Central heating fluid circulation pump - has end of non-metallic shaft accessible for spanner from outside and shaped to prevent bending moment on shaft

摘要

The arrangement is intended for a central heating circulation pump with non-metallic shaft (1). One shaft end (2) is accessible from outside the pump housing after removing a plug and is shaped to permit putting a spanner on to determine the direction of rotation or to free a seized pump rotor. The tool engagement faces (2) of the shaft end are shaped such in relation to the tool, that the tool can only apply a torque and no bending movement. The faces may taper towards the shaft axis (3). The faces may be parts of spherical or cylindrical surfaces, shaped for external or internal tool engagement.