Rotary electrical machine provided with pulley for receipt of belt, and with device for regulation of tension of belt

Abstract

The rotary electrical machine comprises, in front, a pulley (3) secured to a shaft (9) of a rotor (20) passing through the front bearing (1a) of a housing. The bearing includes a base, having a nose (18) for mounting a front ball bearing (7) for rotating the shaft (9), and air inlets (15) defined by arms belonging to an outwardly opening area connecting a peripheral strip of material from the base to the nose (18) in order to shift the nose (18) toward the front in accordance with the central body of a device (100) for adjusting the tension of a belt received in the groove (31) of the pulley (3) and attached onto the housing (1a, 1b). The adjustment device (100) comprises at least one idler (200, 201) for tensioning the belt and a central opening (102) enabling passage of air through the air inlets (15).

Claims

1. A rotary electrical machine, comprising: a housing (1a, 1b) including a front support flange (1a), the housing configured to be secured to a stationary part; a rotor (20) and a rotor shaft (9) integral with the rotor (20); a regulation device (100) configured to regulate the tension of a belt; and a pulley (3) provided with a groove (31), the pulley (3) non-moveably secured relative to the rotor shaft (9) at a front of the housing adjacent to the front support flange (1a), the rotor shaft (9) passing through the front support flange (1a) of the housing; the front support flange (1a) comprising a base (238, 138, 28, 18) provided with a nose (18) receiving a front ball bearing (7) for rotation of the rotor shaft (9), a peripheral strip of material (238) and air inlet openings (15) delimited by arms (138, 28) which connect the nose (18) to the peripheral strip of material (238) of the base; the arms (138, 28) belong to a widened area (138, 28) of the base which widens towards the exterior, connecting the peripheral strip of material (238) to the nose (18), the peripheral strip of material (238) of the base is axially offset from the nose (18) and the front ball bearing (7) so that the nose (18) is disposed axially between the pulley (3) and the peripheral strip of material (238); the belt being received in the groove (31) in the pulley (3); the regulation device being secured on the housing (1a, 1b), the regulation device (100) comprising at least one roller (200, 201) for tensioning the belt, and a central opening (102) permitting passage of air through the air inlet openings (15); the central opening (102) of the regulation device (100) disposed radially around the nose (18) and the arms (138, 28) of the base (238, 138, 28, 18) of the front support flange (1a); the offsetting of the nose (18) at the front relative to the peripheral strip of material (238) depends on a central thickness of the regulation device (100).

2. The rotary electrical machine according to claim 1, wherein a brace (33) is interposed between the rotor (20) and an inner ring of the front ball bearing (7), and wherein the brace (33) has a length which is greater than a length of the inner ring of the front ball bearing (7).

3. The rotary electrical machine according to claim 2, wherein the widened area (138, 28) comprises thicker arms (138), which alternate circumferentially with thinner arms (28) in order to delimit the air inlet openings (15) circumferentially.

4. The rotary electrical machine according to claim 2, wherein the arms of the widened area have equal thickness and delimit the air inlet openings (15) circumferentially.

5. The rotary electrical machine according to claim 1, wherein the widened area (138, 28) comprises thicker arms (138), which alternate circumferentially with thinner arms (28) in order to delimit the air inlet openings (15) circumferentially.

6. The rotary electrical machine according to claim 5, wherein the thicker arms (138) are ribbed.

7. The rotary electrical machine according to claim 6, wherein the thicker arms (138) have a specific radius of connection to the peripheral strip of material (238).

8. The rotary electrical machine according to claim 1, wherein the arms of the widened area have equal thickness and delimit the air inlet openings (15) circumferentially.

9. The rotary electrical machine according to claim 1, wherein the regulation device (100) comprises two coaxial parts (101, 104) which are coaxial to an axis of the rotor shaft (9), and wherein the two parts (101, 104) are rotatable relative to one another against a resilient device with circumferential action.

10. The rotary electrical machine according to claim 9, wherein the two coaxial parts (101, 104) are rotatable relative to one another against a friction device.

11. The rotary electrical machine according to claim 9, wherein the two coaxial parts (101, 104) are perforated centrally in order to permit the passage of the air through the air inlet openings (15), and wherein one of the two coaxial parts is a fixed part configured to be secured on the housing (1a, 1b).

