Patent Description:
In the field of dynamo-electric machines, it is known to use apparatuses and methods for manufacturing coil members to be housed in respective slots formed in the cores of such machines.

Coil members can be used in stators of electric motors or electric generators. In this respect, a number of solutions have been disclosed in International patent application No. <CIT>.

Coil members made in accordance with the present invention may have a fork-like shape or other shapes as well, e.g. they may have an undulated configuration. Generally, the electric conductor has a relatively large cross-section, which permits the formed coil member to be self-supporting, i.e. the shape of the coil member is permanently formed according to a specific geometric configuration, which will not change unless considerable bending forces are applied thereto. Fork-shaped coil members are commonly called "hairpins" in the industry. Another shape, i.e. the undulated configuration, is described in European patent publication <CIT>.

A typical production sequence involving formed hairpins may envisage the following: inserting specific hairpins into respective slots of the core of the dynamo-electric machine, bending the end portions of the hairpins that extend beyond an end of the core of the dynamo-electric machine, welding together predetermined hairpin ends that have become adjacent to each other as a result of the previous bending operation. International patent application <CIT> describes operations of this kind and solutions to ensure an accurate alignment of the hairpin ends that need to be welded together.

The bending necessary for making a coil member requires repeated steps of feeding predetermined lengths of an electric conductor in alignment with a bending tool, as described in the above-mentioned International patent application <CIT>.

During the feeding steps, a bending tool engages the electric conductor and makes some predetermined movements to cause the electric conductor to be permanently bent into a desired shape.

A cutting operations is carried out in order to remove a formed coil member from the rest of the electric conductor, so that such electric conductor can subsequently be fed for making other coil members. International patent application <CIT> describes operations carried out in accordance with these principles.

Furthermore, an apparatus and a method for manufacturing coil members of the above-specified type are also described in International patent application <CIT>.

It is one object of the present invention to provide an apparatus and a method for manufacturing coil members for insertion into slots of the core of a dynamo-electric machine, which are an improvement over the prior art.

In particular, according to the present invention, higher accuracy and repeatability are attained in the bending of the conductor.

According to the present invention, this and other objects are achieved through an apparatus and a method having the technical features set out in the appended independent claims.

It is understood that the appended claims are an integral part of the technical teachings provided in the following detailed description of the present invention. In particular, the appended dependent claims define some preferred embodiments of the present invention that include some optional technical features.

Further features and advantages of the present invention will become apparent in light of the following detailed description, provided merely as a non-limiting example and referring, in particular, to the annexed drawings as summarized below.

With particular reference to <FIG>, there is shown a coil member <NUM> corresponding to a hairpin manufactured in accordance with the teachings of the present invention, starting from an electric conductor <NUM> having a rectangular cross-section. As shown in <FIG>, the hairpin has leg portions 20b and 20c, which are substantially straight, and a head portion 20a. A twisted portion, designated as 20d, is adapted to orient the leg portions by an angle A, so that axes 20e of leg portions 20b and 20c are aligned with radial axis <NUM> of a slot <NUM> of a core (e.g. a stator core, as shown in <FIG>), into which leg portions 20c are fully inserted.

The coil member (not numbered) of <FIG> has an undulated configuration, which can be obtained by following the teachings of the present invention, as will be made clear hereinafter.

With particular reference to <FIG>, there is shown a longitudinal section of an apparatus for manufacturing coil members, like those described above, starting from conductor <NUM>. The apparatus is made as illustrated in International patent application <CIT>,. The number references shown in <FIG> of the present patent application correspond to those described and illustrated in the above-mentioned International patent application <CIT>, and therefore, for the sake of clarity and completeness, they are shown in such figure as they appear in said International patent application. As will be described below, <FIG> only represents one possible example of an apparatus to which the teachings of the present invention are applicable.

The apparatus comprises feeding means of a per se known type, which are configured for feeding portions of conductor <NUM> having a predetermined length through an aperture <NUM>. One example of such feeding means has been described in International patent application <CIT>. In such International patent application, the feeding means are provided in the form of a pair of motorized belts pressing on conductor <NUM> and, by friction, applying a pull/thrust force to conductor <NUM>. A further example of such feeding means has been described in International patent application <CIT>. With reference to <FIG> and <FIG> of such international patent application, the feeding means include a pair of clamping units, each one of which is configured for clamping the electric conductor by means of a pair of jaws. In a per se known way, each pair of jaws can hold and release the electric conductor in a co-ordinated and intermittent manner, driven by the clamping units, in order to feed it as desired.

