ITPD20130064A1 - ELECTRIC CURRENT WITH CONTINUOUS CURRENT PERFORMED, PARTICULARLY FOR GLASSWORKS, SEATS, WIPERS AND OTHER APPLICATIONS IN VEHICLES - Google Patents

Description

IMPROVED DIRECT CURRENT ELECTRIC GEAR MOTOR, ESPECIALLY FOR WINDOW LIFTS, SEATS, WIPERS AND OTHER APPLICATIONS IN VEHICLES

DESCRIPTION

The present invention relates to an improved direct current electric gearmotor, particularly for window lifters, seats, wipers and other applications in vehicles.

Electric motors with associated reducer, in jargon known as 'gearmotors', for application in motor vehicles, for handling window lifters, windscreen wipers, seat parts and the like, are now known and very widespread, whose main peculiarity is the compactness.

These electric gearmotors are in fact able to be housed in narrow spaces such as the inside of a door, or in the rear hatch, or in the hood of a vehicle.

Given the increasing demand from buyers to have vehicles, such as cars, off-road vehicles, but also boats, equipped with servo-assisted devices, such as, but not limited to, window lifters, seats, wipers and the like, and therefore seen the constant increase in demand for such compact electric gearmotors, the need to automate the production of these compact electric gearmotors is nowadays increasingly felt in the sector, in order to respond as quickly as possible to the rapid change of the market, at the same time containing costs at highly competitive levels .

The search for greater production automation implies the simplification and standardization of components, aimed not only at speeding up assembly, but also at determining the production of gearmotors ready to be associated with vehicles of different manufacturers, and having in turn different standards.

In this sense, Nuova Sme has developed and patented, with patent application PD 2011 A000229, an improved structure of a direct current electric gearmotor, particularly for window lifters, seats, wipers and the like, comprising

- an electric motor comprising a containment portion for a stator body and a corresponding rotor with drive shaft,

- a casing bearing reduction gears

- an electronic board for power supply, position detection or motor control

- a connection portion defining an electric plug or socket for powering the electric motor;

the peculiarity of this improved gearmotor structure lies in the fact that

- said containment portion and said casing are in a single body of plastic material,

- in the containment portion being mounted the stator body comprising a tubular magnet, of the rare earth type, surrounded by a tubular metal body for containing the magnetic field, and said rotor whose motor shaft carries the corresponding collector and a magnetic ring, of detection by sensor means for the detection of position and speed, on the side of the free end of the drive shaft, opposite the torque transmission screw section, - the containment portion being closed by a lid, defining the bottom of the same portion containment, mounted in an axial direction and housing said electronic board inside it, or a shaped support, bearing brushes, sensor means for detecting the position and speed of the rotor, and connectors for power supply and for the transmission of signals, - connection pins being incorporated, optionally - either on said board, or shaped body, arranged for insertion in the comp a connection portion of the lid;

- or integrated in said connection portion.

An important peculiarity of this improved structure of gearmotor is given by the fact that the assembly is very simplified, since the stator body, the rotor complete with its various components, the single body, the cover and the electronic board, are easily and can be quickly assembled by means of assembly operations in the direction of the motor axis only. The electronic board is also pre-assembled to said cover before said cover is fixed to the containment portion of said single body.

The pre-assembly of the board to the cover makes the assembly sequence even more streamlined.

Although this improved structure of the gearmotor has numerous advantages, it is not devoid of prefectability.

A first perfectibility concerns the fact that the geometry of the rotor, marked by an axial compactness (in the direction of the motor axis) foresees that the motor shaft has two supports, one for each of its extremities; the end section of the crankshaft more 'internal' to the containment portion is occupied by the worm screw transmitting the torque to the reduction gears, and therefore it is the opposite end section to be gripped by handling equipment for its assembly; this gripping end section is very short, and is not very suitable for safe automatic handling.

This situation, combined with the fact that in a permanent magnet motor, in order to use the magnetic field effectively, it is advisable to have a limited stator-rotor air gap, makes it difficult to identify suitable areas for automatically and solidly and stably grasping the rotor. , as there is no space for the passage of auxiliary tools to the support and movement of the rotor.

The limits to the handling capacity of the rotor during the insertion phase inside the crankcase can cause assembly problems, in terms of the integrity of the shaft bearing bushings and in terms of gearmotor noise.

In fact, the rotor must be inserted with automatic equipment and without its crankshaft hitting the single bush inside the crankcase, since such impacts can damage the bush itself with consequent acoustic problems for the gearmotor. in operation, and with the further risk of rotating the bush from its correct assembly position, if this bush is adjustable, thus preventing assembly altogether.

At the end of the assembly, an additional bushing present in the cover that seals the crankcase must be able to slip on the outside of the rotor shaft and therefore centering problems also arise for this second bushing.

