Field of the Invention

This invention is concerned with a process for manufacturing a dynamo- electric machine stator, and more particularly, to the step of "unfolding" or "closing" of lateral flaps of the polar bases of dynamo-electric machines stators. Said step of "unfolding" or "closing" which includes the aforementioned process of manufacturing a dynamo-electric machine stator is mainly carried out by physical deformation of the sides of the polar bases of the stator.

The present invention further relates to the system for deformation of a dynamo-electric machine stator, and in particular, to a deformation system capable of perform the step of "unfolding" or "closing" lateral flaps of the polar bases of dynamo-electric machines stators.

Background of the Invention

Dynamo-electric machines comprise machines capable of transforming electrical energy into mechanical energy (electric motor, for example) or mechanical energy into electrical energy (voltage generator, for example), and are fundamentally integrated by fixed inductive cores and movable inductive cores.

As it is aware by experts skilled in the art, such dynamo-electric machines have their functional principle based on principles of electromagnetic induction, where the magnetic fields created by the inductive cores are capable of generating movement in the movable inductive cores.

The fixed inductive cores are disposed in the stator while the movable inductive cores are arranged in the rotor.

Typically, and in accordance with the teachings contained in the current state of the art, a stator of a dynamo-electric machine is mainly composed of a metal frame and a plurality of coils (contouring electrical conductors arranged around an shaft), and the coils are arranged in alignment in relation to the metal frame. The metal frame, according to the conventional embodiments, defines radial shafts circumferentially spaced apart and circumferentially joined together by their upper ends (the lower ends being spaced from each other). These shafts ultimately define structures in which electrical conductors are wound, and the spaces between these shafts have the function to accommodate the volume formed by electrical conductors. In this sense, it is possible to note that each shaft and its respective coil comprise a fixed inductive core.

Still according to the teachings contained in the present state of the art, a rotor of a dynamo-electric machine is mainly mounted within the stator, and due to this, the shafts of the metal frame of the stator have a length dimensioned to conform an empty central space, said space being intended to the reception of the rotor.

In this context, it is noted that the stator and rotor of a dynamo-electric machine can be obtained from the junction of multiple metal blades of formats being equivalent to each other. An example of this embodiment can be seen in document US 2011/0127876, wherein it is illustrated and described that a single metal blade (raw material) when subjected to a stamping process may be used for the manufacturing of multiple blades of stator and multiple rotor blades. It is also emphasized that the rotor blades are manufactured from the raw material "waste" of the stator blades. Although the cited document US 201 1/0127876 describes an example of this embodiment, it should be noticed that the disclosed practice is conventional since the mid 1960s.

In these types of embodiments, it is noted that the area of electrical conductors that constitute the stator coils comprises a feature capable of influencing the efficiency of the dynamo-electric machine (electric conductors of smaller area are more susceptible to the occurrence of Joule effect, as well as an intrinsic limitation on the nominal value of the electric current that these conductors support). Therefore, there is an interest that electrical conductors that form the stator coils exhibit the largest possible area.

However, the area of electrical conductors that constitute the stator coils tends to be limited by characteristics of the framework of the stator.

Thus, and as illustrated in figures 1.1 , 1.2, 2.1 and 2.2 (conventional embodiments of dynamo-electric machine stators), it is noted that the shafts 11 , 12 of the stator blade has a final end defined by two lateral flaps 4, which ultimately define the size of "entry" of spaces 2 intended for the accommodation of electrical conductors that form the stator coils.

The size of the "inputs" of spaces 2 for the accommodation of electrical conductors also includes a feature capable of influencing the efficiency of the dynamo- electric machine, wherein the higher are these dimensions, the greater the magnetic dispersion of the inductive core and consequently the greater the loss of yield of the dynamo- electric machine.

Therefore, for a dynamo-electric machine to be efficient, it is common that balance exists between the area of electrical conductors that constitute the stator coils and the magnetic dispersion of the inductive core provided by the space between the side flaps of consecutive shafts. In general, this balance is normally obtained by means of the blades of dynamo-electric machines stators whose side flaps of the shafts are capable of "moving or warping" along the manufacturing process of said stator. Examples of these types of blades and / or processes are disclosed in documents PI 9702724-3, US 4,176,444, US 4,267,719 and US 6,742,238. The document PI 9702724-3 describes an optimized embodiment of the stator blade of electric motor. In this embodiment, the side flaps of the shafts can be manipulated during the process of manufacturing the stator, thereby allowing the "opening" and "closure" of the channel housing of the electrical conductors. More particularly, it is noted that the "opening" and "closure" of the channels occur by means of pivoting the side flaps of the. shafts. The main negative aspect related to the embodiment described in document PI 9702724-3 refers to the need of pivoting the side flaps of the shafts to close and above all, open the channels, since it is extremely complex to group multiple blades whose side flaps of the shafts are pivoted.