With particular reference to <FIG>, the portions of conductor <NUM> are fed by the feeding means along a feeding axis AC' in a feeding direction <NUM>' and adjacent to one or more engagement members <NUM>, <NUM>' capable of engaging conductor <NUM>. Aperture <NUM> is positioned before engagement members <NUM>, <NUM>' in feeding direction <NUM>'.

Furthermore, the apparatus comprises moving means, also of a per se known type, configured for moving engagement members <NUM>, <NUM>' with respect to aperture <NUM> to engage a portion of conductor <NUM> with the engagement members in a transverse direction (designated by letters X and X', represented in <FIG> as a • and an x encircled by respective circles to indicate an outgoing direction and, respectively, an incoming direction in the sheet plane) with respect to the feeding axis AC' for bending conductor <NUM>. One example of such moving means has been described in the above-mentioned International patent application <CIT>, from which <FIG> was taken, and therefore reference should be made to the descriptive text of such International patent application for a description of such moving means.

According to the present invention, as will be described more in detail below with particular reference to the two exemplary embodiments illustrated in <FIG> (first embodiment) and in <FIG> and <FIG> (second embodiment), the apparatus comprises a pressing member <NUM> configured for selectively moving and engaging conductor <NUM> to cause said conductor <NUM> to engage a reaction surface <NUM> proximate to aperture <NUM> through which said conductor <NUM> is configured to be fed. Pressing member <NUM> is positioned, along feeding direction <NUM>' of conductor <NUM>, before engagement members <NUM>, <NUM>' capable of bending conductor <NUM>.

Owing to these measures, it is possible to precisely and repeatedly control the engagement between conductor <NUM> and reaction surface <NUM>. This results in higher accuracy and repeatability of the bending of conductor <NUM>, which is achieved through the action of engagement members <NUM> and <NUM>'. Moreover, according to a preferred aspect, the accurate control over the engagement between conductor <NUM> and reaction surface <NUM> and the consequent programmability of the forces applied to conductor <NUM> make it possible to use he same apparatus for bending differently sized conductors (e.g. to make the apparatus compatible with conductors having different diameters) and to obtain hairpins having different configurations.

With reference to <FIG>, the following will describe more in detail further preferred technical features of the apparatus made in accordance with the first embodiment of the present invention. Such figure shows, in fact, some preferred or optional details associated with pressing member <NUM>.

Preferably, pressing member <NUM> is configured to apply a force on conductor <NUM> in a thrust direction PR substantially transverse to feeding direction <NUM>' during the bending of the conductor carried out by engagement members <NUM> and <NUM>', in order to cause conductor <NUM> to engage reaction surface <NUM>. More preferably, pressing member <NUM> is configured for assuming a selectable predetermined position along said thrust direction PR, which is substantially transverse to feeding direction <NUM>', to apply the force on conductor <NUM>.

Advantageously, but not necessarily, the apparatus further comprises a distribution nozzle <NUM> axially including, at its end, aperture <NUM> through which electric conductor <NUM> is configured to pass. As will be described more in detail hereinafter, in such first embodiment distribution nozzle <NUM> is mounted movable with respect to a frame <NUM> (or, more generally, a supporting portion) of the apparatus.

In particular, the apparatus comprises an actuator <NUM> configured for causing pressing member <NUM> to move in the substantially transverse thrust direction PR. More particularly, actuator <NUM> is configured for translatably moving in feeding direction <NUM>'.

Preferably, the apparatus further comprises a transmission mechanism <NUM> configured for converting a movement of actuator member <NUM> into a movement of pressing member <NUM> in the substantially transverse thrust direction PR. In particular, transmission mechanism <NUM> is configured for converting a translational movement of actuator <NUM> in thrust direction <NUM>' into a movement of pressing member <NUM> in thrust direction PR.

Still with reference to the first embodiment shown in <FIG>, actuator member <NUM> is integral with distribution nozzle <NUM>. In particular, the apparatus also includes a connection member <NUM> configured for mechanically connecting actuator member <NUM> and distribution nozzle <NUM>, making them integral with each other.

