WO2012085419A1

WO2012085419A1 - Permanent-mesh starter equipped with a system for coupling the drive wheel to the rotor of the starter motor

Info

Publication number: WO2012085419A1
Application number: PCT/FR2011/053038
Authority: WO
Inventors: Jean-Sébastien Metral
Original assignee: Valeo Equipements Electriques Moteur
Priority date: 2010-12-21
Filing date: 2011-12-16
Publication date: 2012-06-28
Also published as: FR2969221B1; EP2655861A1; FR2969221A1

Abstract

The invention relates to a permanent-mesh starter motor (1) for an internal combustion engine, notably of a motor vehicle, comprising a cylinder head (3), an electric motor (14), a drive wheel assembly, an epicyclic reduction gearbox (130). The drive wheel assembly comprises a drive wheel (11) able to rotate about its axis and mounted on a drive shaft (111). The epicyclic reduction gearbox (130) comprises two coaxial shafts known as planetary shafts, a first of which forms a sun gear (131) connected to the shaft of the rotor (145), and the second of which forms an annulus gear (133), at least one planet pinion (135) between the two planetaries and a planet carrier (137) coupled in rotation to the drive shaft (111). The starter further comprises a moving part (55) designed to act on the annulus gear (133) to move it from an uncoupled state in which the annulus gear (133) is free to turn with respect to the cylinder head (3) into a coupled state in which the annulus gear (133) is secured in terms of rotation to the cylinder head (3) at least in the direction that opposes the start-up torque.

Description

PERMANENT GEAR STARTER EQUIPPED WITH A COUPLING SYSTEM OF THE ROTOR DRIVE WHEEL

ENGINE OF THE STARTER.

Field of the invention

The invention relates to a permanently meshing starter, in particular a motor vehicle heat engine, equipped with a coupling system for coupling a drive wheel assembly intended to be connected to the crankshaft of the heat engine to the electric motor of the starter.

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 a driven wheel (crown or toothed wheel). For this purpose, the starter comprises a drive wheel rotatably connected to a force transmission line, for example by means of a drive shaft rotated by a rotor of an electric motor. This drive wheel is provided with teeth that can be engaged with teeth of the ring gear or toothed wheel.

The invention finds a particularly advantageous application for vehicles equipped with the function called "stop &star" (described below) equipped with permanently meshing starters. By permanently interlocking starters are meant starters having their drive wheel stationary in translation relative to the starter casing. In other words, once the starter is coupled with the heat engine, the drive wheel remains meshing with the gear or crown coupled to the engine. Unlike the starter starter, the permanently meshing starters have no gear steps of the drive wheel with the gear wheel. In other words, the gear of the meshing starters does not move in translation unlike the starter starter whose pinion moves between a first position geared with the gearwheel connected to the crankshaft of the engine and a second position disengaged therewith. These launcher starters have difficulties in gearing the pinion with the gear wheel to restart a motor in the swinging phase. Indeed, there is a risk of wear, by milling, the pinion or the gear when the latter rotates in the opposite direction.

State of the art

It is known that a motor vehicle, especially when used in the city, consumes energy even when it is stopped as a result of traffic, since its (thermal) propulsion engine continues to run continuously. So we thought of vehicles with a function called "stop & star" that stops the engine, when the vehicle is stopped due to traffic conditions. This type of operation requires very frequent starts, which causes drawbacks, especially at the link between the engine and the electric motor of the starter, explained below in the description.

When the heat engine is about to stop, there may be a phase called "swing phase" where the crankshaft can rotate in the opposite direction, also called in the following "reverse rotation" during a descent d one or more pistons engage the crankshaft in reverse rotation. This balancing phase pauses mechanical problems for the starter.

Indeed, during this swinging phase, the toothed wheel or belt drives the drive wheel of the starter permanently meshing, in the opposite direction. This rotation in the opposite direction of the drive wheel, as well as the reverse torque from the motor, are undesirably transmitted to the starter by driving the armature (rotor collector) of the electric motor. This reverse rotation of the motor armature causes a decrease in the life of the brushes of the electric motor of the starter or a mechanical rupture of the armature.

