Cartridge-type bearing seal for machine tool spindle

Abstract

A cartridge type bearing seal facilitates the prevention of contaminant ingress between a spindle rotor and a spindle housing, particularly in situations where a circumferentially uniform fluid pressure is generated within the annular volume of the spindle housing. The cartridge includes ringlike rotor and stator sections which can be compressed axially to snap fit together, in a manner which enables relative rotation about a common axis. When interconnected, the sections define an inside surface and an outside surface, and a fluid flow path which extends radially outwardly therebetween, and which traverses a collar and tangs construction which enables the snap fit connection. The tangs are arcuate in shape and spaced equidistantly around the axis. The total arcuate space occupied by the tangs is relatively small, compared to the total arcuate space residing between the tangs, and bounded by the two sections adjacent the collar. This structure allows the pressurized purge fluid to flow outwardly from the cartridge during use, to prevent contaminant ingress during operation of the spindle. This construction may be readily adapted to accommodate a spindle of virtually any size or shape, at relatively low cost, and is particularly suitable for retrofitting an existing spindle which has experienced a failed seal.