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Gap, roller gap, roller convexity

If two object edges are joined together, a gap always remains. If the gap has to satisfy technical or visual requirements, the course with respect to the size must be checked. If the gap should be measured completely, laser scanners in the scanCONTROL series are ideally suitable for this. Point laser sensors in the optoNCDT group are also used for precise gap measurement over a track.

Special roll gap measurement on calender press

For continuous, uniform material processing in the field of sealing technology, the gap between the rolls must be set with the hydraulic adjustment device and maintained constant. For this reason the top and bottom rolls are provided with a shoulder and an aluminum ring as measurement objects to the left and right. Using the aluminum ring, errors due to the roll material can be avoided. Two eddy current sensors mounted opposite one another measure the distance to the aluminum ring from a fixed reference point. The roll gap can be found from the sum of the two distances.

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Pistons

Combustion engines must withstand maximum loads during a long service life. In order to deal with this requirement, eddy current sensors from the eddyNCDT series are installed in the engine for many different measurements. As the smallest eddy current sensors in the world, these sensors can be used in the fuelled condition. Examples of measurement already being carried out are: valve lift, needle lift, breathing of the cylinder head, lubrication gap on the cylinder, oil film thickness, crankshaft concentricity, crankshaft axial movement and piston secondary movement

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Piston – Top Dead Centre

The Top Dead Centre of the cylinder movement is measured for adjustment of the precise ignition point in engine development. In doing so, a miniature eddy current sensor is integrated in the cylinder head cover. From this position, it precisely measures when the piston is at the smallest distance from the sensor. The ignition is optimum at precisely this time. Earlier or later ignition would reduce the efficiency of the engine. This measurement is only possible in towing operation.

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Piston Secondary Movement and Piston Ring Position

To improve the construction of internal combustion engines and damage analyses, it is neccessary to measure the thermal and mechanical loads in the engine. Two important variables here are the transverse movement of the piston (secondary movement) and the position and deformation of the piston rings during the individual operating strokes. The measurements must be made under operating conditions in order to provide reliable results. To do this, the engine is run on the bench either in test mode or normal operating mode.

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Piston secondary movement

Among other things, the lateral movement of the piston in the cylinder is crucial for the service life of engines. Miniature eddy current sensors for this are integrated in the piston which measure onto the cylinder wall. If the distance is too large or too small, the piston has too much play or continuous lubrication cannot be ensured. The sensor cables are routed out of the engine along the connecting rod over a rocker in the gearbox.

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Sorting crabs

Crabs are sorted by size in a sorting system. Thereby, the crabs are transported using a vibrating unit on a roller which has a clearance between 20 mm and 40 mm. For checking the clearance, an induSENSOR series LVP is used which measures the changing clearance and shows it on a digital display. The sensor is designed in stainless steel for the food industry.

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Exakt justering av spalter i roterande krossar

Roterande krossar i stenbrott eller malmgruvor kan mala upp till 3500 ton material till önskad kornstorlek på en timme. I denna applikation genererar en excentrisk lagerbussning en roterande-oscillerande rörelse av krossaxeln och ändrar därigenom ständigt spalten mellan krosskäftarna och krosskonen. Vid slipning rör sig den inställda spalten kontinuerligt längs den inre omkretsen av krossrummet. Med en långdistanssensor i hydraulcylindern kan spalten justeras exakt genom att höja och sänka axeln.

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Mätning av mellarum i vindkraftverkslager

Länge mättes mellanrum i lager i vindkraftverk under stillestånd baserat på taktilprincip. Därför krävdes långa inspektionsintervall, vilket ökar risken för haveri. Dessutom orsakar driftstopp för mätning och inspektion betydande extra kostnader. Micro-Epsilons givare förvärvar mätdata under drift, vilket möjliggör pålitlig och kostnadsbesparande realtidsanalys.

Denna mätuppgift utförs med hjälp av det induktiva mätsystemet eddyNCDT 3005 som baseras på virvelströmsteknik. Systemet innehåller en givare med ett mätområde på upp till 6 mm, som ansluts permanent till styrenheten via en 1 meter lång kabel. Eftersom systemet är oljetätt både på fram- och baksidan är det idealiskt även när typiska oljetryck i lagret når 1 till 2 bar. EddyNCDT 3005 används redan i vindkraftverk för att analysera och optimera underhållsintervaller. Dessutom kan data som förvärvats vid tester under hela designperioden beaktas och användas för dimensionering av nya komponenter. Givarna kan användas för tester och i högvolymapplikationer för tillståndsövervakning. Serieproduktion innebär stora fördelar, eftersom givartekniken kan anpassas och justeras exakt redan under installation och idrifttagning.