12. The rotary electrical machine according to claim 11, wherein the fixed part (104) comprises radial projections (103) for securing on the housing, and wherein the front support flange (1a) comprises at least one axial protuberance (438) for securing of one of the radial projections (103) of the fixed part (104).

13. The rotary electrical machine according to claim 11, wherein the other part (101) of the two coaxial parts (101, 104) is rotatable relative to the fixed part (104) and has a projection for support of a roller (200) for tensioning of the belt.

14. The rotary electrical machine according to claim 13, wherein the fixed part (104) has a projection to support another belt tensioning roller (204).

15. The electrical machine according to claim 9, wherein the central opening (102) of the regulation device (100) is frusto-conical and is disposed radially around the widened area of the arms (138, 28) with a gap between the arms (138, 28) of the base and the two coaxial parts (101, 104) of the regulation device (100) for introduction of air into the housing (1a, 1b) through the air inlet openings (15).

16. The rotary electrical machine according to claim 1, consisting of an alternator-starter.

17. The rotary electrical machine according to claim 1, wherein the pulley (3) is non-rotatably secured relative to a front end of the rotor shaft, with intervention of a device for blocking rotation of the pulley (3) relative to the rotor shaft (9).

18. The electrical machine according to claim 1, wherein the central opening (102) of the regulation device (100) is frusto-conical and is disposed radially around the widened area of the arms (138, 28) with a gap between the arms (138, 28) of the base and the central opening (102) for introduction of air into the housing (1a, 1b) through the air inlet openings (15).

19. The electrical machine according to claim 1, wherein the front support flange (1a) is further provided with air outlets (14) spaced from the base (238, 138, 28, 18) of the front support flange (1a) and the air inlet openings (15).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a front view of a front bearing of a rotary electrical machine according to the prior art provided with a pulley for receipt of a belt and a device for regulation of the tension of the belt;

(2) FIG. 2 is a view in cross-section of an alternator according to the prior art;

(3) FIG. 3 is a partial view showing the front of the alternator in FIG. 2;

(4) FIG. 4 is a view in perspective showing the rear of the front bearing according to an embodiment of the invention;

(5) FIG. 5 is a view in perspective showing the front of the front bearing in FIG. 4;

(6) FIG. 6 is a view in perspective of an alternator according to the invention equipped with the front bearing in FIGS. 3 and 4;

(7) FIG. 7 is a view in axial cross-section of the alternator in FIG. 6;

(8) FIG. 8 is a complete view in perspective of another form of an alternator according to another embodiment of the invention.

(9) In the figures, elements which are identical or similar will be allocated the same reference signs.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(10) As far as the elements in FIGS. 4 to 8 are concerned, reference will be made to the description of FIGS. 2 and 3 for further details, with elements which are identical or similar being allocated the same reference signs. The terms front and rear correspond to an orientation from left to right in FIGS. 6 to 8.

(11) As in FIGS. 2 and 3, the rotary electrical machine in FIGS. 4 to 8 comprises at the front a pulley 3 for receipt of a flexible movement transmission belt which intervenes between the pulley 3 and a crankshaft pulley which is implanted on the front face of a thermal engine of a motor vehicle. The belt can also be used to drive the pulley of at least one other accessory of the motor vehicle, such as the pulley of the vehicle air conditioning compressor.

(12) According to the invention, the rotary electrical machine in FIGS. 4 to 8 is provided with a device 100 for regulation of the tension of the belt, comprising at least one tensioning roller 200, 201. The roller (s) 200, 201 is/are aligned with the pulley 3. This device 100 intervenes at the front face of the thermal engine of the vehicle which is connected at the rear to a gearbox.

(13) As previously stated, the rotary electrical machine comprises in FIGS. 4 to 8 a housing 1a, 1b, which is designed to be secured on a fixed (or stationary) part, such as the engine block of a motor vehicle, and on which there is fitted firstly a stator 6 and secondly, centrally, by means of bearings 7, 8, such as ball bearings with one or two rows of balls, a rotary rotor shaft 9, the axial axis of symmetry of which (shown in FIG. 7) defines the axis of rotation of the machine. The shaft 9 is integral with a rotor 20 which rotates inside the stator 6. A pulley 3 is fitted on the exterior of the housing and at one of the ends of the shaft 9, known as the front end, for example by screwing.

