EP2984329A2

EP2984329A2 - Starter having a drive mechanism provided with an intermediate element for reducing friction between a control lever and a driver

Info

Publication number: EP2984329A2
Application number: EP14723462.9A
Authority: EP
Inventors: Jérémy BRANDINI; Guillaume Seillier; Vincent Villard; Dominique DESBOIS
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2013-04-10
Filing date: 2014-04-10
Publication date: 2016-02-17
Also published as: WO2014167254A2; CN205592056U; FR3004497B1; FR3004497A1; WO2014167254A3

Abstract

The invention mainly relates to a starter (30) having a drive mechanism for a heat engine of a motor vehicle comprising: a drive pinion (32) for meshing with a starter ring gear (35) of a heat engine, a driver (81) mounted on a drive shaft (33), a friction clutch (82) inserted between the driver (81) and the drive pinion (32) including a reaction element (91) rotatably secured to the drive pinion (32) and a pressure element (92) rotatably secured to the driver (81) which is mobile relative to the reaction element (91), and a control lever (65) comprising a portion, referred to as a thrust portion (174), capable of pushing the driver (81) in order to switch the clutch (82) from an unlocked state in which the driver (81) and the drive pinion (32) are rotatably uncoupled relative to one another to a locked state in which the drive pinion (32) and the driver (81) are coupled with one another. According to the invention, an intermediate element (181, 181') is mounted between the thrust portion (174) of the control lever (65) and the driver (81), said intermediate element being such that at least one portion of said intermediate element that is in direct or indirect contact with the thrust portion (174) of the control lever rotates at least three times slower than the driver when the clutch (81) is in the locked state.

Description

LAUNCHER STARTER WITH AN INTERMEDIATE FRICTION REDUCTION ELEMENT BETWEEN A CONTROL LEVER AND A TRAINER

TECHNICAL FIELD OF THE INVENTION The invention relates to a starter starter equipped with an intermediate element for reducing friction between a control lever and a driver.

The invention finds a particularly advantageous application for vehicles equipped with the function of stopping and starting the engine (function called "stop and start" in English) according to which the engine of the vehicle is stopped because of the traffic conditions ( especially during a stop at the red light) and then restarted.

STATE OF THE ART

In order to start the engine of a vehicle, it is known to use a starter capable of transmitting mechanical energy to turn a crankshaft of the engine via gear wheels. For this purpose, the starter comprises a pinion installed on a drive shaft driven in rotation by a rotor of an electric motor. This pinion is provided with teeth capable of meshing with the teeth of a toothed wheel coupled to the crankshaft of the engine called starter ring. In the starter starter described in document FR2978500, the drive gear belongs to a launcher mounted to move in translation on a drive shaft to move from a rest position in which the drive pinion is disengaged from the crown. starting at an active position in which the drive pinion engages with the starter ring and vice versa.

For this purpose, a starter starter assembly comprises the drive pinion mounted on a pinion carrier, a driver movably mounted on a drive shaft via a helical link, and a friction clutch interposed between the pinion and the driver. More specifically, the pinion carrier comprises a sleeve on which is mounted the drive gear movable in translation, a plate extending radially from a rear end of the sleeve, and an annular skirt of axial orientation connected to the periphery. external reaction plate.

The friction clutch comprises a pressure element consisting of a shoulder of the driver, a reaction element constituted by the plate of the gear carrier, as well as friction discs located between the pressure element and the reaction plate. . The driver is movable in translation relative to the reaction plate in the limit of an axial play, so as to move the clutch of an unlocked state in which the driver and the pinion are uncoupled in rotation one of relative to each other, to a locked state in which the pinion and the driver are coupled in rotation with each other. The disks are housed in a housing delimited by the reaction plate connected to the pinion, the annular skirt of axial orientation connected to the outer periphery of the reaction plate, as well as by a closure ring traversed centrally by the driver. Furthermore, the ring is hollowed annularly at its outer periphery for mounting an assembly cap.

The trainer further comprises a groove delimited by two transverse walls inside which the lower part of a control lever of the starter is intended to be mounted. A wall called pusher is the wall against which the lever is supported to push the trainer towards the starter ring. The other wall called shooter is a wall against which the lever is supported to move the coach from the starter ring.

The operation of such a starter during a transition from the rest position to the active position is described below. Starting from the rest position, the control lever of the starter which has a cam shape initially acts on the ring of the housing which then axially displaces the drive pinion in the direction of the starter ring along the drive shaft. During this step, the clutch is in an unlocked state so that the pinion is free to rotate in both directions of rotation. The axial movement continues, the pinion arrives in the vicinity of the starter ring. In a second step, the free rotating pinion penetrates slightly into the crown. The lever then has a second portion, said pushing portion, in contact with the pusher which axially moves the driver towards the reaction plate so that the play between the discs is canceled. The clutch then moves from the unlocked state to the locked state for transmitting the torque of the pinion to the starter ring.

However, when the control lever applies a pressure force against the pusher which is then rotating, this has the effect of generating friction between the lever and the driver. This friction is particularly important when the launcher is subjected to counter-reaction forces that oppose the movement of the observable driver, especially when the drive gear is in a tooth against tooth state with the crown but especially when the pinion is at the end of the race. Indeed, these friction are due on the one hand to the rotational speed of the driver and on the other hand to the force of the fork on the driver corresponding to either the counter-reaction force of the pinion in the final position against the abutment or against the reaction force of the pinion in the tooth against tooth position against the crown.

