a flat surface of the compacted material.

The differential allows the drive rollers to rotate at different speeds when the roller turns, which protects the compacted coating material from shifting and reduces wear on power transmission parts.

The differential is equipped with a lock-up clutch that disengages it by linking the left and right output shafts of the gearbox into one. The differential lock is necessary when one of the drive rollers encounters an obstacle or is pushed too hard into the rolling surface.

At the same time, the less loaded drum starts to rotate at a higher frequency (slips) and cannot develop the required traction force.

Suret 4 - Installation of transmission elements on the frame of a three-roller static roller

1,5,8,9,10,11,12,13 - brackets, 2 - engine, 3 - support, 4 - gearbox, 6 - shaft, 7 - reducer

A belt brake is installed on the input shaft of the gearbox, designed for emergency stopping the roller and braking in the parking lot.

The guide roller is turned by means of the roller steering hydraulic cylinder.

A three-axle three-roll static roller, unlike a two-axle one, is equipped with rollers of the same width, located in one line. The roller consists of a frame, a drive roller, driven rollers, an engine with a gearbox located at the rear of the frame, a drum drive gearbox, electric lighting, roller control levers, seats, an awning, devices for cleaning and wetting the rollers.

The design of the three-axle roller allows you to get the most even coverage due to the waveless rolling method. The design of the driven rollers of a three-axle roller is similar to the design of the guide roller of a two-axle roller.

The difference is that the drum king pin is equipped with a lock that fixes the front driven roller and prevents its axial vertical movement.

The lines of contact of all three rollers with the compacted material are in the same plane, which makes it possible to obtain a flat surface.

When transporting, the lock is opened and the drum freely copies the road surface without creating a load on the frame of the roller. When the vibration exciter is off, the rollers work as static ones.

A self-propelled vibratory roller is a two-axle machine, consisting of three units: a vibrating drum with a semi-frame, a power unit, a rear axle with two driving pneumatic wheels. On the frame of the power unit there is a power plant and an air-conditioned driver's cab. Attached to the lower front part of the frame is a hinge joint between the unit and the vibratory drum frame and two hydraulic cylinders for turning the roller.

The roller is equipped with a centralized pneumatic system for tire inflation and rear axle blocking, hydraulic brakes. The skating rink uses a hydrostatic drive of pneumatic wheels, a vibratory drum and steering.

The hydraulic system includes two power circuits with closed circulation of the working fluid and a hydraulic steering wheel. Vibrating roller - welded with a smooth metal shell. It rests on ball bearings mounted in cups connected to the frame through rubber-metal shock absorbers.

Suret 5 - Self-propelled vibratory roller

1 - power plant, 2 - pneumatic wheel, 3 - power unit, 4 - cabin, 5 - pneumatic system, 6 - vibratory drum, 7 - half frame, 8 - hinge, 9 - hydraulic cylinder

Inside the roller in the hubs on roller bearings, a vibrating shaft with two pairs of unbalances is installed. The unbalances are rigidly fixed to the vibrating shaft and are driven together with it by a hydraulic motor through a toothed coupling. The unbalances are freely installed on the cylindrical necks of the vibrating shaft and, when the direction of its rotation is changed, they are rotated by an angle of 135, changing the driving force of the vibration exciter from the minimum value to the maximum.

The vibratory drum in operating mode is driven by a hydraulic motor (not shown in the figure) through a bevel gear and a ring gear.

A self-propelled pneumatic skating rink is a two-axle machine consisting of two articulated units: a power one with four driving pneumatic wheels and a pneumatic wheel with five loaded and pneumatic wheels, of which four are driving. The latter are grouped in pairs on power balancing gears, swinging relative to the longitudinal axis of the rink. This design ensures uniform loading of the wheels, regardless of the unevenness of the compacted surface of the material.

The power unit and the driver's cab are located on the frame of the power unit. Attached to the lower front part of the frame is the hinge of the articulation of the units and two hydraulic cylinders for turning the roller. To achieve the required mass of the rink, the internal volumes of the frame are filled with ballast.

