EP1778970A1

EP1778970A1 - Starter, in particular for motor vehicle, equipped with a friction-driven free-wheel drive assembly

Info

Publication number: EP1778970A1
Application number: EP05783717A
Authority: EP
Inventors: Benoit Dupeux; Olivier Gizolme; Christian Mornieux; André PIREYRE
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2004-06-29
Filing date: 2005-06-29
Publication date: 2007-05-02
Also published as: WO2006010852A1; BRPI0511167A; MXPA06014929A; FR2873170B1; FR2873170A1; CN1997819A

Abstract

The invention concerns a starter comprising a stop (35), an electric motor (11), mechanically coupled to an output shaft (28), a drive assembly (26) mounted on the output shaft (28) and including a driver (33), a part (45) for coupling the pinion (32) to the driver (33) via a mechanical freewheel connection (34) configured in accordance with a friction clutch, and a priming spring (R1) mounted between the stop (35) and the pinion (32).

Description

Starter, in particular of a motor vehicle, equipped with a freewheeling launcher by friction.

Technical field of the invention

The invention relates to a starter for a combustion engine, especially a motor vehicle, having a ring gear with a ring gear, comprising a front support having a bottom, a stop adjacent to the bottom of the front bearing, a output shaft rotatably mounted in the front support and provided with teeth, a launcher, a pinion belonging to the launcher, an electric motor for rotating the output shaft mechanically coupled to the launcher mounted to slide axially on the output shaft between a rear rest position, and a forward meshing position of the starter gear with the ignition gear ring of the combustion engine flywheel, said launcher comprising: a driver driven by a control means between its rear and front positions, and equipped with drive splines in engagement with the complementary toothing of the output shaft, - a coupling part of the pinion to the driver via an a freewheel mechanical assembly formed according to a friction clutch, comprising a first friction surface carried by one of the pinion-driver elements, and a second friction surface secured to the other of the pinion-driving elements, and a device elastic to initiate self-locking of the freewheel.

State of the art

With reference to FIGS. 1 and 2, a starter 10 according to the prior art comprises an electric motor 11 equipped, with a yoke 15, with an inductor stator 12 and a rotor rotor 13 mounted coaxially, the stator 12 surrounding the rotor 13, which is mounted on a rotating shaft 14. The stator 12 is housed inside the yoke 15, which is secured to the front support 16 of the starter intended to be fixed on a fixed part of the motor vehicle. The support 16, here of hollow form, has a bottom 100, here nose-shaped, with a bore in which is mounted a bearing 29, here a sliding bearing alternatively a needle bearing. The rotor 13 comprises a rotor winding in connection with a collector 17 integral with the shaft 14 of the electric motor 11. The stator 12 is constituted by a plurality of permanent magnets fixed on the cylinder head 15. As a variant, the stator 12 comprises wound windings around polar masses integral with the cylinder head as described in EP 0 749 194.

The starter 10 also comprises an electromagnetic contactor 18 extending parallel to the electric motor 11 by being implanted radially above it. The switch 18 is equipped with at least one excitation coil B, a movable contact 27 carried by a control rod (not referenced) and power supply terminals 19, 20. The terminals 19, 20 are shaped to each form a fixed contact inside the insulating cover 21. One of the terminals 19 is intended to be connected to the positive terminal of the battery, the other 20 is connected via a cable 22 to the brush holder 17 'associated with the collector 17, here of the frontal type or Radial variant of the axial type.

FIG. 2 shows a closing element of the yoke 15 bearing a rear bearing, here a smooth bearing, as a variant, a needle bearing, for the rotational mounting of the rear end of the shaft 14 as described in document FR A 2,796,990.

The contactor 18 also comprises a movable core 23, a fixed core 24, a coil support (not referenced) surrounding a guide sleeve (not referenced) of the movable core 23 and a tank (not referenced) for housing the coil B This tank has a bottom fixed to the support 16 and is assembled to the cover 21, here by crimping. Fixed core 24, via its central opening, serves as a guide to the control rod of the contact 27 subjected to the action of a breaking spring (not referenced) intervening between the cover 21 and the movable contact 27.

In Figure 2, for clarity, it has partly removed the coil B and its support, as well as a portion of the fixed core 24 and the guide sleeve.

