Method and station for the construction of a stator winding with rigid bars for a rotary electrical machine

Abstract

Method and station (9) for the construction of a stator winding (3) with rigid bars (4) for a rotary electrical machine; an insulated wire (12) of electrically conductor material and provided on the outside with an insulating layer (14) is unwound from a coil (11); a final end of the insulated wire (12) is bent in a ''U'' shape so as to create a bar (4) having two legs (5) connected to one another by a cusp (6); the insulated wire (12) is transversely cut to separate the rigid bar (4) from the remaining part of the wire (12); and the bar (4) is inserted into a stator slot of a magnetic core (2) of a stator (1); furthermore, the electrical conductivity is measured between the core (13) and the outer surface of the insulated wire (12) by means of a first electrode (25) electrically and permanently connected to the core (13) of the insulated wire (12) and a second electrode (26), which rubs against the outer surface of the insulated wire (12).

Description

technical field [0001] The invention relates to a method and a construction station for constructing a stator winding with rigid bars in a rotating electric machine. Background technique [0002] Usually, the stator winding of an electric machine is obtained by linear flexible conductors with circular cross-section, which are initially wound into coils, which are then inserted into stator slots and then electrically connected to each other. Said construction method is complex and cannot be automated because it is difficult to automate the insertion of the coils into the stator slots, does not have a stable shape of the coils and has to deform while passing through the small axial openings of the slots. [0003] In order to overcome the constructional difficulty of obtaining a stator winding from a linear flexible conductor with a circular cross section, it has been proposed to obtain the stator winding by a rigid rod with a rectangular cross section. In the stator winding o...

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Problems solved by technology

An overly thick insulating layer is especially negated, since on the one hand it increases the production costs of the rod and on the other hand reduces the filling factor of the slot (i.e. the ratio between the useful conductor cross-section present inside the coil and the total cross-section of the slot itself), Reduced (other things being equal) motor power efficiency and motor rated performance

[0006] In addition, it has been noticed that when performing a bending of a rigid rod into a "U" shape, at the part where a greater deformation occurs due to the bending itself, this part of the insulating layer separates, which occurs with a relatively high frequency, Of course, when a part (however a small part) of the insulation is detached, the corresponding rod needs to be discarded, which significantly increases the production cost of the motor

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