LINEAR MOTION FEATURE When it was commissioned to design an adjustable platform for the


hydraulic testing and measurement of customer-specific fuel pumps for aircraft, Sonplas turned to HepcoMotion for its bearings and slides


Designing a platform for aircraft fuel pump testing


A


s a manufacturer of assembly and test stands, German company Sonplas supplies


turn-key solutions in the areas of fuel injection, electro-mobility, aviation technology and security systems in the automotive sector. For a new project, the company was commissioned to design a test stand for hydraulic testing and measurement of customer-specific fuel pumps for aircraft under variable test and ambient conditions. As these pumps are used in aircraft they are subject to especially rigorous test regulations. So, the company needed a gantry system that would not only be suitable for use with highly flammable substances, but that would function for a long time regardless of the highly degreasing effect of the fuel.


MEETING THE REQUIREMENTS Pre-feed fuel pumps on aircraft are designed to take in kerosene using a snorkel and feed the substance to the main fuel pumps. Playing a critical role, these pumps need to function properly at all times, making a well- constructed test system essential to guarantee perfect performance later on. In order to mimic the real-life scenario


as much as possible, Sonplas wanted to realistically map all of the potential pump positions in its test stand. It therefore needed to build an adjustable test platform –


Sonplas specified bearings and slides from HepcoMotion’s HDS2 heavy-duty range


which required a multi-axis gantry unit. However, the combination of the customer’s desire to test components at flow rates of 0.5 to 900 litres a minute, and the comparatively high level of automation required, presented an additional special challenge in the construction process. A further requirement was that system


components were required to run perfectly even without lubrication – despite the target system life for the test station being 20 years. However, avoiding lubrication was necessary to ensure electrical grounding would be possible without problems; a key pre-requisite to meet the requirements of ATEX explosion protection directives. Initially, Sonplas considered


using traditional components and existing solutions from the automotive industry to build the test station, comprising of a complete turnkey-solution including a driven axis unit, similar to the ones traditionally used in the car industry. However, this approach was ultimately


/ DESIGNSOLUTIONS


ruled out since the fire resistant qualities of the component materials could not be fully determined, the company explains.


THE SOLUTION To meet the application demands, Sonplas decided to use bearings and slides from HepcoMotion’s HDS2 heavy-duty range, which can carry loads of up to 68000N. Specifically, they used corrosion-resistant V-bearings and narrow track rollers jointly with surface hardened guide rails to construct an XYZ-gantry system. This resulted in a very stable and shock-resistant construction which also made it possible to test specimens directly on the test apparatus. To check if HepcoMotion’s bearings would


be suitable in terms of corrosion resistance, Sonplas placed the bearings in the kerosene substitute for several days, after which the bearings showed no signs of corrosion. Of further benefit, the bearings perform well


without lubrication. However, naturally, if used without lubrication, wear is greater – so it was critical that HepcoMotion’s bearings could also easily be replaced in order to maintain the full functioning of the test stand in the long-run. This was particularly important to achieve the 20 year life span requirement of the test stand. The test station has been performing well since its installation in mid-2019.


HepcoMotion www.hepcomotion.com


DESIGN SOLUTIONS | NOVEMBER 2020 15


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44