Patent FR2896828 A discloses a permanently meshing starter to avoid this disadvantage. This document describes a meshing starter permanent having a freewheel anti-rotation in opposite direction (called unidirectional clutch) located on the armature shaft (rotor and collector). This free wheel comprises an outer frame and an inner frame, the outer part is integral with the starter casing and the inner part is integral with the motor shaft. The freewheel includes a cam member moving between the two parts to prevent the inner portion (the motor shaft) from rotating when the reverse torque is transmitted to the freewheel.

This document further discloses that the starter comprises a gear reduction gear installed on the transmission line between the drive wheel and the freewheel anti-rotation in the opposite direction. This reduction gear comprises a sun wheel formed at the end of the armature shaft, a crown and satellites. The satellites are connected to an output shaft connected to the pinion. The gearbox works by having the crown not rotating and the satellites rotating both around the sunwheel less than the latter and at the same time each around their axis. Thus, the gearbox reduces the rotational speed of the output shaft relative to the armature shaft. The starter further comprises a torque limiter between the crown and the cylinder head. This torque limiter allows rotation of the crown when a torque exceeds a predetermined holding torque to block the transmission of excess torque to the electric motor. However, these starters have several disadvantages.

A first disadvantage is the wear and / or oversizing of certain parts in the transmission line between the starter rotor and the crankshaft. This wear or oversizing is due to mechanical stresses, during the swing phase. Indeed, all the members allowing the transmission of rotation between the crankshaft and the freewheel, are subjected to very significant mechanical stress due to the resistant torque in particular applied by the heat engine on the freewheel and then on the torque limiter.

Resilient torque means friction forces against rotation. In addition, this resistant torque can be multiplied by the speed reducer. Another disadvantage and that the torque limiter may wear quickly due to the number of swing phase with a system having a type of function called "stop &star". The wear of the torque limiter causes a decrease in the value of its holding torque. Thus, in the case where the holding torque becomes less than the sufficient torque to start the heat engine, the ring rotates during the starting phase preventing the motor from transmitting its torque to the heat engine, in this case through its drive wheel. This wear therefore prevents the starter from starting the engine. Another disadvantage is that the free wheel may deteriorate, causing during the swinging phase, the reverse rotation of the rotor shaft and therefore a risk of premature wear, or even the destruction of the brushes feeding the rotor.

FR2858366 A1 discloses a pulley starter adapted to be connected to a belt for a motor vehicle engine. This starter comprises an electric motor having an armature shaft driving a drive shaft in rotation by means of two rear and front planetary gear units connected in series (also called cascade), such that their reduction rate multiplies and that the reduction is from the armature shaft to the drive shaft. The forward end of the drive shaft not connected to the gearbox is rotatably received, with radial interposition of a series of rolling needles, in a terminal bore of a so-called front end of the starter yoke. The starter further comprises a pulley idly rotatably mounted on the drive shaft between the reducer and the front end with a pair of bearings in between. The starter further comprises a roller having a convex profile facing a convex profile of the pulley. The roller has internal helical splines mounted on a portion of the drive shaft having corresponding splines. The roller is movable in translation along its axis between a disengaged position and coupled with the pulley having their frustoconical faces in contact. This roller advances from the uncoupled position to the coupled position when the starter starts through the splines. The starter further comprises a disk perpendicular to the axis of the drive shaft fixed to the roller and comprises on its peripheral portion a surface capable of cooperating with a wall of the cylinder head. The disk is arranged to deform elastically in the coupled position in order to exert an elastic force of axial return of the roller to the uncoupled position so that it returns to this position when the electric motor no longer rotates.

However in the coupled position, the disc rubs against the wall of the cylinder head braking the roller. Thus, there is rapid wear of the disk against this wall and a significant mechanical loss.

There is therefore a need for a permanent meshing starter which does not undergo premature wear during a swing phase.