By way of example, as illustrated in <FIG>, actuator <NUM> comprises a shaft <NUM>, while connection member <NUM> comprises a flange <NUM>. Shaft <NUM> and flange <NUM> are described and indicated herein by means of the same reference numerals used in International patent application publication <CIT>. As described therein by way of non-limiting example, shaft <NUM> is connected to distribution nozzle <NUM> through flange <NUM>. Also, shaft <NUM> can be moved in feeding direction <NUM>' by a worm-screw drive unit <NUM>. Such drive unit <NUM> causes guide <NUM>, supported by rail <NUM>, to translate in feeding direction <NUM>' (and in the opposite direction), depending on the imparted direction of rotation. Arm <NUM> is supported by guide <NUM> and is fixed to the end of shaft <NUM>, which can thus translate in the feeding direction when drive unit <NUM> is operated, thereby moving distribution nozzle <NUM>.

Preferably, distribution nozzle <NUM> has a transverse passage <NUM> through which pressing member <NUM> can pass. Moreover, in a position facing towards transverse passage <NUM>, distribution nozzle <NUM> internally carries reaction surface <NUM>, against which conductor <NUM> is configured to engage under the action of pressing member <NUM> as the latter passes through transverse passage <NUM>.

In such first illustrative embodiment, with reference to <FIG>, pressing member <NUM> is configured to apply said force on one side only of the cross-section of said conductor <NUM>.

In particular, with reference to <FIG>, pressing member <NUM> is a terminal finger 1a configured to move and push, in a controlled manner, conductor <NUM> against reaction surface <NUM>.

In the first embodiment, transmission mechanism <NUM> is a rod - crank mechanism. In particular, transmission mechanism <NUM> is configured for converting the translational movement imparted by actuator member <NUM> (and then transferred from connection member <NUM> to distribution nozzle <NUM>) into a movement, in particular a rotational or oscillating movement, of pressing member <NUM> in thrust direction PR. Thus, pressing member <NUM> - and preferably its terminal finger 1a - will move to push conductor <NUM>.

In the first embodiment, said rod - crank mechanism comprises a rod member 4a and a crank member 4b hinged to and co-operating with each other.

Rod member 4a is hinged, on one side, to a frame <NUM> (or a stationary support portion) of the apparatus and, on the other side, to crank member 4b. In turn, crank member 4b hinged to rod member 4a is rotatably supported around a pivot member <NUM> carried by distribution nozzle <NUM>.

More in detail, by way of example, the fixed point where rod member 4a is hinged to frame <NUM> is indicated by reference 8a, while the movable point where rod member 4a is hinged to crank member 4b is indicated by reference 8b. Furthermore, the movable point where crank member 4b is rotatably supported (which can move integrally with pivot member <NUM> of distribution nozzle <NUM>) is indicated by reference 8c.

In particular, crank member 4b is configured for moving pressing member <NUM> in thrust direction PR; in particular, pressing member <NUM> is integral with crank member 4b, being for example carried radially thereon. Pivot member <NUM> is mounted to distribution nozzle <NUM>, e.g. being a shelf fixed to (in particular, by means of screws) and protruding transversally from distribution nozzle <NUM>.

Preferably, the position of rod member 4a relative to crank member 4b is adjustable, so that the action of pressing member <NUM> can be adjusted as a function of the bending to which the conductor, fed by distribution nozzle <NUM>, is to be subjected. For example, the adjustability of the position of rod member 4a with respect to crank member 4b is obtained by changing the relative position of mutually sliding portions (e.g. telescopic ones) belonging to the rod member and including the previously described hinge points 8a and 8b.

The following will briefly describe, for completeness' sake, an operative phase wherein the apparatus according to the first embodiment controls the engagement of conductor <NUM>.

As actuator member <NUM> translates forward along feeding direction <NUM>' integrally with pivot member <NUM> (carried by distribution nozzle <NUM>, which in turn is supported by connection member <NUM>), pressing member <NUM> moves - by oscillating or rotating - closer to conductor <NUM> in thrust direction PR under the action of transmission mechanism <NUM>. In particular, as movable rotational support point 8c moves, crank member 4b makes a clockwise (when viewing <FIG>) rotation; this causes terminal finger 1a of pressing member <NUM> to move forwards in thrust direction PR and to engage conductor <NUM> against reaction surface <NUM>. Vice versa, when actuator member <NUM> translates backwards along feeding direction <NUM>', a reverse movement of terminal finger 1a occurs in the direction opposite to thrust direction PR.