A further perfectibility of the improved structure of gearmotor described above lies in the type of tubular magnet in rare earths, which is very expensive in terms of raw material.

The aim of the present invention is to provide an improved direct current electric gearmotor, particularly for window lifters, seats, wipers and other applications in vehicles, capable of obviating the limits of the aforementioned improved structure of known gearmotor.

Within this aim, an object of the invention is to provide an improved gearmotor which is cheaper than the known one, in which an important saving is determined by the non-use of a tubular rare earth magnet.

Another object of the invention is to provide an improved gearmotor no less economical to assemble than known gearmotors.

A further important object of the invention is to provide an improved gearmotor, the assembly process of which can be automated with a guarantee of certain and repeatable quality, without having to give up the technical solutions that favor performance and make the object compact ( stator coupled with minimum gap to the rotor) and silent in operation.

Another important object is that of providing an improved gearmotor which is safe in silence when in operation.

Not least object of the invention is to provide an improved direct current electric gearmotor, particularly for window lifters, seats, wipers and other applications in vehicles, which can be manufactured with known systems and technologies.

This task, as well as these and other purposes which will appear better later, are achieved by an improved direct current electric gearmotor, particularly for window lifters, seats, wipers and the like, comprising a reduction gear housing, from which it develops, in single body with it, a containment containment portion for an electric motor comprising in turn a stator body and a corresponding rotor with motor shaft with ends inserted in rotation bushings, said containment portion being closed by a lid, mounted in the direction axis of rotation of the rotor and housing inside it an electronic card for managing the electric motor, a connection portion developing from said cover defining an electric plug or socket for powering the electric motor, said electric gearmotor being characterized by the fact that said stator body comprises a tubular metal body ico for containing the magnetic field inside which at least two symmetrical permanent magnets shaped and positioned to define mounting spaces for said rotor, of said bushings for supporting the ends of said motor shaft, are arranged and locked with mechanical fixing means at least the bush incorporated in said containment casing presenting the mouth of the through hole, for housing the end on the side of the torque transmission screw, with a beveled edge designed to facilitate centering in the assembly of the motor shaft, said tubular body metal being inserted axially inside said single body, which integrates casing and containment portion, and blocked there by interference, by means of ribs inside the containment portion, said containment portion having properties of elasticity and resilience, said tubular metal body presenting one of its edges, facing the inside of the containment portion , tapered to facilitate its insertion with interference in said containment portion.

Further characteristics and advantages of the invention will become clearer from the description of four preferred, but not exclusive, embodiments of the improved electric gearmotor according to the invention, illustrated, by way of non-limiting example, in the accompanying drawings, in which:

Figure 1 shows an exploded perspective view of an improved gearmotor according to the invention in a first embodiment;

Figure 2 represents a component of the gearmotor according to the invention;

- figure 3 is a longitudinal section of the assembled gearmotor of figure 1;

- figure 4 represents the section along the line IV-IV of figure 3;

figure 5 represents an enlarged detail of figure 3;

Figure 6 is a side view of a portion of a gearmotor according to the invention, again in a first embodiment thereof;

- figure 7 represents the view according to the section line VII-VII of figure 6;

figure 8 represents the view according to the section line VIII-VIII of figure 6;

- figure 9 represents a further enlarged detail of figure 3;

- figure 10 represents another enlarged detail of figure 3;

Figure 11 is an exploded perspective view of an electric gearmotor according to the invention in a second embodiment thereof;

figure 12 is an exploded perspective view of an electric gearmotor according to the invention in a third embodiment thereof;

Figure 13 is a longitudinal section of the gearmotor according to the invention in its third embodiment of Figure 12;

- figure 14 represents the cross section XIV-XIV indicated in figure 13;

- figure 15 represents a detail of figure 13;

- figure 16 represents a cross section of the gearmotor of figure 12, with magnetization coils,

Figure 17 is an exploded perspective view of a gearmotor according to the invention in a fourth embodiment thereof.

With reference to the aforementioned figures, an improved direct current electric gearmotor, particularly for window lifters, seats, wipers and the like, according to the invention, is indicated as a whole of a first embodiment thereof, with the number 10.

This improved electric gearmotor 10 comprises a casing 11 carrying reduction gears, from which a containment portion 12, in plastic material, for an electric motor 13, which in turn comprises a stator body 14, develops in a single body with it. and a corresponding rotor 15 with motor shaft 16, of relatively limited length, with ends 19, 20 inserted in rotation bushings 17 and 18.

The containment portion 12 is closed by a lid 21, mounted in the direction of the rotation axis X of the rotor 15.

The cover 21 houses inside an electronic card, not illustrated for simplicity and to be understood of a known type, for managing the electric motor 13.

From the cover 21 develops a connection portion 22 defining an electric plug or socket for powering the electric motor 13.