During the excitation of the coil B, the mobile core 23 is attracted by magnetic attraction towards the fixed core 24 to simultaneously cause the displacement, via the control rod, of the movable contact 27 towards the fixed contacts of the contactor 18 and actuating a control means 25 of the launcher 26, here in the form of a control lever 25, to control the movement thereof between a rear rest position (Figure 1) and a front position of meshing with a starting ring gear 300 linked in rotation, possibly elastically, with the flywheel of the combustion engine of the motor vehicle. A return spring 42, resting on the tank and on a collar integral with the movable core, is mounted around the movable core 23 to bias it towards the rear rest position. A spring 41, said spring teeth against teeth, is housed inside the core 23, and cooperates with the upper end of the lever 25 connected to the movable core 23 via a rod 43 connected to an axis 44. This spring 41 acts between the bottom of its housing belonging to the core 23 and an end shoulder belonging to the rod 43, whose other end cooperates with the upper end of the lever 25 via the axis 44.

When the movable contact 27 comes into engagement with the fixed contacts of the terminals 19, 20, the electric motor 11 is electrically powered so that the shaft 14 rotates, and drives the output shaft 28, which is rotatably mounted by its part. before in the front support 16 via the bearing 29 front carried internally by the bottom 100 of the support 16. The front portion of the shaft 28 thus enters the internal bore of the bottom 100 in which is fitted, here clamping, the bearing 29 receiving the shaft 28. The forward end of the shaft 14, opposite the collector 17, is configured to form a sun gear belonging to an epicyclic gear train constituting a gear reducer 30, which is interposed between the output shaft 28 and the shaft 14 aligned with the electric motor 11. This train comprises an internally toothed fixed ring gear for engaging the solar gears (not referenced) of the gearbox 30.

A bearing, here a sliding bearing, intervenes radially between the front end of the shaft 14 and the rear end of the shaft 28 provided with a blind hole for receiving the bearing.

The control lever 25, here fork-shaped, is coupled by its upper part to the movable core 23 via the rod 43 and the spring 41, and has in its intermediate portion a pivot axis 31 for its pivotal mounting in the starter.

The lower part of the fork-shaped lever 25 is mounted in an annular groove 133 of the driver 33 and has profiled fingers or pads for action on the flanks of the driver's groove. The axle 31 here comprises two sections extending from opposite sides of the body of the lever 25, here plastic, being advantageously molded with the lever 25.

These sections are pivotally mounted for example in a two-piece bearing having a first portion connected to the support 16 advantageously being molded therewith and a second portion formed vis-à-vis forming a shim between the vessel of the actuator 18 and the cylinder head 15 as described in document FR A 2,699,605.

In a variant it is the wedge which carries two perforated axial wings for mounting the sections of the axis 31, the lever being interposed between the two wings, one of which is visible at 131 in FIG. As a variant, the fixed ring gear of the gearbox comprises an extension shaped to provide a function of articulation of the lever 25. For example, the extension consists of two radially projecting lugs and shaped to receive the sections of the axle 31. In a variant, it is provided a fixed base plate interposed between the support 16 and the cylinder head 15 as described in document FR A 2 725 758. This is the base plate which then carries a hinge support for the axis 31.

The lever is pivotally mounted on a fixed hinge support 131 of the starter in favor of an axis integral with one of the lever elements - fixed hinge support knowing that one can reverse the structures.

The launcher 26 is slidably mounted on the output shaft 28, and comprises a drive gear 32, a driver 33 adapted to be actuated by the fork of the pivoting control lever 25, and a free wheel 34 interposed axially between the The driver 33 is internally provided with helical splines in complementary engagement with external helical teeth 36 carried by the output shaft 28. The launcher 26 is thus driven by a helical movement when it is moved by the lever 25 in the direction of an axially fixed abutment 35 carried by the shaft 28 to come into position before meshing, by means of its pinion 32, in engagement with the starting ring gear 300 of the combustion engine of the motor vehicle. The support 16 has an opening (not referenced in FIG. 1) in which the crown 300 penetrates. In the rear rest position, the rear end of the driver 33, and therefore of the thrower 26, bears against a washer 101. here in metal, in contact with the front face of the ring gear of the gearbox 30. In a variant, the rear end of the gearbox is in direct contact with the front face of the ring gear of the gearbox 30 advantageously made of plastic material reinforced by charges. In case this front face is coated with a layer of grease. For this rest position a small clearance exists between the lever 25 and the lever 25 (see Figure 1).

The abutment 35 is adjacent to the bottom 100 and here is integral with the output shaft 28 being fixed on the front portion of the shaft 28 in known manner by means of a rod (not referenced), which is received simultaneously in an external groove of the shaft 28 and in an internal complementary groove formed in the inner periphery of the abutment 35 here of annular shape. This stop 35 is fixed in translation.

The freewheeling starter 26 is equipped with a friction clutch, here frustoconical, for coupling the pinion 32 to the driver 33. Such a friction clutch is of the type described in document FR-A-2,826,696. (WO 03/002870). It comprises two concave and convex rigid complementary surfaces, for example frustoconical, cooperating by friction and respectively integral with the pinion 32 and the driver 33 for the transmission of the starting torque. For more details we refer to this document FR-A-2 826 696, in particular on pages 13 and 14 thereof.

