Keyed insert plate for curved rotary lobe pump chamber walls

Abstract

A rotary lobe pump comprises a pump housing defining an obround pump chamber and a pair of lobe rotors in the pump chamber. The rotors are mounted on rotatable shafts which are connected by timing gears such that the rotors rotate to cause a fluid to displace through the chamber. The pump chamber is defined in the pump housing by opposed front and rear end walls which are perpendicular to the axes of the rotors and by arcuate side walls with which the rotors make sealing contact and which gradually wear out thereby reducing the tightness of the seal and thus the pumping efficiency of the rotary lobe pump. The rear end wall includes two removable end wear plates which each include a rearwardly projecting key engaged in a corresponding keyway defined in the pump housing with bolts extending from outside of the housing inwardly towards the end wear plates and engaging the keys thereof for securing the end wear plates to the housing. The arcuate side walls take the form of removable curved wear plates which are each semi-cylindrical in shape and which each include an outwardly directed radial curved key which is engaged in a corresponding curved keyway defined in the housing. Bolts which extend through the housing into the keys retain the curved wear plates in position in the pump chamber. The rear ends of the curved wear plates are supported by the peripheral edges of the end wear plates.