Hydraulic Systems

Hydraulics Meets Internet of Things: Avoiding Machine Downtime the Intelligent Way

Guest Contributor: Luisa Franz, Bosch Rexroth

 

IoT-capable hydraulic power unit ensures efficient production

With the newly developed, intelligent CytroBox unit, Rexroth combines the benefits of hydraulics with low energy consumption and software-based functions. The integrated CytroConnect IoT service ensures higher availability and avoids unplanned downtimes. With this IoT service, operators can monitor operating statuses and plan maintenance in a cost-effective manner. As a result, fluid technology has taken a further step towards the factory of the future.

The digitalization of mechanical and plant engineering means more than decentralized intelligence, integrated sensors and connectivity. This applies to hydraulics too. With its power density and immunity to impacts and vibrations, hydraulics plays a central role as an important drive technology in Industry 4.0 too. The compact CytroBox unit is revolutionizing hydraulic pressure supply. CytroBox is a modular hydraulic power unit for the medium performance range from 7.5 kW to 30 kW. It comprises optimally tailored, impressively compact components. Compared to previous units, considerable amounts of space can be saved.

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75% less oil

One of CytroBox’s unique selling points is it compactness. This is possible because the hydraulic power unit can be integrated into a factory like a control cabinet, i.e. upright. The tank no longer supports all other components – Rexroth developed a special supporting structure for this purpose. In addition, a degassing flow-optimized tank is used. On the basis of extensive CFD simulations, the developers improved the tank geometry so skillfully that the new unit needs only a quarter of the oil required by classic designs: instead of 600 liters, 150 liters are now enough – with at least the same service life. The drive unit – a component which usually takes up a large amount of space in hydraulic power units – is equally compact. The asynchronous servo motor has been replaced by a synchronous servo motor. This is the most efficient motor design, producing the same torque even though it is 80 to 90% smaller. The manifold too was redesigned: thanks to 3D printed sand cores, the block including the internal flow geometry is now cast. As a result of this flow-optimized inner structure, less material and space are required. Thanks to all these measures, the CytroBox has a footprint of just 0.5 square meters instead of one and a half to two square meters. This represents a saving of up to 75%. On top of this, there are energy savings of up to 80% as well as a 10 dB(A) reduction in noise emissions. As a result, noise emissions are lower than 75 dB(A).

Connected for the factory of the future

In the CytroBox, machine manufacturers will find a ready-configured drive controller with numerous integrated functions. Various sensors provide information on the current filter, oil or drive status. The collected sensor data are bundled via IO-LinkMaster and pre-processed by the drive controller so that they can be integrated flexibly into modern machine designs. This means that the CytroBox is IoT-ready.

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CytroConnect Monitor

With the CytroConnect digital service, operators have all information regarding the CytroBox at their fingertips at all times – whether it be information regarding the standardized visualization of the component and operating status or chargeable IoT services such as forthcoming maintenance work and predictive maintenance analyses using Rexroth’s Online Diagnostics Network (ODiN).

The data collected are transferred to the browser-based CytroConnect Monitor web dashboard via Multi-Ethernet or 4G-LTE. As a result, operators can be kept up to date regarding the current operating status and key status indicators on any end device (tablet, smartphone, PC). This plug and play service is free of charge and can be used without additional installation work. CytroConnect is implemented in the CytroBox as standard.

Greater availability thanks to additional analysis functions

In addition to the CytroBox’s automatic status monitoring, maintenance personnel and maintenance managers can add extra solutions for various applications as add-ons. These pay-per-use payment models include additional IoT analysis tools and can be subscribed to on a monthly basis.

For optimizing maintenance processes, the CytroConnect Maintain module offers access to historical sensor data as well as messages if maintenance is required or in the event of critical operating statuses. Pre-defined and custom rules allow customers to improve their maintenance strategy on an ongoing basis. Customers benefit from scalable software solutions from the Bosch IoT portfolio such as the Nexeed Production Performance Manager and the integrated know-how of the Rexroth domain specialists. The Nexeed Production Performance Manager is a condition monitoring software solution for systematic production optimization.