(14) The housing comprises a front support flange (or front bearing) 1a adjacent to the pulley 3, and a rear support flange 1b (or rear bearing) which is furthest from the pulley. These support flanges 1a, 1b are known respectively as the front support flange (or front bearing) and the rear support flange (or front bearing), which in combination define the housing 1a, 1b. They are advantageously made of moldable material, and in this case of aluminum. In FIGS. 4 to 8, they have a hollow form, and comprise a peripheral rim (see FIG. 6, reference 338 for the rim of the front bearing 1a).

(15) FIGS. 4 to 8 according to the invention represent only the elements which are necessary for understanding of the invention.

(16) Thus, the flexible movement transmission belt described in the introduction is not represented, in the knowledge that the upper part of the belt is designed to cooperate with the roller(s) 200, 201, whereas the inner part of the belt is designed to cooperate with the groove 31 in the pulley 3.

(17) Similarly, the configuration of the housing for its securing on a fixed part, such as projections for securing of the front 1a and rear 1b bearings on a fixed part, is not represented in FIGS. 4 to 7, since these parts are shown in FIG. 2, and also in FIG. 8 (see perforated ears 111 and 112 belonging respectively to the front bearing 1a and the rear bearing 1b).

(18) The number of projections depends on the applications. In FIG. 8, the ears 111, 112, which are perforated for the passage of means for securing on the engine block of the vehicle, are aligned axially, and belong to a first area of securing on the engine block of the vehicle. In practice, at least one other securing lug is provided, belonging to the bearing 1a or the bearing 1b for formation of a second area of securing on the engine block.

(19) As a variant, one of the bearings 1a, 1b comprises a securing plate with orientation which is tangential relative to its peripheral rim. The plate, implanted in the upper or lower part of the peripheral rim of the bearing 1a, 1b concerned, comprises for example two holes for the passage of means for securing on the engine block, such as screws or tie rods. The holes extend perpendicularly to the axis of the shaft 9. As a variant, one of the bearings 1a, 1b comprises at least one projecting shank for passage of means for securing on the engine block. The shank(s) extend(s) axially or perpendicularly relative to the axial axis of symmetry of the shaft 9. Thus, a single bearing 1a, 1b can comprise two shanks as a replacement for a tangential plate.

(20) According to one embodiment, the front bearing 1a is provided with two diametrically opposite tangential plates for securing of the housing on the engine block, with one of the plates being replaced by two shanks as a variant. The housing is thus secured on the engine block only by the front bearing 1a. The converse is also possible, with the housing being secured on the engine block only by the rear bearing 1b.

(21) In a manner described in the introduction, in the embodiment in FIGS. 4 to 8, the pulley 3 is advantageously a pulley for receipt of a belt of the poly-V type with six teeth which are designed to cooperate in a complementary manner with the six furrows of the groove 31 in the metal pulley 3, which is for example made of steel or aluminium, and is identical to that in FIG. 2. As a variant, the said pulley 3 is covered with plastic material, or as a variant it can be made of plastic material reinforced by fibres and/or fillers.

(22) It will be appreciated that all the aforementioned variants for association of the pulley with the belt can be envisaged, i.e.:

(23) pulley with a groove for receipt of a flat belt;

(24) pulley with a groove for receipt of a trapezoidal belt;

(25) pulley with a groove for receive of a notched flexible belt.

(26) In all cases, the pulley is integral at one end with the shaft 9 which is integral with the rotor 20, and passes through the bearings 1a, 1b.

(27) The pulley 3 is secured on the shaft 9 for example as in FIG. 2, by screwing.

(28) Advantageously, means for blocking in rotation intervene between the pulley 3 and the shaft 9, in particular when the rotary electrical machine is an alternator-starter, in order to prevent the pulley 3 from working loose.

(29) For example, the pulley 3 is welded on the end of the thread of the shaft 9 as described in document WO 2007/099260, to which reference will be made for further details. Thus, FIG. 8 shows the imprints which the pulley has for the receipt of the external tool.

