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MACHINE BUILDING

SAFETY MONITORING

BRAKES, CLUTCHES & COUPLINGS

MODERN SERVO SYSTEMS IN THE
AGE OF INDUSTRY 4.0 REQUIRE
INNOVATIVE BRAKING SOLUTIONS

ervo systems are the standard nowadays in a
large number of drives. Safety brakes play an
important role here. Due to the specific
Scharacteristics of servo drives, important criteria
must be taken into account when selecting these brakes.
Furthermore, the monitoring of servo brakes is a sensitive
issue, especially if the brakes are integrated into the
systems or are very small. Up to now, they have been
considered unmonitorable in these cases – a real
challenge in times of Industry 4.0 and a growing need for
data from the machine.
Servo drives are the standard today in many areas,
such as in machine tools or robots. In other fields, such as
wind power, they are being used more and more frequently
and are replacing the drive variants that have been
common in these fields to date. The design of servo
systems is essentially always the same: control
electronics, often a gearbox and the motor with a safety
brake.
Systems are common in which the brake is already
integrated, ie installed together with the other components
in one housing. This installation situation involves specific allow conclusions to be drawn regarding the state of the An additional advantage of sensorless monitoring is
challenges. Firstly, the temperature: in a servo motor, the overall system. But the safety brake itself remains silent. the absence of mechanical components. In contrast to
temperature can reach up to 120°C. In order to function Even though in closed systems data from the brake would conventional switches, nothing can be adjusted or
safely and reliably even in this high temperature range, all also be very helpful and would enable, for example, damaged by external physical influences. Tolerances due
brake components must be designed for such predictive maintenance. to deviations in the manufacture of components,
temperatures. fluctuating temperatures during operation or incorrect
However, integrated brakes have one weakness. Intelligent braking module installation also do not influence the monitoring and the
Previously, they were considered unmonitorable, as it was Mayr Power Transmission offers exactly these possibilities data supplied.
not possible to use switches or sensors due to the with its intelligent Roba-brake-checker module. It works The Roba-brake-checker detects progressions and
installation situation, the operating temperatures and the without sensors. Instead, it detects the movement of the characteristics instead of exact trigger points. This makes
extremely small air gaps. This is a concern in view of the armature disk by analysing current and voltage, and monitoring with the module extremely reliable and
increasing networking of machines, with the keyword knows what condition the brake is in – all from the control provides considerably more informative data. In the ‘plus’
being Industry 4.0. Of course, the control and regulation cabinet. In addition to the switching condition, version, the module simultaneously also supplies the
electronics of the servo system provide data that also temperature and wear, it monitors the tension path or brake, thus replacing the rectifier. This means that the
tensile force reserve, ie whether the magnet is still able to supply and monitoring functions for the brake are
attract the armature disk. combined in one device. The module is a plug-and-play
On reaching the tensile force reserve, the Roba-brake- solution, ie it is supplied ready for installation and with
checker emits a warning signal early enough so that a completely tested values.
certain operating time for the brake is still possible. In a Selecting the right brake for servo systems depends on
further expansion stage, the module can also be integrated several factors. Ideally, the brake concept takes all the
into a remote maintenance system via a suitable interface. factors, which are decisive for safety and reliability, into
This further reduces service times and costs. account. These factors include first of all reliable
If damage should occur nevertheless, the Roba-brake- mechanics which function independently of temperatures
checker provides users with significantly better analysis and external influences.
options. With previous solutions, such as contactless Secondly, the selection of the friction lining material
release monitoring, users are only able to see the failure plays an important role in ensuring a consistently high
and the destruction pattern. They do not know, however, braking torque throughout the entire service lifetime, even
why the error occurred. Using the Roba-brake-checker, on in emergency stop situations.
the other hand, progressions are made visible and error New, intelligent monitoring technology completes the
analyses can be used and even transferred onto other concept and makes even integrated or very small servo
systems owned by a user. All this data from malfunctions brakes fit for the networked machine of the future. This
and normal operation thus supply valuable input for future is brake technology 4.0
improvements and optimisations. MORE INFORMATION: www.mayr.com

24 INDUSTRIAL TECHNOLOGY • May/June 2020