Driving in a hygienically clean environment

There is a growing demand for hygienic drive technology within the food, meat and packaging industries, driven by changing consumer habits that have seen the growth of a steadily expanding array of individually wrapped or single-serving food products such as sliced meats. Further, more and more machines for manufacturing and processing meat and sausage products are employing an open design, with as little encapsulation or enclosure of individual components as possible. 

These components used within such applications must not only have a hygienic design but must also be easy to integrate and maintain. As a member of the EHEDG (European Hygienic Engineering and Design Group), Wittenstein is familiar with the legal and technical requirements applicable to hygienically designed gearheads, servo motors and servo actuators, which are implemented in various product portfolios. Among the company’s most recently introduced products are the HDP and HDV hygienic design gearheads, developed to assure maximum productivity and availability.

Germ-free, aseptic, extremely dynamic and compact, the HDV meets all of the requirements of hygienic production and packaging machines, while the HDP with an output flange is said to be the only planetary gearhead of its kind in the world, with Wittenstein claiming the product sets new benchmarks in terms of positioning accuracy and power density as well as cleanability and process reliability. With a torsional backlash of less than 1arcmin and a maximum acceleration torque of 760Nm, the HDP series is said to be perfect for highly dynamic and compact applications, for example in delta robotics. Like the HDV with output shaft, the HDP was also designed for use in the sterile and wet areas of production and packaging lines, such as in food and meat processing applications. The optimised design and the materials used ensure hygiene, while the ‘plug and play’ concept makes it a simple matter for manufacturers to integrate the drive units hygienically into an open machine architecture. Their customers profit from the highest possible protection against product and process contamination risks.

Users looking for servo actuators in an EHEDG compliant system design can also look at Wittenstein’s Axenia value series. The motor and gearhead comes as a single unit with IP69K protection, for a complete system conforming strictly to EHEDG design guidelines. The company says these precision actuators provide exceptionally high power density and availability. The actuators com-prise a compact, high performance motor with a precision plan-etary gearhead that is directly mounted in order to save space. 

This power dense type of construction is shared by all Axenia value variants, as is the strict adherence to hygienic design requirements. Machine manufacturers no longer need to adopt cost-intensive measures in the fight against germs, microorganisms and dirt traps – such as enclosures or encapsulations for complete, non-hygienic actuators as protection against wet cleaning or disinfection. Instead of extra costs Axenia value provides increased design freedom, for instance for space optimised equipment with a smaller footprint. 

The single-cable technology which is available as an option reduces the amount of wiring required and halves the risk of liquid ingress. The owner of the machine gets a servo actuator with a higher power density, leading to more performance. At the same time, the high reliability improves the overall equipment effectiveness (OEE). The enhanced process reliability and product safety is a further advantage because the elimination of protective canopies and actuator covers means there are no hidden corners where dirt, corrosion or leaks can occur unnoticed. 

Wittenstein goes further, too, with a fully scalable actuator platform that it says creates new opportunities for the mechatronic drive technology in food processing, bottling and packaging machines. The painted, corrosion resistant housing of the Premo range has neither gaps, depressions, undercuts and dead spaces, nor visible screw heads that could provide a breeding ground for bacteria and microorganisms. The smooth, rounded edges and the lack of horizontal surfaces ensure that any liquids are drained off completely. The sealing concept achieves IP65 (splash-proof) protection while the lubricant has food grade certification. The Premo ‘food’ version satisfies the additional criteria for hygienic design, with paint that conforms to FDA requirements. Optional single-cable technology reduces the amount of wiring and halves the risk of liquid ingress.

Finally, Wittenstein offers its Cyber Dynamic line: corrosion resistant or hygienic brushless DC motors for production and packaging machines. These cover an output range up to 335W and were designed to facilitate hygienic drive automation for production and packaging machines in the meat processing and packaging industry. The motors conform with EHEDG guidelines and therefore ideal for all production and packaging tasks where absolute cleanliness is a must. 

The biggest advantage when these compact servo motors are integrated is that they no longer have to be provided with complex encapsulation or be concealed in the plinth of the machine; instead they can be directly connected to the axes of a pick-and-place robot, for example, without any additional mechanical elements. This generates cost and flexibility benefits for the machine design, avoids the heat problems that tend to be associated with encapsulation and makes an attractive alternative to solutions based on complicated pneumatic drives.