(30) As a variant, the welding is replaced by gluing. As a variant, the front end of the shaft comprises a frusto-conical portion which is designed to cooperate with the edge of the central hole with a complementary form in the pulley. A key can intervene between the shaft and the pulley. It will be appreciated that the rear sleeve of the pulley can be replaced in the aforementioned manner by a ring. Thus, the pulley 3 is always clamped, in particular when it is driving and driven.

(31) In FIGS. 4 to 8, the rotor 20 is a claw rotor provided with teeth with a trapezoidal form and axial orientation, and as a variant is curved as in FIG. 2.

(32) As a variant, in the aforementioned manner:

(33) the rotor of the rotary electrical machine is a rotor with projecting poles;

(34) the claw rotor is provided with permanent magnets between its teeth, as described for example in document FR 2 784 248, with the number of pairs of magnets being equal to, or less than, the number of pairs of teeth;

(35) the rotor with projecting poles is provided with permanent magnets, as described for example in document WO 2013/136021, to which reference will be made;

(36) the rotor of the rotary electrical machine is a rotor with permanent magnets, as described for example in document EP 0831 580 to which reference will be made.

(37) In these FIGS. 4 to 8, the rotary electrical machine is a reversible alternator known as an alternator-starter. In addition to its function as a starter, and its function of starting/stopping the thermal engine of the vehicle, in the aforementioned manner this alternator-starter can carry out other functions according to its power level.

(38) As a variant:

(39) the rotary electrical machine is an electric motor;

(40) the rotary electrical machine is an electric motor which is without brushes, and is controlled by an inverter, as described for example in document EP 0831 580;

(41) the electrical machine is a starter with a belt;

(42) the rotary electrical machine is an alternator.

(43) It will be noted that an electrical machine with a rotor with permanent magnets, such as that in document EP 0 831 580, is reversible when its shaft is integral with an aforementioned pulley for receipt of a movement transmission belt. This motor can thus constitute an alternator when it is driven via the belt by the pulley of the thermal engine of the crankshaft of the vehicle.

(44) It is possible to interpose a free wheel between the shaft and the pulley in order to transform this electric motor into a starter. Thus, via the pulley of the crankshaft of the thermal engine of the vehicle, a single belt can drive the pulley of a starter with a belt and the pulley of a conventional alternator, and optionally the pulley of the compressor of the air conditioning installation.

(45) In all cases the rotary electrical machine comprises at the front a pulley 3 for receipt of a belt integral with a shaft 9 of the rotor 20 which passes through the front bearing 1a of a housing configured to be secured on a fixed part, the said bearing 1a comprising a nose 18 for fitting of a ball bearing 7 for rotation of the shaft 9 and air inlet openings 15.

(46) The nose 18 has a globally annular form, and comprises a sleeve 22 and a ring 32, as in FIGS. 2 and 3. FIG. 5 shows holes which are used for securing of the retention ring (with no reference in FIGS. 6 to 8) of the outer ring of the bearing 7. The inner ring of the bearing 7 is fitted onto the shaft 9.

(47) In these figures, the rotary electrical machine is equipped with a device for regulation of the tension of the belt 100, and it can be seen that, according to a characteristic of the invention, (see FIGS. 4 and 5), the nose 18 for fitting of (or receiving) the ball bearing 7 has been displaced forwards in order to implant the device for regulation of the tension of the belt (FIGS. 6 to 8). In other words, as best shown in FIG. 7, the peripheral strip of material 238 of the base is axially offset from the nose 18 and the front ball bearing 7 so that the nose 18 is disposed axially between the pulley 3 and the peripheral strip of material 238. This offsetting depends on the thickness of the central part of the regulation device 100, which has a central opening 102 (FIGS. 6 to 8) permitting passage of the air through the air inlets (or inlet openings) 15. As best shown in FIG. 7, the central opening 102 of the regulation device 100 is disposed radially around the nose 18 and the arms 138, 28 of the base 238, 138, 28, 18 of the front support flange 1a. In other words, the nose 18 is offset at the front, such that the groove 31 in the pulley 3 is aligned radially with at least one roller 200, 201 of the regulation device 100.

(48) In addition, the axial distance between the nose 18 and the strip of material 238 is at least equal to the axial thickness of the regulation device 100, and in particular greater then the said thickness.

