Oilgear: A Specialist in the Modernization of Hydraulic and Electrical Drives and Control Systems
“The customer gets not only a hardware solution, but also a performance guarantee”
In-depth process understanding, comprehensive analytical competence and professional project management are the three facets of any successful plant modernization project
The hydraulics specialist Oilgear, with its headquarters in Traverse City, Michigan, has long been known for its high-grade pump and valve systems. Recently the company implemented a re-branding programme in which it divided its business into three divisions: Energy, Mobile and Industrial – expressed in a new logo and the slogan ‘Best Under Pressure’ for the entire product range. This includes highperformance components (such as axial piston pumps and valves), in-house test centres, innovative engineering and the installation of turnkey complete systems and a full range of after-sales services. The German Oilgear affiliate, Oilgear Towler GmbH in Hattersheim near Frankfurt, is mainly active in the industrial sector and also specializes in hydraulic and electric drive and control systems for extrusion presses in Germany and neighbouring countries, including Eastern Europe. At the forefront is modernization business, in which Oilgear claims market leadership on account of its profound understanding of the extrusion process in combination with comprehensive analytical competence and a professional approach to project management. The expertise claimed by Oilgear is based on more than 300 equipped extrusion presses of all designs in Europe alone.
Having regard to Oilgear’s new organization, Egon Martini, sales manager for Extrusion Presses at Oilgear, and business development manager Andreas Prosswimmer quote the company’s COO Craig LaFave: “In a changing world, where increased globalization is putting pressure on businesses of all sizes across every industry, more and more engineers are looking to their suppliers to offer ‘added value’ and services to help keep them competitive. With our engineers and partners, we’re able to offer greater flexibility and sustainability than other leading manufacturers.”
Martini and Prosswimmer consider that the particular added value and services that Oilgear offers extrusion press customers stem from the company’s highly developed process know-how, great analytical competence and very professional project management. “Others too can modernize a hydraulic system by replacing pumps and valves,” says Prosswimmer. “What particularly distinguishes us is that we understand the extrusion process down to the smallest detail and, using appropriate analytical tools, we can perform calculations to increase efficiency, reduce idle times and save energy. The customer can also rely on us throughout the project implementation to keep track of progress all the time and stick to the agreed timetable.” And Martini adds: “In a modernization project the customer gets from us not only the hardware systems required, but also a clearly defined and contractually binding performance guarantee as regards efficiency boosting, reduction of idle times and energy saving.” Oilgear is very committed to modernization business – from the planning stage, through the actual implementation, and to preventive servicing. The measures possible cover the hydraulic and electric drive and control systems for extrusion presses, as well as valve technology, automation, electrical hardware (switch cabinets) and software – all with the aim of improving the customer’s process efficiency and quality, minimizing idle times, boosting output and ultimately saving operating costs.
Martini and Prosswimmer consider that the particular added value and services that Oilgear offers extrusion press customers stem from the company’s highly developed process know-how, great analytical competence and very professional project management. “Others too can modernize a hydraulic system by replacing pumps and valves,” says Prosswimmer. “What particularly distinguishes us is that we understand the extrusion process down to the smallest detail and, using appropriate analytical tools, we can perform calculations to increase efficiency, reduce idle times and save energy. The customer can also rely on us throughout the project implementation to keep track of progress all the time and stick to the agreed timetable.” And Martini adds: “In a modernization project the customer gets from us not only the hardware systems required, but also a clearly defined and contractually binding performance guarantee as regards efficiency boosting, reduction of idle times and energy saving.” Oilgear is very committed to modernization business – from the planning stage, through the actual implementation, and to preventive servicing. The measures possible cover the hydraulic and electric drive and control systems for extrusion presses, as well as valve technology, automation, electrical hardware (switch cabinets) and software – all with the aim of improving the customer’s process efficiency and quality, minimizing idle times, boosting output and ultimately saving operating costs.
Increasing process efficiency, cutting idle times
There is much need for modernization all over the world, and in Europe not only in the east or south of the continent but even in Germany as well. Oilgear’s market range extends as far as the Baltic states and Russia. “There are still any number of old extrusion presses and a growing need to modernize t
hose units in order to keep them internationally competitive. Quite often the productivity of those presses can be substantially increased even with little expenditure, and energy savings of 20 or 30 percent achieved – in many cases even considerably more,” says Martini.
Sometimes even a few tips and minor adaptations are helpful in saving energy and a couple of thousand euros a year, without investing anything. “For example, in our talks with customers we occasionally find that for lack of control options or due to erroneous operation of a plant too many pumps are working during the extrusion process. Since every drive involves a certain energy loss, from the energy standpoint it makes sense to work with as few pumps as possible,” he explains.
Of course, technical solutions cannot be reached, so to speak, en passant. In more complex modernization projects one first has to analyze the press and the process sequence and hence also the extrusion and idle times, during which concrete measurements on the plant also take place. On their basis the aims of the project are defined with the customer, and the measures required for boosting efficiency are established. “Naturally, the appropriate products, pumps and valves for becoming more productive are needed, but one also has to understand the process itself in order to know which products it is best to use. The interaction of hydraulics, electrical systems and software is absolutely decisive for designing the extrusion process efficiently. That requires the corresponding control technology know-how, for example to prevent pressure peaks,” says Prosswimmer, since pressure peaks can damage valves and pipelines and in the worst case lead to stoppage of the plant.
