Energy and Data Transmission With Slip Rings

Kubler 1/25/2018

Energy and Data TransmissionNewly developed slip ring generations such as the ones presented here can meet the increasing requirements for use with Industrial Ethernet and IIoT. 

Slip rings have many different application areas: packaging machines, textile machines, robots and handling systems, cranes, bottling plants, rotary indexing tables and many others. The slip ring is an electromechanical component and forms, together with the brushes, a sliding contact. It allows both electrical power and signal transmission between components rotating with respect to each other.

The strongly increasing digital networking in modern production facilities leads to significantly increased demands on the components used. In such automated plants, slip rings supply rotating plant elements such as e.g. rotary indexing machines with electrical power and transmit control signals and data, often also in combination with liquids and gases. The important point here is a long and reliable service life, which can only be achieved with long maintenance cycles and the necessary slip ring robustness.

Newly developed slip ring generations as they are presented here can meet the increasing requirements. The slip rings of the SR120, SR160 and SR250H product families are Ethernet-capable and transmit, besides electrical power up to 120 A and control signals, large data volumes in real-time. High output under efficient production conditions is decisive for the economic operation of modern investment-intensive production facilities. Besides the increase of plant performance by accelerating single processes, an optimized production jobs scheduling and standstill times minimization are key factors for the economic efficiency of the production. The goals in modern industry are defined with superlatives: always reach the maximum, in shortest time, with always more efficient processes.

The trend is moving towards efficient, self-organizing and resource-saving production facilities. Nevertheless, the basis for achieving this is the acquisition and transmission of operational data between plant elements along the value chain, as well as for plant control. Accordingly, the volume of data to be transmitted and the transmission speed are constantly increasing.

Often, in such highly-efficient facilities, the main process steps are carried out on rotary indexing tables in order to save space. The electrical power supply of the active elements mounted on the carousels and data communication with other peripheral plant components take place via slip rings. An application example is given by beverage filling, which includes individual process steps such as filling, closing and labeling. Due to space constraints, these processes are carried out on the rotary indexing tables mentioned above.
Long maintenance cycles and interference-free transmission

The efficiency increase, highest availability and strongly increasing digital networking in modern production facilities lead to significantly increased demands on the slip rings used. Besides transmitting signals and high currents, the slip rings must be integrable in the network and ensure reliable Ethernetbased data transmission. 

In addition, the demand for maximum plant availability makes long service life and very long maintenance cycles indispensable. Discussions with the operators of very large production facilities showed in addition the desire to acquire information about the operating condition of the slip ring, in order to take it into consideration within the framework of predictive maintenance. This would allow reducing further the risk of unscheduled facility downtime.

Modularity allows individual adaptation

The new slip ring generation of Kubler's SR120, SR160 and SR250H product families offers the suitable solution for industrial automation applications. These Ethernetcapable slip rings also transmit, besides the electrical power and the required control signals, large data volumes in the required real-time. The development and market launch of the SR250H product range now allow transmitting currents up to 120 A without interfering with the transmission of the Ethernet data.

High-quality, very reliable contact systems are the basis for the extraordinary long service life and maintenance cycles Various actuators, sensors and drives are mounted on the rotary indexing tables, depending on the application or on the process step within a complete facility.
Consequently, also the requirements for the slip rings are different. Thanks to their modular construction, these slip rings can be individually adapted to the requirements. Many applications require, besides the transmission of electricity, also the transmission of gaseous or liquid media. Solutions are available also for this application: ready-to-mount assembled combinations of an electrical slip ring and a suitable media lead-through ensure a significantly simplified and fast installation in the production plant.
Transmit safely Ethernet data up to 1 gbps

As standard, the transmission of Ethernet data in slip rings is based on a contacting transmission technology. The specially developed electrical shield concept, combined with a high-quality and therefore reliable contact system, allows transmitting very reliably, in addition to electrical currents up to 120 A and electrical signals, also Ethernetbased data. This makes transmission rates up to 1000 megabits per second possible; data transmission is independent of the Ethernet protocol and can therefore be used universally for all Ethernet protocols.

For transmission rates exceeding the 100 mbps limit, Kubler relies on a non-contacting transmission technology, which allows achieving transmission rates up to 1 Gbps It can also be used for almost all usual Ethernet protocols and can be totally integrated in the slip ring housing. The standard connectors mounted on the housing ensure easy integration of the slip rings in the network. 
Condition monitoring: Slip rings with sensors

The collection of relevant operating data is the basic prerequisite for the control and optimization of the production processes and the fastest pace possible for the production orders. In modern facilities, this is achieved thanks to extensive installation of sensors in all plant elements, up to the product.

Also information about the operating condition of the single components is very important. Thanks to predictive maintenance, they contribute to prevent unscheduled facility downtime due to defect or wear of single components. This aspect is gaining importance not only in the area of industrial automation, but also in other branches and applications. Against this backdrop, also the demand for slip rings with integrated sensors is increasing.

This concerns on the one hand the collection of information relating to the operating condition of the slip ring, such as e.g. the remaining service life, but on the other hand also data relating to operating parameters such as the temperature and the angular position. Kubler achieves this with suitable sensors integrated in the slip ring. This gives the traditionally passive component slip ring an increasing active role and it is to be expected that this trend will continue.