Object of the invention

In order to improve the performance of the starters, the invention proposes a combustion engine permanent meshing starter, in particular a motor vehicle, comprising a cylinder head and an electric motor in the cylinder head. The motor comprises a rotor mounted on a rotor shaft and a stator around the rotor. The starter further comprises a drive wheel assembly comprising a drive wheel rotatable about its axis, and a drive shaft on which the wheel is integral. The starter further comprises an epicyclic reduction gearbox dynamically connecting the rotor shaft and the drive wheel assembly. The reducer comprises two so-called planetary coaxial shafts, one of which forms a sun gear connected to the motor shaft, and the second forms a ring gear. The crown can be secured and disengaged in rotation with the cylinder head. The reducer further comprises at least one satellite between the two sun wheels and a satellite door coupled in rotation with the drive shaft. The starter further comprises a movable member acting on the ring gear to move it from a disengaged state, in which the ring gear is free to rotate with respect to the bolt in a coupled state in which the ring is secured to the bolt at least in the meaning opposing the start torque. The movable member is movable in translation between a rest position and an active position.

Preferably, in the rest position of the movable member, the ring is in the uncoupled state and in the active position of the movable member, the ring is in the coupled state.

The starter is arranged so that in its rest state the electric motor does not rotate and the movable member is in the rest position and in the active position, when the electric motor rotates, the movable member is in the rest position . Thus, when the crown is rotatably mounted relative to the cylinder head for example in the idle state (that is to say when the starter is not in operation), when the drive wheel rotates, because the much less resistant torque at the ring gear than that of the sun gear assembly, rotor shaft, rotor, commutator, the drive wheel rotates the crown through the satellites and not the sun wheel. Thus, during the swinging phase, the drive wheel does not cause the armature of the motor to rotate in opposite directions.

Thus, there is no wear of the rotor shaft, collector and ballais during swing phase, since the rotor shaft (thus also the collector) is not rotated in the opposite direction.

In the coupled state, that is to say when the ring is secured to the cylinder head, the electric motor transmits its torque to the drive wheel through the reducer as in the prior art. An advantage of this starter is that the force (torque) required to immobilize the crown relative to the cylinder head is much less than the force exerted between the roller and the drive shaft or the roller and the pulley of the art previous because of the larger diameter of the crown than the roller. Thus, the torque required to secure the crown to the cylinder head, requires less mechanical torque than that to secure the roller and the pulley of the prior art. In addition, this allows to have much less wear, see no wear between the device for returning the crown to the initial state, that is to say in the uncoupled state, and the crown unlike the prior art.

The drive wheel assembly is therefore free to rotate in both directions with respect to the rotor shaft when the ring is in the idle state, also called initial and uncoupled, and can be rotated by the motor by operation when the crown is in the coupled state.

According to one embodiment, the movable member is a fork, and the starter further comprises an actuator, including a switch adapted to actuate the fork to activate and deactivate the clutch device. Activate is meant to move the range of its rest position to its active position.

Preferably, the contactor further comprises a return means for moving the range of its active position to the rest position when the contactor is no longer electrically powered. According to one embodiment, the starter is arranged to move the fork in the activated position before closing a power contact to transmit the electrical energy necessary for the electric motor for starting.

This embodiment has the advantage of controlling the operation of the starter by controlling in stages the starting of the engine at the same time as the coupling. The advantage is that there is no torque limiter that will dissipate the energy stored by the crankshaft in reverse rotation and therefore less wear.

According to one embodiment, the starter comprises a clutch device friction between the ring and the cylinder head, the movable member being arranged to be able to activate and deactivate the clutch device for respectively coupling and uncoupling the ring with the cylinder head.

According to an example, the movable member activates the clutch device when the movable member moves from the rest position to the rest position and deactivates the clutch device when the movable member moves from its active position to its rest position.

Thus, the use of a friction clutch can mitigate possible jolts during startup or mating. In addition, because of the large diameter of the ring relative to the other parts of the force transmission line, the friction surface is larger than these parts. Having more friction surface makes it possible to increase the maximum slip-resistant torque for a predetermined compressive force. Thus, this type of starter has the advantage of not needing a large compression of the friction surfaces of the friction clutch device.