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Air gap measurement in large electric motors

With very large electric motors (diameter larger than 10m) it is important for reasons of cost effectiveness and energy efficiency, to know the radial run out of the rotor from the stator inside the motor. These electric motors are intended for use in rock grinding mills for cement production or mining. Due to imbalances during operation, the rotor may touch the stator, which would cause much damage. This is why sensors are used to measure the distance between the stator and rotor and to monitor the so-called rotor gap whilst the motor is in operation. For this application, capacitive sensors with a measuring range of approx. 30mm are used.

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Inspecting gaps in car trims

In high quality vehicles, the trim typically consists not only of a single material (e.g. plastics) but many different bonded materials. This offers various design options but also many additional functions e.g. illumination using semi-transparent parts. Bonding or welding these elements requires precise handling, as parts that are only slightly misaligned can cause large deviations in the corresponding gap size. In order to meet the high requirements demanded by automotive manufacturers, it is necessary to inspect all trim prior to delivery and to rework any defective parts. And this is where the scanCONTROL 2910-25 laser scanner comes in.

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Detection of turbocharger rotor dynamics

In order to inspect the behaviour of turbochargers during different stress states, eddy current displacement sensors are applied in turbocharger test benches. The miniature design of the sensors and their resistance to oil and high temperatures enable the precise detection of the lubricating gap of hydrodynamically stored rotor shafts.

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Lubrication gap

Sliding bearings are used for crankshaft bearings in the engine. A specific minimum distance is required so that the bearing operates as wear-free as possible. Miniature eddy current sensors are integrated in the bearing for this. They measure the distance through the bearing half-shell on the crankshaft. It can thus be established whether sufficient oil is lubricating the shaft in the bearing. If the film of oil breaks down, the distance to the shaft must be almost zero. This is because a certain minimum clearance from the bearing to the shaft is required due to the viscosity of the oil.

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Measuring the lubricating gap in plain bearings

The lubricating gap of a plain bearing is influenced by several factors such as temperature, speed, angle, load etc. This influence can only be measured under operating conditions.

Therefore, a measurement system which detects the gap size or the shaft displacement is subject to strict requirements: temperature stability, resistance to pressure, oil resistance, small size.

eddyNCDT systems with the miniature sensors U 05 and S 05 have been used successfully for displacement measurements in the crankshaft bearing of internal combustion engines. The special design of these minia-ture sensors enables them to be inserted in even the smallest of bearings where they deliver reliable, accurate measuring results and high resolution of the values.

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Analys av spalt i axialkolvpumpar

Hittills var mätning av spalter inne i pumparna inte möjliga på grund av de extrema kraven. Givarna måste vara resistenta mot höga hastigheter, höga tryck upp till 1000 bar och temperaturer över 100° C. Dessutom är pumparna extremt kompakta, vilket väsentligt begränsar det tillgängliga utrymmet för integration av givare. Tack vare de extremt kompakta givarmodellerna och stabilitet vid höga tryck och temperaturer är de induktiva miniatyrgivarna eddyNCDT idealiska för denna applikation. EddyNCDT 3300 , som är ett av världens mest kraftfulla system baserat på virvelström, används därför på testriggar för utvärdering av pumparna.

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Gap detection on glass

Glass substrates are required for certain medical tests. During manufacture of silicon chips, the substrate is milled in a defined grid with a depth of 800µm. For separation, the substrate is broken at pre-defined breaking points in a breaker station. For this, the glass pane must be positioned precisely. An optoNCDT 1700 sensor is used here for gap measurement.

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Closed-loop gap control in magnetic bearings

A shaft weighing about 40kg is supported in magnetic bearings. A ferromagnetic shaft journal is suspended in a magnetic field which is excited by surrounding excitation coils. To regulate the gap two sensors at each end measure in the radial direction, mutually offset by 90°, and one sensor measures axially against the shaft. Non-contacting and wear-free magnetic bearings are used in ultra-clean atmospheres and in extreme ambient conditions.

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Gap measurement of tripping pins

When triggering a switching operation in test equipment for camshafts, a tripping pin is moved at high speed. A gap measurement detects whether the tripping pin has been completely extended and if it has been triggered with the required speed. Evaluation of the displacement-time-signal determines all parameters reliably. The optoCONTROL 1200/90 optical micrometer carries out these measurements.