The clutch is locked in an engaged position when the electric motor 11 of the starter drives the starting ring gear of the internal combustion engine during starting (driving phase), and is released automatically at the end of starting when the ring gear drives. the pinion 32 at a speed of rotation greater than that of the driver 33 (freewheel phase). The pinion 32 and the driver 33 of the launcher 26 each have a central bore for the passage of the output shaft 28.

Referring to Figures 3 and 4, the pinion 32 of the launcher 26 is secured to a coupling piece of the pinion 32 to the coach 33. This coupling piece is provided at its outer periphery with a first friction surface 37 concave, here frustoconical. The friction surface 37 belongs to the inner periphery of a skirt of the coupling piece secured here to the pinion 26. As a variant, the lining 37 is attached. The driver 33 is equipped at its inner periphery with helical drive splines (referenced at 38 in FIGS. 3 and 4) in engagement with the complementary teeth 36 formed at the outer periphery of the output shaft 28. The driver 33 is also equipped externally with a receiving groove 133 of the fork of the control lever 25, and in front of a friction lining 39 of friction of convex shape, here of frustoconical shape. This lining 39 is based on thermosetting plastic or thermoplastic, advantageously loaded, to obtain the desired coefficient of friction with low wear. The lining 39 is anchored in an annular housing of the driver 33, and has at its periphery a second convex friction surface 40 cooperating in a complementary manner and coaxial with the first friction surface 37 to form a frustoconical friction clutch constituting a connection. freewheel mechanism, here disengageable, between the pinion 32 and the driver 33. Alternatively the friction surfaces are shaped to form a semi-spherical friction clutch.

A cover (not referenced) is crimped on a projection of the coupling piece and intervenes axially between the gasket 39 and the coupling piece. Alternatively, as described in the aforementioned document, the coupling piece is integral with the driver so that the surface 37 belongs to the driver and the surface 39 to the pinion.

It is noted that during the attraction of the movable core 23 against the fixed core 24 of the contactor 18, the clearance d1 between the fixed stop 35 and the pinion 32 in the forward position meshing with the ring gear of the flywheel of the combustion engine, can be either positive (Figure 3) or negative (Figure 4) depending geometrical dispersions starter parts.

In these figures, the fixed core 24 and the movable core 23 are shown schematically, while resting on the fixed core 24. Nevertheless, in this position of the mobile core 23, the driver 33 and therefore the launcher 26 can still move under the action of inertia forces and reactions between the grooves 38 and teeth 36.

In FIG. 4, the pinion 32 bears against the abutment 35, and the negative clearance d1 is absorbed following a stroke d2 of compression of the spring against teeth 41 cooperating with the upper end of the control lever 25. The pivoting of the latter about the axis 31 acts on the driver 33 so as to press the second friction surface 40 of the seal 39 against the first friction surface 37. The self-locking of the launcher 26 is thus initiated, and the couple motor is normally transmitted to pinion 32.

On the other hand, the presence of a positive clearance d1 of the pinion 32 with respect to the uncompressed stop 35 of the spring 41 (see FIG. 3) can cause an absence of contact between the two friction surfaces 37, 40, which inhibits self-locking of the launcher 26. The friction lining 39 then rotates freely or with a sliding effect facing the first friction surface 37 of the coupling piece, and no torque can be transmitted between the driver 33 and the pinion 32. The starting of the heat engine is then impossible.

To be sure to obtain the self-locking effect of the launcher 26, it would be sufficient to size the starter so that the game d1 in the driving phase of the pinion 32 against the stop 35, is always negative. A first disadvantage of such a solution is that, depending on the geometrical dispersion of the starter parts, the actuating force exerted by the lever 25 on the driver 33 during the excitation of the contactor 18 would be very high, causing therefore, an increase in the mechanical pressure of the liner 39 on the first friction surface 37. This high contact pressure in the friction clutch would cause premature wear of the friction clutch, with formation in more than one embodiment. significant residual drag torque that could degrade the freewheel function of the launcher 26. A second disadvantage of this solution with negative clearance, is the mechanical shock to be received by the stop 35 at each docking of the pinion 32 in the training phase.

In Figure 1 an elastic washer axially acting can be mounted axially compressed inside the freewheel, this washer is then interposed between a radial front shoulder of the friction lining, integral in this case with the coach, and the inner face of the aforementioned hood crimped on the coupling piece, so as to resiliently solicit the friction surfaces in contact with each other. This results in a predetermined axial force which applies the friction surfaces against each other. The spring washer can also be replaced by a helical compression spring or belong to the hood. Such a washer, in general such an elastic device for initiating self-locking of the freewheel by friction, is described in the documents FR A 2,826,696 (WO 03/002870) and FR A 2,772,433 (US Pat. 6,237,442).