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CytroConnect Maintain

With CytroConnect Maintain, data concerning the most important components for reliability and operating life (the hydraulic oil and the drive unit) are assessed. Comprehensive insights into the correlation between the speed of the servo motor and the flow allow the monitoring of system leakage, while correlations between motor data and the operating pressure allow conclusions regarding drive behavior. The leakage sensor, temperature and level sensor, particle sensor, water sensor and oxygen sensor are additional data sources which can be used to make a status diagnosis.

Planning predictive maintenance efficiently

A further add-on, CytroConnect Predict, uses the machine learning algorithms of the Rexroth Online Diagnostics Network (ODiN) for a predictive analysis of the system. With this IoT service, the power curves for a wide range of components are recorded for data analysis purposes. In the event of deviations, the system automatically calculates the expected remaining operating life of the relevant component and informs the operator immediately via a push message. As a result, predictive maintenance application cases can be taken into account predictively in the operator’s maintenance plans, thus ensuring maximum availability.

Conclusion

This new form of hydraulics is energy-efficient, quiet, space-saving and intelligent. With the integrated CytroConnect IoT service, the CytroBox offers anything from transparent, efficient machine monitoring to intelligent predictive maintenance measures. Thanks to the CytroBox, fluid technology is now one step closer to the factory of the future.

www.cytroconnect.com

www.boschrexroth.com/cytro

 

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.

TIME IS MONEY: ENGINEERING FOR LARGE POWER UNITS REDUCED TO FIVE DAYS

Time and cost savings through standardization and proven designs

Faster, simpler, more productive and cost-effective: Rexroth’s new modular system called ABMAXX speeds up the engineering and commissioning of large hydraulic power units in projects designed to modernize existing systems or construct new ones. The hydraulics specialists are able to create a quote complete with a hydraulic circuit diagram, a parts list, a 3D model and dimensions all within a maximum of five working days. As such, system manufacturers and end users can reduce engineering lead times alone by 80 %. The pre-configured ABMAXX modules are composed of highly available standard components. The modular approach reduces costs by up to 35 % and increases operational availability.

When constructing new or modernizing existing steelworks and rolling mills, large-scale presses and test systems or the central media supply of factories, hydraulics is and will continue to be the key drive technology both now and in the future on account of its high power density, robustness and durability. Thanks to the wide range of components available, there is plenty of scope for designing tailored solutions. In the past, system manufacturers and major end users defined their own standards which they implemented with their own resources in development. In light of ever increasing cost pressure and a global shortage of qualified specialists, these days they are increasingly scrutinizing that approach. Their main goal is to achieve pressure and quantity as cost-effectively as possible.

This is where Bosch Rexroth’s modular system ABMAXX comes in. The company is the first hydraulics manufacturer to come up with a modular solution with which system manufacturers and end users can significantly reduce the complexity of engineering large power units for 24/7 operations. On the one hand, it enables them to take advantage of all the economic benefits of cross-manufacturer standardization yet, on the other hand, the modular design provides ample opportunity for coming up with application-specific solutions.

Three pressure ratings and five modules

The concept initially covers tank sizes ranging from 2,000 to 12,500 l. With its three pressure ratings, namely 160, 210 and 315 bar, the concept satisfies the trend for higher operating pressures, thus ensuring it will be fit for the future. Achievable flows currently range from 345 l/min to 2,160 l/min. These basic conditions meet the typical requirements of numerous large plants.

In order to transform the benefits of standardization into shorter project lead times, Rexroth has defined five modules: tank, pump block, circulation unit, cooling and filter unit, and safety controls. Each module is based on proven constructions with a tried-and-tested design. As such, Rexroth is able to considerably reduce the risk of initial errors in the construction.

Simplify the design – Up to 80 % time savings in engineering: Offer in a maximum of five working days

The benefits of standardization and modularization are clear to see at the project planning phase. These days, depending on the level of complexity involved, planning customized individual power units in line with relevant company standards can take four to eight weeks. Rexroth is able to whittle this phase down to a maximum of five working days with its modular system ABMAXX. Rexroth is able to provide 3D models complete with dimensions and parts lists as well as the hydraulic circuit diagram and a quote all based on the customer’s specifications within just one week. This shortens the engineering effort by up to 80 %. This enables designers to save valuable time, which they can use on their projects, and enables system manufacturers to shorten the quote phase.