The documents US 4176444 and US 4267719, both derived from a single priority, describes a method and a device for forming stators of electrical machines. The method in question provides a series of steps that, in general, define that the blades are first printed, and subsequently grouped, forming the metal frame of the stator. With the metal frame already formed, the side flaps of the shafts are subjected to deformation by pressure, and since all channels are opened, the housing of electrical conductors is made. Then, the channels are also closed by deformation by pressure, the method is deemed to be completed. In general, the "opening" of the channels is performed in a puncture equipment, where each one of the channels is filled with a puncture tool, and each of the lower ends of the shafts is supported in a sort of deformation template. The movement (from inside outwards) of the puncture tool forces the side flaps of the shafts against the template, and this makes said side flaps to assume the shape of said template.

Otherwise, the current state of the art is still made up of different processes of "closing" the channels intended for the accommodation of electrical conductors. Examples of these different processes are described in US 4829206, US 6242835, US 6742238 and US 6949857.

Document US 4829206 describes a method for "closing" specially intended to the profile of the end of the channels of the blades, where the end of each channel has a gap capable of deformation by external pressure. This deformation ultimately conform elongated edges radially designed so as to "close" the channels of the blades.

Document US 6242835 describes a method of obtaining the rotor and stator where at least one of these components is initially obtained with distal channel ends in "V". In later stages, the ends in "V" are deformed, assuming "T" profiles. The final form ("T") of the ends of the channels finally "close" them.

The document US 6742238 describes, among other aspects, a means to perform the "closing" of the ends of the channels of the blades of the stator, comprising an equipment formed by a support structure and spheres capable of radial movement. Thus, and in accordance with the above illustration, it is noted that the spheres are positioned at the "open" ends of the channels of the blades and pressed against them. This axial force imposed on the spheres is transmitted to "open" ends of the channels of the blades, performing their "closing".

Document US 6949857 discloses an apparatus capable of perform the "closing" of the channels of the stator. This equipment does not provide the deformation of the ends of the channels, but rather the deformation of the central point of structures disposed between the channels. This central deformation finally generates slightly elongated lateral portions. Apparently, these deformations are imposed only on the upper and lower regions of the stator.

In any case, none of the processes, methods or tools described above is capable of providing or construct a stator made by blades whose "waste" can be used to obtain the rotor.

Based on all the context explained above, it is evident to note that the current state of the art lacks a manufacturing solution, or even a process for manufacture a dynamo- electric machine stator free of the negative aspects explained above. It is based on this scenario that the present invention is proposed.

Objectives of the Invention

Thus, it is an objective of the present invention to provide a process for the manufacture of dynamo-electric machine stator capable of providing the obtaining of integrated stators which have fixed inductive cores with substantially equivalent electromagnetic fields.

Thus, another objective of the present invention is that the step of closing channels for housing the electrical conductors to conform the ends of the substantially standardized polar bases.

It is also an objective of the present invention that this step "final finishing", or calibration step, makes the opening of the stator, wherein the rotor is housed, to be homogeneous. Therefore, it is also one of the objectives of the present invention that this process be capable of deforming the stator blades so that their format be substantially equivalent to the initial shape and previous to the step of "opening" of channels.

It is yet another object of this invention to provide a system of stator deformation dynamo-electric machine capable of "processing" said dynamo-electric machine stator according to the fundamental concepts of the process of manufacture of dynamo- electric machine stator.

Summary of the Invention

All the above mentioned objectives are fully achieved by means of the process of manufacturing dynamo-electric machine stator and of the system for deformation of dynamo-electric machine stator, both comprising the objects of the present invention. The process of manufacturing of the dynamo-electric machine stator comprises at least a step of stamping the blades of the stator, at least one step of grouping stator blades, at least one step of forming the inductive cores in the housing channels of electrical conductors and at least one step of closing the housing channels of electrical conductors. More particularly, said step of closing the housing channels of electrical conductors comprises the deformation of the ends of the same polar basis of an shaft of the stator from rotating movement imposed by at least one roller capable be circumferentially moved clockwise and counterclockwise, of which at least one from the circumferential movements of the roller provides a displacement begun in the center of a polar base, and terminated at one of the ends in the same polar base, and at least one of the circumferential movements of the roller provides a displacement begun in stopping point of the circumferential movement previously performed, and finished at the other end of the same polar base.