The peculiarity of the improved electric gearmotor 10 according to the invention lies in the fact that the stator body 14 comprises a tubular metal body 23 for containing the magnetic field, inside which two symmetrical means are arranged and locked, with mechanical fixing means better described below. permanent magnets 24 and 25, clearly visible in figure 2, shaped and positioned to define mounting spaces, indicated with the dashed boxes in figure 5 and indicated there with numbers 26 and 27, for said rotor 15.

A first cylindrical bush 17, incorporated in said containment casing 12, for supporting a first end 19 of the drive shaft 16, has the mouth 28 of the through hole 29, which houses the end 19 on the side of the screw. 30 for torque transmission, with beveled edge 31 suitable for favoring centering, during assembly, of the crankshaft 16.

Similarly, also the second bushing 18, self-centering, or spherical, incorporated in the cover 21 and able to support the opposite end 20 of the drive shaft 16, has a mouth 32 of the through hole 33 having a beveled edge 34.

The two permanent magnets 24 and 25 are shaped in an arc of a circle, or 'tà ̈golo', to coaxially surround two opposite parts of the rotor 15, determining a minimum air gap with it, in order to make the most of the interaction of the rotor magnetic fields. and stator.

The permanent magnets 24 and 25 are preferably ceramic ferrite magnets, so as to reduce the costs of the gearmotor according to the invention 10 compared to known gearmotors with tubular rare earth magnets.

These permanent magnets 24 and 25 are surrounded by the tubular metal body 23, containing the magnetic field, which in the present first embodiment of the invention comprises two opposite flat faces 35 and 36 and two interposed arc-shaped faces 37 and 38, in correspondence of the latter two the permanent magnets 24 and 25 being positioned.

Said tubular metal body 23 is made by drawing a sheet of metal or by bending and longitudinal welding of sheet metal.

This tubular metal body 23 is axially inserted inside the plastic body, which integrates the casing 11 and the containment portion 12, by means of interference, thanks to the ribs 39 inside the containment portion 12, visible in figure 5.

This fixing by interference is possibly assisted by an elastic and resilient design of the containment portion 12 in plastic material.

The mechanical fixing means for the permanent magnets 24 and 25 are given, by way of example, by two opposing fork springs 41 and 42, interposed between the facing edges of the two permanent magnets 24 and 25 and adapted to push the permanent magnets 24 and 25 against the respective arc-shaped walls 37 and 38 of the tubular metal body 23.

The fixing of the magnets is to be understood as also achievable with other spring elements, or other equivalent resilient / elastic elements, at least partially contained in the tubular metal body 23.

To these mechanical fixing means can be added other fixing means, such as gluing, in order to speed up the assembly, which can also be achieved during the hardening phase of the adhesive glue, which in any case has no structural purposes and does not require particularly processes. controlled, since it is exclusively proposed to contain any vibration noise of the permanent magnets 24 and 25.

This type of configuration makes it possible to create an integrated improved electric gearmotor 10, that is, comprising motor and reducer in a single containment body, compact, with two magnetic poles, with `` straight '' magnetization, and obtained by means of a coil that generates a field of magnetization oriented substantially in Y direction, with Y axis as shown in figure 5.

All this with economical assembly of two permanent pan-shaped magnets inside a tubular metal body 23 whose shape, with two opposite circular arc walls and two opposite flat walls, allows a radial-axial coupling by interference with the containment portion 12 which is safe and stable at all operating temperatures, and at the same time not excessive for the integrity of the materials, since the shape of the tubular metal body 23 is capable of opposing rotation under stress and vibrations.

The metal tubular body 23 has its edge 44 turned towards the inside of the containment portion 12, clearly visible in figure 4, which is tapered to define a stop for the apex of the fork spring 41.

The internal diameter D1 of this edge 44 is advantageously larger than the external diameter D2 of the rotor 15, so that it is possible to mount it in the containing portion 12 first of the rotor 15 and then subsequently of the stator body 14.

This is very advantageous since the insertion first of the rotor 15 and then of the stator body 14 ensures that this insertion of the rotor is not disturbed by the magnetic forces expressed by the stator body 14 on the same rotor 15 during insertion, magnetic forces which in the automatic assembly phase can cause the end 19 of the drive shaft 16 to meet incorrectly with the corresponding bushing 17 inside the crankcase 12, with the aforementioned disadvantages.

Fitting the rotor first and then the stator body avoids this problem and ensures a much more precise and repeatable axial assembly.

The chamfered edges 31 and 34 of the bushings 17 and 18 cooperate in the precision of the axial assembly, with the consequent elimination of the operating noise problems of the gearmotor caused by damage to the bushings due to imperfect assembly coaxiality between the motor shaft 16 and bushings 17 and 18.

Furthermore, the axial assembly in the absence of the stator body allows a better manipulation of the rotor 15, which must be taken by an end section, the one opposite to the screw 30, of limited length, axial movement which is therefore preferable to accompany with other auxiliary tools. , in order to make the axial insertion movement more precise.