Streamline the installation – Up to 35 % lower costs through standardization

In comparison to using completely newly designed large power units each time, system manufacturers and end users achieve between up to 35 % direct cost savings on account of modularization and standardization. Internal costs are also reduced thanks to shorter project lead times and shorter time to market for system manufacturers. End users can also use individual ABMAXX modules such as the pump block in order to modernize their systems step by step and improve energy efficiency, for example. The wide range of Sytronix variable-speed pump drives is also able to unlock considerable potential here for reducing power consumption based on demand. Tried-and-tested safety controls help designers to comply with corresponding safety regulations and documentation requirements in line with standards. The choice of standard components also reduces delivery times and cuts costs.

Through its global production network, Rexroth also ensures high local added value and a quick response to customer requirements. Competence centers for power units construction in Europe, Asia and the Americas cover all major regions with short distances.

Maximize the productivity – Latest technology for maximum efficiency

At ABMAXX, Rexroth uses latest technology for all components and the hydraulic design. The components set standards in terms of dynamics and life time. Proven design principles increase productivity through high repeat accuracy and energy efficiency. The wide range of variable-speed pump drives in the Sytronix family opens up considerable potential for reducing energy consumption as required. This reduces life cycle costs sustainably.

With the three pressure stages up to 315 bar, the concept meets the current state of the art, but already reflects the trend towards higher working pressures.

Minimize the downtime – User and maintenance friendliness increases availability

The modules have been designed so as to ensure optimum component accessibility. What’s more, standardization reduces the required maintenance and servicing over the entire life cycle as the standard components used are available at short notice and will be part of the product range over the long term. The modules are composed of highly available Rexroth standard components. They are designed to deal with harsh environmental conditions including humidity, heat, dust, contamination and vibration.

The components are designed to work equally well with mineral oil as with water-based media such as (HFC) and synthetic water-free fluids (HFD). As such, Rexroth’s axial piston pumps achieve the same service life regardless of the media involved.

The pump block and the circulation unit are fundamentally equipped with stand-by units in order to guarantee maximum availability.  The pump block and the circulation unit are always equipped with stand-by units for uninterrupted 24/7 operation.

First power units already in use

Bosch Rexroth has already made several ABMAXX as complete power units and individual modules for modernization projects. System manufacturers for metallurgical plants and operators of steelworks and rolling mills are among the first users. However, potential applications exist across all sectors of industry as well as in large-scale projects.

 

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 SERCOSProfinet RTEthernet/IPEtherCAT, 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 informationwww.boschrexroth.com/iac

Moviehttps://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.

Hydraulics with IO-Link: Reduced effort, high value

Guest contributor: Theobald Herrmann, Bosch Rexroth

In almost all industries, machine users require increased flexibility for production means for small batches and continuous diagnostics of all actuators and sensors to increase availability. In addition to this, there is quickly increasing horizontal and vertical connection of machinery and systems for Industry 4.0 applications. The open standard IEC 61131-9, IO-Link, fulfills these requirements at low connection costs and energy consumption. Flexibility of hydraulics is increased by transmission of parameter changes in running operation. Provision of diagnostics information offers numerous opportunities to extend the concepts of predictive maintenance to increase availability of the systems. The manufacturer-independent IO-Link can be integrated easily and quickly in any industrial automation application.

Standardized wiring and electronic name plate support commissioning and increase availability

• Open standard for bi-directional point-to-point connections in parallel to field bus
• Easy connection with standard cables and M12 connectors
• No additional engineering tool necessary, possible configuration via control system.
• Data for predictive maintenance and quick device replacement
 Industry 4.0-compatible hydraulic components for vertical flow of information

Introduction: Limits of serial field bus communication

The introduction of field bus technology in the 1980s was the starting point for horizontal connection of decentralized actuators within machinery. Serial wiring lead to a considerable reduction in cabling and opened new possibilities for modularization in mechanical engineering. Field buses as well as most current real-time Ethernet protocols are manufacturer-specific, proprietary systems. The protocols have been developed by control system manufacturers and focus on communication between own electric control systems and selected peripherals. For actuators, sensors and other third-party equipment, either their manufacturers or system integrators are required to provide suitable interfaces in hardware and software for the respective field bus. This is very complex as device profiles and software have to be created in the respective PLC for every individual field bus and control system of each manufacturer.