In this scenario, and at a preferred manner, it is further provided, from a polar base of an shaft after the circumferential movements of the roller, two circumferential movements of the roller, wherein the circumferential movement of the roller provides a displacement initiated in the center and finished in the beginning if the end of the polar base of the adjacent shaft of the roller and a further movement initiated at the stopping point of the previously performed circumferential movement and finished in the beginning of the end of the polar base of the adjacent shaft.

Thus, the first circumferential movements of the roller are performed in a first sub-step belonging to the step of closing the housing channels of the electrical conductors and the second circumferential movements of the roller are performed in a second sub-step belonging to the step of closing the housing channels of the electrical conductors. Both movements of the rollers are performed in opposite clockwise directions.

The briefly discussed process is preferably performed in the system of deformation of the dynamo-electric machine stator, which comprises multiple rollers concentrically arranged in at least one alignment structure and at least one cooperating shaft associated with said frame alignment. Such alignment structure is capable of performing rotational motion in clockwise and anti-clockwise directions.

Preferably, the alignment structure basically comprises a fundamentally annular body provided with fastening means able to retain the multiple rollers, and capable of performing rotating movement in clockwise and counterclockwise directions by driving at least one driving source (functionally associated with the shaft). In general, it appears that this driving source may comprise an electric stepper motor, among other options.

Still according to the present invention, it is further noted that the rollers are also capable of rotating movement by means of at least one driving source. Furthermore, the rollers comprise bodies with fundamentally cylindrical profile.

In order the above process can be carried out in separate sub-steps, said system provides a first alignment structure provided with multiple rollers and a in cooperated association with the shaft, and a second alignment structure provided with multiple rollers and in cooperated association with the same shaft, wherein alignment structures are interchangeable to each other.

Brief Description of the Drawings

The present invention is disclosed in detail with basis on the figures listed below, wherein:

Figure 1 .1 illustrates, in schematic manner, a dynamo-electric machine stator with its housing channels of electrical conductors opened, according to the present invention;

Figure 1 .2 illustrates an enlarged detail taken from Figure 1 .1 ;

Figure 2.1 illustrates in schematic manner a dynamo-electric machine stator with its housing channels of electrical conductors closed, according to present invention;

Figure 2.2 illustrates an enlarged detail taken from Figure 2.1 ;

The figures 3.1 , 4.1 and 5.1 illustrate, in general, a dynamo-electric machine stator when subjected to the first sub-step of the step of closing the housing channels of electrical conductors, according to the present invention;

The figures 3.2, 4.2 and 5.2 illustrate, respectively, enlarged details taken from Figures 3.1 , 4.1 and 5.1 ;

The figures 6.1 , 7.1 and 8.1 illustrate, in general, a dynamo-electric machine stator when subjected to the second sub-step of the step of closing the housing channels of electrical conductors, according to the present invention;

The figures 6.2, 7.2 and 8.2 illustrate, respectively, enlarged details taken from Figures 6.1 , 7.1 and 8.1 , and

Figure 9 illustrates in exploded view and in a schematic manner, a preferred embodiment of the deformation system of dynamo-electric machine stator.

Detailed Description of the Invention

In accordance with the explanations above, it is an objective of the present invention to manufacture, by means of a process for manufacturing the dynamo-electric machine stator, a stator of substantially homogeneous internal opening, that is substantially cylindrical. This is because it is desirable to obtain a dynamo-electric machine (for example, an electric motor) whose rotor can act freely in the opening of the respective stator without the occurrence of physical interference between them. Therefore, it is necessary that the shape of the lower end, including the ends of the polar bases of the shafts of the stator blades be slightly deformed so that its final shape is substantially equivalent to the initial format (format prior to the step of "opening" of the housing channels of electrical conductors). Thus, and in accordance with the concepts discussed in the present invention, there is disclosed the closing of the housing channels of electrical conductors (this step being preceded by the "opening" of the said housing channels of electrical conductors, and forming the inductive cores in the housing channels of electrical conductors), which, in general, provides the physical deformation of the ends of the polar bases of the shafts of the stator by means of rotating friction imposed by rollers capable of performing rotating movements in clockwise and anti-clockwise directions.

