Method and apparatus for assembling hairpin windings

Abstract

The present invention relates to an apparatus for assembling a plurality of crown windings such as hairpins, comprising a hairpin feeder, a hairpin inserter into a winding assembly cylinder, and a hairpin handling section from the feeder to the inserter in the assembly cylinder, the hairpin handling section including at least two arms arranged at 180° and arranged such that when one arm end faces the feeder the other arm end faces the inserter, each arm including a gripper for picking up and releasing hairpins, the grippers being mounted to slide along the direction of extension of the corresponding arm, the inserter including an assembly drum moved by a rotation mechanism, both of which are mounted on the same axis perpendicular to the axis of rotation of the arms, the assembly drum including a series of inserts on its outer surface defining a series of radial open slots, the rotation mechanism being sized such that spaces remain between the arms and the slots.The present invention further relates to a method for assembling a plurality of crown hairpin windings, in particular a method for using the apparatus according to the present invention.

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for assembling windings on a conductor such as a hairpin. [Background technology]

[0002] To make a stator or rotor of an electric machine, such as a generator or electric motor, for example for application on a hybrid electric vehicle (HEV), it is commonly known that the stator or rotor winding is formed by a plurality of bar conductors that are folded over each other and variously interconnected to make an electrical winding, also known as a "bar winding." Such folded bar conductors are also called "hairpin conductors" or simply "hairpins." A bar conductor may be formed by one or more groups of concentric windings, also called "crowns," each group of windings already wound on itself (a "winding set").

[0003] In particular, windings with hairpins having a circular cross section (also called "round wire conductors") or a rectangular cross section, or conductors having a variable cross-sectional shape along their length (e.g., a round wire conductor that is rectangularized in the portion received in the slot), are known in the prior art. In this regard, a "rectangular" or "square" conductor wire means herein a wire having four substantially flat sides, each typically joined to an adjacent side by a rounded edge. Bar-shaped conductors having a trapezoidal cross section are known.

[0004] The basic conductors mentioned above are usually preformed by means of bending a straight rod conductor into a "U" or "P" shape starting from the straight rod conductor. Patent US7,480,987 describes an example of a method for preforming a straight rod conductor to form a hairpin. A "U" or "P" shaped preformed conductor, often also called a "preformed basic conductor" in the art, typically has two adjacent legs of equal or different length, each with a free end portion and an opposite end portion connected to the other leg by a bridge-like connection portion. The end portions protrude when inserted into the rotor or stator, and are hereafter referred to as "free protruding portion" and "opposite connecting protruding portion". The protruding connection portion may also be referred to as "head portion" or "bridge-like connection portion". The entire "head portion" of the legs of the same hairpin constitutes the so-called "bridge-like connection portion".

[0005] 1(a), a hairpin 255 is preformed by starting from a linear conductor (not shown) and bending it to form a first leg 255a with its free protruding end portion 255aE and a second leg 255b with its free protruding end portion 255bE. This bent shape simultaneously forms a bridge-like connection 255c between the two legs 255a, 255b. The preformed hairpin has a flattened "U" shape in this example. It is known to give two types of twists to preformed hairpins, for example in the shape of a "U" or a "P", to form stators of electric machines.

[0006] The stator or rotor core of a radial flux electric machine is essentially a ring with two flat faces and two cylindrical faces, with the generator at right angles to the two flat faces parallel to the axis of rotation of the rotor of the electric machine. Hereinafter, radial, circumferential and axial directions refer to the latter axis, unless otherwise stated. One of the two cylindrical faces is adjacent, at least in part, to the air gap of the electric machine to which the stator or rotor belongs, and defines a set of slots in which the straight parts of the windings are accommodated. The two flat faces are divided into an insertion face or side and a face or side opposite the insertion face. The part of the winding protruding from the core is named the header. The ends of the free parts of the conductor belong to the header protruding from the face opposite the insertion side, and the majority of them are subject to welding. Also, if there are protrusions of the windings connected in a bridge manner with the legs inserted in the stator slots, they belong to the header protruding from the insertion side. Hereinafter, regardless of whether the portion protruding from the insertion side is a free end or is connected in a bridge shape, it will be referred to as the portion from the insertion side.

[0007] The area of ​​the stator or rotor core between one slot and the adjacent slot is called a tooth. The number of teeth is equal to the number of slots. The connecting portion of the core teeth which also defines a portion of each slot and is located opposite and relative to the slot opening on the machine air gap is named as yoke.

[0008] The slots can be divided into an array of positions in which the legs of the elementary conductors can be located. Conductors accommodated in the same radial position of the slots define a so-called winding layer.

[0009] In the first type of twisting, also called "twisting from the insertion side", the preformed elementary conductors are suitably inserted into corresponding radially aligned pockets provided in a twisting device adapted to deform such conductors after insertion. The twisting device is in practice used to spread the legs of a "U" or "P" shape so that, after the conductors are removed from the device, the two legs of each conductor can be successively inserted into corresponding pairs of slots of a stator core, angularly offset from one another by a predetermined radial distance substantially equal to the angular distance between the slots into which the legs are successively inserted, and spaced apart by the radial distance between the slot positions respectively occupied by the legs.

[0010] For example, but not by way of limitation, starting with a preformed hairpin as shown in FIG. 1(a), the legs 255a, 255b are spread apart and the bridge-like connection 255c is formed to obtain, for example, the shape of FIG. 1(b), forming a hairpin with a shape suitable for insertion into a stator (or rotor). Reference numeral 255p denotes the pitch of the hairpin, i.e. the linear or angular distance between the legs, or the distance as slot pitch. It is worth noting that, again, the central apex 255c2 of the formed hairpin is a zone in which the cross section of the conductor undergoes a 180° rotation with respect to the central plane of the hairpin (the plane that passes through the inside of the hairpin and includes the two legs). This rotation is effective to swap the layers (slot positions) in the layered hairpin as will be defined, which allows to reduce eddy currents flowing at the ends of the layers when they are welded together, compared to the case in which the same layers are parallel without swapping slot positions in the transition from one leg to the other.

[0011] The patent application published as US2009 / 0178270 describes an example of a method for twisting a preformed rod-shaped conductor at a uniform pitch from the insertion side after inserting a hairpin into a pocket of a twisting device having a rectangular cross section.

[0012] According to the prior art and with reference to Figure 2, hairpins can also be obtained by stamping, i.e. the process of pressing a straight conductor into a cone in a punch and die type system. Figure 2(a) shows such a stamped conductor, which does not have a cross section rotated relative to the central plane of the hairpin.

[0013] This stamped hairpin, or alternatively the preformed and unfolded hairpin obtained as described above, can be subjected to a so-called "weld side twist", in which case a "step-like" shape of the legs 255a and 255b can be introduced, for example leg 255a seen in FIG. 2(b) having a first straight portion 255a1, a step-like portion 255a2 and a second straight portion 255a3 (which substantially corresponds to portion 255aE in FIG. 1).

[0014] With reference to FIG. 3, the shape of the insertion protrusion or bridge-like connection 255c for the stamped hairpin may be composed of three parts 255c1, 255c3, 255c2 starting from the connection with the second leg 255b to the connection with the first leg 255a (hidden in FIG. 3). Part 255c1 has a main extension direction B and a radius of curvature RB, part 255c3 has a main extension direction A and a radius of curvature RA, and part 255c2 has a main extension direction C (and possibly a curvature, not shown). Hereinafter, part 255c2 is called the "layer-changing curvature", which in fact causes the head and leg parts of the hairpin to be on different layers when inserted into the respective slots of the stator pack. Reference numeral α1 denotes the angle between directions A and C, reference numeral α2 denotes the angle between directions A and B, and reference numeral α3 denotes the angle between directions B and C, which is equal to the sum of angles α1 and α2. This is only one final possible hairpin shape, all other shapes with different portions and conformations of both the bridge portion and the legs can be used with the devices and methods according to the present disclosure.

