Page 26 - Industrial Technology April 2021 issue

MACHINE BUILDING

RELIABLE PROTECTION

CLUTCHES AND COUPLINGS

THE EXPERTS AT MAYR POWER TRANSMISSION OFFER THEIR
ADVICE ON SELECTING THE RIGHT TORQUE LIMITERS AND
SHAFT COUPLINGS FOR HIGH SPEED APPLICATIONS.

rive axes in the high-speed range require transmitted on the EAS-HSE clutch, are
reliable clutches and couplings, because if specially selected and symmetrically
collisions occur at high speeds, they can cause arranged, delivering a low-vibration
Dsevere damage. But couplings do not only system that works precisely in the event of
provide overload protection. Dynamic and high-precision actuation.
shaft misalignment compensation couplings also create With the addition to the series, Mayr is
the prerequisites for exact measurement results, especially now offering torque limiters for high-speed
in test stand technology. applications with torques in the standard
In most industries, an increasing demand for dynamic, range from 30 Nm to 15,000 Nm and
fast-rotating drive axes well beyond the classic 1,500 rpm speeds of 25,000 rpm for small and
can be observed. And in particular in the measurement 8,000 rpm for large construction sizes.
and test stand technology, the solutions must also be “We have noticed a kind of speed
highly precise. Furthermore, at the high speeds, the safety maximum at 25,000 rpm to 30,000 rpm for industrial specially adapted to measurement flanges, which creates
and reliability of the drive line is a particular concern, with test stands,” Epple adds. “However, in the area of ideal prerequisites for accurate measurement results.
collisions potentially resulting in serious injuries or research and development, where we cooperate with These disk pack couplings reliably handle the high
damage materials. universities and other research institutes, or in motor speeds and even the standard version made of steel is
For this purpose, mechanical torque limiting clutches sports, there are projects with speeds well above 30,000 compact, has low mass and inertia, and achieves speeds
are used to protect the test pieces and measuring units. rpm. We use the experiences gained from these projects to of up to 30,000 rpm. In addition, these couplings stand
These open the drive line and decouple the running further develop our standard range.” out due to precise manufacturing with very few interfaces,
masses within fractions of a second – faster than He continues: “We have been closely observing the high running smoothness and balance quality. “It is our
electronic monitoring functions. When selecting the right market developments for a long time in order to be ultimate goal to produce couplings that are compact and
clutch, however, it is important to consider a number of prepared for the high speeds. This includes our high-speed of high performance density,” emphasizes Ralf Epple.
points. After all, an imprecise or slow clutch which element clutches as well as our overload clutches.” The “The geometric basis must be right. There is no point
influences the measurement system or triggers at the company has therefore developed a new standard series in simply designing a large coupling in aluminum or
wrong time not only makes evaluation in the test field for the established EAS-Compact-F overload clutch up to titanium, when a compact steel version, which is more
difficult, but also simply defeats its purpose. 12,000 rpm, which takes into account the consistently rigid and can handle more alternating loads, may be better
increasing requirements in terms of speed and dynamics. suited to the application.”
High performance density In the new series, for example, an internal seal ensures That’s why customers should always consider the
The torque limiter, which protects test pieces and reliable lubrication of the functional components. This in application when selecting the coupling and the material.
measuring units from damage due to overload, must fit turn ensures reliable disengagement even under extreme Here, however, it is always necessary to weigh up between
high-precision systems and must be suitable for high- conditions and at high speeds. the material properties, including weight, rigidity or fatigue
speed in terms of its basis. In addition, it is important that strength, and the final customer application, ie the actual
the clutches transmit the torque backlash-free and with Shaft misalignment compensation speeds, load alterations, load cycles, bearing distances
high torsional rigidity. “Our EAS-HSE high-speed element In addition to torque limiters, shaft misalignment and bore diameters. And last but not least, of course, the
clutches are compact, have a high performance density compensation couplings are a key accessory in test price/performance ratio also counts.
and a low mass moment of inertia,” explains Ralf Epple, stands, as they minimise the interference parameters
product manager at Mayr Power Transmission. affecting the measurement flange. Such interference Comparing steel, aluminum and titanium
“With our latest addition to the series, we are parameters or so-called parasitic forces frequently occur In the area of measurement technology, torsional rigidity is
responding to the requirements of the market and offer due to alignment errors in the drive line. For this reason, often an important decision criterion, especially when test
users new, weight-optimised solutions misalignments between the stands have the task of measuring the likes of torsion
even in the standard range. For special input and the output sides angles or elasticities. Not even titanium can match the
applications, we are also occur in almost all rigidity of steel here. However, if the focus is on many
able to go one step applications. acceleration cycles and the mass moment of inertia, then
further and reduce the Shaft misalignment lightweight versions made of aluminum or titanium may
weights even more.” compensation couplings are be the better choice.
The compact, high- therefore used together with Titanium is particularly suitable for endurance tests
performance design of the measurement and when many load alternations occur. And also in this
the clutches is flange. Based on area, developments continue apace.
achieved through a the tried and tested “We are working with leading manufacturers of
small outer diameter backlash-free and measuring flanges in this field,” says Epple. “In future,
with a relatively large torsionally rigid direct connection to new high-speed measurement flanges
bore diameter. Further, ROBA-DS construc- will be possible, and here, too, there will be versions in
the integrated elements, tion series, Mayr offers a various materials.”
via which the torque is version of its compensation coupling MORE INFORMATION: www.mayr.co.uk

26 INDUSTRIAL TECHNOLOGY • March/April 2021