Connected Hydraulics

5 HYDRAULICS MYTHS
Guest Contributor: Dr. Steffen Haack, Bosch Rexroth

br_hydrolicmyths_hero_dec19.jpgNo drive technology is more efficient, compact and robust than hydraulics when dealing with forces in excess of 600 kN. So why is it that the importance of hydraulics is often overlooked in the training and development of our young engineers?

In the modern manufacturing setting, movement is everything along with the resulting data. Little thought is given to hydraulic technology, that is until drive physics comes into play. This is when hydraulic technology comes into its own in managing large forces and delivering robust performance.

Here’s a connected hydraulics ‘Myth Buster’ that demonstrates how the latest smart hydraulics are more versatile and cost-effective than you ever imagined.

THE MYTH: Installation is complex

BUSTED: Designers are no longer required to develop an in-depth knowledge of fluid mechanics and technology and increasingly look for plug & produce modules. These ready-to-install modules simply need an electrical current and a connection to the control communication.

THE MYTH: Commissioning takes time

BUSTED: Our smart, connected hydraulics are now commissioned with the same engineering tools as electric drives and control systems. Functions previously carried out hydromechanically are handled by the latest drive software. There are even software assistants available to guide technicians through the commissioning process and suggest suitable parameters.

THE MYTH: Hydraulics waste energy

BUSTED: There’s a preconception that hydraulics are more energy-intensive than other technologies, but things have changed dramatically. Variable-speed pump drives generate the flow in line with demand and reduce speeds accordingly under partial load conditions. Compared to constantly driven pumps, they reduce power consumption by up to 80 percent – a level consistent with that of electric drives of the same size.

THE MYTH: Hydraulics aren’t IoT ready

BUSTED: Smart hydraulics are a well-established part of IoT in production. Analog valves can be made digitally visible cost-effectively thanks to IO-Link and exchange data available through the control system. Smart valves, with their own control electronics and state of the art field bus connection, are as convenient to use as electric drives.

THE MYTH: Hydraulics are high maintenance

BUSTED: Hydraulics offer a distinct advantage when monitoring operating states and deducing possible wear and expected life cycle. With a few pieces of sensor data, such as pressure differential, oil temperature, optically measured contamination or pressure increase over time, software can assess the health of the system.

This myth busting technology is included in our latest generation of hydraulic power units, allowing young designers and businesses to benefit from all the advantages of our modern, connected innovations.

 

CMA/Flodyne/Hydradyne is an authorized Bosch Rexroth distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

Hydraulic Valves Will Benefit From Connectivity

Guest contributor, Jeroen Brands, Bosch Rexroth

Hydraulic valves: Directional valve with integrated digital axis controller

Hydraulic valves: Directional valve with integrated digital axis controller

What are the current market requirements for hydraulic valves?

We are currently experiencing a transition from classic, analogous hydraulics to connectable digital fluid technology. European machine manufacturers in particular are increasingly digitizing their machine designs and expect that hydraulics can be seamlessly embedded into these connected environments. This means that regarding the level of automation, hydraulics are on a par with electromechanical drives. One of the decisive features in this respect is the seamless integration of intelligent hydraulic valves into different automation topologies via open standards such as multiple Ethernet interfaces.

Which new technical possibilities are available to meet these requirements?

Smart single-axis controllers are already remotely regulating hydraulic motions in a closed control loop. In addition, a powerful motion control is integrated into the on-board electronics of the valve. It performs the target-actual comparison on site and regulates accurately to a few micrometers. The control quality of the system is exclusively determined by the resolution of the measurement systems. These motion controls without control cabinet are increasingly used in saw lines, paper mills and machine tools. In addition, there are smart variable speed pump drives and smart pump controls. They provide completely new possibilities of replacing the throttle controls, which were predominantly used up to now, by more energy-efficient displacement controls. In this way, functions which were previously executed by valves are relocated to the software.

What about the integration of sensor technology into hydraulic valves?

The mass production of sensors for the automotive or the consumer products industry has significantly reduced the costs. Now, sensors are increasingly used in hydraulics. In our opinion, the integration of sensor technology of this kind into existing valve housings is the next step. Regarding condition monitoring, sensors could collect information on fluid quality, temperature, vibrations and performed switching cycles. Via deep learning algorithms, users can then detect wear before it causes malfunction.

Which other possibilities of mechanization does a valve provide?