These phenomena of friction are likely to damage the control levers generally made of a molded plastic material, in particular those fitted to vehicles equipped with the "stop and start" function which undergo a very high number of operating cycles.

OBJECT OF THE INVENTION

The invention aims to effectively reduce friction between the control lever and the driver by proposing a starter motor for a motor vehicle engine comprising:

a drive gear for meshing with a ring gear for starting a heat engine, - a trainer mounted on a drive shaft,

a friction clutch interposed between the driver and the drive pinion comprising a reaction element that is rotatably connected to the drive pinion and a pressure element that is integral in rotation with the mobile trainer relative to the reaction element; ,

a control lever comprising a portion, referred to as a pushing portion,

further comprising an intermediate element mounted between the pushing portion of the control lever and the driver,

the control lever being able to cause the movement of the driver through an intermediate piece, to move the clutch of an unlocked state in which the driver and the drive gear are uncoupled in rotation l relative to each other in a locked state in which the drive pinion and the driver are coupled with each other, and

wherein the intermediate member is arranged so that at least a portion of said intermediate member is in contact with the thrust portion of the control lever when the control lever causes movement of the driver and that portion rotates less fast as the trainer when the clutch is in the locked state and the sprocket is rotated.

Thus, by involving the intermediate element between the control lever and the driver, the invention dissociates the thrust function performed by the control lever relative to the rotation of the driver, which reduces greatly, or even remove, the friction between the control lever and the coach.

According to one embodiment, the portion of the intermediate piece rotates at least three times slower than the driver relative to the fork. The fact that the fork rotates at least three times slower makes it possible to reduce by at least three the speed of rotation between the fork and the part on which it presses compared to the prior art. According to one embodiment, the intermediate element is constituted by a ball bearing.

According to one embodiment, the intermediate element comprises a bearing transfer part positioned around the ball bearing forming the part in contact with the pushing portion of the control lever for transferring a support from the pushing portion of the control lever towards the ball bearing. According to one embodiment, the intermediate element is in direct contact with a so-called thrust face of the driver formed by a face of a shoulder of said driver.

According to one embodiment, the intermediate element covers at least 90% of the thrust face of the driver. As a result, the friction between the intermediate piece and the driver is distributed over a larger area. Wear is therefore less important in the thickness of the driver or the intermediate element. The coach and the fork therefore do not cause disruption on the side-chain and kinematics over a longer life of the coach.

According to one embodiment, at least the portion of the intermediate element in contact with the thrust face of the driver is made of a material resistant to friction.

According to one embodiment, the intermediate element is made of a plastic material loaded with pre-lubricated carbon.

According to one embodiment, the intermediate element in contact with the control lever is locked in rotation with respect to said control lever. According to one embodiment, the control lever comprises two branches each having a thrust portion positioned in diametrically opposed flat-shaped zones formed in the intermediate element.

According to one embodiment, a closure washer is positioned on the driver for an axial retention of the intermediate element.

According to one embodiment, the control lever is adapted to come into direct contact with the closure washer during a movement of the driver during a release phase of the clutch.

According to one embodiment, the control lever is adapted to come into contact with the closure washer via an intermediate contact piece during a movement of the driver during a release phase of the clutch.

According to one embodiment, the clutch further comprises friction discs positioned between the reaction element and the pressure element. According to one embodiment, the drive pinion is slidably mounted on a pinion carrier comprising a sleeve cooperating with the drive pinion, a transverse plate coming from an end of the sleeve and an annular skirt of axial orientation. extending from an outer periphery of the transverse plate. According to one embodiment, a spring is mounted in support on the one hand against a face of the transverse plate of the pinion carrier and on the other hand against a face of the drive pinion.

According to one embodiment, the fork is arranged so that during a first part of the race of the progress of the pinion towards the crown to be in contact with the pinion body in order to translate it then in a second part of the race to push the coach through the middle piece.

BRIEF DESCRIPTION OF THE FIGURES The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given for illustrative but not limiting of the invention.

Figure 1 shows a longitudinal sectional view of a thermal engine starter according to the invention in the rest position;

Figure 2 shows a longitudinal sectional view of the starter of the starter according to the invention;

Figures 3a and 3b show perspective views of a first embodiment of the invention in which the intermediate element mounted between the control lever and the driver is constituted by a ball bearing respectively when the clutch is in a locked state and in an unlocked state;

Figures 4a and 4b show respectively side views of all of Figures 3a and 3b; Figures 5a and 5b show respectively longitudinal sectional views of Figure 4a and Figure 4b;

Figure 6 shows a cross-sectional view of Figure 5b;

FIGS. 7a and 7b show perspective views of a second embodiment of the invention in which the intermediate element mounted between the control lever and the driver is in contact with a pushing face of the driver respectively when the clutch is in a locked state and in an unlocked state;

Figures 8a and 8b show respectively side views of all of Figures 7a and 7b; Figures 9a and 9b show respectively longitudinal sectional views of Figure 8a and Figure 8b;

Figure 10 shows a cross-sectional view of Figure 9b. Identical, similar or similar elements retain the same reference from one figure to another.

DESCRIPTION OF EXAMPLES OF EMBODIMENT OF THE INVENTION

Referring to Figure 1, the starter 30 according to the invention comprises a friction launcher 31 described in more detail below provided with a drive pinion 32 mounted to move in translation on a drive shaft 33. The launcher 31 can move from a rest position (that of Figure 1) in which the drive pinion 32 is disengaged from a starting ring 35 of a heat engine to an active position (not shown) in which the pinion drive 32 engages with a starter ring 35, and vice versa.

