博世力士乐对于未来工业液压技术的展望

作者：Dr. Steffen Haack – Bosch Rexroth

尽管近几十年来共同努力改善其形象，但液压仍被许多用户视为恐龙。因此，它不是年轻新兵中的首选。毕业生往往会被他们的数字商业理念吸引到初创环境，并且在比喻意义上，他们会被欲望的对象 – 一只金色的独角兽所吸引。

在国际上，独角兽象征着创新和创造力 – 以令人惊叹的因素赚取大量金钱。无论外界如何看待液压系统，液压系统的全球经济重要性无可争议，销售额达数百亿美元。矛盾的是，流体动力技术的经济重要性仍然与用户，公众和科学界的方式形成鲜明对比。

液压技术如何将其形象转变为新的世界？答案很简单;恐龙必须通过整合新技术，特别是电子控制和机电动力传输来适应。通过这样做，液压系统将为用户变形为一种新颖的高科技体验。

具体而言，这意味着保留液压系统的优势，并将其与技术“IT消费者世界”中的机遇和优势相结合。用户将把“隐藏式”液压系统视为一个紧凑的，完整的功能模块 – 简单，直观，连接，并迅速安装。无论这种未来愿景如何，液压系统必须保持其对机电驱动器的立场。技术转变在许多领域已经非常先进。

在这里，我们需要保卫我们的领土。与液压系统不同，更容易连接和更简单的IT连接长期以来一直是机电解决方案DNA的组成部分。但是，我们如何才能确保未来十年工业液压系统未来的可行性，以及我们必须做些什么才能使其更具竞争力？瞄准金色的独角兽！

随着工业4.0将这些印象转化为更多的金色独角兽，对水力学作为恐龙技术的错误认识应该会消失。

工业环境

工业液压系统不能免受不断变化的市场环境中发生的变化的影响。然而，时尚新技术主题并不是影响未来几年现场的唯一因素。一些熟悉的趋势将继续对未来的增长至关重要。

能源效率。在考虑主要趋势时，环境和资源稀缺总是起着重要作用。它们需要更节能的驱动系统。例如，在欧洲，能源相关法规适用于组件级别（例如，电动机的IE3标准）。除此之外，例如，许多标准和代码适用于批量生产机器的机器效率标签。

能源效率的重要性正在超越工业化国家。能源在世界许多地区仍然太便宜，而新的，创新的方法只会从供应和价格压力中产生。鉴于其特定的优势（高功率密度，大的力），液压系统注定要用于强大的机器。这尤其适用于节能驱动解决方案特别有益的压力供应站。

外表。持续存在的能效问题引起了速度控制驱动系统使用的稳步上升。高效伺服电机越来越多地取代标准异步电机。技术上可扩展的解决方案已在市场上出售。

(Sytronix变速泵驱动液压趋势，将变速电驱动器与变速电动机和液压泵组合成一体化驱动单元。)

环境挑战

工业液压系统在各种环境条件下使用。管理机构对可持续生产，回收和液压产品的处置实施了具体的区域法规。液压油作为必不可少的压力传递介质和润滑剂，在环境影响和系统功能安全方面起着特殊的作用。尽管可快速生物降解的油已有60多年的历史，但最常使用的是矿物油。然而，持续改进不仅与液压油有关：在与液压油，新材料和几何形状的兼容性方面，还必须进一步开发密封件。降低油量是降低环境风险的另一种方法。这些可以通过智能油箱设计实现，主动脱气或更小，分散的驱动轴。

减少使用的油量和改善环境兼容性仍然是持续存在的问题。预计未来环境法规将变得更加严格。因此，石油，密封和液压制造商可能会形成联盟，以进一步改善环境兼容性。

安全相关要求。在欧洲，机械指令要求机器的设计和制造方式应避免对人类构成潜在风险。已经建立了一系列欧洲液压系统安全标准，并通过相关标准（如压力设备指令）对这些标准进行了补充。