Possibilities for hydraulic connection

Integration of hydraulics in modern automation systems can be realized in different ways. Numerous existing machine concepts apply on-board electronics for control of hydraulic valves. Exchange of digital information is restricted and only possible if the respective device is connected to a superior control system via individual wiring. This state-of-the-art in technology increasingly no longer meets the requirements of end users.

The alternative are valves with integrated field bus connection. These, however, require extensive wiring as well as integration into the control system and the respective field bus protocol by means of dedicated software. Both requires considerable effort that is too high particularly for price-sensitive applications.

Thanks to IO-Link, machine manufacturer and system integrators are enabled to integrate for example proportional hydraulic series valves and sensors into digital communication structures with very little engineering effort. With its simple communication structure, IO-Link has low hardware requirements. Additionally, the standardized M12 connection technology enables simple and cost-efficient connection of hydraulic valves in the field. This way, previously “deaf-mute” components with analog control are transformed in communicating and flexible actuators and sensors.

IO-Link: Manufacturer-independent and compatible with all field bus protocols

The manufacturer-independent IO-Link according to IEC 61131-9 standardizes connection technology for actuators, sensors and other equipment and provides a digital communication protocol for data exchange between control systems and devices regardless of the field bus. Field bus technology is not replaced but extended. Parallel communication enables machine manufacturers use of IO-Link with all protocols and integration of IO-Link-compatible devices into various concepts without additional effort.

IO-Link is currently already supported by around 130 device manufacturers and companies in the field of technology. Around 40 manufacturers offer IO-Link Masters and the standard is supported by nine manufacturers of control systems with central Masters and respective engineering tools. IO-Link devices are in the product range of almost sixty manufacturers of sensors, actuators and other peripherals. Rexroth, for example, now also offers hydraulic proportional valves and pressure sensors with respective technology. Function and performance of these proportional valves are identical to series valves. However, they also offer all options for bi-directional communication via IO-Link. This way, the hydraulics can be integrated seamlessly into connected structures. Parameters can be changed and operating states changed by the control system during running operation.

IO-Link system set-up

A full IO-Link system consists of one centralized or decentralized IO-Link Master, one or more IO-Link devices as well as unshielded 3 or 5-conductor standard cables with M12 connectors. Project planning and parameterization of the IO-Link Master can be realized in the control system hardware or an optional engineering tool. The point-to-point connections between IO devices and the automation system are established by the Master. It serves as the interface to the superior control system.

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IO-Link Masters are offered by around 50 manufacturers for connection of one IO device per port. The selection includes options for the IP20 control cabinet as well as decentralized modules with protection class IP65/67 for installation at machinery. Particularly in large-scale systems, cabling is considerably reduced.

For decentralized IO-Link Masters, the user organization of IO-Link has defined M12 plug-in connectors with three or five conductors. The 5-pole version “Class B” port is used for devices with increased current consumption like hydraulic valves. The 3-pole version “Class A” port provides an energy supply of up to 200 mA which is sufficient for most sensors. In contrast to analog controls, unshielded cables are sufficient for fault-free communication over a cable length of up to 20 meters. IO-Link standardizes connection technology for all actuators and sensors and eliminates numerous sources of errors during the installation of systems. Otherwise complicated and expensive cable dimensioning with individual wiring and shielding is no longer required. In addition, the logistic effort is reduced thanks to application of uniform M12 cables for sensors and actuators.

Rapid commissioning per software

Every IO-Link device features an electronic device description, referred to as IO Device Description (IODD). It provides standardized important information:

• Device data
• Text description
• Identification, process and diagnosis data
• Communication properties
• Device parameters with value range and default value.
• Image of the device
• Logo of the manufacturer

The IODD set-up is identical for all devices of all manufacturers. The IODD enables automatic recognition of the device by the IO-Link Master for immediate parameterization. Also automatically, device descriptions are included in the system documentation.

For project integration of the IO-Link Master in overall automation, commissioning personnel use the engineering tools of the respective PLC manufacturer. The IO-Link Master is selected from the device portfolio and added to overall automation. Depending on the control system manufacturer, all blocks for communication are available in a library for free.

