Cost effective manufacture of a complex drive unit for a medicine dispenser

• What was needed: a complex bevel gear and a drive element in the separating unit
• Manufacturing process: selective laser sintering
• Requirements: small installation space, maintenance-free, running performance of over 5 years
• Material: iglidur® i3
• Industry: Medical industry
• Success through collaboration: Complex components manufactured quickly and cost-effectively, high service life, customised and simple arrangement of the components in the installation space

Thanks to the integrated solid lubricants, iglidur® i3 is maintenance- and lubrication-free, which is particularly advantageous for applications in which good hygienic conditions play a major role. In addition to the hygienic aspect, components made of iglidur® i3 are suitable for all applications with wear. The tests from igus' own laboratory® confirm an abrasion resistance that is 3 to 30 times better than that of conventional materials for laser sintering. The components also have a very high mechanical strength and are therefore particularly suitable for the production of spur gears, bevel gears, drive nuts, special sliders and spherical bearings. This was confirmed in a gear test. The spur gears made of iglidur® i3 had a service life 5 times longer than POM-milled plastic gears.

As a 3D printing gear expert, igus® offers various online tools for the configuration of customised gears. The service life calculator shows a realistic indication of the service life of your gear, based on tests carried out in the igus® test laboratory. In the configurator for gear and gear rack, the components can be easily designed according to individual requirements. In the online calculation, you immediately receive the exact unit price for your component.

The limited installation space in the dispenser made it difficult to optimise the arrangement of the components. The installation of the drive unit was so complicated that it could not simply be solved with standard injection moulding gears. The transport belt of the cutting blade had to be kept under tension, which would damage the drive shaft of the electric motor, which is why the arrangement of the drive elements was different than usual. Installing standard gears would have led to compromises on the components and complex one-off assembly work. However, the dispenser was to go into series production. In addition, the components had to deliver a running performance of over 5 years.

The design freedom of additive manufacturing allowed adapting the components precisely to the requirements of the small installation space. The parts produced from the iglidur i3 SLS powder with selective laser sintering were installed and tested directly. The iglidur i3 SLS powder was developed specifically for laser sintering and has very good tribological properties. This allows component service life expectancy to be up to 30 times that of components made of conventional plastic. Parts could also be produced much faster than would have been the case with injection moulding. The delivery time is usually two to three days - for urgent projects, igus can also ship components within 24 hours.

The bevel gear assembly in the separating unit of the dispenser was subject to various requirements, including a small installation space. A belt moves a roller blade that has a drylin® N miniature guide as a linear guide. The 3D-printed shaft is guided in two igus® bushes in the sheet metal. The use of standard gearwheels would have led to compromises in the installation space and complex one-off assemblies. However, series production of the dispenser was planned, which is why a more sensible alternative was sought. The company found a suitable solution to the problem with additive manufacturing. The customised CAD design of the bevel gear could be easily implemented using selective laser sintering. This meant that the drive unit could be fitted into the dispenser's small installation space without any compromises. In addition to the exact and detailed fit of the components, the durability of the igus® high-performance polymers convinced JDM Innovation GmbH.