Still advantageously, the containment portion 12, obtained by molding plastic material in a single body with the casing 11, as already mentioned above, is shaped in such a way as to allow the maximum possible approach from the outside for magnetization coils of the two permanent magnets 24 and 25, schematized with numbers 46 and 47 in figures 7 and 8.

Such a geometry of the plastic body of the containment portion 12 leaves space available for the magnetization coils to approach and approach at a distance, in the Y direction, which corresponds only to the thickness of the containment portion 12, the same containment portion 12 not presenting reinforcements or frames, neither external nor internal, which would distance the tubular metal body and the magnets from the coils.

This structural solution allows the stator body 14 to be mounted axially with the magnets 24 and 25 not yet magnetically active, which allows for optimal axial mounting of the rotor, in the absence of (disturbing) forces due to the stator magnetic field even if the magnets 24 and 25 are already in place.

The presence of the mounting spaces 26 and 27, determined by the permanent magnets 24 and 25 with tile, or in any case non-tubular, combined with the non-magnetization of the magnets already mounted, allows a much better and more precise axial assembly than the known gearmotors, in the compliance with the best construction features that provide for a minimum air gap between stator and rotor to enhance the effectiveness of the permanent magnets themselves.

The beveled edge 31 and 34 of at least one of the two bushings 17 and 18 has a radial dimension equal to or greater than the stator-rotor air gap, defining a further aid to the assembly of the rotor 15 inside the corresponding bush without damage or impediments to the € ™ operation itself, since even in the worst setting situation, with the rotor touching the stator, in any case the end of the rotation shaft meets with its perimeter edge the beveled edge of the corresponding bushing, with consequent deviation of the shaft in progress towards a structure of sufficient coaxiality.

These rounded edges also prevent worse situations such as undesired rotation of the spherical bushings in their seats, an intolerable event that makes assembly completely impossible.

The metallic tubular body 23, for closing the magnetic field, is, as mentioned, made from sheet metal wound by bending or drawn, and its final configuration is not a closed cup, as is usually the case for known gearmotors for window lifters, but ¬ is configured as a sleeve, possibly equipped with conical or radial inlets, or bent flaps designed to facilitate insertion and interference locking inside the plastic body of the containment portion 12.

As already mentioned, the internal diameter D1 of the tubular metal body 23 is greater than the external diameter D2 of the rotor, in such a way as to allow the rotor itself to be assembled before the stator or part of the stator.

In a second embodiment of the improved gearmotor 110 according to the invention, shown in Figure 11, the tubular metal body 123 is overmolded with the containment portion 112 in the construction of the single plastic body which incorporates both the containment portion 112 and the gear casing 111.

The magnets 124 and 125 with corresponding mechanical fastening means are mounted successively.

The subject of the invention is therefore also to be understood as an improved direct current electric gearmotor 110, particularly for window lifters, seats, windscreen wipers and the like, comprising a casing 111 carrying reduction gears, from which a portion develops, in a single body with it, containment 112 for an electric motor 113 comprising in turn a stator body 114 and a corresponding rotor 115 with motor shaft 116 resting on bushings 17, 18, as shown in figures 9 and 10, at its ends 119, 120; this containment portion 112 is closed by a lid 121, mounted in the direction of the rotation axis X of the rotor 115, from which lid 121 develops a connection portion 122 defining a plug or socket for powering the electric motor 113; this electric gearmotor 110 is characterized by the fact that the stator body 114 comprises a tubular metal body 123 for containing the magnetic field, inside which two symmetrical permanent magnets 124, 125 shaped and positioned are arranged and locked with mechanical fixing means defining mounting spaces 26, 27 for said rotor 115; of said bushings 17, 18 for supporting the ends 119, 120 of said drive shaft 116, the bush 17 incorporated in the containment portion 112 has the mouth 28 of the through hole 29, housing the end 119 on the side of the screw 130 torque transmission, with beveled edge 31 adapted to favor centering in the assembly seat of the drive shaft 116; furthermore, the tubular metal body 123 is overmolded with the containment portion 112 in the realization of the single plastic body which incorporates both the containment portion 112 and the gear casing 111, the magnets 124, 125 with corresponding mechanical fixing means, being subsequently mounted .

A third embodiment of the gearmotor 210 according to the invention is well illustrated in figures 12 to 16.

In this third embodiment, the stator body 214 has two permanent magnets 224 and 225 substantially prismatic, with a metal jacket 223, which conducts the magnetic field, shaped to define two side pockets 250 and 251 for containing these prismatic magnets 224 and 225, and two opposite symmetrical central walls of circular arc section 252 and 253, shaped to surround the rotor 215, determining a minimum air gap.