(49) In these FIGS. 4 and 5, it can be seen that the air inlet openings 15 are delimited circumferentially by inclined arms 28, 138 which connect the nose 18 to a peripheral strip of material 238 with a globally annular form.

(50) This strip of material 238 has globally transverse orientation relative to the axis of the shaft 9 and delimits partly the base of the front bearing 1a with a globally annular form. According to one characteristic, the front bearing 1a comprises a base 238, 138, 28, 18 comprising a peripheral strip of material 238 which is extended forwards by arms 138, 28, belonging firstly to an area which widens towards the exterior, connecting the protuberant nose 18 at the front to the strip of material 238, and secondly delimiting the air inlets 15.

(51) In FIGS. 4 to 8, the front bearing 1a has a hollow form, and this peripheral strip of material 238 delimits the upper edge of the air inlets 15, and the lower edge of the air outlets 14 affecting the peripheral rim 338 of the front bearing 1a with a hollow form. Thus, the front bearing 1a with a hollow form comprises a peripheral rim with 338 with an annular form, which is connected at the front to a base 238, 138, 28, 18 comprising a strip of material 238 which is extended forwards by arms 138, 28 delimiting the air inlets 15, and connected at the front to the protuberant nose 18. Moreover, the air outlets (14) are axially and radially spaced from the base 238, 138, 28, 18 of the front bearing 1a and the air inlets 15. The arms 138, 28 belong to an area which widens towards the exterior, connecting the nose 18 to the strip of material 238 of the base of the front bearing 1a. In other words, the air inlets 15 are delimited radially by the peripheral strip of material 238 and the nose 18, and circumferentially by the inclined arms 28, 138, which connect the nose 18 to the peripheral strip of material 238.

(52) In FIGS. 4 and 5, the widened area comprises two series of arms 138, 28, an arm 138 being interposed circumferentially between two arms 28. The arms 138 are thicker than the arms 28. These thick arms 138 are arms for rigidifying the base of the bearing 1a, and are advantageously ribbed as can be seen in FIG. 5, in order to increase their rigidity further. They affect the strip of material 238, and are extended towards the exterior in order to join a radial protuberance in the form of an ear (with no reference) which the rim 338 has. This protuberance is perforated for the passage of a tie rod for assembly of the front bearing 1a on the rear bearing 1b. One of the tie rods can be seen at 110 in FIG. 8.

(53) The arms 138 have a specific radius of connection to the strip of material 238, in order to reduce the stresses.

(54) The arms 138, 18 can be inclined circumferentially in the direction indicated by the arrow in FIG. 5, corresponding to the direction of rotation of the pulley 3 when the latter is driven (see also arrow F1 in FIG. 2).

(55) As a variant, the base of the bearing 1a has only thinner arms 28, which are or are not inclined circumferentially.

(56) According to one embodiment (not shown) the front bearing 1a comprises a base which is secured directly on the rear bearing 1b provided with the air outlets 16. The securing can be carried out by means of screws.

(57) According to one characteristic (FIG. 7), the brace 33 through which the shaft 9 passes, and which is interposed between the inner ring of the bearing 7 and the front face of the magnet wheel 4 of the claw rotor, has an axial length which is longer than the axial length of the inner ring of the bearing 7. This characteristic makes it possible to offset the nose 18 at the front.

(58) According to another characteristic (see FIG. 7) the axial length of the brace 33 is longer than the axial length of the inner ring of the rear bearing 8 with a smaller diameter than the front bearing 7.

(59) Advantageously, the axial length of the rear bearing 8 is shorter than the axial length of the bearing 7.

(60) In all cases, there is advantageously conservation of the structure of the rotor and of the stator of the machine, as well as of the size of the rear bearing 8 and that of the rear fan 12.

(61) The electronics of the machine can be conserved, in particular the rectifier bridge and/or the means for monitoring the rotation of the rotor. The openings 14, 16, 17 can be conserved, as well as the cover 2 and the fans 10, 12, in the knowledge that, as a variant, the front fan 10 can be a fan flange, as described in the aforementioned document WO 2013/136021.

(62) It will be appreciated that the rear bearing 8, with a smaller diameter than the bearing 7, is subjected to less stress than in a solution in which the nose 18 is not offset at the front, in the knowledge that the belt received in the pulley generates axial and transverse vibrations.

