GB930911A - Improved means for controlling the temperature of an internal combustion engine - Google Patents

Abstract

930,911. Axial - flow fans. H. E. B. DEVELOPMENTS Ltd. June 8, 1961 [June 23, 1960], No. 21999/60. Class 110 (1). [Also in Groups XXIV and XXVII] A combined water pump and fan assembly for a water-cooled I.C. engine for a road vehicle having a fan 10 coaxial with the water impeller 7 and its shaft 5, comprises a pushrod 14 in an axial bore 5a extending from end to end of the impeller shaft 5 and is rotatable with, but axially movable relative to, the impeller shaft 5, the push-rod 14 and the fan hub 12 being provided with complementary interengageable formations 14a, 12b constituting the elements of a clutch, means 11 responsive to conditions affected by engine temperature and adapted to move the push-rod 14 axially to engage and disengage the clutch elements, and means associated with the push-rod 14 to facilitate gradual engagement of the clutch, whereby with the engine running, when the latter exceeds a predetermined temperature, the means 11 moves the push-rod 14 axially in one direction to gradually engage the clutch to rotate the fan 10 and, when the engine falls to the predetermined temperature, the means 11 moves the push-rod 14 axially in the other direction to disengage the clutch. The formation 14a, of square or other non-circular crosssection, is housed in a counterbore 5b of similar cross-section and is rounded at its end to facilitate gradual engagement with the formation 12b of corresponding cross-section. The means 11 responsive to conditions affected by engine temperature may be a thermostat of the bellows type immersed in the circulating water, but is preferably a thermostat of the form shown which consists of a brass or equivalent housing containing a wax which surrounds a flexible material. Associated with the latter is a plunger 15 or the like which moves the rod 14 axially to engage the clutch upon expansion of the wax due to a temperature rise. Instead of a thermostat a device which is responsive to the pressure of the circulating water (and therefore only indirectly responsive to temperature) may be utilized. Such a device may be a diaphragm or rubber or other resilient material.