The degree of freedom regarding connection geometries is already limited by standard requirements. The hydraulics industry discussed the topic of digital hydraulics in great depth some time ago. The idea was and is to control flows in a “stepped” or “clocked” way using single- or multi-bit strategies. In certain applications, this can constitute an advantage compared to continuously variable technology.

Which other innovations in hydraulic valves are relevant in your company?

It is no longer a question whether hydraulic valve technology will benefit from connectivity or not. The only question is when. The current discussions around Industry 4.0 clearly show how important it is to define all required functions and functionalities. Only if mechanisms and sensor technology are standardized across different manufacturers will active connectivity and communication be possible. Even in the future, not every hydraulic-mechanical pressure valve will have digital electronics on board or be connected to a control system or other valves. An imprinted QR code with information on the manufacturer’s settings, functional descriptions or information on replacement seals are a first step towards connectivity. In the area of new materials and production technologies, Rexroth has many innovations in the pipeline. 3D printing of cores for cast housings or direct printing considerably lowers energy consumption during the operation of valves. While the divisibility of the core mold had to be taken into account in the design of the core, this is no longer necessary today thanks to core printing. This means that we can use other channel designs which allow for lower pressure losses and improve energy consumption. For a valve with a flow of 10,000 l/min, the reduction of flow resistance by 10 to 20 percent significantly reduces the operating expenses.

Pressure transducer for hydraulic applications

How do these trends affect your products?

With the IAC (integrated axis controller) valves, Bosch Rexroth offers motion control without control cabinet which is completely integrated into valve electronics. It can be fully connected via open interfaces. The same applies to servo-hydraulic axes with their own fluid circuit. In these ready-to-mount axes, pump, valves and cylinders form an assembly to which the machine manufacturer only has to connect power supply and control communication. They use the same commissioning tools and user interfaces which means that all drive technologies provide the same look and feel. Classic servo valves, however, can also be improved further. New plug-in amplifiers with pulse width modulation for on/off valves by Rexroth reduce the surface temperature of the connectors by more than 80 degrees to only 50 degrees. This is particularly interesting for saw lines where easily inflammable sawdust constitutes an explosion hazard.

Outlook: How will valve technology change in the next 10 years?

In 10 years, valves will allow for easier project planning, more comfortable commissioning and more efficient operation and will provide more information before a service case. If service is required, the valve may already have ordered its spare parts.

 

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized Bosch Rexroth distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

THE LARGEST FLOW ON THE MARKET

Guest contributor: Dr. Till Deubel, Head of Development, Cartridge Valves, Bosch Rexroth

When it comes to valves, maintaining performance with an increased flow rate can be extremely good news for manufacturers. It allows them to meet the same requirements with a smaller machine size or maximize manufacturing performance with a minimized footprint. 

Our brand-new WRC-4X directional high-response cartridge valves not only meet high dynamics and flow requirements, they can also be integrated into networked environments.

As they feature integrated electronics with a multi-Ethernet interface and OCI for Drives, WRC-4X valves can be integrated into networked environments even with an analog signal input.

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Next generation thinking

Once again, we’re pleased to be moving technology forward – increasing performance and communication for hydraulic actuators with our next generation of WRC-4X directional high-response cartridge valves. These valves are more dynamic and consistently achieve flows that could previously only be met by using the next highest available size. In fact, they provide the largest flow on the market.

Integrated electronics (OBE) allow the new valve series to be networked via open interfaces with higher-level control units and Industry 4.0 environments, even when used with an analog signal input. This means that the valves are ready be integrated right away into even the most cutting edge automation concepts and can benefit from predictive maintenance.

Flexing to future challenges

Our new cartridge valve blocks are ideal for applications with high flow and dynamics requirements, such as:

  • Presses
  • Die-casting
  • Injection molding machines

Using sophisticated co-simulations with flow analyses and strength calculations, our developers have optimized channel geometries and enabled different sized valves to achieve significantly higher flow levels. This means they can consistently achieve values that would previously have only been possible by using valves the next size up.

The valves can be operated via digital and analog control signal input. In both cases, the integrated electronics (OBE) enable the valves to be seamlessly integrated into digitally networked automation environments and Industry 4.0 applications. WRC-4X valves also feature an open interface that enables communication with a range of programs. So machine manufacturers and operators can incorporate the valves into condition monitoring systems and benefit from predictive maintenance.