For this purpose, the starter 30 comprises an electric motor 37 composed of a stator 38 and a rotor 39 mounted coaxially. The stator 38 surrounds the rotor 39, which is mounted on a shaft 42 of axis X said rotor shaft inside a yoke 43. The latter is secured to a support 45 of the starter to be fixed on a fixed part of the motor vehicle. The stator 38 comprises for example an inductor winding having two pairs of windings, which are each wound around a pole mass integral with the yoke. The axis of each winding is radial with respect to the X axis of the rotor. Alternatively or in addition, the stator 38 comprises a plurality of permanent magnets.

The rotor 39 mounted on the rotor shaft 42 comprises a bundle of plates provided with grooves for mounting electrical conductors in the form of pins. These conductors are interconnected to form a rotor winding in connection with conductive blades belonging to a collector 48 integral with the rotor shaft 42 cooperating with brushes 49a, 49b described below. The X axis of the rotor shaft 42 coincides with the axis of the drive shaft 33.

The drive shaft 33 has its front end rotatably mounted in a bearing, said front bearing 50, via a bearing 51. The rotor shaft 42 has its rear end mounted in a bearing 52 of a bearing 53 at the rear of the starter, called rear bearing, and which is secured to a brush holder 54.

In the rest of the description, a front-to-back orientation corresponds to a left-to-right orientation in FIGS. 1, 2, 4a, 4b, 5a, 5b, 8a, 8b, 9a, 9b. Thus, a front face of a member is the face facing the front bearing 50 and the rear face is the face facing the rear bearing 53.

The starter 30 further comprises a reduction system 58 mounted between the rotor shaft 42 and the drive shaft 33, one end of which is connected to the rotor shaft 42 and the other end is connected to the shaft 33. The reducing system 58 is in this case an epicyclic gear comprising a cylindrical ring gear 59 immobilized in rotation toothed internally. The teeth of the ring gear 59 mesh with planet wheels mounted to rotate about axes carried by a transverse plate 60 integral with the rear end of the drive shaft 33. The sun gear 61 is connected to the front end of the rotor shaft 42.

Alternatively, the reducing system 58 may be any other type of reducer. For example, the reduction system 58 could comprise two gears, one of which is secured to the rotor shaft 42 and the other of the drive shaft 33. In this example, the two axes of the rotor shaft 42 and the drive shaft 33 are offset parallel to one another. In another example, the reduction system 58 may be geared left or gear concurrent.

The starter 30 further comprises a system for moving the launcher 31 from its rest position to its active position and vice versa. This displacement system comprises an electromagnetic contactor 64 extending parallel to the electric motor 37 being implanted radially above it and a control lever 65 in the form of a fork.

The brush group 49a and 49b is provided for the power supply of the rotor winding 39. At least one of the brushes 49b is electrically connected to the ground of the starter, for example the support 45, and at least one other of the brushes 49a is electrically connected to an electrical terminal 66a of the contactor, for example via a wire. The brushes 49a and 49b rub on the blades of the manifold 48 when the rotor 39 is rotating. The starter 30 may comprise a plurality of brushes.

The contactor 64 comprises, in addition to the terminal 66a connected to the brush, a terminal 66b intended to be connected via an electrical connection element to a positive power supply V + of the vehicle, in particular a battery, not shown. A normally open contact (not shown), located between a terminal V + of the power supply and the terminal 66b controls the power supply of the contactor 64 to start the electric motor.

The contactor 64 comprises a movable contact plate 69 for electrically connecting the terminals 66a and 66b in order to supply the electric motor 37. The contactor 64 is also able to actuate the control lever 65 to move the launcher 31 along the X axis of the drive shaft 33 from the rest position to the active position and vice versa. The switch 64 also comprises a movable core 71, a fixed core 72, a fixed coil 73, a control rod 74 and a movable rod 75.

The control rod 74 passes through the fixed core 72 which serves as a guide. This control rod 74 has its front end bearing on the fixed core 72 and its rear end attached to the contact plate 69. The control rod 74 is subjected to the action of a compressed contact spring (not referenced) between a shoulder of the control rod 74 and the contact plate 69 to ensure the electrical contact of the contact plate 69 with the terminals 66a and 66b when the movable core 71 is in a so-called magnetized position. The movable rod 75 is fixed at its front end to the control lever 65. When the coil 73 is powered, the movable core 71 is attracted to the fixed core 72 to be in contact with the latter in a so-called magnetized position. Its movement simultaneously drives the movable rod 75, the contact plate 69 and the control rod 74 towards the rear. The movable rod 75 is further subjected to a tooth against tooth spring 78 housed inside the movable core 71 and surrounding the movable rod 75. This tooth against tooth spring 78 bears on a front shoulder of the movable rod 75 and a rear shoulder of the movable core 71. This spring tooth against tooth 78 is compressed when the contact plate 69 moves towards the terminals 66a and 66b and that the control lever 65 can not advance the pinion 32. The lever 65 can not advance when the pinion 32 is blocked in translation along the X axis in the direction of the ring 35 by one or more teeth of the ring 35. This blocked state is called "tooth against tooth position". The compression of the tooth against tooth spring 78 absorbs shocks while applying a force on the control lever 65 transmitted to the pinion 32 to the active position. The contactor 64 further comprises a return spring 80, bearing on the fixed coil 73 and the movable core 71 to urge it forward to its rest position and simultaneously move the control lever 65 until that the pinion 32 is in the rest position.