(63) All the forms of the bearing 1a are obtained easily by moulding, as are the securing means, described hereinafter, which the housing has for securing of the device 100.

First Embodiment

(64) In FIGS. 4 to 7, the alternator-starter differs from that in FIGS. 2 and 3 by its nose 18 which is extended forwards in the aforementioned manner, and by its device for regulation of the tension of the belt.

(65) It also differs in that its stator 6 has a stator body 106 in the form of a set of plates, the notches of which are configured for fitting of a winding 107 in the form of bars with two layers extending on both sides of the body 106 of the stator, as described for example in document EP 0 881 752, to which reference will be made for further details. As a variant, it comprises more than two pairs of layers of conductors.

(66) The number of notches in the body 106 depends in the aforementioned manner on the number of phases and the number of teeth of its magnet wheels 4, 5, which can vary from 6 to 8 per magnet wheel 4, 5.

(67) The connection of the rotor shaft 9 to the magnet wheels is also different, with the hub of the claw rotor being in two parts each belonging to one of the magnet wheels 4, 5, as shown in FIG. 7. This connection is carried out in this case by crimping, with the shaft 9 having a centring area and two crimping areas arranged on both sides of the centring area, for securing of the front and rear ends respectively of the wheels 4, 5 by crimping as described in patent EP 2 067 238, to which reference will be made. In the light of this document, it can be seen that permanent magnets can be interposed circumferentially between two consecutive teeth of a wheel 4 and a wheel 5, in order to increase the power of the machine.

(68) It will be appreciated that, as a variant, the wheels 4, 5 are assembled in the aforementioned manner by means of knurled portions of the shaft 9.

(69) Another difference concerns the fact that the electronics of the machine comprise an inverter, fitted on a mezzanine of the housing (with the reference 27 in FIG. 8), fitted above the base of the rear bearing 1b by means of small columns 23, as described for example in document WO 2006/129030 and in document WO 2004/040738, to which reference will be made.

(70) In FIG. 7, the collector has the reference 26, and 24 is the brush-holder tension regulator assembly previously referred to in FIGS. 2 and 3. The reference 25 designates the magnetic target which the alternator-starter has in the aforementioned manner, for monitoring the rotation of the rotor. For further information, reference will be made for example to document WO 01/69762.

(71) In this embodiment, the connector 26 and the brush-holder are interposed between the base of the rear bearing 1b and the mezzanine.

(72) The embodiment in FIG. 8 shows piping (with no reference) for cooling of the mezzanine 27 by means of a cooling liquid.

(73) In this embodiment, the regulation device 100 comprises two coaxial parts 101, 104 fitted such as to be mobile in rotation relative to one another against resilient means (not shown) with circumferential action, and advantageously friction means. These parts 101, 104 have an axis which is combined with that of the shaft 9, and therefore have the same axis as that of the shaft 9.

(74) These parts 101, 104 are perforated centrally, and each support a roller 200, 201 for tensioning of the belt each by means of a projection (with no reference). The holes in the parts have a diameter which permits the passage of air the through the air inlets.

(75) The parts 101, 104 are advantageously made of metal plate for reduction of the thickness of the device 100. The inner bore 102 in the parts 101, 104 has a frusto-conical form designed for the widened area of the arms 138, 28, with a gap existing between the arms 138, 28 and the outer edge of the bore 102, for introduction of air into the housing 1a, 1b of the alternator-starter, which has internal ventilation as in FIGS. 2 and 3.

(76) The axial offsetting of the nose 18 thus depends on the thickness of the central part of the parts 101, 104, and thus on the central part of the device 100 which is perforated centrally. It is the widened area which permits this offsetting of the nose 18 at the front.

(77) Thus, according to the invention, a rotary electrical machine of the aforementioned type, comprising at the front a pulley 3 which is provided with a groove 31 and is integral with a rotor 20 shaft 9 passing through the front bearing 1a of a housing configured to be secured on a fixed part, the front bearing 1a comprising a base 238, 138, 28, 18 provided with a nose 18 for fitting of (i.e. receiving) a ball bearing 7 for rotation of the shaft 9, and air inlet openings 15 delimited by arms 138, 28 which connect the nose 18 to a peripheral strip of material 238 of the base, is characterized in that the arms 138, 28 belong to an area which widens towards the exterior, connecting the strip of material 238 to the nose 18 for offsetting of the nose 18 at the front, in that it comprises a device for regulation of the tension 100 of a belt received in the groove 31 in the pulley 3, and secured on the housing 1a, 1b, in that the regulation device 100 comprises at least one roller 200, 201 for the belt, and a central opening which permits passage of air the through the air inlet openings 15, and in that the offsetting of the nose 18 at the front depends on the central thickness of the regulation device 100.