The containment portion 212 is shaped to contain a similar stator body 214, and also in this embodiment so as to allow the best possible approach for magnetizing coils 246 and 247, as shown in Figure 16, to the possibly inserted magnets 224 and 225 not magnetized inside the containment portion 212 to allow the optimal assembly of the rotor 215, similarly to what has been described above for the first embodiment of the invention.

In this embodiment, the magnets 224 and 225 have a geometry characterized by having the dimension according to a first axis Y, figure 14, prevailing with respect to the direction Z.

The metal jacket 223, in this improved gearmotor 210, is suitable not only for containing but mainly for conducting the flux of the magnetic field.

For this reason, the metal jacket 223 is given for example by two symmetrical parts 254, 255, of sheared / folded sheet metal, possibly partially drawn, which develop mainly in the X and Y directions, as shown in figures 13 and 14; therefore the magnetic field of the permanent magnets is coupled to the rotor 215 also thanks to the intervention of these metal sheet parts; the two symmetrical parts 254 and 255 are for ease of assembly joined to each other by means of junction jumpers 280, exemplified in figure 12, designed to keep the two symmetrical parts 254 and 255 in a stable position with respect to each other during the assembly phase in the axial direction of the metal jacket 223 in the containment portion 212, or during overmoulding in the case in which the metal jacket 223 is incorporated into the containment portion 212 by means of overmoulding.

In correspondence with these jumpers 280, defining contained points of continuity between the two symmetrical parts 254 and 255, the magnetic field becomes saturated without significant losses of magnetic flux available to the rotor.

Thanks to this two-part structure 254 and 255 of the metal jacket 223, the flux of the magnetic field produced by the magnets is not short-circuited by a tubular metal body as in the previous embodiments, but is led to couple to the pole pieces of the rotor 215.

The magnets 224 and 225 have a substantially prismatic solid shape and do not directly face the rotor 215, but both rest directly on the plates, with parallel faces. The fixing of the magnets 224 and 225 is made by means of springs at least partially contained by the containment portion or, alternatively, by gluing, or by exploiting the elasticity and pressure of other resilient elements, such as for example the casing 212 itself which with its side pockets 256 and 257, containing the corresponding side pockets 250 and 251 of the metal body 223, it elastically pushes the two sheet metal parts 254 and 255 of the metal body 223 and then blocks the magnets 224 and 225 in the Z direction.

More than one of the aforementioned fixing systems of the magnets can be used, being able to collaborate with each other.

The rotor 215 has a shaft fixed on two cylindrical or spherical bushings, as described above for the previous embodiments.

This type of configuration makes it possible to create motors with 2/4 stator poles, where the rotor "sees" a stator field with a "straight" or "inclined" profile according to the shape of the sheets.

The magnetization is achieved by means of a magnetization coil 246 and 247, Figure 16, which generates a magnetization field oriented substantially in the Z direction.

The stator 214 is inserted inside the plastic body of the containment portion 212 by interference, possibly assisted by an elastic (mainly in the Z direction) and resilient design of the plastic body itself.

This type of configuration guarantees a male (stator 214) -female coupling (the plastic containment portion 212) with interference almost exclusively in the Z direction, and allows the stator to be securely fixed at all operating temperatures and, at the same time, to urge the magnets to insert into the pockets 256 and 257 of the casing 212 not directly, but through the pockets 250 and 251 of the metal body 223.

The residual pressure due to the interference stresses the magnets, with a squat shape and in the example prism, with a compression force along the Z direction, which they can bear without damage.

An improved direct current electric gearmotor 210, particularly for window lifters, seats, windscreen wipers and the like, should therefore also be considered as the subject of the invention, comprising a casing 211 carrying reduction gears, from which it develops, in a single plastic body, a containment portion 212 for an electric motor 213 comprising in turn a stator body 214 and a corresponding rotor 215 with drive shaft 216 with ends 219, 220 inserted in rotation bushings 17, 18, as already described; the containment portion 212 is closed by a lid 221, mounted in the direction of the rotation axis X of the rotor 215, from said lid 221 developing a connection portion 222 defining a plug or socket for powering the electric motor 213 ; this electric gearmotor 210 is characterized by the fact that said stator body 214 comprises a metal jacket 223, for conducting the flux of the magnetic field, inside which at least two symmetrical permanent magnets, 224, are arranged and locked, with mechanical fixing means, 225 in the aforementioned embodiment, substantially prismatic, shaped and positioned to define mounting spaces, 226, 227 in Figure 14, for the rotor 215; the metallic jacket 223, for conduction of the magnetic field flux, is made up of two symmetrical parts 254, 255, substantially disjoint, shaped to define side pockets 250, 251 for containing these prismatic magnets 224, 225, and two opposite ones symmetrical central walls of circular arc section 252, 253, shaped to surround said rotor 215, determining a minimum air gap; of said bushings 17, 18 for supporting the ends 219, 220 of the drive shaft 216, at least the bush 17 incorporated in said containment portion 212 has the mouth 28 of the through hole 29, housing the end 219 on the side of the torque transmission screw 230, with beveled edge 31 adapted to favor centering in the assembly seat of the drive shaft 216; the metal jacket 223 is axially inserted inside the plastic body, which integrates the casing 211 and casing 212, by means of interference; the metal jacket 223 has its edges 244, 244a, turned towards the inside of the containment portion 212, tapered to facilitate its insertion with interference in said containment portion 212.

