Absolute multiturn angle measurement and revolution counter – non-contact and bearing-free with no mechanical coupling

The tried-and-tested Vert-X 28MT, Vert-X 37MT and Vert-X 46MT absolute multiturn rotary encoders from Contelec continuously record both the current angle of rotation and the number of 360° rotations made. They enable battery-free, self-sufficient revolution counting up to 16 bits with no gearbox. The rotary encoders continue to count when the sensor rotates but is switched off. By counting the number of revolutions, large-scale linear distances can be measured on a rotational basis using a compact sensor. Contelec’s multiturn rotary encoders have proven their worth for years, such as in the field of medical technology."

However, for these product types the measurement process requires a mechanical coupling between the axis of the rotary encoder and the moving part of the application. The connection’s design is complex, it often requires an expensive coupling (which is susceptible to mechanical damage over its service life) and it takes up space. This is why Contelec’s innovative engineering team has developed a new alternative: functionally equivalent multiturn rotary encoders that use an external magnetic encoder (ExMag) without bearings instead of an axis and mechanical coupling. This allows for transmissive measurements through non-ferromagnetic metals, such as an aluminum housing, with the sensor located on one side of the housing and the magnetic actuator on the other.

The absolute revolution counter can be set freely within 16 bits. Alternative, self-sufficient absolute multiturn sensors, which work according to the domain principle and can currently count up to 46 revolutions, have the disadvantage that the user is not free to set the counter. This means that after 46 revolutions the counter stops counting even as it continues to rotate. The sensor has to be rotated to the desired initial position, which can be a major disadvantage in applications or during installation.

The elimination of an axle and coupling allows for a much more compact design and a higher level of integration. In addition, the non-contact and bearing-free ExMag principle allows for greater tolerances during installation and application over the service life. Transverse and axial loads are eliminated, as the sensor principle works without the need for bearings. It is resistant to vibrations that could damage or even destroy the essential mechanical coupling in bearing systems.

As an innovation partner, Contelec actively supports customers with sound expertise in finding the optimal solution for their application or project. For example, the portfolio of new bearing-free ExMag-based multiturn rotary encoders is not limited to standard versions. A wide range of housings, connectors and interface protocols is possible depending on the project requirements.

• Absolute multiturn angle measurement and revolution counter with no mechanical coupling – non-contact and bearing-free
• Revolution counter can be set freely
• Free of wear
• No need for a coupling
• Compact design and better integration
• Greater tolerances than mechanically coupled multiturn rotary encoders during installation and use over the service life