The torque-measuring shaft coupling ROBA?-DSM is based on the tried-and-tested backlash-free shaft coupling ROBA?-DS. This torque measurement coupling can be used in many different applications, from test stand construction to serial machines, right up to condition monitoring. The system allows easy condition monitoring of machines and systems. Using the data collected by the coupling, machines can be optimally used to capacity.

The measurement of rotating parts requires the transmission of energy onto the rotating part and the transmission of data from the rotating part. Many different systems are available for this purpose. In the past, energy and data were mainly transmitted inductively. However, this principle has several disadvantages in comparison to the data transmission of the new ROBA-DSM.

A big disadvantage of the inductive systems is that data can only be transmitted over short distances. Therefore, they work mainly using 'enclosing' stators, which are also partly bearing-supported. The enclosure makes both installation and replacement far more complex. Furthermore, the installation must be carried out very precisely, as the distances are very short. The ROBA-DSM does not require an enclosure and therefore only needs a small installation space. The stator can easily be mounted in any position on the circumference. When adjusting the stator, large tolerances are permitted in all directions. Potential distances of up to 5 mm are substantially larger than on enclosing systems.

Another major disadvantage of the inductive systems is the usually low transmission bandwidth on analogue versions or the low data rate on digital variants. In most cases, such systems are specified up to 1 kHz. Due to the transmission of energy and measurement data via a carrier, these systems require a complex separation of signals.

The new torque-measuring ROBA-DSM makes use of two completely separate paths for the transmission of energy to the rotor and the transmission of data to the recipient. Due to the high bandwidth of up to 3.5 kHz, it can even record fast, dynamic processes reliably.

National Engineering Company (NENCO), Pune. Tel: 020-27474529. Fax: 91-20-27470229. Email: nenco@nenco.org