The roller is equipped with a centralized pneumatic system, hydraulic brakes and a wetting system. The wetting liquid stored in the tanks is supplied under pressure to the nozzles, which spray it onto the working surface of the pneumatic wheels.

Each pair of driving wheels of the power and pneumatic wheel units is driven by a hydraulic motor through a balancing gearbox, which is a three-stage gear. Pins are attached to its body. The trunnions are mounted with a cylindrical part on spherical cast-iron liners, which are fixed in the caps of the unit frame supports.

Transverse oscillation of the gearbox in liners - at an angle up to 8°. This allows the wheels mounted on the gearbox output shaft to copy the bumps in the road. The torque from the hydraulic motor through the gear coupling is transmitted to the drive shaft-gear and then through helical gears to the output shaft of the gearbox.

The wheel hubs are seated on the cone of the shaft and are kept from turning by keys. The wheels are bolted to the hubs. Holes are made in the hubs for air supply from the pneumatic system to the wheels through the tire inflation mechanism, pipeline and stopcock. A pulley for a belt parking brake is installed on the gear shaft of the gearbox.

The pneumatic tire pressure control system is designed to gradually increase the air pressure in tires when compacting road building materials from 0.3 to 0.8 MPa. The system also allows maintaining a pressure of 0.15 - 0.2 MPa in one of the tires of the rink (in case of damage). This makes it possible to continue moving the roller to the base without changing wheels.

A self-propelled combined roller is a two-axle machine consisting of two articulated units: a power unit with four driving pneumatic wheels and a vibrating unit with a vibrating drum.

The working compacting elements of the roller are four pneumatic wheels and a rigid metal vibratory drum. Consistent impact on the compacted material of static and vibration loads increases the performance of the roller.

Suret 6 - Self-propelled combined roller

1 - power plant, 2 - cabin, 3 - vibratory drum, 4 - vibration unit, - hinge, 6 - hydraulic cylinder, 7 - pneumatic system, 8 - pneumatic wheel, 9 - brake, 10 - power unit

Due to the small distance between the axes of the working bodies, the pneumatic wheels are in the zone of the compacted strip, which is under the vibrational effect of the vibrating drum, which increases the compaction efficiency.

The power unit and the driver's cab are located on the frame of the power unit. Attached to the lower front part of the frame is the hinge of the articulation of the units and two hydraulic cylinders for turning the roller.

The articulation hinge is not structurally different from the hinge of a self-propelled vibratory roller. The hinge is located in the middle between the axes of the pneumatic wheels and the vibrating drum. The rotation of the hinge relative to the horizontal axis is possible by 8 when the roller moves on an uneven surface. The hinge is rotated relative to the vertical axis by two hydraulic cylinders. This placement of the articulation joint reduces the turning radius, and also provides the passage of the working bodies of the machine track to track on curved sections.

The roller is equipped with a centralized pneumatic system, hydraulic brakes and a wetting system.

The torque from the engine through the clutch is transmitted to the drive gear of the input shaft of the transfer gearbox. Reversible axial-piston hydraulic pumps and two gear hydraulic pumps are installed on the output shafts of the transfer gearbox through gear couplings.

The roller uses a hydrostatic drive of the vibratory drum and pneumatic wheels, unified with the hydraulic drive of the self-propelled vibratory roller. The difference is that the combined roller uses two hydraulic motors to drive the pneumatic wheels, and not one, like the vibratory roller.

The working hydraulic lines of the adjustable pump in the transport mode are constantly connected to the hydraulic motors of the drive of the pneumatic wheels of the power unit. The rotation on the pneumatic wheels is transmitted from the hydraulic motors through the balancing gearboxes.

In operating mode, the vibratory drum drive hydraulic motor is connected to the pump. The vibratory drum is driven through a bevel gear and ring gear.

The hydraulic lines of the adjustable pump are permanently connected to the vibration exciter drive hydraulic motor. The unbalances are rigidly fixed to the vibrating shaft and are driven together with it from the hydraulic motor through a gear coupling. Around each of the unbalances fixed on the shaft, external unbalances can be rotated, which consist of two disks interconnected by a segment plate.