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Via IO-Link to Industry 4.0

IO-Link enables access to device data either directly from the control system or remotely via networks from any location. Particularly important for future-oriented concepts: Already today, IO-Link offers type and instance data of Industry 4.0 devices according to the definition of the German “Plattform Industrie 4.0” initiative.

This way, also hydraulic actuators meet all conditions for future requirements of Industry 4.0 applications. Additionally, this approach is well-suited for subsequent connection of existing machinery and systems with low effort. Users replace installed proportional valves and sensors by interchangeable options with IO-Link connection for direct communication with actuators and sensors.

Diagnosis functions for increased availability

The diagnosis functions of IO-Link devices enable new maintenance concepts and considerably reduce repair times. Now possible call-up of device information in parallel to the process forms the basis for condition-oriented and predictive maintenance concepts. In this respect, proportional valves report whether they are functional as well as errors like under or overvoltage. In addition, the valve and sensor status is displayed for transparent error analysis. An integrated operating hour indicator enables calculation of the residual life-cycle for maintenance and decision-making on further use of the valve.

In case of faults, IO-Link accelerates diagnosis thanks to remote access for maintenance specialists to identify the type and location of any errors. Precise localization without personal presence at the system alone considerably reduces reaction times. If necessary, the maintenance technician opens the IODD file of the respective device in the control system. Other than before, components do not need to be disassembled to decipher hardly readable labels and manufacturers and types no longer need to be looked for in system documentations. Thanks to the electronic name plate, all this information can now be accessed with just one mouse click to initiate the respective order without delay.

IO-Link follows the plug & play principle. Replaced devices are recognized by the IO-Link Master according to their IODD file and the respective parameters are automatically transferred without any actions in the software. This way, even less experienced technicians are enabled to replace components without problems to considerably reduce system downtimes.

Summary

The open IO-Link standard establishes continuous communication with sensors and actuators irrespective of the used field bus. Now, even hydraulic proportional valves can be intelligently, easily and cost-effectively integrated in bi-directional digital communication. This simplifies commissioning in hardware and software and enables flexible adjustment of hydraulic valves for varying production processes. Increased requirements for flexible machinery and systems are now complied with. Extended diagnosis information enables condition-oriented and predictive maintenance concepts and standstill and maintenance times are reduced. This increases the availability of machinery. In addition, IO-Link enables future-proof integration of hydraulic valves into connected structures as Industry 4.0 components with all their related features.

Why hydraulics and IO-Link? Click here

Learn more about Rexroth and IO-Link

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.

 

Pump control – simple or intelligent?

Guest contributor: Martin Endres, Bosch Rexroth

Control pumps have a fixed place in hydraulics. Your advantage: They only provide as much flow and/or power as is required for the specified movement task. But which pump control  is suitable for which application? Mechanical-hydraulic or electro-hydraulic pump control? What are the differences?

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The advantages and disadvantages of the two pump control types can well be explained using the flow control of a deep drawing press as example. The hydraulic drive of the cylinder is based on a variable displacement pump working in an open circuit. The displacement is 250 cm3, the nominal pressure 350 bar. The mechanical input signal is hydraulically amplified. In this connection, the pump has three typical control tasks: Flow control (N and/or S function), power control (LR function) and pressure control (G function).

01) Mechanical-hydraulic pump control: simple, however limited

The mechanical input signal from the hand lever is hydraulically amplified. In this case, the flow is controlled by means of load-sensing. The pump swivel angle is adjusted independently of the load occurring at the actuator by means of a load sensing valve which is set to a Δp of 20 bar. So the velocity at the actuator remains constant.

The disadvantage: The throttling of the flow at the pump output goes along with a power loss which is completely converted into heat and increases the cooling demand. One advantage, however, is the easy set-up which does not even require a pilot oil pump as the adjustment energy is taken from the high pressure. Due to the continuous Δp of 20 bar, flow control is also possible at low pressures.

Power controllers increase the complexity

There is a need for an additional pilot oil pump if the deep drawing press – for example for safety-related reasons – requires a flow of zero in case of a low counter pressure (maximum of 4 bar). More components are necessary for realizing the power controller.