Oilgear attaches great importance to professional project management, which is indispensable in projects for large company groups but is also greatly valued by smaller extrusion plants. “For every modernization project we appoint a project manager, who co-ordinates the tasks of the technical departments involved, carries overall responsibility for the project and is the central communication partner for the customer. He is also responsible for keeping within the cost framework, for quality assurance and for complying with delivery schedules. He draws up monthly progress reports about the current status of the project work – for example how far the engineering has progressed, what jobs still remain to be done and what the customer still has to provide. On site, there is even a daily report,” he explains.
There are various reasons for modernizing a plant. Perhaps a hydraulic system has to be comprehensively renewed because of its age, or the performance must be substantially improved. In recent years control technology has changed markedly. There are PLC systems which their manufacturers will no longer deal with. “In a current project for a worldwide active extrusion group we are at present modernizing only the control system, whereas the existing hydraulic system is left untouched. With a complete new control system and software we will optimize extrusion and at the same time cut idle times,” says Martini.
With a modern control system having improved sensors, even without hydraulic modifications processes can be accelerated so that as a rule idle times can be substantially reduced. “In this it is important for the improved process to operate rapidly and in a stable manner for many years. This entails avoiding overloads of the mechanical systems and ensuring that the extrusion press operates with minimum wear.”
‘Power on Demand’ for maximum energy saving
Modern drive concepts must also be energy efficient. The central key words are: Power on Demand. What that means is explained by Martini referring to the example of modernizing the electric and hydraulic drives with the help of rotation speed-regulated motors and variable pumps. In that project the specific aim was to provide a drive for a 22-MN long-stroke extrusion press with 250 bar. The press is used to produce profiles of soft aluminium alloys. Here too, the (classical) objective was to improve performance and cut both idle times and energy consumption.
This raised the question of which type of pump would be most effective. “Nowadays, frequency converters are very often used with the promise of saving energy. This, however, is not always the optimum solution, as is shown by checking through the various options,” stresses Martini. No doubt a constant pump with a constant motor is outdated and inefficient technology that wastes a lot of energy. For many years variably adjustable pumps with a constant motor were regarded as the optimum solution. Today, however, a frequency converter is often used either with a constant pump or an adjustable pump.
Yet, which variant is best depends on the type of press concerned and whether hard or soft alloys are being extruded. With hard alloys needing longer extrusion times, idle times are naturally less important than in more rapid extrusion processes. “We analyse the various options using data from the customer, to establish the optimum between modernization expense and performance boost,” says Martini.To consider a concrete example, Oilgear recommended the installation of five type PVV 250 variable pumps, each driven by a 160 kW motor in combination with a frequency converter. Once operation had begun it proved possible to determine the energy saving, since the plant:
- was first operated with the classical drive system, in which the motors ran constantly at 1,500 r/min without active frequency converter operation
- and was then converted to an energy-efficient drive system with dynamic adjustable pumps and a frequency converter with rotation speed-regulation of the motors
The result: with the different variants an energy saving of at least 11% was achieved, this corresponding to an annual cost saving of 98,738 euros. Idle time was also reduced by 0.5 seconds, leading to a further saving of around 50,000 euros a year. The investment paid for itself in just a few months.
Martini points out that a great deal was learned from that project. For a long time it has been usual to equip presses with adjustable drive systems, with a view to improving efficiency. “From the analysis of this situation we are now able to design for the optimum efficiency.”
Growing need for preventive maintenance and plant-specific training
Preventive maintenance and servicing also play a growing part at Oilgear, not only for the company’s own hydraulic equipment but also in plants not having Oilgear products, with the aim of avoiding downtimes and damage due to pressure peaks, keeping regularly abreast of the condition of the plant and making use of optimization potentials in relation to productivity and reliability. For this Oilgear offers the following, among others:
- Testing and checking of the plant and their pumps, valves and accumulators
- Measurements and settings during production (no shutdown)
- Complementary adjustments during planned production stop
- Measurements at all the actuators
- Oil analysis from sample
- Dead cycle time analysis by checking the run-time of each movement during production is checked. A documented history allows detecting changes and points to potential for optimization of dead cycle time
Based upon this the customer receives a technical evaluation of the plant’s condition, with a detailed listing of all the results and proposals for improvements, including an action plan. This concludes a detailed report with commented measurements, documented adjustments, analysis and recommendations.
Furthermore, for maintenance personnel and plant operators Oilgear offers system specific training and practice sessions on-site at the customer – both for extrusion presses and for forging presses. Besides the communication of elementary principles and specific technical knowledge about the hydraulic system and its components, the training extends among other things to filtration concepts, maintenance instructions, the verification and maintenance of hydraulic accumulators, and troubleshooting on the hydraulic system.
“In recent years the need for such training has grown markedly. The decisive factor in this is that our training is carried out on the basis of the customer’s documentation and at his own plant. During this we indicate possible sources of defects and how they can be eliminated,” explain Martini and Prosswimmer, in unison.