External unbalances are freely installed on the cylindrical necks of the vibrating shafts and, when the direction of its rotation is changed, they turn on, changing the driving force of the vibration exciter from the minimum value to the maximum. The gear pump is used to feed power circuits with working fluid and supply fluid to hydraulic boosters of hydraulic pumps. The pump supplies the working fluid to the hydraulic steering wheel. The steering and hydraulic system for turning the roller are not fundamentally different from a similar mechanism and system of a self-propelled vibratory roller.

TO Category:

Asphalt paving machines

Purpose and classification of rollers

The rollers are designed for compaction of bases and coatings made of asphalt concrete mixtures, as well as for layer-by-layer compaction of soils, gravel-crushed stone and stabilized materials during the construction of dams, dams, airfields and roads.

The working bodies of these machines are metal rollers or pneumatic wheels.

The working bodies of the rollers are divided into leading and driven. Torque is transmitted to the leading working bodies from the internal combustion engine. The driven working bodies of self-propelled rollers are guides and serve to turn the machine.

Rollers are classified according to the principle of operation, the type of working body, the method of movement, the number of axles and the number of rollers (GOST 21994-76).
According to the principle of operation, rollers are divided into static and vibration.

On static rollers, the coating is compacted due to the action of gravity when the working body is rolled over the material. On vibratory rollers, in addition to static loading, a dynamic load is transferred to the compacted material due to the oscillatory movements of one roller. To create vibration, an unbalance vibration exciter is built into one of the rollers, driven by the roller transmission.

According to the type of working body, rollers with smooth rollers and pneumatic wheels are distinguished.

According to the method of movement, rollers are divided into semi-trailer and self-propelled. In a semi-trailed roller, part of its mass is transferred to the tractor through the hitch. With semi-trailed rollers, pneumatic wheeled tractors or tractors are used.

According to the number of axles, rollers are divided into single-axle, two-axle and three-axle.

According to the number of rollers, single-roller, two-roller and three-roller rollers are distinguished.

The main parameter of the rollers is the mass. By weight and design, self-propelled road rollers with smooth rollers are manufactured in the following types and designs:
type 1 - light vibration weighing 0.6; 1.5 and 4 t single-axle single-drum (1/1) and two-axle double-drum (2/2);
type 2 - medium vibration and static weighing 6 tons, two-axle two-roller (2/2) and two-axle three-roller (2/3);
type 3 - heavy static weighing 10 and 15 tons, two-axle two-roller (2/2); two-axle three-roller (2/3) and three-axle three-roller (3/3).
Pneumatic semi-trailed rollers are divided into the following types (GOST 16481-70): light (15 tons), medium (30 tons) and heavy (45 tons).
Pneumatic self-propelled rollers are divided into medium (16 tons) and heavy (30 tons).

The most common machines for compacting materials used in road construction are road rollers.

The undoubted leader in the production of sealing equipment is the German company Hamm. The Hamm road roller is characterized by high performance, power and ease of maintenance.

The company BOMAG does not lag behind them. The BOMAG road roller, depending on the model, is used for the construction of footpaths and motorways.

Of the domestic machines, the DU 85 road roller can be noted. It is used for the construction of airfields, dams, port facilities and industrial facilities. Has high performance.

Classification: main types

Rollers are classified according to the method of movement, pressure and design of the rollers. There may be several or one roller at the rink. The processed material is compacted in layers under the action of only the weight of the roller or with the help of additional vibrations.

Different roll shapes are used for different materials.

Types of rollers:

• smooth (cylindrical drum with a smooth surface).
• cam (cylinder, on the surface of which there are protrusions - cams.);
• lattice (the surface of the roller has the form of a lattice made of bars of profiled steel or segments of sheet steel);
• type-setting (wheels with pneumatic tires assembled on the axle). Are used for consolidation of bituminous and asphalt concrete mixes;
• segmented (smooth drums with segments on the rim);
• compactor (cylinder, on the surface of which cams of a symmetrical shape are welded). They differ from cam rollers in a smaller width and a smaller number of rows with cams;
• special (polygonal discs, combined, etc.).

