Engine water pump assembly and method of making same

Claim 1

In an automotive engine water pump assembly having a rotatable shaft with a drive end provided with connection means for rotating the shaft and an opposite impeller end upon which a water impeller is mounted, and with the shaft being divided along its length into a bearing portion adjacent the drive end and a sealing portion adjacent the impeller end; and having a bearing surrounding the shaft bearing portion; with a housing having a body surrounding the shaft and bearing along their lengths and having an enlarged chamber around the impeller end of the shaft, within which the impeller is positioned; and a seal surrounding the shaft seal portion for sealing against the flow of water from the housing impeller chamber to the housing bearing surrounding part, the improvement comprising: said bearing being formed of a unitary, tubular bushing whose interior surface is adjacent the overlapped bearing portion of the shaft; and said bearing having an integral, annular flange formed on one end for surrounding the part of the shaft sealing portion which is adjacent the shaft bearing portion; the housing being formed of an integral plastic molding, with the bearing being bonded to the surrounding surface of the interior of the wall of the housing body; and said seal extending within and sealing the shaft against said bearing flange; whereby the housing and bearing may be formed in a single subassembly, and the shaft and seal may be formed as a separate subassembly, and the shaft and seal subassemblies may be inserted in an axial direction into the housing through the impeller chamber to position the shaft bearing portion within the bearing for assembly of the pump.

Claim 6

A method for making an engine water pump assembly having a rotatable shaft with a drive end and an impeller end upon which a water impeller is mounted, with the shaft being divided between its ends into a bearing portion adjacent the drive end and a sealing portion adjacent the impeller end, with a bearing surrounding the shaft bearing portion, and a housing formed with a body surrounding the shaft and the bearing and with an enlarged chamber at the impeller end of the shaft within which the impeller is positioned, and a seal surrounding the shaft seal portion and arranged to seal water flow from the housing impeller chamber to the part of the housing surrounding the bearing, comprising: forming a bearing in the shape of a tubular bushing having an interior wall sized for closely surrounding the shaft bearing portion, and having an exterior wall and an annular flange extending longitudinally of the exterior wall; molding the housing out of plastic within a molding cavity within which the bearing has been prepositioned with its flange extending towards the impeller chamber for simultaneously molding the housing and bonding it to the exterior wall of the bearing and the annular flange to form a housing-bearing subassembly; inserting the preformed shaft in a longitudinal direction into the bearing through the housing-enlarged chamber, and arranging the seal to fit around the shaft at least partially within the annular flange, and arranging the impeller within the impeller chamber.

Claim 7

A method for making an engine water pump assembly having a rotatable shaft with a drive end and an impeller end upon which a water impeller is mounted, with the shaft being divided between its ends into a bearing portion adjacent the drive end and a sealing portion adjacent the impeller end, with a bearing surrounding the shaft bearing portion, and a housing formed with a body surrounding the shaft and the bearing and with an enlarged chamber at the impeller end of the shaft within which the impeller is positioned, and a seal surrounding the shaft seal portion and arranged to seal water flow from the housing impeller chamber to the part of the housing surrounding the bearing, comprising: forming a bearing in the shape of a tubular bushing having an interior wall sized for closely surrounding the shaft bearing portion, and having an exterior wall and an annular flange extending longitudinally of the exterior wall; molding the housing out of plastic within a molding cavity within which the bearing has been prepositioned with its flange extending towards the impeller chamber for simultaneously molding the housing and bonding it to the exterior wall of the bearing and the annular flange to form a housing-bearing subassembly; inserting the preformed shaft in a longitudinal direction into the bearing through the housing-enlarged chamber, and arranging the seal to fit around the shaft at least partially within the annular flange, and arranging the impeller within the impeller chamber.