Patent ID: 7347674
Filing Date: 2008-03-25
Classification: F04D,H02K

Abstract:
1. A fluid pump of the type in which a housing assembly has a first sub-housing having an electric motor therein which is in line with a second sub-housing having an impeller therein, with the motor having a rotor shaft which extends through a seal of the first sub-housing into the second sub-housing and with the impeller mounted on the rotor shaft so as to be rotatable by the motor, and the second sub-housing having inlet and outlet ports through which fluid, such as water, is able to be pumped through the second sub-housing: wherein the first sub-housing containing the motor is of double-walled construction enabling fluid cooling of the motor, with the double-walled construction provided by a motor casing which houses a stator and the rotor shaft of the motor and by an outer shell spaced from and enclosing the motor casing; wherein, within a chamber of the first sub-housing defined between the casing and shell, there is provided a plurality of elongate baffles for guiding cooling fluid for flow over a major part of the external surface of the casing whereby the operating temperature of the motor is able to be controlled by heat energy extracted by the fluid from the casing; wherein the baffles are of a form providing for a flow of cooling fluid along substantially the full axial length of the motor casing; wherein the baffles provide flow from a first end of the first sub-housing adjacent to the second sub-housing, along the casing to its second end and then back along the casing to the first end by there being alternating longer and shorter baffles, with the longer baffles extending substantially to the second end of the casing and the shorter baffles terminating short of the longer baffles at that second end, whereby cooling fluid is able to flow to the second end of the casing between alternate pairs of baffles, and then pass around the end of each shorter baffles of each pair for return flow to the first end of the casing between next adjacent pairs of baffles; and wherein the first sub-housing has a transversely extending drainage vent which is located at the end of the first sub-housing adjacent to the second sub-housing, the vent extends from the shaft and opens to at least one of opposed sides of the first sub-housing and is located between a respective end wall of the outer-shell of the first sub-housing and of the motor casing, and the transverse extent of the vent is defined by the end wall of the outer shell, a transverse pair of opposed side wall members and a transverse basal wall member which extends between the side wall members, and the shaft extends from the motor casing between the side wall members and through the basal wall member and the end wall.