[0015] There are also what are called "reverse" conductors, in which the bending direction of the bridge-connected hairpins is opposite to that of most of the hairpins forming the same winding. These are used to go from the last layer of one crown to the first layer of the next crown. Furthermore, referring to FIG. 4A, there are layered ("twisted-line") hairpins, whose cross section is inverted at the bending point (FIG. 4A(a)) so that the positions occupied by the layers are exchanged.

[0016] As can be seen from the cross-sectional hatching in Fig. 4A(a), due to the reversal or exchange of positions, the upper layer of the pair of layers in the left slot is lower than the other layer in the right slot. In another hairpin configuration, the reversal of positions can be continuous along the portion of the hairpin housed in the slot (Fig. 4A(b) of US 3837072). The variant shown in Fig. 4B is a layered hairpin without reversal, as shown in patent US8552611 B2. Fig. 4C (taken from Fig. 6 of patent US6,894,417B2) shows a variant of the arrangement of the legs of a double crown-wrapped layered hairpin in different positions in the slot. The reference letters A and B indicate the crown to which the legs (belonging to different hairpins) shown in the slot belong.

[0017] Furthermore, there are conductors named "I-pins", i.e. conductors accommodated in a single slot, which when in the slot have a portion whose free end protrudes from both planes of the stator core. Figure 4D is an example of an I-pin, which does not necessarily have all the turns shown, as it may not have any turns at all, and can also be bent from the output side of the hairpin winding assembly drum. The ends of the I-pins can be welded to the ends of other conductors protruding from the slot, to third party elements (e.g. busbars, eyelets), or they can serve as phase terminals. The portions can be subjected to a "weld side" type of bend. An example of an I-pin can be found in the conductors indicated by reference numbers 81 to 83 in document US7622843B2. "W-shaped conductors" are also known, see for example patent US7,622,843B2 again and see figure 4E. W-shaped conductors can be formed by welding a stamped hairpin with an I-pin, or by welding a fourth conductor with three I-pins. Again, the W-pins do not necessarily have all the turns shown, and may have none at all, and be bent from the output side of the hairpin winding assembly drum.

[0018] With reference to FIG. 4F (taken from US10749399B2), there are also so-called "inverted hairpins", i.e. hairpins that can be formed by spreading the legs (not the insert-side twist method described above) or stamped with a "press and die" system, characterized in that the legs of each slot occupy the same radial position, i.e. belong to the same layer. Thus, their ends will be bent in the same direction on the twist side. In practice, the protrusions on the bridge-like connection side can be folded in the same tangential direction or take a V-shape. The connection may require at least two layer-changing folds.

[0019] Finally, there are pairs of hairpins that are organized and sized to overlap, with homologous legs belonging to different layers (Figure 4G) or the same layer (Figure 4H).

[0020] Hereinafter, "hairpin" types, "I-pin" and "W-pin" are all included in the definition of "basic conductor".

[0021] After the first type of twisting or stamping, the base conductors are typically preassembled with a winding set as described above. The preassembly device will generally have a series of slots into which the legs of each hairpin are inserted, the number of which is equal to the number of stator slots associated with the windings, and will generally be different from the twisting device.

[0022] The winding sets are then inserted in the block into slots of the stator core from their first side (the so-called "insertion side" or "insertion face"), with their respective free portions protruding from a second side of the core opposite the first side (the so-called "welding side" or "connection side" or "welding face" or "flank face").

[0023] Depending on the particular winding pattern to be achieved, the free parts of the elementary conductors protruding from the side opposite the insertion side may be subjected to a second type of twisting, also named "twisting from the weld side", for example after being inserted into pockets made in a suitable twisting tool. The twisting tool in this document has the purpose of bending and twisting the free parts of the conductors to properly shape them so that the proper electrical connections between the conductors can be made to complete the winding. An example of a method for twisting from the weld side of the above mentioned type is described in the patent application published under number US2009 / 0302705.

[0024] Referring to FIG. 5A, patent application US2019 / 0190359 by Odawara Engineering and application US2019 / 0356188 by the same owner describe a system for forming a basic conductor, then assembling it into a winding, and inserting it into a stator in a single plant. Odawara Engineering application US2019 / 0190359 mainly describes a basic conductor forming section, while application US2019 / 0356188 describes a winding assembly and insertion section, with a large overlap with the latter. The application related to the winding assembly and insertion section refers to a "guide means", which is, for example, depicted with reference number 112 in FIG. 24A of application US2019 / 0190359, reproduced as FIG. 5A in this description (the figure of application US2019 / 0356188 related to the same device has the same technical content). According to Odawara Engineering's application, the following parts are described. - In-line forming of the basic conductors (albeit with partial rotation of some elements). - sliding guide means 112; the elementary conductors 17S approach radially towards the slots 109 formed between the radial elements (blades) 108 (oriented radially in the drum section perpendicular to its axis of rotation C) and then open radially outside the drum 105; the dragging gear 123 of the cylinder 105 is of larger diameter than the latter;

[0025] Furthermore, referring to Figure 29 of Odawara Engineering's application and Figure 5B of the present specification, it is clear that the gear mechanism 123 is intended to ensure the rotational accuracy of the drum 105 by the servo motor (see paragraph 205 of the same application) and is an essential solution.

[0026] Furthermore, the blade handling mechanism 108 of the cylinder has a rotating shaft 121 which operates a cam 130, which must be actuated axially, acting not on a wheel 123 (FIG. 31, here shown as FIG. 5C), but on another element 129 connected to the shaft 121. The wheel 123 and the crown 135, being adapted for the take-off of the windings, must have a larger radius than the drum and the blades, while being axially arranged. The mechanism requires the radial insertion of hairpins.

[0027] Indeed, in the Odawara Engineering application, the insertion system into the stator requires a thrust crown 135, as shown in corresponding Figures 34 and 5D herein.

[0028] This overall configuration has several drawbacks, including that the hairpin insertion is performed with an approaching movement to the drum that has radial and circumferential components. The coexistence of the two movements makes the confinement system of the first leg of the hairpin (the non-grip leg) excessively complicated to keep up with the high hairpin formation cadence (e.g., 1.5 seconds). Furthermore, the prior art suffers from low accuracy of the insertion of the hairpin legs into the assembly drum due to the type of handling of the hairpin (which in some cases involves both radial and circumferential handling). It is also noteworthy that the prior art requires the guide of Odawara Engineering's application to be kept at a distance (at least temporarily) from the drum to allow for the radial insertion of the basic conductor, which makes it more likely that undesired movement of the legs will occur in the drum slot (even dislodging). Maintaining the aforementioned movements, even with the addition of standard confinement, complicates other parts of the device.

[0029] A stator winding assembly system according to the applicant is also known from patent document WO 2012 / 007973 A1, where a hairpin gripping system is described as consisting of a number of grippers mounted on a rotating base. The grippers move from a position where the hairpins are fed to a position where they are inserted into the drum of the stator winding assembly. However, the hairpins are not inserted into the drum of the grippers, but rather a sliding blade is activated, which moves the hairpins taken by the grippers (which do not move) until their legs are simultaneously inserted into the slots of the drum. This is possible because the slots of the drum have gaps that run parallel to the axis of the drum and the insertion blades, and because the rotating base is actually above the drum, i.e. its projection along the axis of the drum matches the drum itself.

[0030] In addition to being mechanically incompatible with the system of Odawara Engineering's application, the use of the system of WO 2012 / 007973A1 does not allow the formed winding to be inserted directly into the stator itself afterwards. Therefore, the winding must be removed in the direction in which the hairpins were inserted, moved to another location and inserted into the drum. This significantly increases the cycle time and requires a series of drum mechanisms to correctly connect and compress the hairpins. Furthermore, the use of insertion blades presents significant problems with mechanical precision. The entire device is expensive and has poor productivity.