As is clearly visible in FIG. 2, the friction launcher 31 comprises the drive pinion 32 slidably mounted on a pinion carrier 83, a driver 81 actuated by the control lever 65, and a friction clutch 82 interposed axially. between the driver 81 and the pinion 32. The axes of the pinion carrier 83 and the driver 81 are merged into an axis X 'corresponding to the axis of the launcher 31. When the starter is mounted on the starter, drive 33. The driver 81 is internally provided with helical splines 84 in complementary engagement with external helical gears 85 carried by the drive shaft 33 (see FIG. ). The launcher 31 is thus driven by a helical movement when it is moved by the lever 65 against the stop 88 to come, via the pinion 32, in engagement with the ring gear 35 in the active position.

More specifically, the pinion carrier 83 comprises a sleeve 100 of axial orientation having a bore 101 for its mounting on the drive shaft 33. The sleeve 100 thus serves to axially guide the pinion 32 on a smooth section of the drive shaft 33.

To allow axial movement of the pinion relative to the sleeve 100, grooves formed in the outer periphery of the sleeve 100 cooperate with complementary grooves formed in the inner periphery of the pinion 32. The grooves here are of axial orientation. This assembly creates a rotational connection between the pinion 32 and the sleeve 100. At least one pad 102 is preferably interposed between the section smooth of the drive shaft 33 and the sleeve 100. In this case, two pads 102 are used.

The pinion carrier 83 also comprises a plate 91 of transverse orientation located in the extension of a rear end of the sleeve 100. This plate 91 is itself extended at its outer periphery by an annular skirt 105 of axial orientation. This skirt 105 is directed rearward towards the coach 81. In this case, the sleeve 100, the plate 91 and the skirt 105 are made in one piece.

The friction clutch 82 comprises a reaction member constituted by the plate 91 of the pinion carrier 83, a pressure element 92 constituted by a shoulder of the driver 81, as well as friction disks 93, 94 situated between the pressure element 92 and the reaction plate 91.

The disks 93, 94 are housed in a housing 108 delimited by the reaction plate 91 connected to the pinion, the annular skirt 105 of axial orientation connected to the outer periphery of the reaction plate, as well as by a closure ring 106. elsewhere, the ring 106 is annularly hollowed at its outer periphery for mounting an assembly cap 151 of the ring to the pinion carrier 83. It is noted that the shoulder 92 penetrates partly inside the the ring. Its outer diameter is smaller than the inner diameter of the ring, which reduces the axial size of the launcher.

The disks 93 and 94 are alternately rotatably connected to the drive pinion 32 and to the driver 81. For this purpose, first disks 93, called internal disks, have at their inner periphery a plurality of lugs inserted inside corresponding notches 109 located in the outer periphery of the driver 81. These notches 109 are for example grooves whose depth extends radially in an outer wall of the driver 81 and whose length extends along the axis X '. Second discs 94, called external discs, have at their outer periphery a plurality of tabs inserted inside corresponding notches 1 10 located in the inner periphery of the annular skirt 105. These notches 1 10 are for example grooves of which the depth extends radially in the annular skirt 105 and whose length extends along the axis X '. The Internal disks 93 are thus connected in rotation with the driver 81 and the external disks 94 are connected in rotation with the drive gear 32 via the annular skirt 105. The disks 93, 94 can slide along the axis X 'by the bias notches 109, 1 10 and their corresponding legs. The discs 93, 94 for example made of a friction material, such as bronze and steel, allow friction torque to be transmitted between the driver 81 and the pinion 32. In this case, the number of internal disks 93 is two and the number of external disks 94 is three. However, this number of disks 93, 94 is likely to vary according to the intended application and the torque to be transmitted. It will thus be possible to increase the number of disks 93, 94 in order to transmit more torque without having to increase the diameter of the driver 81.

The driver 81 is movable in translation relative to the reaction plate 91 in the limit of an axial play so as to move the clutch of an unlocked state in which the driver 81 and the pinion 32 are uncoupled in rotation relative to each other, to a locked state in which the pinion 32 and the driver 81 are coupled in rotation with each other, and vice versa.

The launcher 31 also has a resilient means 1 exerting a force away from the driver 81 of the reaction plate 91 towards the disengaged position. For this purpose, the elastic means 1 15 is mounted in compression between a radial face of the reaction plate 91 and an end of the driver 81.

More specifically, the elastic means 1 15 is positioned inside a groove 1 17 closed by a washer 1 18, said retaining washer, connected in rotation with the reaction plate 91. The groove 1 17 is formed by a circular groove around the axis X '. The groove 1 17 thus corresponds to a reduction in thickness at the inner periphery of the reaction plate 91. The groove 1 17 is open axially on the rear side and radially closed by two annular walls of axial orientation.

In addition, the groove 1 17 has at its outer periphery a set of slots 124 spaced angularly in a regular manner intended for receiving lugs 130 of corresponding shape located at the outer periphery of the retaining washer 1 18.

The retaining washer 1 18 closes the open axial end of the groove 1 17 inside which is positioned the elastic means 1 15. Thus, the retaining washer 1 18 is connected in rotation with the reaction plate 91 and is movable in translation relative to this plate 91 insofar as the lugs 130 of the retaining washer 1 18 can slide inside the corresponding notches 124 formed in the reaction plate 91.

The elastic means 1 15 is in this case a spring washer positioned inside the groove 1 17. In an exemplary embodiment, this washer 1 15 has a cylindrical helical shape. This washer is provided with corrugated turns. The spring washer 1 15 is mounted compressed between the bottom 1 19 of the groove 1 17 and the retaining washer 1 18 bears on the end of the driver 81 to separate the driver 81 from the reaction plate 91. The spring washer 1 15 is thus preserved from wear by the retaining washer 1 18 which closes the groove 1 17.

