In hydraulic terms, the efficiency of construction machinery cannot be defined based on operating pressure and flow rate alone; instead, total cost, size, weight and especially a high level of reliability are decisive factors in designing hydraulic systems for mobile applications.

Requirements can be extreme, as exemplified by pavers. For these machines, designed to maximize uptime, ARGO-HYTOS offers innovative hydraulic solutions with a focus on function; these solutions are the result of decades of application expertise.

Construction machinery manufacturers often have to find new approaches to keep up with ever-changing demands and to position themselves successfully in the market.

A keen attention to details is vital in order to reach goals such as optimum use of energy, maximum uptime and reduced overall operating costs. Results can be improved decisively by finding the best possible way to realize the hydraulic functions of a given application, not only when designing new systems but also when analyzing and modifying existing hydraulic circuits. 

Whether they are newly designed or redesigned, the demands posed on construction machinery are often extreme. These machines must be very rugged, efficient and long-lasting in order to achieve maximum performance despite variations in temperature and vibration.  In addition, they must also function properly when operated by inexperienced persons.

All these criteria call for component manufacturers’ extensive knowledge of and experience across different technologies. This is why ARGO-HYTOS has been closely collaborating with the leading construction machinery manufacturers for decades; the continuous development and enhancement of valve and sensor technology and filtration, as well as the clever combination of these to create subsystems, ensure that the customers’ demands are met – for a multitude of construction machines.

The paver as a prime example
This is also true for highly demanding pavers. Uptime is key with these machines, due to the fact that – contrary to other construction machines – there is usually only one paver per construction site. Pavers are logistically integrated into an elaborate work concept and schedule involving numerous dump trucks or material transfer units, which supply the material for the road surface – pavers simply must function. If they do not, a downtime of just two hours would lead to several truckloads of asphalt becoming unusable, turning into special waste.   It is utterly vital to prevent such costly damages. For this reason, the reliability of all the components installed is of highest priority; moreover, it should be possible to quickly, easily repair and service these components on site if problems do occur.

Identify potential for improvement
ARGO-HYTOS components are used for operating all hydraulic functions of the tractor and the screed, except the closed circuit drives. There is a wide range of applications – from hopper wing, scraper, crown adjustment and auger to extending screed. ARGO-HYTOS is far more than a component manufacturer; thanks to years of application experience, the company plans, designs and produces complete, ready-to-use systems.

For both new projects and the enhancement of existing machinery, this combined expertise is the ideal basis for identifying potentials for improvement in existing applications and for developing new solutions with future-oriented technology. Combining parts and components in new ways creates various valve and filter assemblies, which in turn results in new, extended or enhanced features. Individual requirements concerning installation space, design, performance and costs can be fulfilled thanks to a comprehensive product portfolio based on standard and near standard parts. Any function required can be realized with compact systems or assembly units – this is an important fact for OEMs, considering the wide range of design options especially for pavers.

Moderation and energy conservation
Despite all the differences in standard and optional versions, actuators in mobile machinery can be classified into two categories: frequently or constantly operated actuators and temporarily operated actuators.

However, even constantly operated actuators do not require maximum pressure supply at all times. In order to avoid power and performance losses, load-sensing systems in combination with a variable displacement pump operate in a power-on-demand mode: the pump supplies exactly the flow that is needed for the active actuators at any given time; this way, energy consumption can be reduced significantly.

ARGO-HYTOS’s guiding principle is ‘Just enough’ – no more components than are necessary to realize the required function – in designing complete systems. The focus is on function, not on individual components, such as a pressure relief valve. Because of this, hydraulic schematics and solutions may vary significantly, depending on whether size, weight or efficiency / energy efficiency are prioritized. Thanks to this approach, customers get systems that fully meet the specified requirements.

Modularity for a wide range of functions
For faster implementation ARGO-HYTOS has developed a modular system in NG 6 – a manifold, ideally suited for pavers in the medium performance range. The combination of standard and application-specific parts makes the realization of different functions simpler. At the same time, the manifold guarantees a high degree of flexibility: both the number of actuators and the functionality itself can be changed late in the project through minor modifications or adjustments.

This innovative manifold is made up of three sections. In section 1, standard directional control valves serve as a simple throttle control. Since the actuating and auxiliary functions supplied here are only used sporadically, a load-sensing circuit is not necessary. Instead, savings in terms of cost, weight and space are emphasized. Section 2 is an application-specific manifold with screw-in and bankable valves; sandwich sections in NG 6 are the basis for section 3. These two sections work directly together, and sample and process the LS signal that controls the variable displacement pump.

Cleverly combined benefits
Switching between LS system and constant pressure system is controlled by means of a screw-in valve in the central inlet section. The pressures in the LS- and the constant pressure section can be adjusted separately. Moreover, it is possible to have either parallel operation of the two sides or a priority circuit for one of the two functional units. The central inlet section is designed or modified according to the specifics of the given application regarding size, port and connection arrangement, as well as position in the machine. Switching logic and functionalities are based on tried and tested concepts and solutions that have been implemented in mobile hydraulics for years.

Thanks to its operating principles and modular design, the manifold fulfills all requirements regarding reliability, energy efficiency, serviceability and compact design. Developed to meet the extremely high demands of pavers, the system can also be used in a variety of other construction and agricultural machines. The clever combination of screw-in, CETOP and sandwich valves with sensors and filtration results in compact functional units. This, in turn, results in reduced costs for mounting and tubing and in reliable, safe machines characterized by maximum uptime.

Full hydraulic control
ARGO-HYTOS supplies application-specific systems for high-performance construction machines such as pavers:

• Manifolds for proportional control of motors and cylinders
• Proportional speed control for tampers, vibration and conveyors
• Breathers, suction filters, pressure and high-pressure filters, as well as filter systems with integrated fluid collection
• Sensors with data evaluation for oil condition monitoring

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