(78) On its outer periphery, the part 104 has radial projections 103, in this case perforated radial ears 103, for its securing on the housing 1a, 1b, which, in another embodiment, can be in three assembled parts, i.e. a front bearing 1a, a rear bearing 1b and an intermediate part interposed axially between the bearings 1a and 1b, and supporting the stator. As a variant, this intermediate part can support the electronics of the machine by means of the plate. As a variant, the electronics of the machine can be supported by a plate of the rear bearing 1b. As a variant, the projections 103 consist of radial lugs.

(79) In FIGS. 4 to 8, three radial ears 103 are provided, secured on protuberances of the housing of the machine.

(80) In the embodiment in FIGS. 4 to 7, the bearing 1a comprises an axial protuberance 438 for securing a radial ear 103 by means of a screw 301 on an axial protuberance 438 which the peripheral rim 338 has on its outer periphery.

(81) The two other ears 103 are connected by tie rods to projecting ears which the mezzanine has. For this purpose, reference will be made to FIG. 8, which at 300 shows one of the tie rods and one of the ears of the mezzanine. As a variant, as can be seen in FIG. 8, one of the ears can be secured by means of a screw on a radial ear of the front bearing 1a of the mezzanine.

(82) As a variant, the part 104 is secured via its three ears 103 on axial protuberances of the type such as the protuberance 438 which the bearing 1a has. In this case, the bearing 1a is advantageously provided in the aforementioned manner with two plates, one of which can be replaced by two shanks.

(83) The number of ears 103 depends on the applications, and can be more than three.

(84) In all cases, the part 104 is a fixed part, whereas the part 101 is mobile in rotation relative to the fixed part 104, and constitutes the regulation arm of the device 100.

(85) The part 104 supports a roller 201 for tensioning of the belt by means of a projection (with no reference), which in this embodiment is globally in the form of an ear.

(86) Similarly, the part 101 supports a roller 200 for tensioning of the belt by means of a projection (with no reference), which in this embodiment is globally in the form of an ear. The parts 101, 104 have a globally annular form, and each have a projection for support of a roller, respectively 200, 201.

(87) The rollers 200, 201 are implanted on both sides of the pulley 3, below the latter, as can be seen in FIGS. 6 and 8. It will be appreciated that the rollers 200, 201 are aligned axially with the pulley 3. The roller 200 is subjected to stress when the alternator-starter is in alternator mode, whereas the roller 201 is subjected to stress in alternator mode. The belt forms a loop at the rollers 200, 201 and the pulley 3. More specifically, the upper part of the belt, engaged with the pulley of the crankshaft, comes into contact with the roller 200, then, by means of its lower part, it comes into contact with the base of the groove 31, and finally comes into contact with the roller 201, before being wound on the pulley of the crankshaft, whilst optionally passing via the pulley of the air-conditioning compressor at the outlet of the roller 201.

(88) The roller 200 can be displaced under the action of resilient means with circumferential action which act between the parts 101, 104 in order to tension the belt, and regulate its tension in an optimum manner, in particular in order to prevent sliding of the belt, and to filter the vibrations in the above-described manner. The part 101 is thus a mobile regulation part.

(89) The rollers 200, 201 are fitted such as to rotate respectively on the part 101 and on the part 104 by means of a pivot, such as a bolt, as in the aforementioned document EP 0 459 894. A bolt of this type can be seen in FIG. 8. A bearing can be interposed between the pivot and the inner edge of the roller 200, 201, as described in document EP 0 459 894.

