Microdispensing in Brushless Motor Production

ISCRA dielectrics, a distributor specialized in fluid dispensing equipment, has solved the application requirement of a major brushless motor manufacturer that needed to soak the stator of small motors with a two-component epoxy resin. The solution is called STD DUO 600, a volumetric dispenser with progressive cavitation pumps that has made it possible to automate the dispensing process.

by Sergio Soriano

In recent years, resins and adhesives have been increasingly used to soak, seal, glue, protect and isolate electrical and electronic components and more. Alongside the single-component compounds, the two-component products have grown significantly. These systems are based on the combination of resin and hardener, which guarantee superior features.
If the process of applying the single-component resin is fairly simple, as it is a single fluid, the preparation and dispensing of two-component liquids is more delicate. In particular, the proportioning and mixing of the two components are the most critical stages, with a higher risk of errors. Resin and hardener must be proportioned according to a well-defined ratio, indicated by the manufacturer and carefully mixed in order to avoid material waste and long production time. Mixing with the wrong ratio can cause the product to harden, resulting in waste in the manufacturing process. For this purpose, the MMD (Meter Mix Dispensing) dispensers were created: easy-to-use precision equipment that proportionate, mix and dose in a reliable and repeatable manner.

Automating the dispensing process
ISCRA dielectrics, a distributor specializing in fluid dispensing equipment, has solved the application issues of a major brushless motor manufacturer that needed to soak the stator of small motors with a two-component epoxy resin. The critical aspect laid in the delivery stage, which involved the slow and in-sequence deposition of 10 doses of 1.0 g each within a very small space. A constraint that forced the operator to perform a long and accurate filling job, constantly taking care to avoid the leakage of resin from the stator casing. The operation was performed completely by sight, with great time consumption and psycho-physical effort. The solution studied by the ISCRA dielectrics technical staff made the whole process (from proportion to dispensing) completely automated. The solution is called STD DUO 600, a volumetric dispenser with progressive cavitation pumps, driven by two brushless motors with encoder.

No imperfections
By programming the dispenser controller, it was possible to create a work recipe capable to set the basic parameters of the product: resin/hardener volumetric ratio; unit volume per dispensing cycle; dispensing speed: number of dispensing cycles; dispensing interval. Once these simple parameters were set, and after some experimental tests, they moved on to production. The result was to prepare a correct proportion of resin and hardener, mix it carefully using a simple static disposable mixer and, finally, deliver the (10) 1.0 g doses in a fully automatic way, completely encapsulating the small stator without any imperfection. The STD DUO 600 technology makes it possible to dose a wide range of fluids, from those with very low viscosity (water, oils, etc.) to very viscous products (up to 1,000,000 Cps) such as greases, pastes, silicones , various sealants, two-component resins – as well as additives with abrasive charges – ensuring a homogeneous and constant supply in every situation.