[0031] There is a need for an apparatus and method for assembling basic conductor windings that has a simple structure, short cycle times, and in some cases allows the assembled winding to be directly inserted (axially without displacement to a different position) into the stator. Summary of the Invention [Problem to be solved by the invention]

[0032] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to provide an apparatus and method for assembling a basic conductor winding which overcomes the problems and shortcomings of the prior art either completely or partially.

[0033] The subject of the invention is an apparatus and a method according to the appended claims. [Brief description of the drawings]

[0034] The invention will now be described, by way of example only, with particular reference to the accompanying drawings in which: [Figure 1] FIG. 1 (a) shows a prior art hairpin preformed into a "U" shape, and (b) shows a prior art formed hairpin. [Diagram 2] FIG. 2 shows (a) the stamped conductor and (b) the conductor after being subjected to twisting of the weld side. [Diagram 3] FIG. 3 shows the hairpin of FIG. 2(a) above, according to the prior art. [Figure 4A] FIG. 4A shows (a) a layered ("twist line") hairpin with a cross-section inversion at the bend point according to the prior art, and (b) a continuous position reversal along the portion of the hairpin received within the slot according to the prior art. [Figure 4B] FIG. 4B shows a type of layered hairpin. [Figure 4D] FIG. 4D shows an example of an I-pin according to the prior art. [Figure 4E] FIG. 4E shows an example of a "W pin" according to the prior art. [Figure 4F] FIG. 4F shows an example of an "inverted hairpin" according to the prior art. [Figure 4G] FIG. 4G shows an example of overlapping hairpins belonging to different layers according to the prior art. [Figure 4H] FIG. 4H shows an example of overlapping hairpins that belong to the same layer according to the prior art. [Figure 5A] FIG. 5A corresponds to FIG. 24A of patent application US2019 / 0190359 by Odawara Engineering, with some of the elements mentioned above circled. [Figure 5B] FIG. 5B corresponds to FIG. 29 of patent application US2019 / 0190359 by Odawara Engineering, with some of the elements mentioned above circled. [Figure 5C]FIG. 5C corresponds to FIG. 31 of patent application US2019 / 0190359 by Odawara Engineering, with some of the elements mentioned above circled. [Figure 5D] FIG. 5D corresponds to FIG. 34 of patent application US2019 / 0190359 by Odawara Engineering, with some of the elements described above circled. [Figure 6] FIG. 6 is a side view of an embodiment of an apparatus according to the present invention. [Figure 7] FIG. 7 shows a bottom view of an embodiment of the device according to the invention. [Figure 8] FIG. 8 shows the guide of FIG. 7 without the arms. [Figure 9] FIG. 9 shows the arm from the previous figure, viewed from a slight angle. [Figure 10] FIG. 10 shows an example of a radial movement mechanism for the gripper holder carriage along the arm of the previous figure. [Figure 11] FIG. 11 is a perspective view of a portion of FIG. [Figure 12] FIG. 12 is a side view of the arm working section described above with radial guides for the gripper. [Figure 13] FIG. 13 is a side perspective view of the arm, including part of the winding, where α is the inclination angle of the plane of the two legs of the base conductor relative to the motion plane of the arm. [Figure 14] FIG. 14 (a) shows a detailed view of the structure of a portion of an assembly section with an assembly cylinder or drum, a guide, and a guide containment element, and (b) shows a detailed view of a retractable element of the assembly cylinder according to one embodiment of the present invention. [Figure 15] FIG. 15 shows the drag of a hairpin inserted into an assembly drum, in (a) on the upper semicircular part of the cylinder, and in (b) showing further detail on a small arc of the circumference. [Figure 16] FIG. 16 shows another embodiment of an assembly with a hairpin containment system inserted into a slot. [Figure 17] FIG. 17 is a perspective view of an assembly similar to that shown in the previous figure. [Figure 18] FIG. 18 is the same view as the previous figure, but with the first set of hairpins inserted into the slots and partially onto the guide arms. [Figure 19] FIG. 19 is a detailed perspective view showing one embodiment of a hairpin insert on an assembly drum. [Figure 20] FIG. 20 is a similar view to the previous one, but more expanded and including a portion of the hairpin transport arm. [Figure 21] FIG. 21 shows the hairpin position on the guide arm of the previous figure. [Figure 22] FIG. 22 shows the hairpin position on the guide arm from the previous figure, viewed from the opposite side. [Diagram 23] FIG. 23 shows a similar situation to FIGS. 21 and 22, with the hairpin shown in the position it will occupy at the end of the rotation of the arm. [Figure 24] FIG. 24 shows a similar situation to FIGS. 21 and 22, with the hairpin shown in the position it will occupy at the end of the rotation of the arm. [Diagram 25] FIG. 25 shows a similar situation to that of FIGS. 21 and 22, with the hairpin shown in the position it will occupy at the end of the rotation of the arm. [Figure 26] FIG. 26 shows the arrangement of inserts for radial and circumferential positioning of the straight sections of the hairpins, the required positions for insertion of the hairpin windings into the stator core. [Figure 27] FIG. 27(a) shows an example of a winding insertion device obtained on a stator or rotor core with a device according to the present invention, viewed from the insertion side, and (b) shows a detailed view of inserts of two alignment arrays according to one example of the present invention. [Figure 28] FIG. 28 shows a drum with a winding crown inserted into the transport system by a transport arrangement. [Figure 29]FIG. 29 shows a winding transfer or insert arrangement for positioning the legs of the hairpins for insertion into the stator pack, (a) in an open position for passage of the drum and (b) in a closed position, positioning the legs of the hairpins properly for continued axial handling and insertion into the stator pack. [Figure 29b] FIG. 29b shows the arrangement of FIGS. 28 and 29, showing two additional winding containment elements which complete the containment around the entire perimeter. [Diagram 30] FIG. 30 shows a transport arrangement and insulating inner liner case according to one embodiment of the present invention, where the positioning arrangement has beveled fingers / teeth useful for precise positioning of the conductor for insertion into the stator cavity. [Diagram 31] FIG. 31 shows (a) the support structure of the closure cap of the pusher and (b) the approach of the closure cap of the pusher. [Diagram 32] FIG. 32 shows the insertion of the windings into the stator pack. [Diagram 33] FIG. 33 shows the completed insertion of the windings into the stator pack after expansion of the carrier array. [Diagram 34] FIG. 34 shows the insertion of an inverted hairpin with the circumferential insertion guide facing in the opposite direction to that shown in the previous figure, looking at the hairpin from its foot end. [Diagram 35] FIG. 35 shows the situation of FIG. 34, looking at the hairpin from the bridge-like connection. [Diagram 36] FIG. 36 shows the situation from FIGS. 34 and 35, with the bridge connection visible once the gripper has passed through the three-sided insertion guide. [Figure 37] FIG. 37 shows an embodiment where the insert is within the stator pack, with two drum assembly systems mounted on two coexisting carriages to transport the systems from the central hairpin loading position to a lateral position, thereby increasing the production cycle. [Figure 38] FIG. 38 shows another embodiment of the handling of the elementary conductors between the supply and the drum, instead of the arm system.

[0035] It is worth noting that, as those skilled in the art can easily understand from the following description, the elements of different embodiments can be combined without limitation to provide further embodiments while respecting the technical spirit of the present invention.

[0036] This specification refers to the prior art for its implementation, even with regard to detailed features not described, such as, for example, minor elements commonly used in the prior art in solutions of the same type.

[0037] Whenever an element is introduced, it is understood that there can be "at least one" or "one or more."

[0038] Where a list of elements or features is given herein, it is understood that the invention according to the invention "comprises" or alternatively "consists of" such elements.