安全问题也将成为未来的优先事项。其他地区，特别是新兴国家也预计会有更严格的法规（例如，批准检查，设计指南）。

数字信息采购

工业用户越来越期望他们习惯于从消费者世界配置器，可用性，移动设备，应用程序，云解决方案等中获得相同水平的便利性。根据需求，产品本身将具有来自简单数字接口的任何东西（例如， IO-Link）具有实时功能的多以太网连接。

从2023年开始，新的5G通信标准将导致更多的私有工业网络在工业环境中使用。利用这些基于边缘云的网络，可以实现小于1毫秒的传感器 – 执行器循环时间。结果，可以满足塑料加工机器中的典型控制器要求。集成到产品中的传感器和5G通信将为状态监控提供信息，甚至可用于预防性维护的数据使用。因此，预计会有大量基于数据的商业模式。

电液部件将受益于自动化和IT世界的技术影响。与电气自动化一样，液压元件供应商正准备与人工智能和基于云的解决方案的其他相关供应商合作。将需要更多的跨技术合作伙伴关系，特别是对于尖端的IT主题。

个别制造商将不再拥有所有必要的技能。目前关于伙伴关系的观念也将发生变化。在某些情况下，未来的合作伙伴将是以前的合作伙伴，而一些以前的合作伙伴可能会成为竞争对手，新的合作伙伴也会出现。如果在数字化，连接和通信方面发生必要的结构变化并且员工具备必要的资质，传统的机械工程和工厂建设只会受益于IT世界中更短的创新周期。

培训和经验。一段时间以来，显而易见的是，拥有专业液压知识的潜在员工数量正在下降。这适用于商业和工程部门。就专业基础和进一步培训而言，例如在德国，没有公认的资格。目前，液压专家主要从相关专业招聘，如农业或建筑机械装配工，工业机械或机电技师。

事实上，没有特定的培训可以作为流体机电一体化专家的资格。大学不提供专门的液压课程，液压技术几乎不是工程课程的基本模块。大学的情况令人不满意。当液压系统作为主题提供时，课程几乎完全受限于标准液压系统而非电液系统。我们在国外看到类似的情况。

实现工业独角兽需要现代化，最新的教学，技术转让以及在学术和商业领域创建新的“流体/机电一体化专家”资格。这是教育政策制定者，行业和国家/国际流体技术协会面临的关键联合任务之一。

未来，将需要两个不同的液压领域的职业概况。一个是具有机械工程技能的组件导向专家，他们开发和优化产品。另一个是面向系统的流体机电一体化专家，他具有控制技术知识，并精通液压和机电驱动的工具箱。

尽管付出了努力，但目前的教育情况不太可能在不久的将来发生很大变化。在未来的岁月中，改善教育将导致深入的知识将是至关重要的。这是因为如果控制技术，数字化，软件或运动学方面缺乏知识，那么无论技术有多好，电液系统解决方案都不会成功。

机器制造商已经将工程外包给供应商，并且越来越多地采购完整的子系统作为“功能模块”。大型终端用户越来越多地寻求专业公司进行维护工作。因此，维护液压系统应尽可能方便用户，液压系统应继续为年轻人提供有吸引力的面向未来的职业。

未来生存能力

对于所有应用，肯定没有标准的首选技术。无论是液压还是机电，每种类型的驱动器都有其自身的优点和缺点，只能根据它们对特定应用的适用性进行评估。为了对未来的可行性（超过10年的观察期）做出可靠的陈述，进行了一项调查，以确定是否可以替代10个主要工业液压领域中最重要的应用。

(工业液压的重要行业和应用概述。)

针对上述主要应用考虑了以下驱动器类型：

线性运动：> 80％的应用

液压系统：通过阀门或泵控制和紧凑型轴驱动气缸

机电：滚珠或滚柱螺杆组件

旋转运动：占所有应用的20％

液压系统：泵控制或二级控制

机电：直接驱动或减速电机。

(液压和机电驱动技术中的驱动类型。)

