Drive system for a frozen food product dispenser

Abstract

In one preferred embodiment, a freeze cylinder is used having a closed end and an open end. Around the cylinder adjacent the closed end, a three phase DC stator is placed. The stator is connected to a three phase DC power supply that includes an AC to DC inverter. An electrical rotor is positioned in the cylinder adjacent a spacer plate. The rotor consists of metal ring around the perimeter of which are secured eight permanent magnets. The magnets and tube are encased in a food grade plastic creating a rotor disk having a central hole. A scraper extends along the axis of the cylinder and includes a central rod end that extends through the rotor and into the bearing of the spacer disk. The scraper includes a skirt portion around the rod end for securing to the rotor. In operation, the stator and rotor constitute a three phase DC motor that is operated by the power supply to rotate the scraper within the cylinder. No dynamic seal is needed as no rod end of the scraper is required to extend out of the cylinder for mechanical connection to a drive motor. In a further embodiment, a freeze cylinder is used that also has a closed end and an open end. A conventional motor and gear drive are used, however the gear drive is adapted to rotate a circular magnetic drive plate. This external magnetic drive plate is positioned so that the magnetic surface thereof faces and is closely adjacent the exterior surface of the cylinder closed end. Within the cylinder a similar circular magnetic ring is rotatively mounted therein carried on and within a stainless steel disk. This internal disk is secured to a rod end of the scraper and the magnetic face of the magnetic ring faces the internal surface of the cylinder end and is positioned closely adjacent thereto. In operation, the external drive plate is magnetically coupled to the magnetic ring of the internal driven disk wherein rotation of the driven disk results in rotation of the scraper.