[0039] In the following description, a "winding" or a "winding set" is understood to be either complete or in its partial assembly stage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] In Fig. 6 a side view of a possible embodiment of a device 1000 according to the invention is shown. A table 1200 is provided which supports a motor 1120 having a rotation axis 1110. The rotation is transmitted to a central element having a series of radial arms 1310 (four arms in the embodiment; generally, either one arm or an even number of arms), each equipped at its far radial end with a gripper 1321 for gripping and carrying a hairpin or base conductor 200 (conventionally including any of the known types mentioned above, including what is conventionally referred to as an inverted hairpin, hereinafter 200R).

[0041] Each arm 1310 transports at least one hairpin from a collection or feeding zone (not shown) on the right side of the figure to an assembly 1400 supporting an assembly frame or drum 300 resting on a base 1410 and having slots adapted to receive one or more legs of an elementary conductor (shown in the figure below). The assembly frame 300 has a cylindrical shape with an axis 310 arranged at right angles to the axis 1110 of rotation of the arms 1310. Figure 7 is a bottom view of the device 1000 of Figure 6. This view shows the movement of the connected gripper 1321. In the position indicated by PA, the gripper picks up an elementary conductor from the elementary conductor feeding area. Immediately after gripping the elementary conductor, the gripper 1321 retracts radially towards the center 1350, for example via a specific connection guide 1230 shown in Figure 8 (showing the guide without the arms). At this point, the arm that has taken the basic conductor rotates 180° following the guide 1220 and passes through the lower intermediate position PB until the gripper 1321 and the basic conductor 200 are oriented with the legs facing the assembly frame 300, parallel to the axis of the frame 310. In position PC, the gripper 1321 moves again radially, but away from the center 1350, until at least one of the legs of the basic conductor is at least partially inserted into a corresponding slot (not shown) in the frame 300. When this is achieved, preferably without the need for further radial movement, the gripper detaches itself from the basic conductor (from its end where it was gripped) and the rotation can continue clockwise, constrained by the guide 1210, by passing through the upper intermediate position PD and returning to the picking position PA, thus completing the load / unload cycle. Obviously, since there are four arms in this example, each 90° rotation allows gripping at position PA and insertion into the frame at position PC, thus four times the speed compared to the case where there is only one arm. In general, if N is not equal to 1, the rotation of the star on the arms is performed at intervals of N / 2 equal angular steps, with N being the number of arms.

[0042] As a preliminary step to inserting the elementary conductors axially into the drum, the initial position of the drum (position around the axis of rotation) can be set so that one of the slots coincides with the insertion direction of the elementary conductors.

[0043] In accordance with a preferred embodiment of the present invention, the gripper does not have complex motion involving rotation about an axis other than that of the arm rotation. A single orbit can be used with the 180° intervals required for radial movement, i.e., 1220 will be at the same radial distance as 1210.

[0044] With reference to FIG. 9, it can be seen that the gripper support element 1320 may be a carriage that moves radially by a blade that slides on either the guide 1230 or the guide 1240 with a slider on the opposite side, on a case by case basis (see below).

[0045] The part of the arm mechanism opposite the table 1200 is shown with reference to figures 10 and 11. Attention should be paid to the motor 1355 which rotates the cross arm opposite the central axis 1350, the guide 1240 for the radial sliding of the blade and then the carriage 1320 which is moved by means of a motion transmission by means of sliders 1615, 1625 illustrated in two sliding positions (the second one is shown at 1615', 1625'). Such sliders are moved by linear motors 1620, 1610 respectively. The reference number 1325 indicates the actuating element of the radial movement of the blade and therefore by means of a motion transmission the actuating element of the gripper (not shown) is connected to the carriage 1320. The element 1325 is connected to a "U" shaped element 1323 of the carriage 1320 which is driven by a particular motor 1620 and which surrounds the slider 1322.

[0046] FIG. 12 is a side view showing a state in which a radial guide 1240 is provided on the arm operating portion.

[0047] FIG. 13 shows a side perspective view of the arm with a part of the assembly 1400. In addition to the elements of the previous figures, the slider 1322 of the arm 1320, which is adapted to slide in a semi-circumferential groove (not shown) (intentionally shown outside the guides 1230 or 1240, i.e. in a position that would not be possible in normal operation), and the winding frame 300, which is moved in rotation by the pulley system 1320, are exemplarily shown. Also shown are sliding guides 400 over a part of the frame 300, which will be better explained later. Instead, it is immediately seen here that there is a (free) gap between the approach direction of the elementary conductor 200 and the top of the winding frame / drum 300, so that there is no obstacle to the radial approach of the elementary conductor (parallel to the axis of rotation / symmetry of the frame) and the insertion of at least one of its legs into the slots of the frame 300 itself. In other words, the circumferential part of the cylindrical frame 300 is not hindered in the axial direction, which can be conveniently achieved by acting on the shape and arrangement of the rotation mechanism of the cylinder 300. That is, the gap in the drum slot (described in more detail below in an embodiment) extends radially about the drum, along the drum axis, and the gap opens radially outward from the drum and extends parallel to the drum axis.

[0048] Referring now to FIG. 14, there is shown an assembly cylinder 300 that may include retractable inserts 320 (disposed circumferentially, i.e., on the outer cylindrical surface of the drum) that include a surface layer 330 and mutually define a slot 324 therebetween (with what was referred to in the previous paragraph as a gap). It should be noted that the retractable inserts may have radial and axial extensions and a circumferential thickness. FIG. 14(b) shows that the retractable inserts 320 may have a central recess 323. In this regard, since the inserts perform a "lead-in" function upon the entry of the non-grip legs into the drum slot, it is convenient for at least one pair to protrude from the pre-inserted conductor or slot bottom by an amount that sufficiently exceeds the radial thickness of the entry legs upon said entry. For simplicity of construction and operation, in one embodiment of the present invention, all the inserts, not just one pair, are kept at the same radial height from the axis of the device. In this case, the central recess 323 of the insert is necessary to allow the elements of the containment system to compact the legs of the elementary conductors in the slots of the drum, taking them in a radial position relative to the axis of the machine as close as possible to the position that the legs themselves would take in the stator when referenced to the axis of the stator itself. When the legs are placed in such respective positions, the maximum level of occupation of the drum slot by the legs is less than the level of the circumference circumscribing the insert. Without such a central recess 323, the containment system can only hold the legs of the hairpin within the circumference circumscribing the drum insert. Moreover, to ensure dragging of the hairpin and to avoid possible jamming, it is desirable to have its legs well compressed and stiff when released from the insert. The recess 323 defines two teeth 325 on its lateral sides. Optionally, the two teeth 325 have a bevel 322 on both sides, the direction of the bevel forming an angle with respect to the radial direction. The optional bevel serves to facilitate sliding the legs of the base conductor into the slots 324 .In particular, since the cord of the inclined hairpin is smaller than the cord between the inserts, the bevel is for the leg not to be pinched as it falls out of the guide 410, and the drag forces the inserted leg into the insert. This is on one side of the insert. In fact, the chamfer on the other side is not for this purpose, but is only useful if the drum is rotated in the opposite direction, which is necessary for the reverse hairpin (see below). In this case, however, a guide that is a mirror image of the one shown so far is needed. In the case of the I-pin, it is no longer of any use, since there is no second leg to insert by gravity.

[0049] The sliding guide 400 may include a guide arm 410 and, optionally, a guide containment element 420. It can be seen how the legs of the basic conductor 200 are gradually inserted into the slot 324. As shown in the example, the basic conductor has two legs, one of which is inserted axially into the slot and the other is contextually laid on the arm of the guide 410 under the containment element 420 (optional). Since the guide arm is limited in the circumferential direction, after inserting the leg into the slot at a given drag angle, the other leg on the guide arm will also fall onto the slot, as will be better shown from now on. In other words, the sliding guide has a circumferential exit end of the basic conductor in the drum rotation direction to drag the non-gripping leg. It is further noted that when the axial insertion of the basic conductor into the drum is completed, parts of the gripping legs still remain on the sliding guide. In this case, according to one embodiment of the present invention, a further rotation of the drum would be required to complete their sliding on the sliding guide until they fall into the corresponding slot. This can be done at any stage of the winding set, for example after the formation of the crowns, or after the formation of the final crown (the outermost crown). Additionally, repositioning of the slots about the drum axis of rotation 400 can be performed at any useful time during the assembly procedure by rotating the drum in one circumferential direction or the other for any number of slot steps as needed for the assembly of a particular winding.

