Page 98 - ENGINEERING REVIEW APRIL 2022 DIGITAL MAGAZINE

TECH INNOVATION
# SENSOR SOLUTIONS

rise and, in extreme cases, the gap will linearization procedures.
close. This would lead to damage of the Not only in wind turbines but in almost
bearing and in turn to a possible plant any application in diverse industries,
failure. Therefore, the sensor is mounted innovative sensor technology prevents
horizontally to the bearing shoe. It repairs, reduces failures, helps to predict
measures through the oil film and the maintenance cycles and reduces costs.
plain bearing directly onto the shaft. Here, Compared to manual inspection where
eddyNCDT 3001 and 3005 non-contact differences can depend on the person’s
eddy current displacement sensors are tiredness and changing mood, sensors
used. They stand out due to a robust, provide high precision, reliable and
compact design with integral controller. Inductive sensors from Micro-Epsilon repeatable measurement results. Micro-
Eddy current sensors from Micro-Epsilon based on the eddy current principle are Epsilon is a leader in high precision
are often used in applications where often used in applications where harsh measurement technology. The product
harsh ambient conditions are present and ambient conditions are present and range comprises inductive, confocal
where maximum precision is required. where high precision is required. chromatic and capacitive sensors,
Immunity to pressure, lubricants and together with laser, eddy current,
extreme temperature are distinctive capacitive sensors are used to measure draw-wire and temperature sensors,
features of eddy current sensors. Other the distance between the stator and including inspection and measurement
requirements with respect to the sensor rotor and to monitor the rotor gap whilst systems, e.g. for modern 3D surface
technology are fast commissioning and the motor is in operation. The sensor inspection. The sensor solutions, which
the possibility to retrofit to existing plant. technology is based on capacitive sensors are customer-specific in most cases,
Due to the worldwide use of these plants, with a measuring range of 0 to 8mm. are from a single source. The sensor
the sensor should be easy to replace. Capacitive sensors from Micro- manufacturer develops, produces
Epsilon are designed for non-contact and distributes the technology. More
Air gap monitoring in the generator measurement of displacement, distance precision, miniaturization and easy
With very large generators and electric and position. They stand out due integration into machines as well as
motors, it is important to determine to long-term stability, reliability and data transmission via state-of-the art
the radial run out of the rotor inside temperature stability. During air gap interfaces are key factors. With 25
the motor compared to the stator. Due monitoring in a generator, the average subsidiaries at home and abroad, the
to imbalances during operation which temperature is approx. 120 °C. However, company bundles long-term knowledge
could be due to wear caused by extreme modern and innovative Micro-Epsilon of high precision metrology and offers
wind and weather conditions, the rotor sensor technology enables highly a worldwide unique product range of
might touch the stator. This could lead to precise measurements under extreme cutting-edge technologies for future
catastrophic failure. This is why optical & conditions. The sensors used are industry requirements.
specially adapted to measurements in a
generator. They are resistant to vibration
and are protected by a special housing.
Their unique, triaxial design enables flush
installation into electrically conductive
materials as the guard ring electrode
and grounding are also located on the
front edge of the sensor alongside the
measurement electrode. Capacitive
sensors from Micro-Epsilon stand Author:
Capacitive sensors from Micro- out due to their high electromagnetic Michael Kuran
Epsilon are designed for non-contact compatibility. Exchanging the sensors Beratung & Vertrieb Sensorik
measurement of displacement, distance does not require any new recalibration Micro-Epsilon Messtechnik
and position. They stand out due to whilst conventional systems were Michael.Kuran@micro-epsilon.de
long-term stability, reliability and
temperature stability. subject to complex calibration and www.micro-epsilon.de

96 | APRIL 2022