Depending on the geometrical dispersion or wear of the launcher parts, inaccurate positioning of the spring washer or spring inside the freewheel may cause a variation of the contact pressure of the friction surfaces, which may assign the self-priming function of the friction clutch or the freewheel function of the launcher.

Object of the invention

The object of the invention is to provide a starter equipped with a freewheeling launcher that overcomes the aforementioned drawbacks, and reliably initiates internal self-locking of the launcher in training phase.

Another object of the invention is to increase the life of the starter.

The starter according to the invention in which the control means cooperates with a spring said teeth against teeth is characterized in that the elastic device comprises at least one spring separately from the teeth against teeth spring and in that the priming spring is arranged outside the free wheel between the stop and the pinion and is intended to generate a drag force low intensity at the friction surfaces.

Thanks to the invention can reduce the axial length of the freewheel since the priming spring is located outside the freewheel shaped according to a friction clutch.

This priming priming spring makes it possible to obtain contact between the friction surfaces in order to initiate self-locking of the freewheel, which thus reliably operates.

This priming spring also has a filter function because it damps vibrations and reduces shocks between friction surfaces. The matting phenomena of the friction surfaces are therefore reduced.

The friction surfaces of the freewheel are thus arranged so that the life of the starter is increased.

The mounting of the priming spring outside the freewheel and therefore the friction clutch can be achieved easily because of the space saving, and allows a reliable internal ignition of the freewheel in the driving phase, with visual control of the presence and condition of the spring during final assembly.

This check is easier to perform than in the case where the spring washer or spring is mounted inside the freewheel as in the documents FR-A-2 772 433 and FR A 2 826 696 above, this solution leading to increase the axial length of the free wheel which is not the case in the present invention. This priming spring can be of the desired size to exert a precise effort and is not polluted by the dust coming from the friction surfaces of the freewheel because it is implanted outside the freewheel.

This priming spring also makes it possible to clean the output shaft because in one embodiment it surrounds the output shaft.

In addition, the stop may be rigid or elastic because the launcher comes into contact with the priming spring and not with the stop.

In an embodiment, the abutment is constituted by the abutment 35 of FIGS. 1 and 2 adjacent to the bottom 100 and carried by the output shaft. The stop in this case belongs to the front part of the output shaft. Alternatively the stop is formed directly on the support for example by the face 102 of Figure 1 defining the rear face of the bottom 100 in the form of nose. In this case, the abutment 35 can be retained and the priming spring surrounds the abutment. In this case the stop is fixed axially and fixed in rotation.

The stop is arranged opposite the front face of the pinion.

Advantageously, the priming spring is mounted without clearance between the stop and the pinion.

In one embodiment this priming spring is mounted clamping, that is to say under prestressing, between the abutment and the pinion.

In general, the friction surfaces are held in contact with each other, that is to say pressed against each other, on the one hand, under the action exerted by the spring on the pinion and on the other hand, by the action exerted by the control means on the driver, such as the control lever in contact with the driver or alternatively any other means of control acting on the driver, such as an electromagnetic force acting on the coach as described in document FR A 2,841,941.

Advantageously, the priming spring cooperates with the pinion to generate, within the freewheel, between the friction surfaces, a friction drag torque, said torque being sufficient to initiate self-locking of the launcher during the training phase, but relatively low so as not to significantly decrease the speed differential in freewheeling phase.

This spring has a lower action on the launcher than that exerted by the spring teeth against teeth via the control lever to not obliterate the action thereof.

Thanks to these provisions, the priming spring does not unduly brake the relative movement between the friction surfaces during the freewheel phase.

This drag torque is sufficient to precisely initiate self-locking of the launcher during the training phase, but remains relatively low so as not to significantly decrease the speed differential in freewheeling phase and not to obliterate the action of the spring teeth against teeth.

Other features may be used alone or in combination to precisely initiate self-locking of the launcher.

The priming spring is economically formed by a compression spring mounted around the front portion of the output shaft.

In one embodiment this priming spring consists of an elastomer or rubber-based tube which protects the portion of the output shaft which it surrounds.

In another embodiment this priming spring is a helical spring of cylindrical or frustoconical shape. This compression spring is an alternative to a helical spring type variable pitch.

Several priming springs can be provided. These springs are mounted for example in series or intervene staggered.

For example, it is alternatively provided several Belleville washers mounted in series advantageously with the interposition of washers between the washers Belleville.