Advantageously, also the side edges 290 and 291, i.e. the edges extending in the direction of the X axis in assembly position, of the symmetrical parts 254 and 255, are folded to make the insertion with interference of the metal jacket 223 in the portion easier and more immediate. containment 212.

With this configuration, the lateral edges 290 and 291 slide into the containment portion 212 without scratching and incising its internal surface.

In an alternative embodiment, the sheet metal parts 254 and 255 of the metal jacket 223 are, partially or entirely, incorporated into the plastic body of the containment portion 212 by overmoulding, instead of being inserted axially with interference, leaving the compartment inside which the rotor 215 will be inserted and a large compartment inside which magnets 224 and 225 must be inserted together with guide tools and elastic widening of the sheets in order to exploit the elastic design (mainly in the direction Z) and resilient body of the containment portion 212 itself, as well as the natural elasticity of the sheets, so as to fix the ceramic magnets by interference without causing damage, such as chipping, of the same.

For this purpose, the magnets are inserted inside a protective casing 260, clearly visible in the detail of figure 15, before being inserted between the containment and transmission plates of the magnetic field.

This protective casing 260 of the magnet 224 and 225 against direct ceramic / metal contact can be given by a film of polymer, or of shaped paper, or a box or a cage made of polymer or a paint made on the magnets.

This type of configuration guarantees a male (stator) -female (plastic body) coupling with interference almost exclusively in the Z direction, and allows the stator to be securely fixed at all operating temperatures and, at the same time, to stress the magnets to the Insertion inside the sheet metal compartment in a very contained way, thanks to a large compartment of the magnets themselves which allows the access of â € œelastic enlargementâ € tools of the compartment, which tools, once the insertion of the magnets is finished, are extracted and the seat narrows in the Z direction, however leaving space for fastening elements such as fastening springs, or adhesives, or other similar and equivalent combined systems.

In a fourth embodiment of the improved gearmotor 310 according to the invention, Figure 16, the tubular metal body 323 of the state body 314 is substantially cylindrical, and its correct centering and maintenance of the correct angular attitude is allowed by a protruding tooth 370 from the cover 321 in an axial direction, suitable for coupling with a counter-shaped recess 371 defined on the tubular body 323 itself.

In practice it has been found that the invention achieves the intended aim and objects.

In particular, the invention has perfected an improved gearmotor which is cheaper than the known one, in which an important saving is determined by the non-use of a tubular rare earth magnet, replaced by two ceramic ferrite magnets.

In addition, the invention has developed an improved gearmotor which is cheaper to assemble than known gearmotors, thanks to the mounting spaces for auxiliary tools for axial assembly of the rotor, and to the bushings with chamfered leading edge, suitable for always determine the correct centering of the motor shaft on the same bushings, with further advantages in terms of integrity of the bushings and therefore of overall noise of the finished and operational gearmotor.

Further, with the invention an improved gearmotor was developed, whose assembly process can therefore be automated with a guarantee of certain and repeatable quality, without having to give up the technical solutions that favor performance and make the object compact ( stator coupled with minimum gap to the rotor) and silent in operation.

Last but not least, the invention has perfected an improved direct current electric gearmotor, particularly for window lifters, seats, wipers and other applications in vehicles, which can be produced with known systems and technologies.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; moreover, all the details can be replaced by other technically equivalent elements.

In practice, the materials employed, so long as compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

Where the features and techniques mentioned in any claim are followed by reference marks, such marks have been affixed for the sole purpose of increasing the intelligibility of the claims and consequently such reference marks have no limiting effect on the interpretation of each element. identified by way of example by these reference signs.

