Patent ID: 7117580

Claim:
A method of manufacturing a watertight brushless fan motor comprising: preparing a stator assembly combining a stator and a circuit substrate; preparing a case comprising a bearing supporting cylindrical section, a plate-like section extending from an end of the bearing supporting cylindrical section in a direction perpendicular to a center line of the bearing supporting cylindrical section, and an outside cylindrical section extending from an outer end of the plate-like section in a direction of the center line of the bearing supporting cylindrical section along the bearing supporting cylindrical section; preparing a die comprising a cylindrical body and a blockage wall having an engaging portion that can be engaged with the bearing supporting cylindrical section, for blocking one opening of the cylindrical body, other opening of the cylindrical body being blocked by the plate-like section and the outside cylindrical section of the case with the die being fixed to the case; preparing an annular member being made of a resin and being mounted to the die, for aligning a center line of the cylindrical body of the die over the center line of the bearing supporting cylindrical section with an inner peripheral end surface of the annular member being brought into contact with an outer peripheral surface of the outside cylindrical section when the die is fixed to the case; mounting the stator assembly on the bearing supporting cylindrical section of the case; engaging the bearing supporting cylindrical section with the engaging portion, bringing the inner peripheral end surface of the annular member into close contact with the outer peripheral surface of the outside cylindrical section of the case, and then attaching the die with the annular member to the case; fixing the die and the annular member to the case; and pouring an insulating resin into the die to mold spaces between the plate-like section and the bearing supporting cylindrical section with the insulating resin in such a manner that the stator and the circuit substrate are included inside.