[0050] The guide arms can advantageously be positioned at an appropriate distance from the drum to prevent the conductor inserted into the drum slot from withdrawing / entering. In the Odawara Engineering application, this is not necessary or even possible, since the space is used for the non-grip leg of the hairpin to move radially into the drum slot. When assembling multiple crowns, the guide arms can be moved to allow space for the radial withdrawal / expansion of the insert required to assemble the next crown.

[0051] According to another embodiment of the invention shown in FIG. 16, the assembly cylinder 300 faces a containment system 500 that can be formed from an array of elements 510 that can have a structure such that a positive bond can be achieved to compensate for discontinuities that may occur between the elements when the inserts expand, as shown in FIG. 16(b). The Z-shape is advantageous to reduce possible "snagging" of the conductors of the crown during the step of assembly where the discontinuous surfaces meet between the inserts. In fact, if the inserts do not have a complementary circumferential expansion, the facing discontinuous surfaces between one insert and the other would be parallel to the axis of the device and essentially parallel to the legs of the hairpin, creating niches where they could escape or get caught. With a circumferential expansion, the part of the conductor in contact with the expansion of the adjacent tooth can be divided into two parts. When the conductor is crossing the discontinuity between the extensions of two adjacent inserts, the first part is continuously maintained in radial containment, the second part crosses the first discontinuity between the extensions and thus, due to the rigidity of the conductor, avoids getting caught on the first discontinuity (circumferentially on the right side in the figure) and the second part is continuously maintained in radial containment; when the first part crosses the second discontinuity between the extensions (circumferentially on the left side in the figure), due to the rigidity of the conductor, avoids getting caught on the second discontinuity.

[0052] As can be seen in FIG. 17, the array 500 of containment elements is positioned axially at a distance from the axis less than that of the circumference of the drum such that the elements occupy recesses in the retractable insert.

[0053] Referring to Fig. 19, according to one embodiment, a gripper 1321 holds one of the two legs of the illustrated hairpin in place, the other leg resting on a guide arm 410, which has an abutment 411 arranged and shaped to position the non-gripping leg in the slot 324 of the assembly drum 300 before radial shifting of the insertion of the same non-gripping leg. Fig. 20 shows the same situation, but on a larger scale, making the arm 1310 in its entirety visible, together with the guide 1240 for the radial slide. Two servo motors 1500 are also visible, one to rotate the drum 300 and the other to extend the insertion of the drum itself.

[0054] 21 and 22 show two opposite side views of placing a hairpin on the guide arm 410 as described above. Reference numeral 900 denotes the non-gripping leg of the introduction guide and reference numeral 930 denotes the support structure of the introduction guide 900. In the case of a W-pin, since multiple legs are not gripped, there may be an additional guide for the second non-gripping leg, which is not shown in the figures.

[0055] 23-25 ​​continue to show the same situation as before. The hairpin is shown in the position it occupies at the end of the arm rotation. At the end of this rotation, in one embodiment of the invention, the free / hairpin end is at a radial height relative to the axis of rotation of the arm that is greater than the minimum radial distance of the insertion guide from said axis. The guide device 900 reduces the height of the free end and at the same time allows for a precise axial insertion. In this regard, a first constriction 911A is arranged on the abutment 911 (shown generally in FIG. 19) on the guide arm from the side facing the gripper 1321. This initial constriction allows the non-gripping leg of the hairpin to gradually align with the three-sided slot 915 with the subsequent radial movement, recovering the misalignment of the leg by springback. During the step of forming the hairpin, a slight divergence can be intentionally assigned to the legs of the hairpin so that the first constriction works properly, thus making it possible to predetermine the position of the legs of the hairpin. Alternatively, it is possible to assign a slight angular offset from the radial direction with the same gripper. If the elementary conductor shows the possibility of the legs converging, a movable element is required to create a fourth side of the slot 915, which, together with the other three, coincides to enclose the non-gripped legs at a known position. The movable element must be removed at some point to allow the hairpin bridge-like connection to pass. After the first constriction 911A in the direction towards the drum 300, there is a second part 911B, which gradually brings the said leg of the hairpin closer to the third side used to guide the conductor. Finally, there is a second constriction of the guide to enter the three-sided slot 915 along the same direction as the third part 911C. There may be a distance between the first and second constrictions to take into account the different leg lengths of the set of hairpins that can be processed with the device.

[0056] Although a three-sided insertion guide has been exemplified here, other types of hairpin insertion guides are possible, for example a four-sided arrangement for axially storing the non-grip legs.

[0057] Here, the insertion of the hairpin winding into the stator core and the rotor core will be described.

[0058] FIG. 26(a) shows an arrangement 340 of inserts 341 for radial and circumferential positioning of straight portions of hairpins already inserted in the drum in a suitable position for insertion of the stator pack into the slot by axial sliding on the inner surface of the drum. Two adjacent inserts 341 define an outer periphery within (or substantially flush with) the outer periphery of the stator core slot (not shown) for that winding at a minimum distance from the axis. Inserts 351 of an inner liner backing comb 350 (commonly used for electrical insulation of various hairpin layers) are inserted with radial movement between successive protrusions of paper. The inner liner is prevented by the insert from moving axially during insertion of the conductor into the slot by its flared portion resting on the beveled portion of the insert.

[0059] Figures 26(b)-(d) show from different sides the elements of the alignment array used to transfer the windings to the stator pack, as shown below. The initial array 650 is composed of alternating retractable elements 651 of suitable shape and intermediate elements 652 that hold them in the correct radial position. Reference numeral 651A denotes the wall of the element 651 that contacts the conductor 200 to be transferred, and reference numeral 651B denotes a bore useful for fully drawing the insert 651 into the array 650. A second array 660 can be arranged further in the direction of insertion into the stator pack (shown in the following figures) for finer alignment. Preferably, the array 660 has stationary teeth 661.

[0060] FIG. 27 shows a complete block 600 containing two arrays 650 and 660 in tooth detail, where one of the teeth 651 has been omitted to show tooth 661 of array 660.

[0061] In this regard, once the assembly of the winding crown is complete, the drum 300 keeps the straight bundles to be inserted into the respective slots of the stator pack separated by their fully extracted inserts 320. At this point, the assembly system including the drum 300 approaches the insert array 650 shown in Figs. 28-33. Positioning of the drum 300 for the transfer of successive windings includes an angular positioning step and an axial positioning step in the transfer system so that the inserts 320 of the drum 300 are radially aligned with the inserts 651 of the transfer array 650, as shown in Fig. 28. Before transferring the windings, there may be a step including rotation of the drum alignment to the stator slots according to the positions assigned according to the winding type.

[0062] During the transfer of the windings to the stator pack, the drum 300 keeps the straight leg bundles separated, but usually does not allow the hairpin legs, especially the legs furthest from the axis of the machine, to be positioned with a degree of accuracy suitable for insertion into the stator pack. In fact, the slots for receiving the conductor bundles in the drum are trapezoidal, as shown in FIG. 29. The leg bundles of the hairpins filling the stator slots must be positioned within the rectangular perimeter contained in the slot before the windings are inserted into the stator pack. For this purpose, the inserts 651 of the transfer array are moved radially (from the position in FIG. 29(a) to the position in FIG. 29(b)) towards the machine or winding axis, preferably in synchronism with the indentation of the inserts 320 of the drum 300, see FIG. 29. Once the extraction is complete, the legs of the hairpins are restrained in a position suitable for subsequent insertion into the pack.

[0063] Positioning the drum for continuous winding transport involves angular positioning and axial positioning within the transport system so that the inserts on the drum are radially aligned with the inserts in the transport array, as shown in FIG.

