kubler articles

Small, Smart, Round: New Motor Feedback Encoders

Kubler 11/1/2017

New Motor Feedback EncodersKubler's new motor feedback encoders are based on a platform offering great advantages: reduction of the number of motor variants, standardization of the mechanical installation, favorable valueadded chain and many electrical interfaces. 

The communication between a motor feedback system and the drive controller can be a decisive factor for the performance of the drive system, in particular in case of dynamic axes, smooth speed control and high positioning accuracy.

Until today, proprietary interfaces, and not the requirements placed on the application, were deciding on the choice of the components. The drive manufacturers are increasingly following a secondsource strategy in order to minimize costs and risks. As it moreover appears that proprietary interfaces are opening, this will in the future lead to higher flexibility and improved cost efficiency. 
 
The current trend 
 
The single-cable solution, which belongs today without doubt to the main developments, is another trend in the electrical drive technology. It allows further cost savings and at the same time simplifies the drive system, thus offering significant benefits to the user.

Today, many companies are strongly investing in development in order to improve their products and shape the future with new technologies such as digitization and networking. More and more machinery and equipment operators are requiring preventive maintenance by means of intelligent data analysis in order to improve the availability and reliability of production plants. 
 
Intelligently preventive 
 
Intelligent sensors allow fast error diagnosis and significantly contribute to the reduction of unscheduled downtimes or production outages. The drive manufacturers confront this task with the development of smart motor concepts.

Based on the requirements of the branch and relying on its many years of experience in the drive technology, Kubler presents its new motor feedback encoders products family. Kubler developed these new encoders in close cooperation with well-known servomotor and converter manufacturers. They are based on a platform that offers a wide range of possibilities and advantages for servomotors. 
 
The particular feature of the new Sendix S36 Motor-Line encoders is their compact size of only 36.5 mm for a maximum resolution of 2048 SinCos / revolution or 24 bits fully digital. The great advantage is that one single size allows realizing several performance levels, which until now required at least two different encoder sizes. 
 
Variants reduction 
 
The mechanical connection between motor and encoder is independent of the required performance level. The Sendix S36 combines all this in one compact size and therefore allows a substantial reduction of the number of motor variants. A tapered or a blind hollow shaft and various torque stops are available for standardization. This ensures maximum flexibility for the drive manufacturer when selecting the mechanical connection. Servomotors naturally also can operate in applications with strong shock moments and vibrations, which are very demanding on the encoder.

Experience has shown that also the connection technology is an area that has to be considered, as the plug connection on the encoder can become loose in case of high shock or vibration values. This is a potential source of errors. Kubler has taken up this challenge and developed an innovative connector concept that holds the connector in place, even in tough and rough environments. 
 
Genuine cost advantages 
 
Baumer, Hengstler and Kubler belong to the leading encoder manufacturers and they will in the future offer a common opensource interface. This future began on October 10, 2017, when the manufacturers presented the new SCS open link interface at the Motek trade fair. It is well known that cables and connectors are one of the main cost drivers in every automation architecture.

The single cable technology can contribute here greatly to save material costs, installation work and not least space, by achieving power supply and data transmission through one single cable. This is decisive above all for servomotors in the 40 millimeter size. The generally tight mounting space in servomotors requires compact sensors and optimized connection possibilities during assembly. SCS open link allows transmitting energy and data through one single connection cable. 
 
Lack of space 
 
But not only the reduction of the costs related to the connector, the cable and the integration make the single-cable solution so interesting. Space for routing cables is often very limited in the applications. The advantages are thus obvious: Simplification of the connection technology and less components. In addition, the single-cable solution is also predestined for smart motor solutions because of its fully digital and real-time capable protocol.

Besides the usual information such as position and speed, the new motor feedback encoders provide additional information. They will in the future provide also functions such as the electronic data sheet (EDS), saving customer-specific user data and condition monitoring for monitoring machine condition. Moreover, connecting additional sensors such as e.g. temperature sensors used for measuring the winding temperature and transmitting it to the servo inverter via the fully digital protocol of the single-cable technology is possible.