As can be seen in FIGS. 3a, 3b, 4a, 4b, 7a, 7b, 8a, and 8b, the control lever 65 pivotably mounted relative to the support 45 has an upper portion 160 mechanically coupled to the contactor 64. and a lower portion 161 having two fork-shaped branches 162 mounted in a groove 163 of the driver 81. These two parts 160, 161 are interconnected by a connecting portion 165.

More specifically, the control lever 65 has in its upper portion 160 two tabs 166 separated from each other by a slot 167 for passage of the front end of the movable rod 75. Each tab 166 comprises a receiving recess a hinge pin 170 passing through the rod 75 (see Figure 1).

The lever 65 is mounted pivotally connected relative to the support 45 of the starter via a pivot axis comprising two sections 172 extending from opposite faces of the connecting portion 165, here made of plastic, advantageously coming from molding with the lever 65. These sections 172 are pivotally mounted for example in a bearing in two parts having a first portion connected to the support 45 and a second portion formed vis-a-vis forming a wedge between the switch 64, more precisely the tank thereof, and the motor yoke secured to the support 45. For more For more details, see for example document FR 2699605.

As is clearly visible in Figures 4a, 4b, 8a, and 8b, each branch 162 has at its lower end a portion 174, said push portion, adapted to push the driver 81 so as to pass the clutch 82 from an unlocked state to a locked state as described in more detail below.

This thrust portion 174 is extended by a protruding cam 175 extending in axial projection relative to the front face of the lever 65. Each cam 175 has a crown portion extended by a curved portion 176 of disengagement extending towards the pushing portion 174. The cams 175 carried by the lever 65 are, via their summit portion, capable of bearing on the ring 106 in two diametrically opposite zones thereof for axially displacing the drive pinion 32 towards the start crown while the clutch 82 is still unlocked. The cams 175 may be monobloc with the lever 65 or reported relative thereto in a variant.

All the shapes of the lever 65 are easily obtained by molding. The lever 65 is made of a rigid thermoplastic material preferably reinforced with fibers.

Furthermore, an intermediate element 181, 181 'is mounted between the thrust portion 174 of the control lever 65 and the driver 81. This intermediate element 181, 181 'is such that a portion of said intermediate element 181, 181' in direct or indirect contact with the thrust portion 174 rotates at least ten times slower than the driver 81 when the clutch 82 is in position. locked position. The case of an indirect contact corresponds to the embodiment described in more detail below wherein a support transfer part 187 intervenes between the intermediate element 181 and the control lever 65. Thus, this configuration makes it possible to dissociate the thrust function of the lever 65 with respect to the rotation of the driver 81, which makes it possible to greatly reduce or even eliminate the friction between the lever 65 and the driver 81 when a clutch locking phase 82. In the embodiment of Figures 1, 2, 3a, 3b, 4a, 4b, 5a, 5b and 6, the intermediate element is constituted by a ball bearing 181. As can be seen clearly in FIG. 6, the bearing 181 comprises an inner ring 183 of axial orientation cooperating with the outer periphery of the driver 81 and an outer ring 184 of axial orientation on which is mounted a transfer member. 187 support described more precisely below. The inner ring 183 and the outer ring 184 delimit with annular walls of radial orientation a cage for the balls 185 of the bearing.

Due to this rolling, the portion of the intermediate element in contact with the fork rotates less quickly than the driver due to the pressure exerted on the fork pinion position coupled in rotation with the driver.

According to an example not shown, the material of the portion of the intermediate element in contact with the fork and the material of the fork each comprise a material so that when the pinion is coupled with the driver, the coefficient of friction is quite important so that this part is immobile with respect to the fork. In the examples shown, the part of the intermediate element in contact with the fork is locked in rotation by means of the fork, so that the part of the intermediate element in contact with the fork is immobal and does not wear the fork . Because of the ball bearing, the friction between the parts integral in rotation with the driver and the parts integral in rotation with the fork do not cause wear parts as in the prior art.

The bearing 181 is mounted around the driver 81 between the shoulder 92 forming the pressure element of the clutch 82 and the rear end of the driver 81. The bearing 181 is set back from the shoulder 92 of the driver 81, as shown in Figures 5a and 5b.

The support transfer piece 187 is positioned around the outer ring 184 to transfer a support from the pushing portion 174 of the control lever 65 to the bearing 181. For this purpose, the piece 187 comprises a radial flange 188 forming a wall, called pusher, against which bears the thrust portion 174 of the control lever 65 to push the driver 81 towards the reaction plate of the clutch 82 during a locking phase of said clutch, as shown in Figure 5a.

Preferably, the support transfer member 187 is locked in rotation with respect to the control lever 65. For this purpose, as can be seen in FIGS. 3a, 3b and 6, the component 187 comprises at least two zones 189 Flat-shaped formed in its outer periphery against which the internal faces of the legs 162 of the lever 65 facing each other. In this case, the support transfer member 187 has four flattened areas so that the piece 187 has a substantially rectangular or square shape in front view (see Figure 6). In a variant, the rotational locking system of the part 187 with respect to the lever 65 is formed by grooves formed in the outer periphery of the part 187 inside which the ends of the branches 162 of the control lever 65 are positioned.