[0064] With reference to Figure 29b, the arrangement 650 of Figures 28 and 29 may be faced with at least one further winding containment element 670 in order to complete the containment of the elements 500, 510 around the entire circumference of the winding. This arrangement is advantageous for leaving space for the insertion of the elementary conductors into the drum, without placing mobile enclosures in the upper half of the drum concerned with the insertion of the elementary conductors.

[0065] Further refinement of the position of the conductor bundles is achieved through the use of a positioning arrangement ("comb arrangement") 660 shown in FIG.

[0066] At the end of the above mentioned movements, or overlapping therewith, the pusher 800, consisting of two parts 810 and 820, is brought closer (in the direction of the arrow 840) to the winding header 300 from which the bridge-like connector of the hairpin protrudes, as shown in Fig. 31. The pusher is made in two parts because, at an early stage of the assembly, one of its parts 810 must be removable to make space for the insertion of the hairpin into the drum slot 300. Therefore, the part 810 can also move in a perpendicular direction (direction 830 perpendicular to 840).

[0067] Once the pusher is assembled, it can be moved to push the conductors into the slots of a stator or rotor pack 750, 760 supported by the apparatus 700, as shown in Figure 32. Reference numeral 750 denotes a stator yoke and reference numeral 760 denotes an inner liner of the stator pack. Before insertion of the conductors into the slots is complete, the transport array 650 is brought to an open position to allow the bridge-like connectors to slide over the surface of the drum 300. The winding insertion can be completed by continuing the motion shown in Figure 33 (right to left direction).

[0068] Finally, with reference to Figures 34 to 36, we will explain in detail an embodiment in which a reverse pin is inserted into the winding. It is clear that the definition of a normal hairpin or a reverse hairpin is conventional, for example if a hairpin with a right-hand bend direction is taken in the bridge-like connection, the reverse hairpin has a left-hand bend direction and vice versa. The rotation of the drum 400 is reversed in the two cases.

[0069] As can be seen from Fig. 34, for example, on drum 300, a basic conductor has already been inserted and now it is desired to insert an inverted pin. For this purpose, an upper guide 410R is used instead, which has the opposite circumferential extension direction to guide 410 (from left to right instead of right to left as seen from the free leg end in the figure). Fig. 35 shows the same situation, but starting from an inverted pin bridge-like connection. Fig. 36 is a perspective view from the bridge-like connection side of the inverted pin.

[0070] FIG. 37 shows an embodiment of the insertion into the stator pack, in which two drum assembly systems 700 are placed on an equal number of carriages 710 that transport the systems from the central hairpin loading position to a side position, thus increasing the production cycle. Once the winding assembly is completed, it is transported to a position where the loading into the stator pack takes place. In one embodiment, the assembly system (drums, actuators for rotation and expansion of the insert, radial containment system) is placed on a carriage 710 that can move perpendicularly to the drum axis from the hairpin loading position (Pos1) to one of the winding loading positions (Pos2 / Pos3) of the stator pack, as shown in FIG. 37. According to an advantageous aspect of the invention, two drum assembly systems coexist, placed on an equal number of carriages that transport the systems from the central hairpin loading position to a side position between Pos2 for the right drum and Pos3 for the left drum. This coexistence allows the process of transporting and inserting the windings into the stator pack and the process of loading the hairpins into the drums to overlap in time, thus increasing the productivity of the factory.

[0071] According to FIG. 38, the arm system is replaced by a "carousel" 1500 in which there are several handling units 1510 equipped with grippers for gripping the legs of the elementary conductors 200 and arranged to move from the supply 1550 to the drum 300 without them moving at a predetermined mutual distance (this is also true even if the handling units are themselves unconstrained arms). According to one aspect of this embodiment, the handling units 1550 can move along an oval guide 1520. The handling units are equipped with sliding guides (not shown) for inserting the elementary conductors into the drum, while they may or may not have similar guides or sliding means for taking the elementary conductors on the supply 1550. Alternatively, an element can move from the supply 1550 to the handling unit to carry the elementary conductors. The rest of the apparatus can be as described above, with or without one or more of the optional or preferred elements.

[0072] Based on the characteristics of the device described above, but also more generally, the steps of one embodiment of the method of the invention for handling and assembling hairpins or elementary conductors are described below. F1. When one of the N handling units 1310, 1510 is in a position corresponding to one of the one or more supply stations, it activates the gripper 1321 to grip the legs 255a, 255b of the basic conductor 200, the legs being termed gripping legs. F2. The handling unit is displaced relative to a given axis 1110 (or "machine axis") to transport it to one or more of the assembly stations. F3. In the position reached in step F2, the gripper 1321 is displaced in a direction perpendicular to the given axis 1110 towards the building drum 300, alternately until: - If the gripping legs are the only legs of the hairpin 200, inserting the gripping legs into the gaps of the slots 324 of the assembly drum 300. - if the hairpin has multiple legs, the legs not gripped by the gripper 1321 are inserted into the gaps of the slots 324 of the assembly drum 300, while the gripping legs remain facing the second surface of the insertion guide 400. F4. Release the hairpin 200 by the gripper 1321. F5. The handling unit of steps F1-F4 is displaced relative to a given axis 1110 until it is positioned at one of one or more supply stations. F6. Repeat steps F1-F5, involving rotation of the drum 300 by at least one slot step in a direction towards the circumferential exit end of the slide guide 400. F7. Finally, the drum is rotated further until all the basic conductors 200 on the basic conductor slide guides 400 are out.

[0073] According to one aspect of the present invention, the handling unit may be N handling arms 1310 of the basic conductor 200, where the N arms are rotatable about a given axis 1110, where N=1 or N is any number equal to or greater than 2, and for any number N equal to or greater than 2, the N arms are as follows: - uniformly angularly disposed about a given axis 1110; - configured to rotate together in a given plane about a given axis 1110; - equipped with respective grippers 1321 which grip and transport the elementary conductors, the grippers 1321, along the arms by actuating the gripper slide means.

[0074] Preferably, in step F1, the gripper 1321 is moved in a direction perpendicular to the predetermined axis 1110 towards the supply station.

[0075] If N is 2 or more, each complete rotation of the arm in steps F1-F6 occurs at a pitch of 360° / N, and the arm takes up the elementary conductor in step F1 while simultaneously inserting into the assembly drum 300 an elementary conductor that was already gripped one or more pitches earlier by a different arm than in steps F1-F6.

[0076] According to one aspect of the invention, between steps F5 and F6 the following further steps are carried out: F5b. Resetting the position of the drum slot upon rotation of the drum itself in one circumferential direction.

[0077] According to one aspect of the invention, N=4.

[0078] According to a further aspect of the invention, in step F1, the gripping legs and non-grip legs of the basic conductor form an angle α such that in step F3, the gripping legs can remain facing the second side of the insertion guide 400 without rotation of the gripper 1321.

[0079] As indicated above, the set of slots 324 may be advantageously formed by alternating a corresponding set of radial drum inserts 320. The radial inserts 320 are advantageously retractable and radially expandable, with corresponding radial retraction or expansion being adjusted during assembly of the winding set according to steps F1-F7.

[0080] The distance between the sliding guide (400) and the radial insert (320) is adjusted during assembly of the winding set by steps F1 to F7 so as to have a value that prevents the basic conductors inserted in the slots 324 facing the first side of the sliding guide 400 from falling out.

[0081] In the case of a multi-legged elementary conductor, a guide device for axially inserting the non-gripping leg of the hairpin 200 into the slot 324 can be conveniently interposed between the gripper 1321 and the slot 324 in step F3.

[0082] According to one aspect of the invention, the radial insert 320 has an axial recess 323 adapted to receive the circumferential storage element 510 of the elementary conductor 200 in a slot 324 moved by the storage system 510 .