Brief description of the drawings

Other advantages and features will emerge more clearly from the following description of embodiments of the invention given by way of non-limiting example, and represented in the accompanying drawings, in which:

Figure 1 is a schematic perspective view and partially cut away at the starter, a starter known according to the prior art; Figure 2 shows an axial sectional view of the starter of Figure 1; FIGS. 3 and 4 show schematic views of a known launcher in the driving phase, respectively with a play against positive stop (no friction cone plating in the clutch), and negative (cladding of the two surfaces of the clutch); friction of the clutch); Figure 5 is a schematic view similar to Figure 3 showing a first embodiment of the priming spring according to the invention; Figure 6 is a partial view similar to Figure 1 for a second embodiment of the priming spring according to the invention.

Description of exemplary embodiment of the invention With reference to FIGS. 5 and 6, the same reference numbers will be used to designate parts identical or similar to those of FIGS. 1 to 4.

In FIG. 5, the launcher 26 comprises a drive gear 32, a driver 33, adapted to be actuated by the fork of the control lever 25 of FIG. 1, and a free wheel 34 shaped according to a friction clutch, here of frustoconical shape alternatively semi-shery form. The latter is provided with two friction surfaces 37, 40 of annular and complementary shape. These surfaces are concave and convex. These surfaces 37, 40 are in this rigid embodiment.

The first friction surface 37 is carried internally by the frustoconical skirt 48 of a bell-shaped coupling piece 45 directed towards the driver 33. The skirt 48 is delimited axially by a bottom 46 integral with the pinion 32 and by a rear stop 47 secured to the coupling piece 45 at the free end of larger diameter. The skirt 48 and the coupling piece 45 are parts of revolution

The bottom 46 extends radially between the skirt 48 and the pinion 32 and is arranged facing the front face 50 of the driver 33 and the lining 39. The stop 47 is formed by an annular flange radially flanking the lining 39. .

For more details, see document WO 03/002870.

Thus, in one embodiment, the bottom 46 is attached by welding, for example of the laser type, to the pinion 32 having a tubular extension for this purpose. Alternatively, a crimped attachment of the bottom 46 can be made to the tubular extension as in FIG. 11 of WO 03/002870.

By making separately the pinion and the coupling piece it is possible for each of these parts to choose the material of these according to the function to be realized.

In a variant, the pinion 32 and the coupling piece 45 form a single piece made of a single piece of the same material or material, for example a bi sintering. as in Figures 1 and 2 or Figure 3 of the WO document

03/002870.

In a variant, the bottom 46 is inclined as can also be seen in FIG. 3 of this document WO 03/002870. The stop 47 consists of an embodiment in a circlip as in Figure 8 of WO 03/002870.

In this case the skirt 48 internally bears the friction surface 37, formed by the inner periphery of the skirt in FIG. 5, and has at its free end a housing, such as a groove, for mounting a circlip for cooperate with the coach and make captive parts of the launcher that is thus manipulable and transportable.

Alternatively this circlip is replaced by a rim or tongues of radial orientation obtained (s) by folding inward of the free end of the skirt. As a variant, the abutment is constituted by a cover crimped on the free end of the skirt, which has a protrusion for this purpose, as in FIGS. 1 and 2.

Alternatively the free end of the skirt has blind mortises, while the abutment has radial tenons at its outer periphery engaging complementary manner in the grooves of axial orientation. Then we locally crush the side edges of the mortises in contact with the tenons resting on the bottoms of the mortises.

Alternatively the abutment is molded with the skirt of the coupling piece.

A stop 47 is thus integral with the coupling piece 45 of annular shape, which comprises, on the opposite side to the abutment 47, a bottom 46. The second friction surface 40, in Figure 5, is located on the lining

39 at the outer periphery of the driver 33, and extends parallel to the first friction surface 37, but a shorter axial distance.

The friction surfaces 37, 40 are complementary.

The lining 39 is secured to the driver by being for example fixed by gluing in an annular housing thereof or alternatively fixed by the overmolding technique on the coach advantageously plastic so that the liner 40 is anchored in the coach.

Of course, the size of the abutment 47 is defined in such a way that it can cooperate with the rear face of the lining 39 (see FIG. 5).

This stop 47 thus makes it possible to create a captive, manipulable and transportable launcher before mounting the launcher on the shaft 28. This stop 47 limits the relative movement between the driver 33 and the pinion 32 especially at the beginning of the starting of the engine. with combustion.

In the training phase, the blocking of the freewheeling starter 34 by friction is obtained by the combined action of the splines 38 of the driver 33, driven by the electric motor via the teeth 36 of the output shaft, and of the friction cone after engagement of the two friction surfaces 37, 40.