As can be seen in FIGS. 5a and 5b, the bearing 181 is held axially on the one hand by a radial shoulder 190 defined by a slight difference in the external diameter of the driver 81 and on the other hand by a locking washer 192 To this end, the washer 192 has a generally annular shape of axial orientation having an inner diameter corresponding to an outer diameter of the portion of the driver 81 extending between the shoulder 190 and the rear end. The front end of the closure washer 192 penetrates inside the bearing transfer part 187 to come into contact with the rear radial face of the bearing 181. The front end of the closure washer 192 thus extends radially between the outer periphery of the driver 81 and the rear part of the piece 187 which is slightly raised radially relative to the outer periphery of the coach 81. Furthermore, the rear end of the piece 187 is in axial abutment against a shoulder 193 of the closure washer 192 located between the portion of the washer 192 entering the part 187 and a radial wall 194. This radial wall 194 called shooter is the portion of the washer 192 against which comes into contact with the control lever 65 in particular to move the driver 81 relative to the reaction plate of the clutch 82 during an unlocking phase of said clutch. The groove 163 of the driver inside which is mounted the lower part of the lever 65 is thus delimited by the two walls of transverse orientation 188 and 194. The section of the groove 163 is generally U-shaped.

Alternatively, the lever 65 is adapted to come into contact with the wall 194 of the closure washer 192 via an intermediate contact piece during a movement of the driver 81 during a release phase of the clutch. In a variant, the support transfer piece 187 has a U-shaped section delimiting the groove 163, the closure washer 192 then being devoid of shoulder 194. In a variant, the starter being devoid of a support transfer part 187, the lever 65 is directly in abutment against the outer ring 184 which comprises for this purpose a radial wall forming the pusher extending outwardly from a front end of the outer ring 184. The zones 189 in the form of flat against which are supported the branches of the lever 65 are then formed at least in portions of the outer ring 184 diametrically opposite.

In the embodiment of FIGS. 7a, 7b, 8a, 8b, 9a, 9b and 10, the intermediate element 181 'is mounted free to rotate relative to the driver 81 and is in direct contact with a face 200 of thrust constituted by a rear face of the shoulder 92 of the driver 81 opposite the face in contact with the friction discs 93, 94 of the clutch. More specifically, as is clearly visible in FIGS. 9a and 9b, the intermediate element 181 'has a portion 201 extending along the driver 81 provided with a cylinder bore to allow the passage of the rear end of coach 81. This bore has a diameter substantially equal to the external diameter of the cylindrical section 202 on which is mounted the intermediate element 181 ', which has an outer diameter slightly greater than the outer diameter of the cylindrical section 203 around which is mounted a closure washer 204. The difference in external diameter between the two sections 202, 203 defines a shoulder 206 against which abuts the closure washer 204.

The portion 201 of the element 181 'is extended at its front end by a radially oriented wall 207 extending outwards from the element 181' intended to come into direct contact via its front face against the face of 200 push of the coach. The pushing portion 174 of the lever 65 is intended to come into contact with the rear face of the wall 207. To increase the contact surface between the intermediate element 181 'and the driver 81 and consequently to reduce the local contact pressure. , the intermediate element 181 'covers, via its radial wall 207, at least 90% of the thrust surface 200 of the driver. In this case, the thrust face 200 of the driver 81 is completely covered by the radial wall 207.

At least the portion of the intermediate member 181 'in contact with the thrust wall 200 is made of a friction-resistant material. In this case, the assembly of the intermediate element 181 'is made of a plastic material filled with pre-lubricated carbon. In addition, the intermediate element 181 'is locked in rotation with respect to the control lever 65. For this purpose, as is clearly visible in FIGS. 7a, 7b, 8a, 8b and 9, the intermediate element 181' comprises at least two diametrically opposite flat surfaces 21 1 against which the internal faces of the branches 162 of the lever 65 face one another. These flattened zones 21 1 are formed in the outer periphery of the portion 201. In this case, the portion 201 of the intermediate element 181 'has four zones 21 1 flat-shaped so that the intermediate element 181' has a rectangular shape or square in front view. In a variant, the rotational locking system of the intermediate element 181 'with respect to the lever 65 is formed by grooves formed in the outer periphery of the portion 201 of the element 181' inside which the ends are positioned. branches 162 of the control lever 65.

Thus, when the lever 65 pushes the driver 81 via the radial wall 207 and the latter is rotating, in particular during a locking phase of the clutch 82, the friction is almost zero between the lever 65 and the driver 81 who have no relative movement with respect to each other. On the other hand, friction occurs between the driver 81 and the intermediate element 181 'in a contact zone referenced Zc situated between the thrust face of the driver 81 and the front face of the wall 20. the intermediate element 181 'which absorbs friction when the driver 81 is rotating and not the control lever 65 as was the case in the configuration of the state of the art described in the document FR2978500. The lever 65 is thus preserved from premature wear.

The intermediate element 181 'is held axially rearward by the closure washer 204 resting against the shoulder 206. For this purpose, the washer 204 has a generally annular shape of axial orientation having an internal diameter corresponding to the diameter external section 203 of the coach 81.

The front end of the washer 204 penetrates inside the rear end of the intermediate member 181 '. For this purpose, the rear end of the intermediate element 181 'has an annular hollow at its inner periphery allowing passage of the front end of the closure washer 204.