[0083] Once the winding sets have been assembled on the drum 300, the following additional steps may be performed to insert the windings into the stator or rotor pack. F8. Store the radial inserts 320 of the drum 300. F9. Thrust means 810, 811, and 820 are arranged to apply thrust to the windings set on the drum (300) from the bridge-shaped connection portion side of the basic conductor 200. F10. The thrust means 810, 811, 820 are actuated in the direction 840 of the drum axis 310 towards the stator or rotor pack 750, 760 to insert the free ends of the base conductors 200 into the corresponding seats of the stator or rotor pack 750, 760.

[0084] For this purpose, a further step may be performed before step F10 of aligning the free ends of the basic conductors to their respective positions in the slots of the stator or rotor pack, the respective positions being assigned according to a predetermined winding pattern, the alignment being performed by one or more alignment arrangements 200 for alignment of the free ends of the basic conductors.

[0085] In this case, one or more alignment arrangements at the free ends of the base conductors 200 may include an arrangement having a movable radial element movable towards the axis of the drum 300 .

[0086] If the elementary connector of the winding set comprises bridge-like hairpins with different connecting bend directions (reverse hairpins, see above), in step F3, a sliding guide 400 with opposite circumferential outlet ends is used in each case.

[0087] Before step F3, the mutual distance between the drum shaft 320 and the gripper 1321 can be conveniently adjusted.

[0088] In order to increase the productivity of the device according to the invention, two handling units are provided at the same assembly station 300, in which the following steps are carried out: F11. Activate the first of the two handling units to move it from the in-axis position of step F3 to an offset position. F12. Activate the second of the two handling units to move it from the offset position to the in-axis position of step F3. F13. Execute steps F8 to F10 on the first handling unit. F14. Execute steps F1 to F7 on the second handling unit. F15. Repeating the cycle of steps F11 to F14, wherein the first handling unit is identified as having exited step F14 and the second handling unit is identified as having exited step F13.

[0089] In the device and method according to the invention, the situation seems to be different both morphologically and functionally compared to the prior art described in patent applications US2019 / 0190359 and US2019 / 0356188 by Odawara Engineering. Indeed, the pulley wheel 1320 is smaller than the assembly cylinder 300 (see FIG. 13) and a dedicated opening is provided for accessing the latter. The contrast observed in the Odawara Engineering application is missing, since in this case, even if an axial shift of the hairpin were to be made (which is not even proposed), in addition to having to modify the respective mechanisms, the cylinder drag gear would have a larger diameter than the latter, and this diameter would serve for the operation of the other parts of the device, so there would be no space for such an operation.

[0090] The system according to the invention solves in particular the problem of translating and rotating the basic conductor by 180°. The starting point is that the basic conductor is fed from the previous station with its cusp (bridge-like connection) towards the assembly system, i.e. with the legs further away from the cusp. In order to function, the assembly system needs to rotate the hairpin by 180° before inserting it.

[0091] In general, the present invention can use any of the base conductors 200, 200R described in the prior art section, including I-pins, W-pins, and inverted pins.

[0092] Two or more of the above mentioned parts (elements, devices, systems) can be freely associated and considered as a kit of parts according to the present invention.

[0093] Advantages of the present invention include the following: 1. The axial insertion of the hairpin legs between two consecutive retractable drum inserts allows for better control of the hairpin position and helps to better control the movement of the conductor array in the filling zone on the drum. This movement is delicate due to the risk of blockage due to interference between the bridge-like connections of the hairpins. With better control this risk can be avoided. 2. The distance between the guide arm and the insert must not exceed the thickness of the conductor forming the hairpin. In the Odawara Engineering application, this is not possible because of the radial insertion (the Odawara Engineering application has a pusher in the axial direction, which at best allows the guide to close after the hairpin has passed radially, but this is not disclosed in any case). Even if the hairpin could pass radially and remain in a position where there is no opening in the guide arm due to the radial displacement, it may actually come back out partially through the same inlet opening before the rotational displacement and get jammed with the rest of the arm. The guide in the present invention acts as both a guide and a containment, so that the second leg does not fall by gravity but is entrained. This is particularly important because, although the basic conductor is never perfect, the entrainment allows it to recover from small shape variations. 3. The axial insertion allows a shorter crown assembly time than in the prior art, in conjunction with the need to properly store the hairpin leg between two successive retractable drum inserts. In fact, in the prior art, the hairpin is inserted with an approaching movement relative to the drum having radial and circumferential components (TBV). The coexistence of these two movements makes it more complicated to devise a hairpin storage system for the first leg that can keep up with the high hairpin formation period (1.5 seconds). In other words, adding a storage device for the first leg of the hairpin in the prior art device achieves advantage 1, but at the cost of the additional complexity required to free up space for the insertion of the next hairpin. To avoid this additional movement, it is advantageous to move the hairpin axially to place it on the drum, using a device that can fully and consistently utilize the movement for this purpose. 4. In the system according to the present specification, the guide arm can be positioned at a suitable distance from the drum to prevent the conductor inserted in the drum insertion opening from slipping out / entering, whereas in the case of Odawara Engineering's application, the space between the guide arm and the drum insertion is used to insert the non-grip leg of the hairpin into the drum slot. Advantageously, the guide is radially movable to vary its distance from the drum.

[0094] Although preferred embodiments of the present invention have been described herein and some variations have been proposed, it is understood that those skilled in the art can make modifications and changes without departing from the respective scope of protection defined by the appended claims.

Claims

1. A method of assembling a basic conductor (200) of a winding set of an electromechanical stator or rotor, comprising: using one or more basic conductor supply stations (200), each basic conductor including one or more legs; The method also includes: using N handling units (1310, 1510) for handling the basic conductor (200), each handling unit being provided with a respective gripper (1321) for gripping the basic conductor and transporting it along a respective path about a predetermined axis; The method also includes: using one or more basic conductor assembly stations for one or more winding sets; The assembly station includes: an assembly drum (300) rotatable about a drum axis arranged parallel to a predetermined axis and including a series of slots (324) arranged at circumferentially spaced intervals of one slot pitch on the outer cylindrical surface of the drum; each slot having a gap extending radially along the axis of the drum, the gap penetrating parallel to the axis of the drum and opening radially outward from the drum; The assembly station also includes: a basic conductor slide guide (400) having a first side facing a circumferential arc of the drum (300) and a second side facing opposite the first side, and having a circumferential outlet from which a basic conductor exits from one end of the circumferential arc during rotation of the drum (300); The method includes the following group of steps: F1. Actuating the gripper (1321) to grip the legs (255a, 255b) of the basic conductor (200) when one of the N handling units (1310) is in a position corresponding to one of the one or more supply stations, the legs being referred to as the gripped legs; F2. Displacing the handling unit relative to a predetermined axis (1110) and transporting it to one of the one or more assembly stations; F3. At the position reached in step F2, in a direction perpendicular to the predetermined axis (1110) and towards the assembly drum (300), - by means of the gripper, when the gripped leg is the only leg of the basic conductor (200), inserting the gripped leg into the gap of the slot (324) parallel to the axis of the assembly drum (300); - When the basic conductor has a plurality of legs by means of grippers, inserting the legs not gripped by the gripper (1321) into the gap of the slot (324) parallel to the axis of the assembly drum (300), and the gripped legs remaining facing the second face of the insertion guide (400); displacing until they occur alternately; F4. After step F3, releasing the basic conductor (200) by the gripper (1321); F5. Displacing the handling unit of steps F1 to F4 relative to a predetermined axis (1110) until it is positioned at one of the one or more supply stations; F6. Repeating steps F1 to F5 simultaneously with the rotation of the drum (300) by at least one slot pitch in the direction towards the circumferential outlet end of the slide guide (400); F7. Finally, further rotating the drum until all the basic conductors (200) on the basic conductor slide guide (400) have exited. A method comprising. **Claim 2** The handling unit is N handling arms (1310) of the basic conductor (200), the N arms being rotatable relative to a predetermined axis (1110), N = 1 or N is either 2 or more, for any N of 2 or more, the N arms are - uniformly angled about a predetermined axis (1110), - configured to rotate integrally on a predetermined plane centered on the predetermined axis (1110), - each provided with a gripper (1321) for gripping and transporting the basic conductor, and the gripper (1321) slides along the arm by actuating gripper slide means. The method according to claim 1. **Claim 3** In step F1, the gripper (1321) is moved in a direction perpendicular to the predetermined axis (1110) towards the supply station. The method according to claim 2. **Claim 4** When N is 2 or more, the complete rotation of the arms in steps F1 to F6 occurs at a pitch of 360° / N respectively, and the arm takes the basic conductor in step F1 and simultaneously inserts the basic conductor already gripped more than one pitch earlier by a different arm than in steps F1 to F6 into the assembly drum (300). The method according to claim 2 or 3. **Claim 5** When rotating the drum in one circumferential direction of the drum itself, a further step of resetting the position of the drum slots is executed between step F5 and step F6, The method according to claim 1.