In the locked position of the clutch of the free wheel 34 (driving phase), the electric motor 11 drives the pinion 32 and the ring gear for starting the internal combustion engine. The clutch is released in the freewheel phase when the combustion engine drives the pinion 32 to a rotational speed greater than that of the driver 33. The driver 33 has an annular groove 133 for receiving the lower part 125 Fork-shaped lever 25 of Figure 1.

To allow the reliable operation of the launcher 26, the invention proposes to initiate the internal self-locking of the free wheel 34 in the driving phase. The initiation of the self-locking is provided by an elastic device 51 external to the free wheel 34, shaped according to a friction clutch, and intended to generate a low intensity drag force. The presence of this ignition device 51 generates a frictional drag torque between the driver 33 and the pinion 32, said torque being sufficient to initiate the self-locking of the launcher 26 in training phase, but relatively low not to significantly reduce the speed differential in the freewheel phase.

In the embodiment of FIG. 5, the initiation of the self-locking of the friction clutch is ensured by an elastic device 51 comprising at least one priming spring R1 arranged outside the freewheel 34 between the clutch. stop 35, here of annular shape, and the pinion 32 of the launcher 26.

This abutment is fixed axially and is carried to fixing, in the aforementioned manner, by the shaft 28. It is adjacent to the bottom 100, more precisely to the rear face 102 delimiting the bottom 100 of the support 16 shown partially. The priming spring R1 is distinct from the teeth against teeth spring 41 and is intended to generate a low intensity drag force at the friction surfaces 37,40.

This spring R1 is sized to generate a low intensity drag force between the pads 37,40.

Thus the action exerted by the priming device 51 on the pinion 32 is less than the axial action exerted by the spring against teeth 41 at the level of the driver 33 via the lever 25.

The elastic device 51 according to FIG. 5 comprises a spring R1 constituted for example by a cylindrical compression spring of the coil spring type. As a variant, this compression spring R1 consists of a tube based on elastomer or rubber. This spring is interposed axially between the front face 132 of the pinion and the rear face 135 of the abutment 35. Here the spring R1 bears on the faces 132, 135 so that it is mounted without clearance between the abutment 35 and the pinion 32 and this advantageously under prestressing. In this case, as shown in FIG. 5, the friction surfaces 37, 40 are pressed against each other. In a variant, this spring R1 is mounted between the faces 135, 132. Advantageously this game is weak so that a weak game can exist between the surfaces 37,40. This game is caught when the thrower moves. Then the thrower moves against the force exerted by the spring R1.

The abutment 35 may be made of rigid material or of elastic material, such as elastomer or rubber, because the pinion 32 does not come into direct contact with the abutment 35. This abutment may be rigid or comprise an elastic part. .

This stop may be of the type of Figure 1. Alternatively it is a rigid washer fixed on the output shaft for example by welding or stapling. The stop may consist of a circlip mounted in a groove of the output shaft. The abutment 35 may be in several parts and comprise a ring broken into pads for contact with the priming spring.

The spring R1 loosely surrounds the front portion of the output shaft 28 and allows cleaning thereof when the launcher 26 moves. Advantageously this game is weak for a better cleaning. The operation of the starter is therefore improved.

The presence of this priming spring R1, which cooperates with the pinion 32, generates a friction drag torque between the friction surfaces 37, 40, said torque being sufficient to initiate the self-locking of the launcher 26 during the training phase. , but relatively low so as not to significantly decrease the speed differential in the freewheel phase.

As is apparent from FIG. 5 when the movable core 23 leaves its rest position (coil B of FIGS. 1 and 2 electrically powered), the surfaces 37,

40 are held in contact, on the one hand, by the spring R1 acting on the pinion and secondly, by the lever 25 acting on the coach 33 in favor of the throat 133 thereof. This relationship is achieved as soon as the coach leaves his rear rest position.

The cylindrical R1 spring of the coil type, that is to say of the helical compression type, being wedged axially between the faces 135, 132, possibly after catching a game, this results in a plating force between the surfaces. friction 37,40. The section of the turns of the spring is circular or advantageously comprises at least two flats for better contact when the turns of the coil spring R1 are contiguous. The section of the turns is in rectangular or square variant.

The plating force depends on the applications and is chosen so as not to unduly disturb the movement of the driver relative to the pinion and the action of the spring teeth against teeth 41, that this spring exerts on the driver 33 via the lever 25 intended for its inner portion in the form of fork 125 to bear against the side of the throat 133 closest to the lining 39 and therefore the free wheel 34. For the record it will be recalled that the fork 125 has two branches each with their free end of a profiled finger or shoe, as shown in Figure 1, for local contact with one of the flanks of the groove 133 according to the direction of movement of the launcher relative to the shaft 28.