对未来最合适的驱动器类型的总体评估是基于对以下四个主要类别的调查，每个应用总共有13个标准：

功能：动态，稳健性，静态功率限制，准确性，安全性

集成：安装空间，灵活性，用户友好性

成本效益：成本，效率，使用寿命

生态学：生态友好，维护

总而言之，很明显，线性运动的机电系统最大可达500 kN或更高。对于额定值小于100 kN的系统，机电系统在许多应用中具有取代液压系统的巨大潜力。虽然通过进一步开发材料，涂层和几何形状可以实现功率和速度的轻微改进，但似乎不太可能出现革命性的跳跃。然后，通过机械传动的功率和扭矩的任何进一步增加将受到要加速的质量的限制。

(线性运动技术的这种比较表明，液压在速度和力量方面继续超过机电致动器。)

液压驱动装置已经传递的力比过去大100倍。就机电系统的物理性能限制而言，与液压系统不同，没有明显的中断。因此，预计在这两个领域都会有进化的进一步发展。金属切割机和转子驱动器中的液压系统可能面临更加激烈的竞争。然而，通过阀门控制系统以及更加用户友好的产品和系统，也将有机会实现节能。就线性应用而言，液压系统将通过紧凑型轴的进一步创新开发来保持甚至改善其位置。

一旦这样的开发是自动电液轴，其由电动泵单元，歧管和汽缸组成。这些轴几乎不需要维护，其调试与机电驱动相同。与液压相关的细节已经包含在软件库中。因此，即使是复杂的行程轮廓 – 例如用于成形，连接，注塑和其他大力应用的行程轮廓 – 也可以非常容易地进行参数化。作为规范过程的一部分，机器制造商和系统集成商也可以达到SIL 3的安全等级。

(这种自动伺服液压执行器是一体化单元，可以使用与机电执行器相同的技术进行调试。)

发展趋势

各种市场，行业和应用领域对工业液压系统提出了截然不同的要求。近几十年来出现的发展领域主要集中在以下方面：

能效（减少流动力，减少压力损失，提高效率）

降噪

减少油箱容量

压力水平更高，安装空间更小

改善材料和油性能

更高的可用性和预测性维护

用户友好性（车载电子设备，调试软件）

安全

虽然这些问题在未来仍将发挥作用，但它们本身已不再足够。3D金属印刷等工业趋势为液压技术提供了新的技术机会，例如优化的核心设计（砂印工艺），以改善流动性或伺服阀的生产。

(这个伺服阀歧管作为3D打印如何使组件更紧凑，更轻，甚至更高效的一个例子。)

在敏感环境中的应用

一部分工业液压系统的特点是特殊的环境条件，通常是连续工艺。它包括海洋和近海工业，水利工程钢结构，冶金，铸造机械，采矿等，其中系统安装在室外或类似环境中。对于涉及连续过程的生产系统，重点是OEE（整体设备效率），通过优化流程，提高质量和实施预测性维护来实现生产力的提高。基于机器学习的高性能诊断系统 – 例如力士乐的在线诊断网络（ODiN） – 已经可以可靠地预测组件何时出现故障，正在以液压技术开发。

(基于机器学习的当前诊断系统 – 例如力士乐的在线诊断网络（ODiN） – 可以可靠地预测组件何时发生故障，正在以液压技术开发。)

在许多情况下，需要符合环保等级（例如防爆），冗余压力供应站以及可生物降解流体的使用。鉴于此处描述的环境，未来可能会实施进一步的环境法规。避免流体溢出风险的有效方法是减少系统中使用的油量。进步的基础是罐体设计，允许自然被动脱气。使用包括传感器的主动脱气模块来监测流体中释放的空气的比例可以导致油量的进一步减少。与传统设计相比，油量可减少多达70％。其他积极影响包括安装空间减小50％并显着降低油耗。

除了进一步开发技术和流体以帮助改善环境兼容性之外，这些行业还将经历数字化推动的转型过程，例如智能采矿，冶金4.0或自动船舶。

生产应用

另一个细分市场受到未来工厂的发展和趋势的影响。这涉及例如安装在现代工厂中的压力机，塑料加工机器，组装系统，机床，测试机器和类似机器。在确定对工业液压系统的要求之前，必须先描述未来的工厂。主要目标是通过透明度提高生产力和效率。