02) Electro-hydraulic pump control

Data recording and comparison by control electronics Compared to that, an electro-hydraulic system with only one fast high-response valve at the pump and amending control electronics is the more elegant solution. The regulated variables (path, force and velocity) correspond to the analog hydraulic variables flow and pressure.

The principle: A swivel angle sensor on the actuating piston and a separate and/or attached pressure transducer record the actual flow and pressure values. After comparison to the specified command values, the control performs all flow, pressure and torque limitation tasks and forwards a command value to the valve. Figure 2 shows different pump control systems which are autarkic subsystems and connected to the machine control via corresponding
interfaces.

Today, there is a whole range of motion controls and NC controls for hydraulic actuators available. It comprises single-axis controllers without control
cabinets where the electronic controls are integrated completely in the valve, up to multiple axis controllers with control cabinets for more complex tasks. In addition, intelligent pump controllers are improving the system performance. These control systems communicate via established field buses or Ethernet protocols with superior systems, and with these open standards it is possible to completely integrate them into Industry 4.0 architectures – this way, intelligent, networkable hydraulics are completely Industry 4.0 ready.

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03) Decision-making aid: Selection of the pump control type

It first of all depends on the physical variable to be controlled whether the mechanical-hydraulic or the electro-hydraulic variant is finally the better choice for the relevant application. Flow and pressure can be controlled with both types. For limiting the torque, however, the mechanical-hydraulic method needs an additional power controller changing the flow with constant pressure and simultaneously increasing the complexity of the hydraulics. Here you can find the selction guide

Master-slave pump combinations

A master-slave pump combination interesting for many applications is only feasible with an electrohydraulic control; however, it allows for combined pump systems with special properties. If, for example, by an early swiveling out of the pump, the master pump provides a certain flow from a certain point in time, it can be positioned at the maximum swivel angle already upon start-up of the motor and deliver into the system, which again increases the velocity and precision of the application.

How dynamic and accurate should the pump be?

The required dynamics and precision are more decision-making criteria. If, for example, particularly high dynamics with up to 80 ms are required, a primarily controlled pump would be suitable. With regard to precision, electro-hydraulic control systems with a repetition accuracy of <= 0.2 % for the pressure and a linearity deviation for the swivel angle of <= 1 % show convincing results. Compared to that, mechanical-hydraulic controls achieve about +/- 1.5% repetition accuracy for the pressure and a linearity tolerance of 2.5 to 7 % of Vgmax. All values are valid for a constant operating temperature of 50°.

Conclusion

The strength of the mechanical-hydraulic pump control is its simplicity. It is, however, only convincing in correspondingly clear applications. With increasing requirements with regard to function, precision and energy efficiency, there is no alternative to electro-hydraulic control systems which allow for pressure and flow control with high control quality according to the demand. As digital control electronics with integrated Multi-Ethernet interface can moreover be integrated into most different structures, it moreover also masters the prerequisites for the increasingly demanded networking in the sense of Industry 4.0.PC 4 Tabellen_EN-1-927x1200.png

Info graphics: Decision-making aid for the selection of the pump control type.

Learn  more about an electro-hydraulic pump control: www.boschrexroth.com/hpc

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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.

 

New Design for Hydraulic Power Units

Guest contributor:  Andreas Günder, Bosch Rexoth

Optimum power, less installation space: Thanks to new intellectual and design approaches, compact hydraulic power units increase the economic efficiency of machine tools.

Powerful force in a very confined space

In the production world, hydraulics are firmly established. Machine tool manufacturers appreciate hydraulics for their high power density, toughness and modular design. In the lower performance range up to 4 kW, however, there are also some challenges. Since the installation space is often limited, designers and technical purchasers are constantly looking for increasingly compact solutions.

Installation space is valuable

The demand for compact hydraulic drives is not only due to the structurally limited flexibility regarding extensions, modernization measures and refittings but also due to the requirements regarding acquisition costs and assembly times or structural extensions of the working space with given machine dimensions. In addition to the level of integration of the functions, energy efficiency often plays an important role as well. Last but not least, many manufacturers are following the miniaturization trend. If workpieces become increasingly smaller, the moved mass of the machine tool has to be decreased accordingly.