In all cases advantageously the resulting force at the launcher, more precisely at the throat 133, and produced by the elastic device according to the invention is lower in all embodiments than that produced by the spring teeth against teeth 41 via the lever 25.

The spring R1 of FIG. 5 makes it possible to obtain a long elastic race and is alternatively variable pitch to obtain a better progressivity. In a variant, the helical spring R1 is of frustoconical shape. Alternatively the fixed stop is formed directly on the front support 16. Thus in the embodiment of Figure 6 this stop is formed in favor of the rear face 102 defining the rear face of the bottom 100 in the form of nose. In this case, the stop 35 of FIG. 1 can be retained, in order to limit the displacement of the pinion 32, knowing that in FIG. 5 this limitation of the deflection can be achieved by contiguous turns of the coil spring R1. In this Figure 6 the pinion 32 has a larger diameter than that of Figure 5. Thus the spring R1 has an internal diameter greater than the outer diameter of the abutment 35, here in the form of circlips of rectangular section mounted in a groove. the output shaft 28.

The abutment 35, 102, disposed facing the front face of the pinion 32, may be provided at its rear face with a shoulder for centering the spring R1. Such a shoulder is visible in Figure 6. Similarly, the front face 50 of the pinion 32 is alternatively provided with a centering shoulder of the spring R1.

The priming device 51 comprises, in a variant, several springs connected in series, for example at least two Belleville washers with mounting of a separating washer between the two Belleville washers. Preferably to get a long run it is expected more than two Belleville washers. Alternatively the springs are delayed and staggered action, a first spring intervening first and then two springs.

The parts of the launcher 26 can be reversed. Thus the coupling piece 45 with the friction surface 37 is alternatively integral with the driver 33, and the second convex friction surface 40 is in this case secured to the pinion 32 as in FIGS. 5 and 6 of WO 03 / 002870 cited above.

The skirt with its inclined bottom or radial orientation can be in one piece or be reported on the element 32, 33 which it is secured. The driver 33 and the pinion 32 may therefore be metal or sintered material.

Here the driver 33 and the lever 25 are preferably made of plastic to easily obtain by molding the desired shape for these parts. One of the flanks of the groove 133, the one closest to the free wheel 34, may be coated with a metal part, for example by overmolding. The other side, the furthest from the freewheel 34, is advantageously metallic while being attached to the driver, for example by overmolding. This flank consists for example of a metal washer. In this case we always get a metal contact on plastic material.

The invention also applies to a starter without speed reducer 30 between the electric motor 11 and the launcher 26. In this case the shaft 14 is also the output shaft. In a variant, the output shaft is radially offset relative to the shaft of the electric motor, a gear device intervening between the two shafts.

The switch 18 is alternatively remote and extends for example perpendicularly to the shaft 14 of the motor 11 in the vicinity of the rear bearing of the shaft 14 as described in document FR A 2 843427. In this case the connecting rod to the core mobile, which acts on the upper part of the lever 25, is connected to the movable core by a second rod acting on the spring teeth against teeth and a return mechanism intervening between the two rods. The rod 43 thus acts directly or indirectly on the spring teeth against teeth.

The lever 25 carries an axis 31 for its pivotal mounting on a fixed hinge support 131 of the starter 25 (Figure 2). In a variant, it is the fixed hinge support which carries the axis, the lever being perforated for passage of the axis. As a variant, the contactor is mounted coaxially with respect to the electric motor so that the launcher acts as a mobile core as described in document FR A 2 841 941 to which reference will be made. The control means for moving the launcher can therefore be of the electromagnetic type and is therefore not necessarily a lever.

The spring teeth against teeth is alternately implanted between the driver 33 and the end or lower part of the control lever. In all cases the control means cooperates with a spring teeth against teeth.

The support 16 is alternatively shallower so that the thrower 26 penetrates at least partially inside the support 16. In FIG. 6, the thrower 26 has left its rest position and fully penetrates, as in FIG. Inside the support 16. In all cases the electric motor is mounted in a housing comprising the front support 16, the cylinder head 15 and the rear bearing. In Figure 1 tie rods are supported on the rear bearing and are screwed into the support 16 to achieve the assembly of the housing. Other fixing means are possible.

