Positive displacement rotary pump with bearings in countersunk portions of the rotors

A positive displacement rotary pump for circulating a viscous product, comprising a housing having an interior cavity through which the product is pumped, one wall of said cavity being defined by a removable cover;

• a pair of spaced substantially parallel shafts extending into said cavity, each shaft having one end thereof supported by said cover and a second end extending through a wall of said cavity opposite said cover;
• first means for driving and supporting the second ends of said shafts;
• meshing rotors mounted on said shafts, each rotor having internal means in driving engagement with said shaft on which the rotor is mounted, said internal means being located between planes defined by opposing walls forming the cavity, said rotors being disposed entirely within said cavity, the endface of each rotor adjacent said shaft one end having a substantial countersunk portion with a terminus adjacent said rotor internal means;
• bearing means substantially isolated from the product and disposed entirely within the countersunk portion of said rotor and supportingly engaging segments of said shaft one end, said bearing means having at least a portion thereof disposed adjacent the rotor internal means;
• and second means fixedly carried by said cover and extending into said countersunk portion and supporting said bearing means;
• each shaft being provided with an exterior shoulder adjacent the cavity-forming surface of the wall opposite said cover and against which one endface of a rotor engages and adjustable means carried on said shaft and spaced from said shoulder for engaging said rotor whereby the shoulder and adjustable means coact to restrain relative movement of said rotor on said shaft;
• said adjustable means including an elongated liner disposed within the countersunk portion and encompassing a segment of the shaft, one end of the liner abutting the terminus of the rotor countersunk portion, and a longitudinally adjustable element removably mounted on the shaft one end and engaging an opposite end of said liner and retaining the latter in abutting relation with said rotor terminus.