The FORTiS enclosed linear scale is an absolute encoder designed for use in harsh environments such as machine tools. A key feature of the FORTiS encoder enables significant reductions in purge air consumption.
The FORTiS encoder design is built upon Renishaw's RESOLUTE encoder technology and provides high resistance to the ingress of liquids and solid debris contaminants. It features an extruded enclosure with longitudinally attached interlocking lip seals and sealed end caps. The read head body is joined to a sealed optical unit by a blade, which travels through a pair of DuraSeal lip seals along the length of the encoder. Linear axis movement causes the read head and optics to traverse the encoder's absolute scale (which is fixed to the inside of the enclosure) without mechanical contact.
Helping Machine Builders Adopt a Smarter Approach to the Encoder Air Purge
Renishaw has 50 years of experience in manufacturing and supplying the machine tool market with products such as probes, software and calibration equipment. As a manufacturer itself, Renishaw faces many of the same challenges as its customers and has developed strategies and products that solve problems across the industry.
In terms of sustainability challenges relating to encoders, the largest source of electricity consumption over the encoder's lifetime is the sealing air purge. Corrie Fearon, Product Manager for FORTiS encoders at Renishaw, explained how low purge air consumption can have a positive impact on the carbon footprint of a machine tool.
Fearon said: "The reliability benefits of using a clean, dry air purge to evacuate a machine tool's linear encoders are well known, leading to widespread adoption by many machine builders. However, supplying that air purge over the lifetime of a machine tool consumes a considerable amount of electricity, resulting in a cost impact for the machine user. With the FORTiS range of linear encoders, Renishaw has developed a way to retain the reliability benefits of an air purge, whilst significantly reducing the cost of doing so. DuraSeal lip seals have been specially developed for FORTiS encoders and provide superior sealing properties for ultra-low leakage. Lower leakage enables lower purge air flow rates to be used while still maintaining the IP64 ingress protection that our customers expect. The design of the DuraSeal lip seals is so effective that they facilitate a 70% reduction in air consumption when compared with conventional enclosed encoders. As a result, reduced air purge requirements mean a corresponding reduction in the encoder's attributable CO2e emissions, and lower total cost of ownership for the machine user, due to less electricity required to provide that air purge."
Fearon continued: "Furthermore, Renishaw is promoting a smarter approach to encoder air purge use to help realize even greater savings. The sealing of the FORTiS encoder is so effective that the air purge pressure can be set according to the level of ingress protection required for each linear encoder axis of a machine tool. In high-risk cases where encoders are heavily exposed to coolants and cutting chips, or when the machining operation generates aggressively abrasive particles, Renishaw recommends using the full 1 bar (0.1 MPa) air purge pressure. But many machine tools have linear encoders behind shielding or high up in the machine, so while these encoders will still be exposed to particulates, coolants and oils throughout their lifetime, it will be at a lesser rate and the risk is therefore lower. For medium-risk and low-risk axes, the purge air supply to the FORTiS encoder can be set at a lower pressure, which decreases the purge air usage even further. In many cases, machine builders can help boost their customers' air consumption savings beyond 70% and up to 91%."
For more information contact:
Renishaw, Inc.
1001 Wesemann Dr.
West Dundee, IL 60118
847-286-9953
usa@renishaw.com
www.renishaw.com/fortis