Gear pump bearing

A method of manufacturing a gear pump bearing block, the method including steps of:

• providing a bush formed of antifriction alloy, the bush having a cylindrical portion providing a bore adapted to receive a bearing shaft of a gear of the pump, and further having a flange portion extending radially outwardly at an end of the cylindrical portion to provide a thrust face adapted to slidingly engage with a side surface of the gear;
• forming an annular groove in the rear face of the flange portion and surrounding the bore, the groove being spaced from the surface of the bore and from the thrust face;
• partially filling the annular groove with an annular insert having a depth less than the depth of the groove, thereby forming an enclosed volume constituting an annular gallery between a bottom face of the insert and the floor of the groove;
• forming an inlet to and an outlet from the annular gallery such that, in use, fluid flows from the inlet, through the annular gallery to provide cooling of the thrust face, and then to the outlet;
• and
• covering a radially outer surface of the cylindrical portion and the rear face of the flange portion of the bush with a backing layer, the backing layer being formed of relatively less dense alloy compared to the antifriction alloy.