Lubricating oil circuit of gear type pump - contains thermostatically controlled valves between high and low pressure sides

摘要

The pump casing (11) contains two shafts (16) which carry meshing gear wheels (15). The projecting ends of the shafts are supported in bearings (18, 19) in bearing blocks (13, 14) within the casing (11). Each bearing block has two blind holes (27) drilled from the end face inwards. A radial aperture (29) connects each of these holes with one of the bearing surfaces. A coiled bimetal strip (32) is inserted in the blind hole (27) and blocks the opening of the radial aperture (29) when it is cold and opens the passage when the temperature rises. Oil can flow through this aperture from the high pressure outlet (34) of the pump and leak back through the bearing to the low pressure connection (35). Thus the oil flow is controlled to limit the bearing temperature.