Hannover Messe Hall 25, Stand D18
The torque measuring Shaft coupling "Roba-DDSM "from Mayr Antriebstechnik based on the Backlash-free shaft coupling "Roba-DS", The field of application of this torque measuring coupling ranges from test bench construction through use in series machines to condition monitoring. The system enables easy condition monitoring of machines and plants. With the data from the clutch, machines can be optimally utilized.
Measurements on rotating parts require the transmission of energy to the rotating part and the transmission of data from the rotating part. There are different systems for this. In the past, energy and data were mainly transmitted inductively. This principle has some disadvantages compared to the wireless data transmission of the new Roba DSM.
A major disadvantage of inductive systems is the small distance over which the data can be transmitted. Therefore, they usually work with "enclosing" stators, some of which are also stored. The enclosure makes assembly and replacement more complex. In addition, the assembly must be more accurate, since the distances are very small. Other disadvantages are lower tolerances in terms of vibration and concentricity. Stored systems also require a torque arm. Attention must also be paid to the installation position so as not to influence the friction moments of the bearing. Non-mounted systems require a mounting aid to center the rotor and stator.
The Roba DSM does not require enclosing and thus only a small space. The stator can be easily mounted anywhere on the circumference. It allows for large tolerances in all directions. The possible distances of up to 5 mm are significantly greater than with comprehensive systems. Another serious disadvantage of the inductive systems is the usually low bandwidth of the transmission or the low data rate in digital variants in analog versions. Such systems are usually specified up to 1 kHz. Due to the transmission of energy and measurement data via a carrier, these systems require a complex separation of the signals.
The Roba DSM uses two completely separate ways of transferring energy to the rotor and transferring data to the receiver. With its high bandwidth of up to 3,5 kHz, it also reliably captures fast, dynamic processes. The preparation of the data on the rotor enables optimal gain and offset compensation. On the rotor there is a programmable amplifier, which is programmed via the radio interface. This allows the user to perform offset compensation directly on the rotor even after installation. In addition, address coding and radio channel can be set using software.
Another advantage is the use of a coded radio system in the 2,4 GHz ISM band. The company is license-free in the EU through general approval. In other markets is the system also usable however, this requires additional approvals. The system uses up to 80 channels. This makes it easy to operate multiple clutches in the same environment. The data transmission is coded with an address, so that only the corresponding receiver can receive and evaluate the signal.
At the receiver, the function of the radio connection can be controlled via a simple display. Since the data transmission is bidirectional and each packet is acknowledged, the quality of the radio connection can be monitored. Faults in the radio connection or missing data from the transmitter are reported by the receiver. Thanks to the high sampling rate and the fast wireless connection, the Roba-DSM achieves very good values for jitter (maximum ± 68 μs) and delay (typically 2 ms), which are usually much higher with digital systems. Like industry standard systems, the Roba DSM provides an output signal of ± 10 V for the right / left torque, which can be used as input to a PLC. However, as more and more control systems are based on PC, direct acquisition of the digital data is an advantage.