Learn more:  https://www.boschrexroth.com/en/xc/products/product-groups/industrial-hydraulics/index

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized Bosch Rexroth distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

Embedding axis controllers made by any manufacturer
Guest contributor: Theobald Herrmann, Bosch Rexroth

Automating hydraulic drives as easily and conveniently as electrical ones with combined monitoring and remote maintenance of all the technologies used – this increasingly important economic requirement can be fulfilled using valves with integrated axis controllers (IAC). What can they offer and how easy is it to implement manufacturer-independent integration at controller level?

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Bus systems play a key role in automation. They provide a flexible way of saving time and money when integrating hydraulic drives into higher-level control networks. However, in order to give the engineering plenty of freedom, this should ideally be independent of the controller manufacturer.

Ethernet – open communications standard

The basis for this manufacturer-independent communication is the network standard Ethernet. Thanks to the large address space and switch cascading facilities, networks can then be scaled to any size and can give an almost unlimited number of participants equal bus access. The most common Ethernet-based bus systems used in industrial automation to control hydraulic axes are SERCOS, Profinet RT, Ethernet/IP, EtherCAT, Powerlink and Varan.
All these bus systems can use multi-Ethernet interfaces to provide flexible availability – both for the engineering and for the end user.

What can IAC valves achieve with multi-Ethernet interfaces?

Multi-Ethernet interfaces are a key component of control valves with integrated digital axis controllers (IAC). The integrated switch (bus in and bus out)
makes it easy to comprehensively integrate your hydraulic drives into a uniform control concept. Using standardized M12 technology also enables you
to efficiently integrate a variety of sensors. The software-based control functions are particularly interesting to users. They enable the motion control
of a hydraulic drive to be handled in the same way as an electric one, ultimately depicting the operation and control of both types of drives in exactly the same way.

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Specific hydraulic axis control functions

Viewed precisely, an IAC (Integrated Axis Controller) is a digital controller equipped with control and regulation algorithms that is integrated into the valve together with all the necessary sensor interfaces for controlling position, pressure, force and flow. The extended function range includes alternating control (position, force) and status feedback for position control. This means that hydraulic motion sequences can be quickly implemented without the need for any programming. Another advantage is that control algorithms and parameters can be integrated into the valve and then selected by the higher-level controller as appropriate for the specific application. In this way, possibly supplemented by electric drives, they can be used as a cost-effective way of implementing tailored machine concepts and individual application requirements.

Commissioning, monitoring and engineering

Using standardized M12 technology reduces the cabling effort required and permits faster commissioning. Additional time and cost are saved by the wizard integrated into the software that guides the user through the few steps needed before final commissioning and also calculates all the necessary control parameters. Important for the plant’s availability are monitoring functions which, among other things, detect tracking errors and monitor the limits of travel.
In addition to these, some manufacturers also provide software tools to help motion control system users with commissioning and parameterization, and diagnostic functions such as multi-channel oscilloscopes and data loggers, so that the number of interfaces can be kept as low as possible – making the system faster and easier to configure.

Integrated machine safety (safe stop)

For the engineering IAC valves facilitate a modular construction system that can flexibly enhance system concepts. And not least, these include internally implemented DGUV-certificated safety functions. This gives you an economical and future-proof way to lay the foundations for safe stop, for instance by shutting down a channel as specified in EN 13849-1, and thus fulfill the requirements of the Machinery Directive even for large-scale plants.

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Case study 1: High precision control tasks

The role that IAC valves play in the accuracy of machine tools is made very clear by the example of a new rotary transfer machine with 54 electrical and hydraulic CNC axes. For this new development the manufacturer not only made use of a powerful CNC system solution with real-time communication via SERCOS, but also incorporated a module in controller format with software that was already capable of taking into account all the special features of fluid technology and was thus able to separate the drive level from the control level. This enables the machine to be constructed more compactly and with lower heat input. Thanks to the stable temperature, the vibration-damped sleeves of the circular array of processing axes can achieve a repeatable precision in the hydraulic servo axes of less than +/- 1 μm, corresponding to 5 μm on the workpiece. The travel speed is up to 30m/min.

Case study 2: A retrofitted core shooting machine

In addition to new designs, IAC valves with multi-Ethernet interfaces also offer considerable potential when it comes to modernizing legacy machines. For example, the well thought-out retrofit of a 50 year old core shooter coupled with new hydraulic components resulted in significantly improved efficiency. A total of eight IAC valves regulate the hydraulic cylinders on the basis of the set positions given by a CNC controller. Their possibilities and high level of precise repeatability made it possible to reduce the figures for setup time (system changeover) and waste (nibs). Altogether, despite operating three shifts, the machine’s availability increased by more than 10%, corresponding to 500 hours. Using a secure logic controller meant that safety was also brought up to date.