Claims (16)

CLAIMS 1) Improved direct current electric gearmotor (10), particularly for window lifters, seats, wipers and the like, comprising a casing (11) carrying reduction gears, from which a containment portion develops in a single plastic body ( 12) for an electric motor (13) comprising in turn a stator body (14) and a corresponding rotor (15) with drive shaft (16) with ends (19, 20) inserted in rotation bushings (17, 18), said containment portion (12) being closed by a lid (21), mounted in the direction of the rotation axis (X) of the rotor (15), from said lid (21) developing a connection portion (22) defining a pin or electric socket for powering the electric motor (13), said electric gearmotor (10) characterized by the fact that said stator body (14) comprises a tubular metal body (23), containing the magnetic field, inside which are arranged and blocked, with m mechanical fixing means, at least two symmetrical permanent magnets (24, 25) shaped and positioned to define mounting spaces (26, 27) for said rotor (15), of said bushings (17, 18) for supporting the ends ( 19, 20) of said drive shaft (16) at least the bush (17) incorporated in said containment casing (12) presenting the mouth (28) of the through hole (29), housing the end (19) on the side of the torque transmission screw (30), with beveled edge (31) designed to facilitate centering when assembling the motor shaft (16), said tubular metal body (23) being inserted axially inside said single body , which integrates the casing (11) and the containment portion (12), and blocked there by interference, by means of ribs (39) inside the containment portion (12), said containment portion (12) having properties of elasticity and resilience, said metal tubular body (23) presenting one edge (44) thereof, facing towards the inside of the containment portion (12), tapered to facilitate its insertion with interference in said containment portion (12). 2) Improved gearmotor, according to claim 1, characterized by the fact of comprising two permanent magnets (24, 25) shaped in an arc of a circle, or 'tà golo', to coaxially surround two opposite parts of the rotor (15). 3) Improved gear motor, according to the preceding claims, which is characterized by the fact that said permanent magnets (24, 25) are ceramic magnets made of ferrite, or other similar and equivalent material. 4) Improved gearmotor, according to the preceding claims, which is characterized by the fact that said tubular metal body (23), containing the magnetic field, comprises two opposite flat faces (35, 36) and two interposed arc-shaped faces ( 37, 38), the permanent magnets (24, 25) being positioned in correspondence with the latter two. 5) Improved gearmotor, according to the preceding claims, which is characterized by the fact that said mechanical fixing means for the permanent magnets (24, 25), are given by two opposite fork springs (41, 42), interposed between the facing ones edges of the two permanent magnets (24, 25) and adapted to push the permanent magnets (24, 25) against the respective arc-shaped walls (37, 38) of the tubular metal body (23). 6) Improved gearmotor, according to the preceding claims, which is characterized by the fact that other fixing means, such as gluing, are added to these mechanical fixing means, in order to speed up assembly even during the hardening phase of the adhesive glue . 7) Improved gearmotor, according to the preceding claims, which is characterized by the fact that the internal diameter (D1) of this edge (44) is larger than the external diameter (D2) of the rotor (15), to make it possible the assembly in the containing portion (12) first of the rotor (15) and then subsequently of the stator body (14). 8) Improved gearmotor, according to the preceding claims, which is characterized by the fact that said containment portion (12) is shaped in such a way as to allow the maximum possible approach from the outside for magnetization coils of the two permanent magnets (24, 25 ), schematized with the numbers (46, 47) in figures 7 and 8, the same containment portion (12) not presenting neither external nor internal reinforcements or frames, which would distance the magnets from the coils, such a geometry of the plastic body of the containment portion (12) leaving space available for the magnetization coils to approach and approach the metal tubular body (23) at a distance, in the Y direction, which corresponds only to the thickness of the containment portion (12). 9) Improved gearmotor, according to the preceding claims, which is characterized in that said beveled edge (31, 34) of at least one of the two bushings (17, 18) has a radial dimension equal to or greater than the stator-rotor air gap. 10) Improved direct current electric gearmotor (110), particularly for window lifters, seats, wipers and the like, comprising a casing (111) carrying reduction gears, from which a containment portion (112 ) for an electric motor (113) comprising in turn a stator body (114) and a corresponding rotor (115) with drive shaft (116) resting on bushings (17, 18) at its ends (119, 120), said portion container (112) being closed by a lid (121), mounted in the direction of the rotation axis (X) of the rotor (115), from said lid (121) developing a connection portion (122) defining a plug or socket electric motor for powering the electric motor (113), said electric gearmotor (110) being characterized by the fact that said stator body (114) comprises a tubular metal body (123) for containing the magnetic field, inside which they are arranged and locked , with M mechanical fixing means, at least two symmetrical permanent magnets (124, 125) shaped and positioned to define mounting spaces (26, 27) for said rotor (115), of said bushings (17, 18) for supporting the ends ( 119, 120) of said drive shaft (116) at least the bush (17) incorporated in said containment portion (112) presenting the mouth (28) of the through hole (29), housing the end (119) on the side of the torque transmission screw (130), with beveled edge (31) designed to facilitate centering in the assembly seat of the drive shaft (116), said tubular metal body (123) being overmolded with the containment portion (112) in the realization of the single body of plastic material which incorporates both the containment portion (112) and the gear casing (111), the magnets (124, 125) with corresponding mechanical fixing means, being subsequently mounted. 