(90) The resilient means with circumferential action can be a spiral spring, as in document EP 0 459 894, to which reference will be made, one of the ends of the spiral spring being integral in rotation with the fixed part 104, and the other end of the spiral spring being integral in rotation with the mobile part 101. The rotary fitting of the mobile part 101 can be carried out as in document EP 0 459 894, to which reference will be made. The friction means, such as a friction washer, can be interposed between the outer face of the part 101 and the inner face of the folded-back end of the fixed part 104, whilst being glued on the part 101, or on the folded-back end of the part 104.

(91) As a variant, the resilient means with circumferential action consist of a torsion spring, as described for example in utility model CN 203431112U to which reference will be made. In this case, the part 104 can have an inner centring sleeve for the part 101, with intervention of friction means. The inner diameter of the sleeve is sized for passage of the air through the openings 15.

Second Embodiment

(92) In document EP 0 459 894, a version is provided with a curved spring which intervenes between the two parts of the regulation device. A spring of this type can be fitted between the two parts 101, 104. In this embodiment in FIG. 8, the curved spring is replaced by a blade 105 in the form of an arc of a circle which intervenes between the two parts 101, 102. The ends of this spring are secured on the parts 101 and 104 in the vicinity of the rollers 200, 201. Advantageously, the ends of the spring 105 are in the form of loops which are each wound around the pivot, such as a bolt concerned of the rollers 200, 201. The pivots are then extended, and each loop is interposed between the part and the roller concerned. This therefore forms a pendulum which intervenes between the two parts 101 and 102.

(93) This pendulum makes it possible to absorb the tension peaks in the belt, and moderates the sliding of the belt. It makes it possible to increase the tension of the belt, and increases the service life of the front roller 7.

(94) In this variant, the fixed part can have centrally a sleeve for centring of the mobile part 101, and a rear washer for fitting of a friction washer which intervenes between the fixed part 104 and an inner collar which the mobile part 101 has.

(95) It will be noted that the rotor in this embodiment can be a rotor of the type described in the aforementioned document WO 2013/136021.

Third Embodiment

(96) The invention applies to the alternator in FIGS. 2 and 3. In this case, the front bearing 1a is configured as in FIGS. 4 and 5 and their variant, and the roller 201 associated with the fixed part 104 is eliminated. It will be appreciated that all the structural variants in FIGS. 4 to 8 are applicable to the modified alternator in FIGS. 2 and 3

Other Embodiments

(97) The structures can be inverted. Thus, the fixed part 104 can be secured on the axial protuberances which the strip of material 238 has, with the mobile part 101 being interposed axially between the front bearing 1a and the fixed part 104. In this case, the device 100 must be fitted after the belt.

(98) In all cases, the device 100 comprises two coaxial parts 101, 104, which are fitted such as to be mobile in rotation relative to one another, against resilient means with circumferential action, and the offsetting of the nose 18 depends on the central thickness of the device 100 which is perforated centrally for passage of the air through the air inlet openings 15. The axis of the parts 101, 104 corresponds to the axis of the shaft 9. The solution clears space at the outer periphery of the bearing 1a.

(99) The central opening 102 in the device can be circular, with the inner diameter of this opening permitting passage of the air through the air inlet openings 15.

(100) The stator of the machine can comprise teeth on which coils are fitted, some of which are connected to one another in order to form one of the phases of the rotary electrical machine. For further details, reference will be made for example to document WO 2007/031679 which describes the number of teeth.

(101) The teeth can be added onto a head.

(102) The stator winding can comprise two or more continuous wire layers in stead of bars.

(103) The rotary electrical machine can comprise a single front fan 10 and a front bearing provided with openings 14, 15, the other bearing being cooled by circulation of liquid, such as water for cooling of the thermal engine of the vehicle, by means of a channel which it has for this purpose. The front bearing 1a can thus be shallower, or comprise only a base, with the air outlet openings 14 being provided in the rear bearing 1b.

(104) The fans 10 and 12 can have the forms described in particular in the introduction. A single fan can be provided, i.e. a rear fan 12 which aspirates air. In this case, the bearing 1a can comprise only air inlets 15.

(105) Applications

(106) In the aforementioned manner:

(107) the rotary electrical machine is an electric motor;

(108) the rotary electrical machine is an electric motor which is without brushes and is controlled by an inverter;

(109) the rotary electrical machine is an alternator;

(110) the rotary electrical machine is an alternator-starter;

(111) the rotary electrical machine is a starter with a belt.