By the strength of the impact on the material are divided into:

• light: distributed load no more than 40 kN / m, engine power up to 20 kW, weight 5 tons. Used for preliminary compaction of coatings and bases;
• medium: load 40-60 kN / m, engine power 25-30 kW, weight 6-10 tons. Used for both intermediate and final compaction of lightweight coatings;
• heavy: load over 60 kN/m, engine power over 30 kW, weight over 10 tons. They are used for the final compaction of gravel or crushed stone bases, as well as asphalt concrete pavement.

By the number of rollers there are:

• single drum with supporting wheels or rollers;
• two-roller, having one or two driving rollers;
• three-roller (two-axle, equipped with an additional roller of small diameter or without it, as well as three-axle with one or three driving rollers).

According to the method of movement are:

• trailed;
• self-propelled.

The trailed road roller is a metal frame on which a cylindrical roller is fixed. The unit clings to the tractor, which pulls it along the compacted surface.

A self-propelled road roller is a machine that does not require additional traction power. Rollers of this type are maneuverable, have a higher productivity than trailed ones. Some of them are capable of speeds up to 14 km / h.

According to the method of impact on the soil, the models are divided into:

• static;
• vibrating.

Static rollers compact the material by gravity.

The vibrating road roller compacts the road base of the road with the continuous action of the vibrating roller. It oscillates, due to which the material is compacted with fewer penetrations.

The domestic self-propelled road roller DU 54 belongs to the vibration ones.

Types of road rollers and their importance in modern construction

During the construction of roads, the quality of compaction of bulk soil and asphalt concrete plays an important role. After all, the life of the future facility will directly depend on this. For these purposes, special road-building equipment, namely rollers, is used. What are they? A road roller is a special machine designed to compact material during the construction of a road surface. It is produced by rolling one or more working devices on the surface to be treated.

Types of road rollers

According to the method of movement, road rollers can be divided into three types:

trailed;

semitrailer;

Self-propelled.

The first one does not have its own drive, and its mass is transferred to the coating with the help of a working body. The mass of rollers of the second type is transferred to the compacted coating not only by rotating the roller, but also by means of a tractor. And finally, self-propelled road rollers are equipped with their own engine, propeller and power transmission.

Self-propelled road rollers

This group of equipment today makes up the main fleet of road vehicles in our country. The ability to independently get to the place of work and move freely between sites makes self-propelled rollers simply indispensable. They can have a different number of rollers, differ in the number of axles, be equipped with any of the working bodies, have a certain principle of operation, but their main difference from trailed and semi-trailed models is this is the best performance.

According to the method of impact on the material, all road rollers can be divided into:

static;

Vibrating.

During the operation of the first type of machine, the surface is compacted due to the effect of gravity, which makes it possible to achieve the smoothness of the roadway. The second type of rollers should be considered in more detail.

Vibratory road rollers

Models of vibratory road rollers compact the pavement not only by their own weight, but also by periodic vibrations that occur during the movement of the rollers. Such special equipment is used to perform a huge number of road works, namely for compacting roads, airfields, the lower and upper layers of the base of the canvas. In some cases road roller of this type can be equipped with a dozer blade or a cam bandage.

Compared to static models, vibratory rollers have the best level of performance, and are most effective when working with various types of soil. That is why most of the compacting machines currently in use fall into the vibrating category.

The next difference between road rollers from each other are the types of working bodies. According to which they are divided into:

Smooth-roller;

Cam;

lamellar;

lattice;

Ribbed;

Pneumatic.

There is one more variety among these models - combined road rollers. Such equipment is equipped with several types of interchangeable working bodies at once. This makes it possible to adapt to different types of terrain and the characteristics of the compacted soil.

And finally, according to the number of axles, road rollers are divided into:

Single axle;

biaxial;

Triaxial.

For the compaction of the base layers, models with one or two axles are most often used, but for the final compaction of the pavement, a road roller with three axles is more suitable. It allows you to even out the smallest roughness and protrusions due to high pressure and rational distribution of mass.