11) Improved direct current electric gearmotor (210), particularly for window lifters, seats, wipers and the like, comprising a casing (211) carrying reduction gears, from which a containment portion develops in a single plastic body ( 212) for an electric motor (213) comprising in turn a stator body (214) and a corresponding rotor (215) with drive shaft (216) with ends (219, 220) inserted in rotation bushings (17, 18), said containment portion (212) being closed by a lid (221), mounted in the direction of the rotation axis (X) of the rotor (215), from said lid (221) developing a connection portion (222) defining a pin or electric socket for powering the electric motor (213), said electric gearmotor (210) characterized by the fact that said stator body (214) comprises a metal jacket (223), for conduction of the magnetic field flux, inside which I am avail at least two symmetrical permanent magnets (224, 225), substantially prismatic, shaped and positioned to define mounting spaces (226, 227) for said rotor (215), said metal jacket (223), and blocked by mechanical fixing means, conducting the magnetic field flux, being made up of two symmetrical parts (254, 255), substantially disjoint, shaped to define side pockets (250, 251) for containing these prismatic magnets (224, 225), and two opposite symmetrical central walls of circular arc section (252, 253), shaped to surround said rotor (215) determining a minimum air gap, of said bushings (17, 18) for supporting the ends (219, 220) of said shaft motor (216) at least the bushing (17) incorporated in said containment portion (212) presenting the mouth (28) of the through hole (29), housing the end (219) on the side of the screw (230) transmitting the pair, with beveled edge (31) att o to favor centering during assembly of the motor shaft (216), said metal jacket (223) being inserted axially inside the plastic body, which integrates the casing (211) and casing (212), by means of interference, said metal jacket (223) having its edges (244, 244a), turned towards the inside of the containment portion (212), tapered to facilitate its insertion with interference in said containment portion (212). 12) Gearmotor according to the preceding claim, which is characterized by the fact that the side edges (290, 291), i.e. the edges developing in the direction of the X axis in assembly position, of the symmetrical parts (254, 255), are folded to make the insertion of the metal jacket (223) into the containment portion (212) easier and more immediate. 13) Improved gearmotor, according to one or more of the preceding claims, which is characterized by the fact that the containment portion (212) is shaped to contain a similar stator body (214), so as to allow the best possible approach for coils of magnetization to the magnets (224, 225) possibly inserted non-magnetized. 14) Improved gearmotor, according to one or more of the preceding claims, which is characterized by the fact that the fixing of the prismatic magnets (224, 225) is carried out by means of springs at least partially contained by the containment portion or, alternatively, by gluing or again exploiting the elasticity and pressure of other resilient elements, such as the casing (212) itself which with its side pockets (256, 257) elastically pushes the two sheet metal parts (254, 255) of the metal body ( 223) and blocks the magnets (224, 225) in the â € œZâ € direction. 15) Improved direct current electric gearmotor (210), particularly for window lifters, seats, wipers and the like, comprising a casing (211) carrying reduction gears, from which a containment portion develops in a single plastic body ( 212) for an electric motor (213) comprising in turn a stator body (214) and a corresponding rotor (215) with drive shaft (216) with ends (219, 220) inserted in rotation bushings (17, 18), said containment portion (212) being closed by a lid (221), mounted in the direction of the rotation axis (X) of the rotor (215), from said lid (221) developing a connection portion (222) defining a pin or electric socket for powering the electric motor (213), said electric gearmotor (210) characterized by the fact that said stator body (214) comprises a metal jacket (223), for conduction of the magnetic field flux, inside which I am avail at least two symmetrical permanent magnets (224, 225), substantially prismatic, shaped and positioned to define mounting spaces (226, 227) for said rotor (215), said metal jacket (223), and blocked by mechanical fixing means, conducting the magnetic field flux, being made up of two symmetrical parts (254, 255), substantially disjoint, shaped to define side pockets (250, 251) for containing these prismatic magnets (224, 225), and two opposite symmetrical central walls of circular arc section (252, 253), shaped to surround said rotor (215) determining a minimum air gap, of said bushings (17, 18) for supporting the ends (219, 220) of said shaft motor (216) at least the bushing (17) incorporated in said containment portion (212) presenting the mouth (28) of the through hole (29), housing the end (219) on the side of the screw (230) transmitting the pair, with beveled edge (31) att or to favor centering in the assembly seat of the drive shaft (216), said metal jacket (223) being overmolded with the containment portion (212) in the realization of the single plastic body which incorporates both said containment portion (212) that gear casing (211), the magnets (224, 225) with corresponding mechanical fastening means, being mounted successively. 16) Improved gearmotor, according to one or more of the preceding claims, which is characterized by the fact that said tubular metal body (323) of the stator body (314) is substantially cylindrical, and its correct centering and maintenance of the correct angular attitude It is allowed by a tooth (370) protruding from the cover (321) in an axial direction, suitable for coupling with a counter-shaped recess (371) defined on the tubular body (323) itself.