Furthermore, the rear end of the intermediate element 181 'bears axially against a shoulder 208 of the washer 204 situated between the portion of the washer 204 penetrating the intermediate element 181' and a radial wall 213. This wall radial called shooter 213 is the portion of the washer 204 against which comes into contact with the control lever 65 in particular to move the driver 81 relative to the reaction plate of the clutch 82 during an unlocking phase of said clutch. The groove 163 of the driver 81 inside which is mounted the lower part of the lever 65 is thus delimited by the two walls 207, 213 of transverse orientation. The section of the groove is generally U-shaped. Alternatively, the control lever 65 is adapted to come into contact with the wall 213 of the closure washer 204 via an intermediate contact piece during a movement of the driver. during a phase of unlocking the clutch. Alternatively, the intermediate element 181 'has a U-shaped section defining the groove 163, the closure washer 204 can then be devoid of the radial wall 213.

In addition, as can be seen in FIG. 2, a spring 141, here of frustoconical helical shape, bears on one of its axial ends, in this case the end of smaller diameter, against a transverse rear face. the pinion 32. This face of the pinion 32 comprises an axially oriented shoulder 321 located at the inner periphery of said pinion for centering the spring 141 on the drive pinion 32. The other axial end of the spring 141 moreover large diameter is supported on the transverse front of the plate 91. This front face of the plate 91 has a portion inclined in a direction opposite to the drive gear 32. Such inclination allows the spring 141 to maintain its mechanical properties when in a compressed state.

It is noted that the rear face of the pinion 32 has a corresponding inclination in the direction of the pinion carrier 83 so that the two faces of the plate 91 and the pinion 32 facing each other delimit a substantially frustoconical space in which can the spring 141 is housed in a compressed position. In addition, the front face of the plate 91 has at its outer periphery a shoulder 91 1 of axial orientation for the radial retention of the spring 141 when the latter is subjected to a centrifugal force. In addition, the pinion carrier 83 comprises an axial stop 142 preferably formed by a circlip mounted in a groove machined in the front end of the sleeve 100. In the rest position of the launcher 31, the spring 141 urges the pinion 32 into position. direction of the axial abutment 142. When the pinion 32 is in abutment on the ring 35 and does not penetrate into it, the spring 141 is compressed and the pinion 32 moves back towards the reaction plate 91.

The operation of the starter 30 according to the invention is described below when the launcher 31 moves from the rest position to the active position and vice versa.

In the rest position, the driver 81 being in the uncoupled position, the disks 93, 94 are not tightened so that there is an axial clearance distributed between the pressure element 92, the internal disks 93 and external 94 and the reaction plate 91. Starting from the rest position and the contactor 64 being electrically powered, the movable core 71 is attracted to the fixed core 72 until it is in a magnetized position. Its displacement simultaneously drives the movable rod 75, the movable contact 69 and the control rod 74 towards the rear.

The lever 65 moved by the movable rod 75 then acts firstly on the ring 106 of the housing 108 via the cams 175 which then move the pinion carrier 83 and the pinion 32 axially in the direction of the ring 35 along the length During this step, the driver 81 is in the uncoupled position so that the pinion 32 is free to rotate in both directions of rotation. The axial movement continues, the pinion 32 arrives in the vicinity of the ring 35.

In a second step, the pinion 32 free in rotation penetrates slightly into the crown 35. During this second step, the thrust portions of the lever 65 come into contact with the flange 188 of the support transfer piece 187 (in the embodiment of Figures 1, 2, 3a, 3b, 4a, 4b, 5a, 5b and 6) or the radial wall 207 of the intermediate member 181 'bearing against the thrust face 200 of the driver 81 (in the embodiment of Figures 7a, 7b, 8a, 8b, 9a, 9b, and 10) while the top portions of the cams 175 move away from the ring 106.

The control lever 65 thus axially moves the shoulder 92 towards the reaction plate of the clutch. With the movable core 71 bearing against the fixed core 72, the movable contact 69 makes contact between the two terminals to power the electric motor. With the electric motor 37 energized, the rotation of the drive shaft 33 drives the driver 81 to the coupled position through the helical splines 84, 85. The forward end of the driver 81 moves to the tray 91 so that the spring washer 1 15 is compressed and the clearance between the disks 93, 94 is canceled. The clutch 82 is then progressively locked for transmission of the torque of the pinion 32 to the crown 35.

According to an example not shown, the intermediate element rotates at a rotational speed between the speed of rotation of the driver and a zero speed. According to one preference, the intermediate element rotates at least three times slower than the driver. The fact that the intermediate element rotates at least three times slower makes it possible to reduce the wear of the fork which comprises a contact surface with the intermediate element which is less important than the surface in contact with the intermediate element with the driver. .

According to an example not shown, the material of the intermediate element, the fork and the driver as well as the contact surface of the intermediate element with the fork and the one with the driver are chosen so that when the pinion is coupled with the driver, the coefficient of friction is large enough that the intermediate element is stationary relative to the fork.

In the examples shown, the intermediate element in contact with the fork is locked in rotation by means of the fork, so the intermediate element in contact with the fork is stationary and does not use the fork.

Note that in the embodiment of Figures 1, 2, 3a, 3b, 4a, 4b, 5a, 5b and 6, the friction between the control lever 65 and the support transfer part 187 are almost zero when the clutch 82 is locked to the extent that the inner ring 183 of the ball bearing 181 rotatably connected with the driver 81 rotates freely relative to the support transfer member 187 kept stationary in rotation with respect to the lever order 65. In the embodiment of FIGS. 7a, 7b, 8a, 8b, 9a, 9b, and 10, the friction between the control lever 65 and the intermediate element 181 'is also virtually zero when the clutch 82 is locked in the extent to which the intermediate element 181 'in friction against the thrust face 200 of the driver 81 is stationary in rotation with respect to the control lever 65.