未来的工厂将非常敏捷。高灵活性和适应性是关键目标，而透明度将有助于避免意外，昂贵的停机时间。墙壁，地板和天花板将保持原位 – 其他一切都将是移动的。装配线将采用模块化设计，机器将进行重组，以便为新用途创建新的生产线。它们将通过5G相互无线通信，并通过地板上的感应充电系统供电。

(高灵活性和适应性是未来工厂的关键目标，透明度有助于避免意外停机。墙壁，地板和天花板将保持原位 – 其他一切都将是移动的。)

在未来的工厂中，一切都将连接起来 – 从现场级到基于云的IT系统。自动化和驱动解决方案只能通过开放标准通信适应这种环境。它们易于配置，功能和类存储在设备数据中，并由固件控制或管理。工业液压必须采用已经在使用的多以太网和IO-Link等开放标准来适应这个世界。通过实时扩展，所有组件，模块和机器将共享信息。

然后，这些数据需要在未来的所有产品中实施，因为未来工厂中的价值流映射将被数字化。数字商业模式将继续基于构成新的和现有基础设施的所有执行器，模块，传感器和机器的准备运行数据。

(带IO-Link /蓝牙的压力阀（左）和带有多以太网接口的高响应阀，用于位置，压力和力控制以及闭环控制（右）。)

其中一个是来自博世力士乐的CytroBox，这是我们最新一代的液压动力装置。CytroBox是一个分散的单元，既可移动又灵活。它具有即插即用的概念和分散的智能，为机器制造商提供了具有众多内置功能的现成驱动控制器。包括关键安全功能和驱动控制，因此可以轻松集成和配置以适应特定应用。集成和有线传感器提供有关过滤器，流体和驱动条件的信息。收集的传感器数据通过IO-Link捆绑在一起，并由驱动控制器预处理，与现代机器设计网络连接。

类似的机器及其模块将是无线的，将通过开放接口交换信息和指令，并持续监控自己。凭借其多以太网接口和开放式核心工程，CytroBox提供了这种未来的可行性。与现代机电驱动器一样，该装置使用博世力士乐的CytroConnect进行IoT准备。所有关于设备的信息 – 从组件和运行状态或定期维护工作到力士乐在线诊断网络（ODiN）的预测性维护分析 – 都可以方便地获得。根据要求，维护功能，故障检测和预测性维护的其他附加软件包可作为附加服务提供。

(CytroBox是一体化液压动力单元，包含变速泵驱动器，尺寸减小的油箱，以及用于监控，控制，诊断和通信的先进电子设备。)

“把它包起来”

传统的液压系统将在未来10年内发生重大变化。智能，传感器，电子和软件将越来越多地融入钢铁和铸铁中。这将受到IT和自动化趋势的强烈影响。用户将体验工业液压作为现成的功能模块，具有与IT消费者世界相同的用户友好性。虽然它被许多人认为是恐龙，但工业液压系统将逐渐演变成一种有吸引力的独角兽 – 明天的工业液压系统。电气自动化和IT技术的新发展将使工业液压系统更容易集成，并使其更具竞争力。

提供工业水力发展潜力的领域包括紧凑的轴，能源效率和用户友好性。基于IT的新自动化世界的发展将补充以前液压领域的关键领域。数字化（软件，连接，专用网络，应用程序等）以及数据使用（传感器，Web服务器，数据分析，物联网服务，云解决方案等）将不可避免地征服工业界。

Hydraulics of the Future

Image problems notwithstanding, hydraulics is well-positioned to make the transition from dinosaur to golden unicorn.

Dr. Steffen Haack – Bosch Rexroth

In spite of concerted efforts to improve its image in recent decades, hydraulics is still seen as a dinosaur by many users. As a result, it is not the first choice among young recruits. Graduates tend to be drawn to start-up environments with their digital business ideas and, in the figurative sense, to the object of desire—a golden unicorn.

Internationally, the unicorn symbolizes innovation and creativity—ideas with a wow factor that make a lot of money. Regardless of how the outside world perceives hydraulics, the global economic importance of hydraulics is undisputed, with sales amounting to many tens of billions of dollars. Paradoxically, the economic importance of fluid power technology still contrasts sharply with the way it is perceived by users, the public, and the scientific community.

