Centrifugal finishing apparatus embodying improved seal and method

Abstract

Apparatus for finishing parts or workpieces in the presence of liquid in a finishing chamber having outer upstanding wall and bottom members which are symmetrically arranged about a common axis and relatively rotatable about the axis, for imparting motion to the contents of the chamber for finishing of the parts or workpieces therein, and means for causing the relative motion, having an improved resilient seal between the bottom and the wall members in the form of a resiliently-restricted zone, comprising a partial bottom-forming lip or other partial bottom-forming element, and means for pumping fluid into said zone at a sufficient pressure so that the fluid enters the zone and then flows upwardly into the finishing chamber, is disclosed. Storage chambers below the bottom and adjacent the upstanding wall are employed for storage of fluid to be introduced into the finishing chamber. Separate drainage means for internal drainage of fluid from the finishing chamber is provided so that no drainage of fluid and 'fines' goes through the seal. In a preferred embodiment a rotatable shaft associated with a rotatable bottom is hollow and passageways are provided from interior of the finishing chamber cavity into the hollow passageway for drainage of fluid out of the apparatus. A greatly improved seal having an extended life and permitting closer tolerances, as well as closer control and more efficient maintenance of tolerances, is thereby provided. An improved method for finishing parts involving purging of the seal comprising the resiliently-restricted zone with fluid under pressure from the various aforementioned sources outside the finishing zone proper as above-described is also disclosed.