In the first embodiment illustrated in <FIG>, actuator member <NUM>, connection member <NUM>, transmission mechanism <NUM> and pressing member <NUM> are placed externally to distribution nozzle <NUM>.

<FIG> show the apparatus represented in <FIG> made in accordance with a second embodiment of the present invention, illustrating some preferred or optional details associated with pressing member <NUM>.

Those parts and elements which are similar to - or which perform the same function as - those of the above-described embodiment have been assigned the same reference numerals. For simplicity, the description of such parts and elements will not be repeated below, and reference should be made to the above description of the preceding embodiment.

In the second illustrative embodiment, pressing member <NUM> is configured to apply said force on two sides of the cross-section of said conductor <NUM>. In particular, such sides are adjacent.

Unlike the first embodiment illustrated herein, distribution nozzle <NUM> is mounted substantially stationary with respect to frame <NUM> of the apparatus and is not movable under the action of actuator member <NUM>. In fact, as will be described more in detail below, connection member <NUM> (e.g. its flange <NUM>) is slidably mounted in distribution nozzle <NUM>, so as to cause the displacement of pressing member <NUM> via the associated transmission mechanism <NUM>.

As visible in <FIG>, distribution nozzle <NUM> is fixed, in particular at the front, to frame <NUM> by means of a plurality of screws <NUM>. For example, said screws <NUM> comprise a plurality of fastening screws 9a and a plurality of adjustment screws or dowels 9b configured to adjust the position of distribution nozzle <NUM> with respect to the frame along feeding direction <NUM>'.

In particular, with reference to <FIG>, pressing member <NUM> is a movable body 1c that can slide transversally within distribution nozzle <NUM>. Advantageously, but not necessarily, movable body 1c is axially constrained to distribution nozzle <NUM>, being only capable of moving transversally relative to the latter. In said figure, the structure of the illustrated engagement members <NUM>, <NUM>' is different from that of those shown in <FIG>; nevertheless, engagement members <NUM>, <NUM>' still perform the same function of engaging the conductor and applying a transverse force in order to bend it by their movements.

In the second embodiment, movable body 1c comprises a pair of internal thrust faces 1d, 1e adjacent to each other, which form the sides whereon said force is applied. Accordingly, reaction surface <NUM> carried by distribution nozzle <NUM> defines an associated pair of internal reaction faces 2d, 2e adjacent to each other and transversally facing towards internal thrust faces 1d, 1e. In operation, as conductor <NUM> is fed through the cavity of distribution nozzle <NUM> in the section upstream of aperture <NUM>, it becomes surrounded by internal thrust faces 1d, 1e and by internal reaction faces 2d, 2e. In particular, owing to transmission mechanism <NUM>, an axial or longitudinal displacement of connection member <NUM> in feeding direction <NUM>' corresponds to an associated transverse displacement of movable body 1c, so that internal thrust faces 1d, 1e will apply, in a controlled manner, a transverse force on two adjacent sides of conductor <NUM> against reaction surface <NUM> defined by internal reaction faces 2d, 2e.

In the second embodiment, transmission mechanism <NUM> is a cam mechanism. In particular, transmission mechanism <NUM> is configured for converting the translational motion in feeding direction <NUM>' imparted to connection member <NUM> into a translation of pressing member <NUM> in thrust direction PR, thus causing internal thrust faces 1d, 1e to move and push conductor <NUM>. For example, said cam mechanism comprises an elongated hole 4c formed in pressing member <NUM>, which is inclined relative to the feeding direction; moreover, the cam mechanism comprises also a slider 4d integral with connection member <NUM>, which can slide in the elongated hole 4c. In particular, pressing member <NUM> acts as a follower, since it is moved due to the axial movement of slider 4d of connection member <NUM> that transversally pushes elongated hole 4c.

With particular reference to <FIG>, movable body 1c is, when viewed in an axial or longitudinal section, substantially L-shaped.

In particular, as shown by way of example in <FIG>, movable body 1c lies, and is movable in a guided manner by transmission mechanism <NUM>, in an axial plane belonging to the bundle of planes generated by said feeding axis AC'.

Also in the second embodiment, with reference to the representation shown in <FIG>, actuator member <NUM> comprises shaft <NUM>, while connection member <NUM> comprises flange <NUM>, which can be connected to each other.