As a variant, at least one coating is provided on at least one of the faces facing the abutment 35, 102 and the pinion 32, for example on one of the faces 135, 132 for supporting the priming spring R1. For example in one embodiment the stop 35 is made of elastomer and the rear face 135 of the abutment 35 is constituted by a metal washer integral with the abutment 35 for example by gluing or overmolding technique. The abutment 35 comprises an elastic part, which in this case belongs to the elastic device 51. In a variant for reducing the wear, a metal washer is interposed between the rear end of the priming spring R1 and the front end of the pinion 32 as visible at 103 in FIG. 6. In a variant, the coating is an anti-noise material made for example on the front face 132 of the pinion 32. The priming spring R1 thus bears directly or indirectly on the rear face of the abutment 35, 102 and on the front face of the pinion 32.

The friction surface 40 may be formed directly at the outer periphery of the driver, while the friction surface 37 may belong to a friction lining attached to the inner periphery of the skirt of the coupling piece. The skirt 48 can therefore be of cylindrical shape.

In the description, the starter is a starter for a combustion engine, also called a combustion engine, of a motor vehicle.

The combustion engine can be stationary and drive, advantageously via a clutch, a motion transmission shaft, such as a PTO. Alternatively the control lever is coupled by its upper part to an auxiliary electric motor whose output shaft controls its displacement

The motor vehicle, light or heavy type, is a variant boat.

All combinations are possible.

Thus in one embodiment the elastic device is of the composite type and comprises for example a coil spring associated with a portion of elastomeric tube or at least one of its axial end to an elastomer-based washer. The presence of the stop 35 in FIG. 6 is not mandatory.

Claims

1. Starter for a combustion engine, in particular of a motor vehicle, equipped with a ring gear wheel (300), comprising, a front support (16) with a bottom (100), a stop (35, 102) adjacent to the bottom (100), an output shaft (28) having teeth (36), a launcher (26), a pinion (32) belonging to the launcher (26), an electric motor (11) for driving in rotation output shaft (28) mechanically coupled to the launcher (26) axially slidably mounted on the output shaft (28) between a rearward position of rest and a front position of meshing of the pinion

(32) with the ring gear of the flywheel of the combustion engine, said launcher (26) also comprising: a driver (33) controlled by a control means between the rear and front positions, and equipped with splines (38) d driving in engagement with the complementary toothings (36) of the output shaft (28), a coupling part of the pinion (32) to the driver (33) via a mechanical freewheel link Friction-compensated clutch (34) having a first friction surface (37) carried by one of the pinion (32) - driver (33), and a second friction surface (40) integral with the other driving elements (33) - pinion (32), and an elastic device (51) for initiating the self-locking of the free wheel (34), - said coupling piece being integral with one of the pinion elements (32)

- Trainer (33) said first element, wherein the control means cooperates with a spring (41) said spring teeth against teeth characterized in that the elastic device (51) comprises at least one priming spring (R1) separate from the spring teeth against teeth (41) and in that the priming spring (R1) is arranged outside the free wheel (34) between the stop (35) and the pinion (32) and is intended to generate a low intensity drag force at the friction surfaces (37,40).

2. Starter according to claim 1, characterized in that the priming spring (R1) is mounted without play between the stop (35, 102) and the pinion (32) and surrounds the output shaft (28).

3. Starter according to claim 2, characterized in that the priming spring (R1) is mounted under prestressing between the stop (35, 102) and the pinion (32).

4. Starter according to claim 1, characterized in that the priming spring (R1) is a helical compression spring.

Starter according to Claim 1, characterized in that the friction surfaces (37, 40) are held in contact with each other on the one hand by the action exerted by the priming spring ( R1) on the pinion (32) of the launcher (26) and, secondly, by the action exerted by the control means (25) on the driver (33) of the launcher (26).

6. Starter according to claim 5, characterized in that it comprises a fixed hinge support (131), in that the control means (25) consists of a control lever (25) having an intermediate portion mounted to pivoting on said support (131), in that the driver (33) has a groove (133), in that the control lever (25) has a fork-shaped lower portion (125) mounted in the groove ( 133) of the coach for action on it.

7. Starter according to claim 6, characterized in that it comprises an electromagnetic contactor (18) having a movable core (23) inside. which is located the spring (41) teeth against teeth and in that the control lever (25) has an upper portion coupled to the movable core (23) via a rod (43) acting between the spring (41) and the upper part the control lever (25).

8. Starter according to claim 1, characterized in that the friction clutch of the freewheel (34) is of frustoconical shape, in that the coupling piece (45) has a bottom (46) integral with the first element pinion (32) -center (33) and a skirt (48) of frustoconical shape connected to the bottom (46) and in that, on the side opposite its bottom (46), the coupling piece (45) carries a stop (47).

9. Starter according to claim 1, characterized in that the stop (35) belongs to the front portion of the output shaft (28).

10. Starter according to claim 1, characterized in that the stop (102) belongs to the support (16).