A method includes: forming a sand core including a main portion and core-head members connecting the main portion; applying a casting process to produce a frame casting having a first end, a first-end inner wall, a second end, a second-end inner wall, a closed water channel between the first-end inner wall and the second-end inner wall, a water inlet, a water outlet and sand-expelling holes at the first end; shaking the frame casting to have part of the sand core to leave the closed water channel via the water inlet, the water outlet and the sand-expelling holes; pressurizing a fluid into the closed water channel via the water inlet to carry the rest of the sand core to leave the closed water channel via the sand-expelling holes and the water outlet; and applying screw bolts to lock the sand-expelling holes to manufacture a closed-type liquid-cooling motor frame.

A hollow metal part is used as a pipe component for a refrigerant flow path of a rotating electrical machine adapted to cool a stator coil with a refrigerant. The rotating electrical machine includes a connection arm that couples the stator coil and a power supply terminal at a stator coil end portion of the stator coil, and an insulating hose that is coupled to the stator coil and the connection arm through a first hollow metal part in order to supply the refrigerant to the stator coil and the connection arm. The first hollow metal part is formed integrally by joining a part formed of stainless steel to a part made of oxygen-free copper.

A conductive coil for an electric application having a cooling channel for a coolant liquid or gas. The coil includes a wire winding of a plurality of wire turns. The wire winding is compressed about a cooling channel which is disposed between adjacent turn segments of the plurality of wire turns. The wire winding is formed and pressed against a shaping element to form the coolant channel within the compressed winding.

A method for repairing solder joint leakages on a connection unit designed to feed cooling water into hollow metallic stator bars of a stator winding of an electrical machine, wherein the connecting device includes a metallic bar-receiving body with a passage opening in which the stator bars are inserted, aligned using metallic spacers and connected fluid-tightly to the bar-receiving body and to the spacers by substance bonding using a solder. The free ends of the stator bars terminate substantially flush with the free ends of the spacers and with an end face of the bar-receiving body. A cup-like metallic cover element surrounds and connects the free ends of the stator bars fluid-tightly to the bar-receiving body by substance bonding so as to form a cooling water chamber. A metallic cooling water line connection is provided on the cover element and connected fluid-tightly to the cooling water chamber.

An electrical motoris provided, comprising a rotor (2), a stator (3), and a housing (4) enclosing the rotor (2) and the stator (3). The stator (3) comprises at least one end turn connection device (6) arranged on one axial end thereof, and a plurality of hollow winding pins (5) extending through the at least one end turn connection device (6).

An assembly and a method for connecting ends of generator stator coils with a manifold are presented. The assembly includes an adapter having a sleeve connection conduit connected to a sleeve of the manifold and two hose connection conduits. Two hoses are connected between the two hose connection conduits and end of top stator coil and end of bottom stator coil respectively. The adapter provides two separate coolant flow paths from one sleeve of the manifold to the top stator coil and the bottom stator coil through two hoses. The assembly provides a simple modification to resolve connection issues between generator stator coils and manifold during stator coil rewinding as well as a possibility to monitor coolant temperatures of top and bottom stator coils independently.

A conductive coil for an electric application having a cooling channel for a coolant liquid or gas. The coil includes a wire winding of a plurality of wire turns. The wire winding is compressed about a cooling channel which is disposed between adjacent turn segments of the plurality of wire turns. The wire winding is formed and pressed against a shaping element to form the coolant channel within the compressed winding.

A method for producing a stator for an electric machine includes providing a stator with an annular stator body, from which a plurality of stator teeth protrude radially inwardly, wherein an intermediate space is formed in each case between two stator teeth that are adjacent in a circumferential direction, encapsulating two stator teeth adjacent in the circumferential direction with a first plastic mass, arranging a stator winding on a stator tooth, fixing the stator winding on the stator tooth by encapsulating said stator winding with a second plastic mass, following the encapsulation with the first plastic mass and before the fixing of the stator winding, a first mask is introduced into the intermediate space between the two stator teeth, such that the volume of the intermediate space that is filled with the first mask remains free from the second plastic mass to form a cooling duct during the encapsulation.

According to an embodiment, a stator winding comprises: a plurality of stator bars; and a connection structure. Each of the stator bars penetrates each of the stator slots and has at least one hollow element wire inside of which a flow hole for a cooling medium is formed. A connection structure has: a sleeve whose axial one end is fitted to the vicinity of an end of the stator bar; a closing plate disposed at the other end of the sleeve; and a hollow extension pipe. The hollow extension pipe is disposed in a space defined by the sleeve and the closing plate at the end of the stator bar, and makes the flow hole of the hollow element wire and an outside of the space communicate each other. A brazing material is filled in the space.

According to an embodiment, a coil assembling method comprises: a bundling step bundling coil elements including a hollow coil element and extending parallel to one another, thereby forming a coil element bundle; a mold-setting step setting a mold around the coil element bundle formed in the bundling step; a first brazing step supplying a first brazing material into the mold while heating at least one of the first brazing material and the coil element bundle, thereby filling the mold with the first brazing material; a mold-removing step removing the mold after cooling and hence solidifying the first brazing material; and a second brazing step brazing a water supply/drain box to an end of the coil element bundle brazed with the first brazing material by using a second brazing material thereby communicating a hollow part of the hollow coil element with an inner space of the water supply/drain box.