How can hydraulics technology transition its image to the new world? The answer is simple; the dinosaur must adapt by integrating new technologies, especially electronic control and electromechanical power transmission. By doing so, hydraulics will metamorphose into a novel, high-tech experience for users.

In specific terms, this means retaining hydraulics’ strengths and combining them with the opportunities and benefits found in the technical “IT consumer world.” Users will then perceive “hidden” hydraulics as a compact, finished functional module—simple, intuitive, connected, and quickly installed. Regardless of this vision of the future, hydraulics must maintain its position against electromechanical drives. The technological shift is already highly advanced in many sectors.

Here, we need to defend our territory. Unlike hydraulics, easier connectivity and simpler IT connections have long been integral to the DNA of electromechanical solutions. But how can we ensure the future viability of industrial hydraulics over the next decade, and what must we do to make it more competitive? Aim for the golden unicorn!

The mistaken perception of hydraulics as dinosaur technology should disappear as Industry 4.0 transforms these impressions into more of a golden unicorn.

The Industrial Environment

Industrial hydraulics is not immune to the developments taking place in a constantly changing market environment. However, hip new technology topics are not the sole factors shaping the scene in the years ahead. Several familiar trends will continue to be essential to future growth.

Energy efficiency. When considering major trends, invariably the environment and the scarcity of resources play an important role. They require more energy-efficient drive systems. In Europe for example, energy-related regulations apply on a component level (e.g., the IE3 standard for electric motors). On top of this, many standards and codes are in place for machines—efficiency labels for mass-produced machines, for example.

The importance of energy efficiency is growing beyond just industrialized nations. Energy is still far too cheap in many regions of the world, and new, innovative, approaches will only emerge from supply and price pressures. Given its specific advantages (high power density, large forces), hydraulics is predestined for powerful machines. This applies especially to pressure supply stations where energy-saving drive solutions are particularly beneficial.

Outlook. The ever-present issue of energy efficiency has sparked a steady rise in the use of speed-controlled drive systems. Highly efficient servo motors are increasingly replacing standard asynchronous motors. Technically scalable solutions are already available on the market.

Sytronix variable-speed pump drive of a trend in hydraulics that combines a variable-speed electrical drive with a variable-speed electric motor and hydraulic pump into an integrated drive unit.

Environmental Challenges

Industrial hydraulic systems are used under a wide variety of environmental conditions. Governing bodies impose specific regional regulations on sustainable production, recycling, and the disposal of hydraulic products. As an indispensable pressure transmission medium and lubricant, hydraulic fluid plays a special role in terms of environmental impact and the functional safety of systems. Although rapidly biodegradable oils have been available for more than 60 years, mineral-based oils are still used most frequently. However, continuous improvement is not only pertinent to hydraulic fluids: Seals must also be further developed as regards their compatibility with hydraulic fluids, new materials, and geometric forms. Lower oil volumes are another way of reducing the environmental risk. These can be achieved through an intelligent tank design with active degassing or smaller, decentralized drive axes.

Outlook. Reducing the oil volumes used and improving environmental compatibility remain ongoing issues. Environmental regulations are expected to become more stringent in the future. As a result, oil, seal, and hydraulics manufacturers will probably form alliances in order to further improve environmental compatibility.

Safety-related requirements. In Europe, the Machinery Directive requires machines to be designed and built in such a way that potential risks to human beings are avoided. A range of European standards for the safety of hydraulic systems have been established, and these are complemented by related standards, such as the Pressure Equipment Directive.

Outlook. Safety issues will remain a priority in the future, too. Stricter regulations (e.g., approval checks, design guidelines) are also to be expected in other regions, especially emerging nations.

Digital Information Procurement

Industrial users are increasingly expecting the same level of convenience they are accustomed to from the consumer world—configurators, usability, mobile devices, apps, cloud solutions, etc. Depending on the requirements, products themselves will have anything from simple digital interfaces (e.g., IO-Link) to real-time-capable multi-Ethernet connections.