More specifically, the aforementioned step of closing of the housing channels of electrical conductors comprises deforming the ends of the same polar base of the shaft of the stator from rotating friction imposed by at least one roller capable to be circumferentially moved in clockwise and counterclockwise directions.

One of these circumferential movements (clockwise or counterclockwise) of the roller provides a displacement initiated in the center of a polar base, and terminated at one of the ends of the same polar base. This circumferential movement is responsible for deformation of only one of the ends of the same polar base, making thus performing the partial closing of a housing channel of electrical conductors.

The other of these circumferential movements (clockwise or counterclockwise) of the roller provides a displacement initiated at the stopping point of the circumferential movement previously performed, and terminated at the other end of the same polar base. This circumferential movement is responsible for deforming the other end of the same polar base, thus making the total closing of a housing channel of electrical conductors.

It can therefore be asserted that, in accordance with the concepts of the present invention, it is possible to close all housing channels of electrical conductors of a stator from two circumferential movements of a roller. Of course, these two circumferential movements are subsequent and performed in opposite directions.

With this it is possible to achieve a major goal of the present invention, namely, to deform (or "close") the ends of the polar bases of the shafts of the stator in order to give shape and diameter as close as possible to that obtained when stamping the blades of the stator. Therefore, it is important that the centers of polar bases remain essentially unchanged, so as to ensure a "inner circumference" of the stator wherein a rotor is functionally housed.

About the preferred embodiment of the step of closing the housing channels of electrical conductors

The fundamental concept disclosed above refers to close all housing channels of electrical conductors of the stator at a single step provided with two movements which are subsequent and performed in opposite clockwise directions.

Thus, and in accordance with the stators shown in Figures 1.1 and 2.1 , it is necessary to use twenty-four rollers synchronized in a cooperating manner with each other.

However, and as a matter of high torque involved in the unfolding, and the physical space involved, the step of closing the housing channels of electrical conductors is preferably performed on two separate sub-steps, thereby involving a total of four circumferential movements the rollers.

In this preferred case, the first sub-step is responsible for closing twelve from the twenty-four housing channels of electrical conductors (or even deform the ends of twelve of the twenty-four polar bases) and the second sub-step responsible for closing the remaining twelve from the twenty-four housing channels of electrical conductors (or even deform the ends of another twelve of the twenty-four polar bases).

This subdivision is entirely founded on the fundamental concept of the present invention and for didactic purposes, it is best illustrated in figures 3.1 , 4.1 , 5.1 , 6.1 , 7.1 and 8.1 , as well as their respective enlarged details shown in Figures 3.2, 4.2, 5.2, 6.2, 7.2 and 8.2.

In relation to these figures, it is then noted that the shafts of the stator 1 are purposefully referred with different indications 1 1 and 12, which are used interchangeably, as best illustrated in Figures 1.1 and 2.1. This differentiation is only symbolic and aims to facilitate the understanding of the preferred embodiment of said step of closing the housing channels (where the first sub-step changes only the ends 4 of the polar bases of the shafts 11 and the second step only changes the ends 4 of the polar bases of the shaft 12). Within this context, it is interesting to emphasize that the shafts 11 and 12 of the stator 1 are similar among them.

Figures 3.1 , 3.2, 4.1 , 4.2, 5.1 and 5.2 illustrate - schematically - the first sub- step which includes the step of closing the housing channels of electrical conductors.

In Figures 3.1 and 3.2, it is noted that only the ends 4 of the polar bases of the shafts 11 are effectively deformed. This is because there are used only twelve rollers 5 arranged in an interleaved manner.

In Figures 4.1 and 4.2, it is noted that the rollers 5, after performing the circumferential clockwise movement D1 , already deform the right ends 4 of polar bases 4 of the shafts 11 , partially closing the channels 21.

In Figures 5.1 and 5.2, it is noted that the rollers 5, after performing the circumferential counterclockwise movement D2, already deform the left ends of the polar bases 4 of shafts 11 , fully closing the channels 21.

Based on these figures, it is also noted that the circumferential movement D1 provides a displacement initiated at the center 3 of a polar base, and terminated at one of the ends 4 of the same polar base. The circumferential movement D2 provides a displacement initiated at the stopping point of the circumferential movement D1 previously performed, and terminated at the other end 4 of the same polar base.