6. where N = 4, The method according to claim 1.

7. In step F1, the grip leg and the non-grip leg of the basic conductor form an angle α so that in step F3, the grip leg can remain facing the second side of the insertion guide (400) without rotation of the gripper (1321). The method according to claim 1.

8. A series of slots (324) is formed by alternately arranging a corresponding series of radial inserts (320) of the drum. The method according to claim 1.

9. The radial inserts (320) are radially stowable and expandable, and the corresponding radial stowage or expansion is adjusted during the assembly of the winding set according to steps F1 - F7. The method according to claim 8.

10. The distance between the slide guide (400) and the radial insert (320) is adjusted during the assembly of the winding set according to steps F1 - F7 and has a value such that the basic conductor inserted into the slot (324) facing the first side of the slide guide (400) does not come off. The method according to claim 9.

11. In step F3, in the case of a basic conductor having a plurality of legs, a guide device for axially inserting the non-grip leg of the basic conductor (200) into the slot (324) is interposed between the gripper (1321) and the slot (324). The method according to claim 1.

12. The radial insert (320) axially has a recess (323) adapted to accommodate the circumferential storage element (510) of the basic conductor (200) in the slot (324) moved by the storage system (510). The method according to claim 1.

13. When the winding set is assembled on the drum (300), the following group of steps: F8. A step of storing the radial insert (320) of the drum (300); and F9. A step of arranging thrust means (810, 811, 820) for applying a thrust to the winding set set on the drum (300) from the side of the bridge connection of the basic conductor (200). Step F10 of actuating thrust means (810, 811, 820) in the direction (840) of the axis (310) of the drum towards the stator or rotor pack (750, 760) in order to insert the free end of the basic conductor (200) into a corresponding seat of the stator or rotor pack (750, 760); is executed, A method according to claim 9.

14. An additional step of aligning the free ends of the basic conductors to respective positions within the slots of the stator or rotor pack is performed prior to step F10, each position being assigned according to a predetermined winding pattern and the alignment being effected by one or more alignment arrangements (200) for alignment of the free ends of the basic conductors. A method according to claim 13.

15. One or more alignment arrangements of the free ends of the basic conductors (200) include an arrangement having movable radial elements movable towards the axis of the drum (300). A method according to claim 14.

16. If the basic conductors of the winding set include basic conductors with bends in different directions of the bridge connection, then accordingly in step F3 a slide guide (400) having opposite circumferential outlet ends is used. A method according to claim 1.

17. Prior to step F3, the mutual distance between the drum axis (320) and the gripper (1321) is adjusted. A method according to claim 1.

18. Two handling units are provided at the same number of assembly stations (300), where the following group of steps: F11. Actuating the first unit of the two handling units to move it from the in-axis position of step F3 to an offset position; F12. Actuating the second unit of the two handling units to move it from the offset position to the in-axis position of step F3; F13. Executing steps F8 to F10 with the first handling unit; F14. Executing steps F1 to F7 with the second handling unit; F15. Repeating the cycle of steps F11 to F14, where the first handling unit is identified as having exited step F14 and the second handling unit is identified as having exited step F13, is executed, A method according to claim 1.

19. An apparatus for assembling a basic conductor (200) of a winding set of an electrical machine stator or rotor, including one or more basic conductor supply stations (200), each basic conductor including one or more legs, the apparatus also including N basic conductor handling units (1310), each handling unit being provided with a respective gripper (1321) for gripping a basic conductor and transporting it along a respective path centered on a predetermined axis, the apparatus also including one or more basic conductor assembly stations for one or more winding sets, the assembly station including an assembly drum (300) rotatable about a drum axis arranged parallel to the predetermined axis and including a series of slots (324) arranged at a continuous pitch of one slot pitch circumferentially on the outer cylindrical surface of the drum, each slot having a gap extending radially along the axis of the drum, the gap being open radially outward from the drum passing parallel to the axis of the drum, the assembly station also including a basic conductor slide guide (400) having a first side facing the circumferential arc of the drum (300) and a second side facing the opposite of the first side, and having a circumferential exit from which the basic conductor exits from one end of the circumferential arc when the drum (300) rotates, each respective gripper (1321) - when the grip leg is the only leg of the basic conductor (200), inserting the grip leg into the gap of the slot (324) parallel to the axis of the assembly drum (300), - when the basic conductor has a plurality of legs, inserting the leg not gripped by the gripper (1321) into the gap of the slot (324) parallel to the axis of the assembly drum (300), and the grip leg remaining facing the second side surface of the insertion guide (400), is configured to occur alternately, furthermore, when the grip leg is inserted into the drum, the basic conductor (200) is configured to be released and stored perpendicular to the predetermined axis, the apparatus.

20. The handling unit is N handling arms (1310) of the basic conductor (200), the N arms being rotatable with respect to a predetermined axis (1110), N = 1 or N is either 2 or more, for any N of 2 or more, the N arms - are uniformly angled and arranged about a predetermined axis (1110), - configured to rotate integrally on a predetermined plane centered on a predetermined axis (1110), - each gripper (1321) for gripping and transporting a basic conductor and a gripper (1321) along an arm by operating gripper slide means, The device according to claim 19.

21. where N = 4, The device according to claim 20.

22. A series of slots (324) is formed by alternately arranging a corresponding series of radial inserts (320) of the drum, The device according to claim 20 or 21.

23. The radial insert (320) is radially stowable and expandable, The device according to claim 22.

24. In the case of a basic conductor having a plurality of legs, a guide device for axially inserting the non-gripping legs of the basic conductor (200) into the slots (324) is provided between the gripper (1321) and the slots (324), The device according to claim 19.

25. A circumferential storage element (510) of the basic conductor (200) is provided in the slots (324) and is moved by a storage system (510), The radial insert (320) has a recess (323) axially adapted to accommodate a circumferential storage element, The device according to claim 19.

26. Thrust means (810, 811, 820) are provided for pushing a winding set into the drum (300), The thrust means are - arranged on the side of the bridge connection of the basic conductor (200), - configured to be actuated towards the stator or rotor pack (750, 760) in the direction (840) of the axis (310) of the drum for inserting the free end of the basic conductor into the corresponding seat of the stator or rotor pack (750, 760), The device according to claim 19.

27. One or more alignment arrays are provided for alignment of the free ends of the basic conductor (200), The alignment array is configured to align the free end of the basic conductor to its respective position within the seat of the stator or rotor pack assigned according to a predetermined winding pattern, The device according to claim 26.

28. One or more alignment arrays of the free ends of the basic conductor (200) include an array having a movable radial element movable towards the axis of the drum (300), The device according to claim 27.

29. If the basic conductor of the winding set includes a basic conductor with bends in different directions of the bridge connection, accordingly, in step F3, a slide guide (400) having opposite circumferential outlet ends is further provided. The device according to claim 19.

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