A new 5G communications standard will result in more private industrial networks being used in an industrial setting from 2023. With these edge cloud-based networks, sensor-actuator cycle times of less than 1 msec can be achieved. As a result, typical controller requirements in plastics processing machines can be met. Sensors and 5G communication integrated into a product will provide information for status monitoring and even data use for preventive maintenance. Consequently, a large number of data-based business models are to be expected.

Outlook. Electrohydraulic components will benefit from the technological influences of the automation and IT world. As is the case in electrical automation, hydraulic component providers are preparing to work with other relevant providers on Artificial Intelligence and cloud-based solutions. More cross-technology partnerships will be needed, especially for cutting-edge IT topics.

Individual manufacturers will no longer have all the necessary skills under one roof. Current mindsets about partnerships will also change. In certain cases, future partners will be the previous ones while some previous partners may become competitors, and new partners will come along, too. Conventional mechanical engineering and plant construction will only benefit from the much shorter innovation cycles in the IT world if the necessary structural change as regards digitalization, connectivity, and communication takes place and employees are equipped with the necessary qualifications.

Training and experience. It has been apparent for some time now that the number of potential employees with specialist hydraulic knowledge is declining. This applies to both the commercial and the engineering sector. As far as professional basic and further training are concerned, in Germany, for example, there are no recognized qualifications. At the moment, hydraulics specialists are mainly recruited from related professions, such as agricultural or construction machine fitters, industrial mechanics, or mechatronic technicians.

In fact, no specific training leads to a qualification as a fluid mechatronics specialist. Universities do not offer dedicated hydraulics courses, and hydraulics is barely a basic module in engineering courses. The situation at universities is unsatisfactory. When hydraulics is offered as a subject, the curriculum is restricted almost exclusively to standard hydraulics rather than electrohydraulics. We see a similar scenario abroad.

Reaching the Golden Unicorn requires modern, up-to-date teaching, the transfer of technologies and the creation of a new “fluid mechatronics specialist” qualification in both academic and commercial fields. This is one of the key joint tasks facing education policymakers, industry, and the national/international fluid technology associations.

In the future, two different career profiles in the field of hydraulics will be needed. One will be a component-oriented specialist with mechanical engineering skills who develops and optimizes products. The other will be a systems-oriented fluid mechatronics specialist who has a knowledge of control technology and is well versed in the toolboxes for hydraulic and electro-mechanical drives.

Outlook. Despite the effort invested, it is unlikely that the current educational situation will change much in the near future. In the years ahead, improved education leading to in-depth knowledge will be essential. This is because if knowledge is lacking in control technology, digitalization, software, or kinematics, electrohydraulic system solutions will not succeed, no matter how good the technology is.

Machine manufacturers already are outsourcing engineering work to suppliers and are increasingly procuring complete subsystems as “functional modules.” Large end-users are increasingly enlisting specialist firms to carry out maintenance work. Maintaining hydraulic systems should, therefore, be made as easy as possible for users and hydraulics should continue to offer young people an attractive future-oriented career.

Future Viability

There is surely no standard preferred technology for all applications. Whether hydraulic or electromechanical, each type of drive carries its own set of strengths and weaknesses that can only be assessed according to their suitability to specific applications. To make reliable statements regarding future viability (over a 10-year observation period), an investigation was carried out to determine whether the most important applications in 10 of the main sectors for industrial hydraulics could be substituted.

Overview of important industries and applications for industrial hydraulics.

The following drive types were considered for the aforementioned main applications:

• Linear movements: >80% of all applications
• Hydraulics: cylinder drive via valve or pump control and compact axes
• Electromechanics: ball or roller screw assembly
• Rotational movements: <20% of all applications
• Hydraulics: pump control or secondary control
• Electromechanical: direct drive or geared motor.

Drive types in hydraulic and electromechanical drive technology.

