Drive device for coolant pumps

Abstract

A drive device for coolant pumps having a pump shaft, a boss having a bore in which the pump shaft is rotatably disposed and a driven gear made from synthetic resin to transmit the rotational power from the crankshaft to the impeller to move the coolant into circulation through the coolant jacket for engine cooling, is disclosed which comprises a pin, fixedly implanted in radial pattern in the circumference of the pump shaft, a couple of radially extending grooves outwardly from the center of the driven gear bore in that side of the driven gear facing the impeller to receive therein fittingly the pin, respectively, and a washer mounted about the pump shaft between the front end face of the bore and the pin so as to prevent the pump shaft from falling off from its bore. When the driven gear is driven by the crankshaft, the pin closely fitted in the grooves transmits the torque to the pump shaft, without any slip. This arrangement can eliminates the conventional metal bushing fitted in the driven gear about the pump shaft to insure fit between the pump shaft and driven gear.

Dependencies are inferred from the claim text.