Innovative solutions for the fluid power industry
02.02.09
Fluid Power Journal January/February 2009
Innovative solutions for the fluid power industry
Even in the 21 first century planners and designers of fluid power systems are challenged by the end user to provide cost effective and space economic products.
As a consequence of an unrelieved pressure to rationalise we observe a strong tendency to designs providing good accessibility to maintenance points, standardised components and high life expectancy.
Since we cannot assume that these requirements will reduce the already existing high concentration of components which are stacked on top of the power packs, it becomes more essential to think about solutions providing a high integration of functions.
This article presents some new innovative detailed solutions and details that might help the designers to meet the challenge.
About a decade ago the Nivovent range of products introduced a qualified breather filter with integrated level and temperature controls. This mile stone reduced the number of necessary interface ports on the tank top and eliminated another two single control units. However, the Nivovent’s design was limited to a particular type of breather principle which handicapped a universal use. Furthermore, new developments have entered the scene and new future-oriented solutions become due.
In the field of factory automation new connector types like the M12 micro have been popular, the power supply standardised almost completely on 24 DC and other global standards had to be recognized.
The Nivovent series (Figure 1) offers a bunch of innovative solutions and thus enhances the benefits of this industrial field significantly. A breather flange with 73 mm is still based on the worldwide accepted standard. (In some countries even officially standardized.) The head of the breather flange has been redesigned; the electrical connectors at the side of the flange enable a free installation of breather filters of different brands.
(Figure 1)Nivovent 75
Although the level contacts are still adjustable the inner parts of the units have been also completely redesigned. Based on the standard lengths of 250, 370 and 500 mm a gold-plated printed circuit board has been developed which carries up to four cordless level contact cartridges which are adjustable in position and function (NC/NO). This new arrangement is called the easyjust system (Figure 3).
(Figure 3) Nivotemp 64
To control the temperature, the Nivovent offers bi-metal contacts with various settings, a Pt 100 RTD or a 4-20mA analogue transmitter. All of the items can be plugged in cordlessly.
The new concept allows a very fast and effective adoption to the individual application and reduces the sum of spare parts. Consequently the Nivovent 7 series can be combined with continuos level controls of standard or variable length as well as with filling and sample ports even for the connection with automatic particle counters (Figure 2).
(Figure 2) Fluid control terminal G3/ 4-7x/-8x
Special versions allow the integration of water alarms and visual indicator of the liquid level.
A very popular version is the combination of Nivovent with easyjust level contacts and a digital contact thermometer controlled by a microprocessor. This unit is available with temperature display only, with up to two adjustable alarm outputs, or with 4-20 mA continuos signal.
Compact units enhance design flexibility and reduce required volume....
and in addition improve on the accessibility of maintenance and repair.
The most advanced development is the Multiterminal (Figure 4). The design integrates also the return line filter and provides the filling port with solenoid shut-off valve optional. This cartridge solenoid valve is directly coupled with a level control. A maximum level contact is wired directly to the valve, thus the filling operation will be shut down as soon as the maximum liquid level has been reached. This makes topping up and filling a trouble-free operation and avoids oil spills which occur frequently during the procedures. A DIN standard filter element is accommodated in the return filter which makes the whole unit independent from a specific brand. Newly developed capacity indicators monitor the dirt holding capacity of the filter element, granting the most economical use of the element’s life time, eliminating losses due to cold start signals.
(Figure 4) Multiterminal
Another innovative product is the filter cooler combination BKF (Figure 5). Traditional designs use commercially available components composed together to perform the desired function. These components are connected by pipes and fittings and very often need special supports to be attached to the respective power pack. The BKF reduces the physical volume as well as the production cost.
(Figure 5) External Loop filter/cooler
The BKF unit combines the functions external loop filtration and cooling in a small casing, which is easy to install. A die-casted baseplate incorporates a gerotor pump with low noise emissions, and a by-pass valve for pump protection. The filter housing is bolted on directly so is the highly efficient plate heat exchanger. The unit can be placed directly on top of the reservoir by straight suction and return pipes, or can be placed appropriately at the side of it.
Changing traditional installation methods.....
Safes time and money and opens new ‘view points’.
Traditionally, the control of the operating pressure has been done either by pressure gauges or mechanical pressure switches. During the last decade electronic pressure switches with an integrated display captured the market. These units more precise signals; however, they carried on with the traditional installation techniques.
The new Pressotronic series (Figure 6) opens now a new avenue. With the separation of a pressure transmitter from the control unit, the installation becomes much easier and more cost effective. The pressure transmitter is directly installed at the measuring point. Since this unit does not contain any device that needs adjustment or particular visibility, the location of the measuring point can be anywhere in the system. If the visibility of the pressure in an application is required, the controlling unit can be located at such a place which provides good visibility and accessibility. The Pressotronik controller is fixed on a 35 mm rail. The connection between the transmitter and the controller is wired by a flexible cable. This eliminates the traditional rigid pressure pipes with fittings and clamps.
(Figure 6) Pressotronik
The same type of controller can be calibrated to other values and used to display temperature readings or level readings as well. In such cases it will be connected to respective level and temperature transmitters, such as the Nivotemp 63 series.
Summary
As the demonstrated pictures (Figures 7 and 8) show, the use of these highly integrated innovative products allow the improvement of the design of power packs and as additional benefits, easy accessibility to the maintenance points and good visibility of displays. Furthermore, employing such components contributes to lower installation cost as well as administration cost.
(Figure 7) Traditional Design
(Figure 8) Advanced Design
Innovative Solutions for the Fluid Power Industry, in: FluidPower Journal 2009, January/February, Page 12-13
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