Conclusion

IAC valves with multi-Ethernet interfaces and integrated axis controllers enable mechanical engineering companies to easily utilize the productivity potential offered by hydraulic and hybrid drives.

Combining them with engineering tools, including industry-specific and application-specific control structures makes it possible to cost-effectively
implement tailored machine concepts and modernizations, with the result that the manufactured results can be optimized faster and more easily.

More information: www.boschrexroth.com/iac

Movie: https://www.youtube.com/watch?v=fVBOYCP31P0

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized Bosch Rexroth distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.

New hydraulic design for presses

Guest contributor: Stefan Zimmerman

New drive concept makes hydraulics economical and intelligent

By means of variable-speed pump drives, new, patented hydraulic axes simplify the design and control of presses of any kind. They considerably reduce the power consumption as well as the required oil quantity by up to 90 percent. To this extent, the control technology of a valve control moved into the software of intelligent servo drives of a displacer control. This reduces the complexity and opens up new levels of flexibility and of condition monitoring.

Worldwide, the climate change has increasingly drastic effects on the everyday life. Thus, governments and international organizations have defined climate targets in order to limit the CO2emissions. What has already become standard in light bulbs and household devices also takes increasingly more effect in the industry. Energy-efficiency has become a decisive criterion for the machine users when it comes to the selection of machinery and systems. They expect a considerably increased output with clearly reduced current and resource consumption. Apart from that, numerous companies have already publicly obliged themselves to reduce their CO2 emissions by defined quantities. They can only achieve these targets if new machinery and systems are considerably more energy-efficient. So it is the challenge of machine manufacturers to develop new concepts.

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Using the hydraulic force density as required

In large systems with very high processing forces as they are required for forming methods, the hydraulics as main drive is one of the largest power consumers. The end users have accepted this for a long time as they wanted to have the maximum force available at any time, even if the process did not permanently require it. Modern hydraulic drives distinguish themselves by the physical unique selling points such as power density and robustness; however, they clearly reduce the power consumption by controlling the displacer as required. Thanks to its hybrid concept, the new hydraulicAxis patented by Bosch Rexroth for presses of different kinds, from low to high drive power, connects the advantages of hydraulics with those of the electric drive technology. First equipment according the new concept has shown that the power consumption can be reduced by more than 30 percent. The required oil quantity of the hydraulic installation can be reduced by up to 90 percent.

Conventional hydraulic systems

For decades, conventional systems have proven of value for presses in the medium and high performance range as drive technology of choice. In this connection, these systems mostly work with a central hydraulic power unit with several variable displacement pumps.  Moreover they are operated by electric motors directly connected to the mains. Apart from that, central or decentralized manifolds with on/off and proportional servo valve technology are required in order to control the cylinder(s) in rapid traverse, working or pressing mode and in the so-called return.

One disadvantage of this concept are idling losses during the standstill times. In the control of the cylinders, there are also throttle losses caused by the valve control. There is partly considerable heat introduction into the hydraulic oil, which must afterwards be compensated again by corresponding cooling.

Hydraulic axis replaces central power unit

A new, patented hydraulic concept replaces the previously common central power unit with valve control by a patented hydraulic axis with speed-controlled displacer control and a closed, decentralized fluid circuit. The hydraulic axis consists of a differential cylinder with a cylinder chamber and ring chamber. The cylinder chamber is for a powerful working movement and the ring chamber for the fast rapid traverse movement. An auxiliary cylinder takes up the oscillating volume during the different movements and in this way creates a closed circuit. A central oil tank is no longer necessary and thus completely omitted.

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The flow is generated by variable-speed pump drives. In order to satisfy the high precision and dynamics requirements, servomotors in combination with adjustable axial piston pumps lend themselves. Thus, all options of the 4-quadrant operation are available to the design engineers. With several cylinders, a corresponding number of Hydraulic axes is used. The synchronization control is performed by the software of the intelligent servo drives, synchronized by means of real-time communication.