The overall assessment of the most suitable drive types for the future was based on an investigation of the following four main categories, with a total of 13 criteria for each application:

Functionality: dynamics, robustness, static power limit, accuracy, safety

Integration: installation space, flexibility, user friendliness

Cost-effectiveness: costs, efficiency, service life

Ecology: eco-friendliness, maintenance

Outlook. All in all, it is evident that electromechanical systems for linear movements max out at around 500 kN or more. For systems rated less than 100 kN, electromechanical systems hold great potential to replace hydraulics in many applications. Although slight improvements in power and speed could be achieved by further developing materials, coatings, and geometries, revolutionary jumps seem unlikely. Any further increase in power and torque through mechanical transmissions will then be limited by the masses to be accelerated.

This comparison of linear motion technologies shows that hydraulic continue to outpace electromechanical actuators in both speed and force.

Hydraulic drives already transmit forces that are more than 100 times greater than in the past. As far as the physical performance limits of electromechanical systems as distinct from hydraulic systems are concerned, there is no obvious disruption. Evolutionary further developments are thus to be expected in both areas. Hydraulic systems in metal cutting machines and rotor drives will likely face even stiffer competition. However, there will be opportunities, too—through energy savings with valve control systems and more user-friendly products and systems. As far as linear applications are concerned, hydraulics will maintain and even improve its position through further innovative developments in compact axes.

Once such development is autonomous electrohydraulic axes, which are composed of a motor-pump unit, manifold, and cylinder. These axes are virtually maintenance-free and commissioned the same as with electromechanical drives. The specifics relating to hydraulics are already included in software libraries. As a result, even complex travel profiles—such as those for forming, joining, injection molding, and other large-force applications—can be parametrized very easily. Machine manufacturers and system integrators can also achieve safety levels up to SIL 3 as part of the specification process.

This autonomous servohydraulic actuator is an all-in-one unit that can be commissioned using the same techniques as with electromechanical actuators.

Development Trends

The various markets, sectors, and fields of application make very different demands on industrial hydraulics. The development areas which have emerged in recent decades essentially concentrate on the following:

• Energy efficiency (reduced flow forces, reduced pressure loss, higher efficiency)
• Noise reduction
• Reduced tank volumes
• Higher pressure level and reduced installation space
• Improved material and oil properties
• Higher availability and predictive maintenance
• User friendliness (onboard electronics, commissioning software)
• Safety

Although these issues will still play a role in the future, they will no longer be sufficient on their own. Industrial trends such as 3D metal printing offer new technical opportunities for hydraulics, for example in optimized core design (sand printing procedure) to improve flow properties or in the production of servo valves.

This servovalve manifold, left as an example of how 3D printing can make components more compact, lighter, and even more efficient.

Applications in Sensitive Environments

One segment of industrial hydraulics is characterized by special environmental conditions and often by continuous processes. It includes industries such as marine and offshore, steel construction for hydraulic engineering, metallurgy, foundry machines, mining, etc., where systems are installed either outdoor or similar environments. When it comes to production systems involving continual processes, the focus is on OEE (overall equipment effectiveness), whereby productivity improvements are achieved by optimizing processes, improving quality, and practicing predictive maintenance. High-performance diagnostic systems based on machine learning—such as Rexroth’s Online Diagnostics Network (ODiN)—which can already reliably predict when components will fail, are being developed in hydraulics.

Current diagnostic systems based on machine learning—such as Rexroth’s Online Diagnostics Network (ODiN)—can reliably predict when components will fail, are being developed in hydraulics.

In many cases, compliance with environmental protection classes (explosion protection, for example), redundant pressure supply stations, and the use of biodegradable fluids are required. In light of the environment described here, further environmental regulations are likely to be imposed in the future. An effective method of avoiding risk from fluid spills is to reduce the volume of oil used in a system. The basis for progress is tank design that allows natural passive degassing. Using an active degassing module that includes sensors to monitor the proportion of air released in the fluid can lead to further reduction in oil volume. Compared to conventional designs, the oil volume can be reduced by as much as 70%. Other positive effects include a 50% smaller installation space and significantly reduced oil costs.

Outlook. In addition to the further development of the technology and fluids to help improve environmental compatibility, these industries will undergo a transformation process prompted by digitalization, for example with smart mining, metallurgy 4.0, or autonomous ships.