In the case where the pinion 32 is locked in translation in the direction of the ring gear 35 by one or more teeth of the ring gear (tooth-to-tooth position), the control lever 65 continues to move the trainer to bring the disks into contact with each other. This displacement is made possible by the compression of the spring 141 when the pinion 83 is moved relative to the pinion carrier 83. Where appropriate, the tooth against tooth spring 78 located between the movable rod 75 and the bottom of the movable core 71 may also be compressed to absorb shocks while applying a force on the lever 65 transmitted to the pinion 32 to the active position.

When the ring gear 35 rotates faster than the shaft 33 carrying the drive gear 32, the friction clutch 82 is released because the driver 81 makes an axial backward movement due to the helical connection between the 81 and the shaft 33. The coach 81 unscrews to move from the coupled position to the uncoupled position. This action is amplified by the spring washer 1 15 which relaxes and pushes the coach 81 backwards via the holding washer 1 18 resting on the end of the coach 81 which slides inside the throat 17. In addition, the return spring 80 acts to bring the movable core 71 and the control lever 65 back to their rest position, which can be seen in FIG. 1. The lever 65 thus moves the launcher 31 backwards by pushing on the shooter 194 or 213.

In case of contact between the reaction plate 91 and the end of the driver 81 during the disengaging phase, the spring washer 1 15 is protected by the retaining washer 1 18. Indeed, it is the washer of holding 1 18 linked in rotation with the reaction plate 91 which rubs against the end of the driver 81. In an alternative embodiment of the friction clutch 82, the latter comprises only a pressure element 92 and a reaction element 91 having two frustoconical surfaces of complementary shape in contact with each other. A starting torque can be transmitted to the crown when a bearing force allowing the coupling in rotation of these two surfaces will be applied by a displacement of the driver 81. In this case, the clutch 82 is devoid of intermediate friction elements located between the pressure element 92 and the reaction element 91.

Claims

1. Starter motor (30) for a motor vehicle engine comprising:

- a drive pinion (32) for meshing with a starting ring gear (35) of a heat engine,

a driver (81) mounted on a drive shaft (33),

a friction clutch (82) interposed between the driver (81) and the drive pinion (32) comprising a reaction element (91) rotatably connected to the driving pinion (32) and a pressure element ( 92) integral in rotation with the movable driver (81) with respect to the reaction element (91),

a control lever (65) comprising a portion, referred to as the pushing portion (174),

- further comprising an intermediate element (181, 181 ') mounted between the pushing portion (174) of the control lever (65) and the driver

(81),

the control lever being adapted to cause the movement of the driver (81) through an intermediate piece, to move the clutch (82) from an unlocked state in which the driver (81) and the drive pinion (32) are uncoupled in rotation relative to each other in a locked state in which the drive pinion (32) and the driver (81) are coupled with each other , and

wherein the intermediate member (181, 181 ') is arranged so that at least a portion of said intermediate member (181, 181') is in contact with the thrust portion (174) of the control lever when the control lever causes the driver to move and in that this part rotates less quickly than the driver (81) when the clutch (82) is in the locked state and the pinion is rotated.

2. Starter according to claim 1, wherein the intermediate element (181) comprises a ball bearing.

The starter according to claim 2, wherein the intermediate member comprises a bearing transfer member (187) positioned around the ball bearing (181) forming the portion in contact with the portion thrust (174) of the control lever for transferring a support from the thrust portion (174) of the control lever (65) to the ball bearing (65).

4. A starter according to claim 1, wherein the intermediate element (181 ') is in direct contact with a so-called thrust face (200) of the driver (81) constituted by a face of a shoulder of said driver (81). ) and wherein the intermediate element covers at least 90% of the thrust face (200) of the driver (81).

6. Starter according to claim 4 or 5, wherein at least the portion of the intermediate member (181 ') in contact with the thrust face.

(200) of the driver (81) is made of a friction-resistant material.

7. Starter according to claim 6, wherein the intermediate element (181 ') is made of a plastic material filled with pre-lubricated carbon.

8. Starter according to one of claims 1 to 7, wherein the intermediate member (181 ') in contact with the control lever (65) is locked in rotation relative to said control lever (65).

Starter according to claim 8, wherein the control lever (65) comprises two branches (162) each having a thrust portion (174) positioned in diametrically opposite flattened zones (21 1) formed in the intermediate element (181 ').

10. Starter according to one of claims 1 to 9, wherein a closure washer (192, 204) is positioned on the driver (81) for an axial retention of the intermediate member (181, 181 ').

1 1. Starter according to claim 10, wherein the control lever (65) is adapted to come into direct contact with the closure washer (192, 204) during a movement of the driver (81) during a phase releasing the clutch (82).

12. Starter according to claim 10, wherein the control lever (65) is adapted to come into contact with the closure washer (192, 204) via an intermediate contact piece during a movement of the driver (81). ) during an unlocking phase of the clutch. The starter according to one of claims 1 to 12, wherein the clutch (82) further comprises friction discs (93, 94) positioned between the reaction element (91) and the pressure element ( 92).

Starter according to one of claims 1 to 13, wherein the drive pinion (32) is slidably mounted on a pinion carrier (83) having a sleeve (100) with the drive pinion (32), a transverse plate (91) issuing from an end of the sleeve (100) and an annular skirt (105) of axial orientation extending from an outer periphery of the transverse plate (91).

15. A starter according to claim 14, wherein a spring (141) is mounted in support on the one hand against one side of the transverse plate (91) of the pinion carrier and on the other hand against one face of the drive pinion ( 32).