In the second embodiment, therefore, differently from <FIG>, shaft <NUM> is not prearranged for controlling the movement of distribution nozzle <NUM> parallel to the feeding direction, but for controlling the action of pressing member <NUM>.

In the second embodiment, with particular reference to <FIG> and <FIG>, connection member <NUM> is connected to actuator member <NUM> by means of a quick-coupling mechanism, e.g. a bayonet-type coupling. In the illustrated embodiment, this coupling occurs between flange <NUM> and shaft <NUM>. In particular, flange <NUM> has an elongated seat 193a, while shaft <NUM> has a T-shaped terminal head 190a configured to be inserted and then turned in elongated seat 193a. An integral assembly can thus be created, which can be easily mounted to the rest of the apparatus, wherein such assembly comprises distribution nozzle <NUM>, connection member <NUM> and pressing member <NUM>, including transmission mechanism <NUM>.

Advantageously, the quick-coupling mechanism is configured to permit a releasable and restorable coupling between connection member <NUM> (e.g. flange <NUM>) and actuator member <NUM> (e.g. shaft <NUM>). This makes it possible to reversibly separate said assembly from the rest of the apparatus. The apparatus can thus be adapted for processing conductors <NUM> of different sizes and cross-sectional shapes and/or for different types of bends of the hairpins to be manufactured, simply by using different types of such assemblies depending on the desired operating conditions of the apparatus.

In the second embodiment illustrated in <FIG>, connection member <NUM>, transmission mechanism <NUM> and pressing member <NUM> are mounted inside distribution nozzle <NUM>.

The following will describe some preferred aspects of both embodiments illustrated herein, in regards to the application of the force by pressing member <NUM> in thrust direction PR.

Preferably, the force by means of which pressing member <NUM> engages conductor <NUM> is reduced during the feeding of conductor <NUM> towards engagement members <NUM>, <NUM>'.

Preferably, the force by means of which pressing member <NUM> engages conductor <NUM> is increased during the transverse movement and engagement of conductor <NUM> against engagement members <NUM>, <NUM>'. This results in the bending of the portions of electric conductor <NUM> intended to form coil members <NUM>.

Preferably, the force by means of which pressing member <NUM> engages conductor <NUM> is kept substantially constant during the feeding of conductor <NUM> and the simultaneous transverse engagement of conductor <NUM> against engagement members <NUM>, <NUM>', without said engagement members <NUM>, <NUM>' being moved. This creates a curvature of the portions of electric conductor <NUM> intended to form said coil members <NUM>.

Of course, without prejudice to the principle of the invention, the forms of embodiment and the implementation details may be extensively varied from those described and illustrated herein by way of non-limiting example, without however departing from the scope of the present invention as set out in the appended claims.

For example, in the illustrated embodiments the apparatus comprises a plurality, in particular a pair, of engagement members <NUM>, <NUM>'. However, in further implementation variants the apparatus may include just one engagement member.

Claim 1:
Apparatus for manufacturing coil members (<NUM>) for insertion into slots (<NUM>) of the core of a dynamo-electric machine; said coil members (<NUM>) being formed by bending portions of an electric conductor (<NUM>); said apparatus comprising:
- feeding means configured for feeding portions of said conductor (<NUM>) having a predetermined length through an aperture (<NUM>); said portions being fed along a feeding axis (AC') in a feeding direction (<NUM>') and adjacent to at least one engagement member (<NUM>, <NUM>') capable of engaging said conductor (<NUM>); said aperture (<NUM>) being positioned before the engagement member (<NUM>, <NUM>') in the feeding direction (<NUM>'); and
- moving means configured for moving the engagement member (<NUM>, <NUM>') with respect to the aperture (<NUM>) to engage a part of the conductor (<NUM>) with the engagement member (<NUM>, <NUM>') in a transverse direction (X, X') to the feeding axis (AC'), so as to bend said conductor (<NUM>);
said apparatus being characterized in that it further comprises a pressing member (<NUM>) configured to be moved and to selectively engage said conductor (<NUM>) to cause said conductor (<NUM>) to engage a reaction surface (<NUM>) which is proximate to said aperture (<NUM>); said pressing member (<NUM>) being situated before said engagement member (<NUM>, <NUM>') in said feeding direction (<NUM>') of said conductor (<NUM>), thereby implying the high accuracy and repeatability of the bending of the conductor (<NUM>) obtained by means of said engaging member (<NUM>, <NUM>').