“Installation space eaters” hydraulic power units

To reduce the installation space, solution manufacturers can start mainly with the following components: hydraulic power unit and control cabinet. When considering this split, it becomes evident that compact power units which are also easy to integrate require completely new design approaches to eliminate all features which waste unnecessary space in the performance spectrum up to 4 kW and to ensure that the units are still compatible with many different machine designs.

Highly integrated design approaches

The features of such innovative design concepts according to the EU Eco-Design Directive 2009/125/EC for example include a tank which is optimized for efficient degassing and reduces the oil volume by up to 80 percent. A much more decisive factor for gaining space is, however, that all functions can actually be integrated in one small power unit – from an economic variable-speed drive for demand-based power output to sensor technology with filling level, temperature, pressure and filter contamination sensors to a completely wired frequency converter.

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Compact and ready for Industry 4.0

For the future viability of this approach with regard to Industry 4.0, a data interface is essential as well. Only with permanent condition monitoring can the operating conditions be optimized comfortably and relevant faults be detected early on. With this equipment, the user only has to connect the electric power, the data interface and the hydraulic supply during installation and the hydraulic power unit is ready for operation

New cooling with heatpipe

So-called heatpipes are considered to be a space-saving innovation regarding the cooling of hydraulic power units. Their high-performance passive thermal conduction allows for a further reduction of the frame size. The heatpipes absorb the thermal energy of frequency converter, motor and hydraulic oil and efficiently transfer it to a central heat sink such as e. g. cooling water…
This ensures an intelligently optimized thermal management within the hydraulic power unit and optimally utilizes the cooling power of the cooling water. There is no need for a separate hydraulic circuit for oil cooling. This reduces installation space, noise emissions, energy consumption and possibilities for leakage.

Heatpipe – Functional principle

Basically, a heatpipe consists of air-tightly sealed copper pipes with underpressure. Inside, there is a medium which transfers thermal energy. In the temperature range of hydraulic power units, the medium may be e.g. distilled water. The boiling temperature of the water is significantly reduced by the low pressure within the heatpipe, which means that a boiling or condensation process can already take place at low temperatures.

Functionality: If you dip the heatpipe for example in hot hydraulic oil, the thermal energy at the lower immersed part of the heatpipe is transferred to the water. The water exceeds the boiling point, evaporates and absorbs a large amount of thermal energy with low temperature difference (latent heat). The water steam rises to the upper part of the heat pipe which is cooled by e. g. a cooling element. Here, the water steam condensates and gives off the thermal energy to the cooling water. Thanks to the latent heatabsorption and dissipation, the thermal conductivity of heatpipes can be up to 1000 times higher than the thermal conductivity of copper pipes. Due to the high elasticity of the copper pipes, the heat pipe can be easily shaped. In this way, ideal heat paths can be formed inside the hydraulic power unit and the installation space can be considerably optimized. Similar application ranges with equal optimization potential can be found in computer technology. Here, the thermal energy in laptops caused by heat sources such as the CPU are transferred to the central cooling elements using heatpipes.

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Plug & Play: no control cabinet

The frequency converter has a high potential for gaining installation space as well. If it has already been equipped with Multi-Ethernet interface for Sercos, Profinet and other standards by the manufacturer, machine and plant manufacturers are able to reduce the control cabinet requirement for the hydraulic unit by up to 100 percent. As a precondition, however, the sensor technology and the motor in the power unit have to be wired to the frequency converter in such a way that the frequency converter can control the hydraulic pressure autonomously. This means that the control cabinet can not only be designed with smaller dimensions. Sometimes it can even be completely omitted together with the corresponding installation effort and related sources of error.

Conclusion

Fully integrated small power units based on a completely innovative design approach for the performance range up to 4 kW provide machine and plant manufacturers with the advantages of hydraulic drives with very little space requirements. As an alternative to purely electrical solutions, the required energy can be converted into a linear movement in a precise and costeffective manner directly at the working area using a simple hydraulic cylinder. If sensor technology, frequency converter and data interface are integrated as well, users not only benefit from comprehensive condition monitoring but also from a significantly reduced control cabinet footprint or even from a design without control cabinet.
More information fully integrated power units: www.boschrexroth.com/cytropac

Operating principle: https://www.youtube.com/watch?v=sSPemS94G2I

cropped-cmafh-logo-with-tagline-caps.png

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.