Reversal of the movement by changing the direction of rotation

The area switchover for the relevant movement is effected by means of two valves. During the pressing process, the cylinder areas are large. Thus, the cylinders reach high forces at low velocity. During the return of the cylinders, however, the areas in the ring chamber are small in order to achieve the maximum rapid traverse velocity with low forces and to thus reduce the downtimes of the presses. For the reversal of the movement, the servomotors change their direction of rotation. If adjustable axial piston pumps are used, the swash plate of which can be swiveled through zero, the direction of the movement can also be changed by adjusting the swivel angle.

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Energy efficiency in practice: Presses consume more than 30 percent less

The hydraulic axis works in a strictly need-oriented manner. At partial load, the servo drive controllers reduce the speeds of the pump motors to the lowest value possible. During standstill times, e.g. for cooling down the tools, the motors are standing and do not consume any energy. During that time, safety valves support the return. Depending on the cycle times, variable-speed pump drives allow for energy savings of more than 80 percent as compared to constantly driven power units without variable displacement pumps. In practice, the first presses with hydraulic axes achieved reduced consumption of 30 percent as compared to already energetically optimized, conventional hydraulic solutions.

BR_Homburg_Booster-105Regarding the Sytronix family, Rexroth offers more than one hundred pump drives with variable speed relating to power and function. These can be integrated into all usual automation structures thanks to multi-Ethernet interfaces.

Exceeding the savings due to the need-based closed-loop speed control, additional functions increase the energy efficiency of the presses even further. In the lowering movement, the servomotors recuperate the braking energy and either feed it into an electric accumulator, make it available to other actuators, e.g. handling axes, via an intermediate circuit or feed it back into the mains.

Synchronization control of the hydraulic cylinders via intelligent software

The synchronization control can be effected via all common real-time protocols such as PROFINET, Ethernet IP, EtherCat or Sercos if the servo drive controllers provide corresponding multi-Ethernet interfaces. Changes in motion sequences are only transmitted via the machine control by means of software command to the intelligent drives. Mechanical adjustment works at the hydraulic axis are not necessary. So due to short changeover times, end users gain flexibility. At the same time, you can continuously document the manufacturing processes of every component by means of the servo-drive data. This satisfies the increasing demands on the traceability of products.

90 percent less hydraulic oil – central tank omitted

Due to the new concept of the hydraulic axis, the movements are primarily controlled via variable-speed pumps rather than the throttling of the flow by the valves. So considerably less heat is introduced into the hydraulic oil and only minor agitation results. Result: In the first presses with hydraulic axes, the manufacturer could reduce the oil volume from e.g. 10,000 liters to only 900 liters. This saves space for the tank and reduces the operating costs as in an oil exchange, less than ten percent of the previously used oil quantity have to be purchased and disposed of.

An additional advantage is the clearly reduced average noise emission. With variable-speed pump drives, it is up to 20 db(A) below that of constantly driven pumps. During standstill, the noise level of the hydraulics falls to zero. Due to the omitted tank and complex piping for a power distribution, resonance bodies for the structure-borne sound are omitted. With the new concept, the expenses for the noise insulation are considerably lower.

Easier hydraulic construction with quick commissioning

For manufacturers of hydraulic presses, the conversion to hydraulic axes brings about considerable savings in the design, assembly and commissioning. Tank, cooling and piping are completely or largely omitted as is the valve technology. The variance of different motion sequences is moved from the valve technology into the drive controller software. Here, Bosch Rexroth has, for example, integrated best-in-class controllers for different force/path and synchronization controls. Due to the corresponding commissioning software, the engineers don’t even need in-depth hydraulic knowledge for the initial commissioning. Software wizards propose suitable parameters. This considerably shortens the commissioning phases of a hydraulic press.

Condition monitoring increases the availability

The data that is gathered by the intelligent servo drives anyway and that can be amended by more sensors is particularly interesting for end users. It forms the basis for condition monitoring strategies increasing the availability. Based on the analysis of the data, the corresponding software identifies wear and errors before they will lead to standstills. So machine downtimes are replaced by scheduled maintenance measures.

Find out more about self-contained hydraulic actuators here.

cropped-cmafh-logo-with-tagline-caps.pngCMA/Flodyne/Hydradyne is an authorized Bosch Rexroth distributor in Illinois, Wisconsin, Iowa and Northern Indiana.

In addition to distribution, we design and fabricate complete engineered systems, including hydraulic power units, electrical control panels, pneumatic panels & aluminum framing. Our advanced components and system solutions are found in a wide variety of industrial applications such as wind energy, solar energy, process control and more.