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Eddy current sensors in tribology testers

Eddy current sensors from Micro-Epsilon are used for various measurement tasks in tribology testers of the ITR in Clausthal. They withstand the harshest ambient conditions there as they measure directly on the shaft in the tester. A tester with water lubrication and a tester which examines plain bearings for the automotive industry have already been realised. The position of the test bearing case and the relative movement between the rotor and the test bearing is detected in the tester using eddy current sensors.

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Övervakning av oljefilm i hydrostatiska lager

Hydrostatlager används i stora anläggningar och maskiner såsom stenkrossar, teleskopinstallationer etc. Att övervaka spalten för oljefilmen är en kritisk faktor eftersom eventuella störningar i hydrauliken kan orsaka tryckfall, vilket i extrema fall resulterar i att mellrummet sluts, vilket i sin tur resulterar i skador på lagren och i slutändan systemfel. Därför är det viktigt att använda ett system som är lätt att installera eftersom även åldrande anläggningar måste kunna eftermonteras. På grund av lång livslängd och global användning i olika anläggningar bör givarna vara lätta att byta ut. Av denna anledning används beröringsfria virvelströmsgivare i eddyNCDT 3001-serien.

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Oil film thickness measurement in an internal combustion engine

Included in the objectives of current engine development are minimization of pollutants and the reduction of oil consumption. In order to be able to take measures in achieving these objectives, then along with a number of other factors, it is very important to obtain knowledge of the behavior and the thickness of the oil film between the cylinder wall

and piston or piston rings In this respect the upper third of the cylinder bore is of particular interest.

oil-film-thickness-measurement.jpg

Measuring glass cups

In the production of drinking glasses, the stem and cup are connected using a gas burner. In order to enable the precise connection of the glass stem and cup, the distance between stem and cup needs to be measured. Monitoring this gap size allows for feed rate control during production. An optoCONTROL optical micrometer measures this gap.

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Valsmellanrum

Avståndet mellan valsarna eller från valsen till stödytan är avgörande för valsning av metaller, plast eller andra material. Vid känsliga processer och hög materialnoggrannhet måste avståndet ständigt kontrolleras så att kassering undviks. För detta ändamål är induktiva givare för kontaktmätning eller beröringsfria tekniker lämpliga. Vid kontaktmetoder monteras givaren på utsidan på styrningen av valsen. Förändringen i avstånd överförs till en kolv vars lägesförändning mäts av den induktiva givaren. När det gäller beröringsfria metoder befinner sig valsen mellan sändaren och mottagaren på en optisk mikrometer. Den utsända ljusridån täcks delvis av rullen och återstoden av ljuset når mottagaren genom spalten. Mellanrummet kan beräknas baserat på mängden ljus.

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Övervakning av deformation vid aluminiumgjutning

Övervakning av verktygsdeformation med hjälp av induktiva virvelströmsgivare möjliggör hög produktkvalitet kombinerat med förbättrad livslängd och minskat ombearbetande. Vanligtvis används tre till fyra eddyNCDT 3005 virvelströmssystem för att säkerställa ett jämna mellanrum vid flera mätpunkter.

Ett system består av en kompakt och robust styrenhet, kabel och givare. Den integrerade systemdesignen ökar robustheten och motståndet mot yttre faktorer, vilket gör systemet okänsligt för höga temperaturer, damm, smuts och tryck samt ger noggranna resultat oavsett miljö.Tack vare sin kompakta design kan eddyNCDT 3005 när som helst integreras i en befintlig maskin.

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Windscreen gap

The final appearance of a product plays a crucial role everywhere that panes are positioned automatically. Apart from the shape, stability, colour etc., the final appearance is also dependent on the position of the glass in the frame. The pane must be inserted in as centred a position as possible. A laser scanner also detects automatically for the insertion of the glass whether the gap is the same on all sides or not. If differences occur, the pane can still be moved somewhat. The extremely difficult conditions of the different reflection factors of glass and frame (metal, wood, plastic) do not affect the quality of the measured data.

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Cylinder breathing of the cylinder head gasket

Specially shaped eddy current sensors are integrated directly in the crankcase where they measure, for example, the expansion of the cylinder head gasket during the stroke. Pressures of up to 50 bar are produced for every ignition of a cylinder, which slightly raise a tightly bolted cylinder head. This movement is compensated for by the cylinder head gasket, which is why it is referred to as “cylinder head gasket breathing”. How far the cylinder head moves is measured by eddy current sensors. This data provides information about the durability of the gasket and save customers from fatal engine damage.

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