Figures 6.1 , 6.2, 7.1 , 7.2, 8.1 and 8.2 illustrate - schematically - the second sub-step which includes the step of closing the housing channels of electrical conductors.

In Figures 6.1 and 6.2, it is noted that the ends 4 of the polar bases of the shafts 11 are already deformed, whereby only the ends 4 of the polar bases of the shafts 12 will be effectively deformed. Therefore, there are used twelve rollers 6 arranged in an interleaved manner. Preferably, the rollers 6 have a slightly larger diameter than the diameter of the rollers 5.

In Figures 7.1 and 7.2, it is noted that the rollers 6, after performing the circumferential clockwise movement D3, already deformed the right ends 4 of the polar bases of the shafts 12, partially closing the channels 21.

In Figures 8.1 and 8.2, it is noted that the rollers 6, after performing the circumferential counterclockwise movement D4, already deformed the left ends of the polar bases shaft 12 fully closing the channels 22.

Based on these figures, there is still the circumferential movement start D3 provides a displacement in the center of a base 3 of a polar shaft 12, and finished at the top of the base end 4 of the polar shaft 12 'adjacent.

Already the circumferential movement D4 provides a displacement started from Stop motion circumferential D1 previously held, and finished fourth at the other end of the same polar base, stopping point of the circumferential movement D3 previously held, and finished at the beginning of the end of the 4 base polar shaft 12" adjacent.

Thus, each sub-phase is responsible for unfolding dose arranged interchangeably polar bases (closing twelve channels arranged interchangeably).

The first sub-step route of cylinders is small and must not reach the ends of polar bases which have not yet been developed (unfolded be in the second sub-step), after all, these polar bases, if met, will have their ends deformed in a direction wrong (which is totally prohibitive, because it leads to the collapse of these ends, making the stator 1 unusable).

The second sub-step can be limited to the polar bases still undamaged (comprising only a "repeat" of the first sub-step), or may be further extended to all polar bases.

For this second option, it is only necessary that the paths of the cylinders are increased. In this case, the first movement is started at the center of a polar base unharmed and terminated near the center of polar base adjacent (already deformed), and the second movement is initiated at the stopping point circumferential movement of the anterior and terminated near the center of the "other "polar base adjacent (now deformed).

Furthermore, and also in relation to the second sub-option in the second step, are used cylinder diameter slightly larger (relative to the cylinders used in the first sub-step). Thus, the deformed edges of polar bases in the first sub-step homogenized will diameter and shape the ends of polar bases deformed in the second sub-step.

To check this technical advantage, it is essential that the cylinders rotate during both steps. This is because these spins reduce the sliding friction, which is responsible for the generation of cracks of the material of the stator.

About the preferred embodiment of the system of deflection of dynamo-electric machine stator

In general, the system should be able to provide means capable of performing the process described above, and with respect to obtaining the torque moment, which is the driving force to generate the unfolding, which can be obtained in different ways.

Preferably, and as illustrated in Figure 9, the system of deflection of dynamo- electric machine stator comprises multiple rollers 5, 6 concentrically disposed in at least one alignment structure 51 , 61 and at least one shaft 52, 62 cooperatively associated with said alignment structure 51 , 61.

Still preferably, it is noted that the whole set is associated with an operational base 8 which has means of maintaining static the stator of the dynamo-electric machine.

The alignment structure 51 , 61 , which is apt to perform rotating movement in clockwise and anti-clockwise direction comprises an essentially annular body provided with fastening means able to retain the multiple rollers, preferably, it is also noticed that the rollers 5, 6 are in fact "stuck" to the alignment structure 51 , 61 by intermediates of closing plates 7.

As previously mentioned, said alignment structure 51 , 61 is apt to carry out rotating movement in clockwise and counterclockwise through at least one driving source (not shown), which is functionally associated with the shaft 52, 62 and can comprise an electric stepper motor, among other alternatives.

Finally, and also as a preferred form, it is also noticed that the rollers may be subject to rotating movement, and this feature aids in the reduction of the sliding friction of the stator (in the unfolding operations of the nozzles of the stator shoes). This movement can be free, or even by at least one driving source (not shown).

Having illustrated schematic examples of results achieved by the present invention as well as preferred embodiments of certain aspects of the process, it should be understood that the scope of the invention embraces other possible conventional variations to those skilled versed in the subject, said scope of the present invention being solely limited by the content of the claims, including therein the equivalent possible means.