Sensors are a key method of data collection in manufacturing processses. Sensotect is a revolutionary coating from world bearings and digital technology leader Schaeffler that allows components to become sensors in their own right. By Mark Ciechanowicz.

In all industrial machinery, components add value to the system, and the lifecycle of the system creates an entire value. Digital technologies typically play an important role in analysing data from components and sending this back to the cloud, to what we call a ‘digital twin’. This data can be used to optimise maintenance schedules or improve the performance of the system by changing the way that it is used.

Sensors are one of the main methods of data collection, and are commonly placed on parts such as bearings, shafts, axles, bending beams and other moving parts. But they can’t always measure component parts, because of limited space or a lack of availability.

To solve this accessibility problem, and revolutionise the way we think about sensors, Schaeffler has developed new technology that allows the industrial or automotive component to be the sensor. Schaeffler’s Sensotect coating system is a directly coated sensor layer that can sit over the top of components such as bearings to measure forces in previously unavailable places within machinery, which can help achieve fuel and energy savings. With the aid of modern thin film technology, the component becomes a sensor and the sensor becomes a component.

Sensotect is a globally significant technology that has enormous potential in Australasia for use as intelligent sensors, offering data transmission in real time. With Sensotect, the forces and torques that act on a component can also be rapidly recorded in places where existing sensors cannot be used.

Sensotect is engineered to have a number of advantages, including no adhesives, a high strain sensitivity, no aging drift and no temperature creeping. The innovative coating system opens up strain and force measurement possibilities that have always been impossible with adhesive strain gauges, due to their limited operating life.

This innovative measuring technology means that it is also possible to precisely determine the torque acting on drive shafts and vehicle transmissions, and to adjust the engine’s output to exactly match the occurring load. Sensotect therefore makes an important contribution to achieving energy and fuel savings, and helps to reduce CO2 emissions as well.

Coating performs measuring tasks

With Sensotect, the actual measuring function is performed by a thin PVD (physical vapour deposition) coating that is sensitive to expansion. After the component has been coated, this layer is then created using a micromachining process. The structures that are thus created undergo the same degree of distortion as the carrier component, which makes it possible for the distortion to be measured. Schaeffler has already successfully demonstrated the function of this type of sensor system in its demonstration vehicles.

One of the greatest challenges posed by this type of sensor coating system is the manufacturing process itself. By using very high-performance coating sources and adhering to particularly high requirements with regard to cleanliness in the manufacturing process, Schaeffler can achieve a level of quality previously only found on planar substrates in semiconductor technology, even in components with narrow radii.

Sensotect allows multi-functional surfaces that are characterised in particular by their sensor properties to be created without affecting the design envelope – in other words, components that are coated with it become sensors in their own right.

Development of the technology for applications in Australia and New Zealand is supported by Schaeffler’s local manufacturing and research facilities, backed by the extensive international research facilities of the Schaeffer Group, which employs more than 90,000 people at 170 locations in over 50 countries.

Sensotect benefits

  • Very precise measurement of force and torque on functional components where the possibilities associated with conventional methods are limited
  • Sensor layer is deposited directly on the substrate surface
  • Measurement possible on 2D and 3D geometries
  • Sensor technology with neutral effect on design envelope
  • No use of adhesives or transfer polymers
  • Continuous measurement of force and torque during operation
  • High sensitivity with very little deviation in hysteresis and linearity
  • No temperature deviations
  • No ageing effects
  • Wireless transfer of data and energy (telemetry).

Schaeffler’s digitalisation offensive

Advantages such as those offered by Sensotect are integral to Schaeffler’s global initiatives at the forefront of Industry 4.0 automation and data exchange technologies. Smart technologies highly relevant in Australia and New Zealand include the latest evolutions of Schaeffler’s SmartQB and SmartCheck condition monitoring systems, along with a host of digitalisation and cloud-based technologies that harness the advantages of Industry 4.0, such as Schaeffler’s BEARINX software.

Schaeffler’s latest predictive maintenance solutions enable machinery operators to look ever more clearly into the future – they provide machine operators with vital information about the future condition of their machines. Predictive maintenance allows not only the capacity utilisation of factories, mines, utilities and processing plants to be optimised, but also makes it possible to plan maintenance intervals at precisely the right time for optimised “Total Cost of Ownership” calculations.

An important prerequisite for predictive maintenance is automated rolling bearing diagnostics, a function that is used in motor gearbox units, for example. These units are used not only in machine tools but also in belt conveyors, presses, and steel mill rollers, for example.

Schaeffler BEARINX software is one of the leading programs for performing rolling bearing calculations. It enables rolling bearing supports to be analysed in detail – from single bearings to complex gear systems and linear guide systems. All calculations are performed in a consistent calculation model. Even for complex gears, the contact pressure on each rolling element is considered in the calculation.

Because machine drives are operated virtually without interruption, they require intensive maintenance in order to prevent production downtimes. This is why it is so important for operators to know the condition of the drive components at all times, and why the bearings are becoming particularly important as a central machine element.

The latest generation of the FAG SmartCheck diagnostic system now represents a further step forward for Schaeffler in these areas. In addition to identifying the threat of bearing damage, wear, and irregularities such as imbalance and misalignments based on vibration pattern changes, this system also features a cloud connection. The system creates an automated diagnosis in the cloud from the raw data supplied by the FAG SmartCheck and from additional data, e.g. from the machine control system.

Applications for which this technology applies include bulk handling and conveyor applications, mining and energy; building, construction and access equipment installations, such as forklifts and logistics; food and beverage and agribusiness processes, including paper and packaging; manufacturing, metals and process engineering, transport and industrial motor and transmission applications, including pumping and HVAC installations and utilities including electricity, water and waste water.

Mark Ciechanowicz is Manager – Industrial Services at Schaeffler Australia.