Production Applications

The other market segment is influenced by developments and trends from the factory of the future. This relates, for example, to presses, plastics processing machines, assembly systems, machine tools, testing machines, and similar machines installed in modern factories. The factory of the future must be described before we can identify the requirements imposed on industrial hydraulics. The main aim will be to increase productivity and efficiency through transparency.

The factory of the future will be highly agile. High flexibility and adaptability are key objectives, while transparency will help to avoid unplanned, costly downtimes. The walls, the floor, and the ceiling will remain in place—everything else will be mobile. Assembly lines will have a modular design and machines will be restructured to create new lines for new purposes. They will communicate wirelessly with each other via 5G and will be supplied with power by an inductive charging system in the floor.

High flexibility and adaptability are key objectives of the factory of the future, with transparency to help avoid unplanned, downtime. The walls, the floor, and the ceiling will remain in place—everything else will be mobile.

In the factory of the future, everything will be connected—from field level to cloud-based IT systems. Automation and drive solutions will only fit into this environment with open-standard communication. They will be easily configurable, with features and classes stored in the device data and controlled or managed by the firmware. Industrial hydraulics must adapt to this world by adopting open standards such as multi-Ethernet and IO-Link, which are already in use. With real-time extensions, all components, modules, and machines will share information.

Outlook. These data then need to be implemented in all future product generations because value stream mapping in the factories of the future will be digitalized. Digital business models will continue to be based on prepared operating data from all actuators, modules, sensors, and machines that make up both new and existing infrastructure.

Pressure valve with IO-Link/ Bluetooth (left) and high-response valve with multi-Ethernet interface for positional, pressure, and force control as well as closed-loop control (right).

One these is the CytroBox from Bosch Rexroth, our latest generation of hydraulic power units. The CytroBox is a decentralized unit that is both mobile and flexible. It has a plug-and-run concept and decentralized intelligence, offering machine manufacturers a ready-made drive controller with numerous built-in functions. Key safety functions and drive controls are included and, therefore, can be easily integrated and configured to suit a specific application. Integrated and wired sensors provide information on the filter, fluid, and drive conditions. The collected sensor data are bundled via IO-Link and preprocessed by the drive controller to network with modern machine designs.

Similar machines and their modules will be wireless, will exchange information and instructions via open interfaces, and monitor themselves continuously. With its multi-Ethernet interface and open core engineering, the CytroBox offers this future viability. Like modern electromechanical drives, the unit is IoT-ready using Bosch Rexroth’s CytroConnect. All information on the unit–from component and operating status or scheduled maintenance work to predictive maintenance analyses from Rexroth’s Online Diagnostics Network (ODiN)—is conveniently available. Depending on requirements, other additional packages for the maintenance function, fault detection, and predictive maintenance are available as an add-on services.

The CytroBox is an all-in-one hydraulic power unit containing a variable-speed pump drive, reduced-size reservoir, and advanced electronics for monitoring, control, diagnostics, and communication.

Wrapping It Up

Conventional hydraulics will change significantly over the next 10 years. Intelligence, sensors, electronics, and software will increasingly be incorporated into steel and cast iron. This will be strongly influenced by IT and automation trends. Users will experience industrial hydraulics as a ready-made functional module with the same level of user-friendliness they are accustomed to in the IT consumer world. Although it is currently perceived as a dinosaur by many, industrial hydraulics will gradually evolve into an attractive unicorn—the industrial hydraulics of tomorrow. New developments in electrical automation and IT technology will make it easier to integrate industrial hydraulics and will make it more competitive.

Areas that offer industrial hydraulics potential for development include compact axes, energy efficienc,y and user friendliness. Developments from the new IT-based world of automation will complement previous key areas in hydraulics. Digitalization (software, connectivity, private networks, apps, etc.) as well as data use (sensors, web servers, data analytics, IoT services, cloud solutions, etc.) will inevitably conquer the world of industry.

Dr. Steffen Haack is head of the Industrial Hydraulics Business Unit, Bosch Rexroth AG, Lohr am Main, Germany.