According to one embodiment, the friction clutch is disks comprising at least one inner disk rotatably integral with the ring and at least one outer disk facing the inner disk and integral in rotation with the cylinder head and in which to Coupled state the discs are compressed against each other such that the slip start torque is greater than the maximum torque of the electric motor at the ring for starting a heat engine.

This embodiment makes it possible to increase the total friction surface. According to another embodiment, the friction clutch device is conical clutch, wherein the ring comprises a frustoconical first friction surface and the cylinder head or a piece integral with the cylinder head comprises a second friction surface form frustoconical complementary vis-à-vis the first friction surface. This embodiment makes it possible to be simpler due to the smaller number of rooms.

According to one embodiment, the movable member is arranged for the active position, press the crown against the clutch device to activate it and for when it moves from the rest position to the rest position decompress the crown to deactivate the clutch. Thus, the crown acts directly on the clutch and it is not necessary to add a part. The size is thus reduced.

According to another embodiment, the movable member is arranged to move a member integral in rotation with the cylinder head, against the ring gear by means of the clutch device to activate it and move the member to deactivate the clutch.

In one example, the movable member moves the integral member against the crown as it moves from the idle state to the active position and disengages the clutch as it moves from the active position to the home position. This embodiment makes it possible to have a static crown in translation along its axis, in contrast to the case where it is moved, which makes it possible to have less wear but also less power because the effort will not position itself directly against the couple.

According to one embodiment, the movable member activates the clutch by acting directly on the clutch device. In this embodiment, the movable member is integral in rotation with the yoke and comprises a friction surface facing the friction surface of the crown. This embodiment also makes it possible to have a static crown in translation along its axis. In one example, the movable member activates the clutch as it moves from the idle state to the active position and disengages the clutch as it moves from the active position to the home position.

According to another embodiment, the movable member is the sun wheel which displaces the ring gear and the at least one planet of the epicyclic reduction gear while moving.

According to an example of this embodiment, the sun gear comprises internal helical splines corresponding to external splines on the rotor shaft for moving the epicyclic reduction gear with respect to the rotor shaft from an initial position (not engaged) to a final position (engaged). According to an example of this embodiment, the starter further comprises a spring between the ring and the cylinder head to move the reducer to its initial position (uncoupled).

According to another example of this embodiment, the spring is placed between the epicyclic reduction gear and a member on the transmission line between the gearbox and the drive wheel.

This embodiment has the advantage of being less bulky. Indeed, in this embodiment, it is not necessary to have a switch to move the movable member from its rest position to its active position.

Thus, the electric motor and the helical splines provide the actuator function to move the movable member from its initial (deactivated) position to its final (activated) position and the spring provides the actuator function to move the movable member. from its active position, also called final, to its so-called initial resting position.

According to another embodiment, the movable member is arranged to move from its initial position to its final position towards the ring so as to form in the final position an antirotation stop at least in a direction of rotation of the ring relative to the breech and in initial position to release the rotating crown

According to an example of the embodiment, the ring comprises lugs on one side intended to cooperate with the movable member to form the stop.

According to another embodiment, the lugs are ratchet-shaped.

According to another embodiment, the movable member moves a member of the epicyclic reduction gear to move its crown.

According to one embodiment, the ring is mounted directly pivotally relative to the cylinder head.

According to another embodiment, the ring is pivotally mounted relative to the cylinder head by means of a bearing or other part.

According to one embodiment, the drive wheel is a pinion. According to one embodiment, the drive wheel is a pulley.

The invention further relates to a vehicle comprising a starter described above.

The drive wheel is intended to be coupled with a driven wheel coupled to a heat engine.

More specifically, the drive wheel may be a pinion or a pulley, adapted to rotate a crankshaft of a combustion engine including vehicle respectively through a toothed wheel or a belt coupled in rotation to the crankshaft . By "drive wheel assembly" is meant the drive wheel and all the members coupled in rotation (at least in one direction) with the drive wheel regardless of the state of the crown.

By "power transmission line of the engine" is meant in the application, all the members coupled in rotation with the rotor shaft of the starter motor to transmit a torque to the drive wheel whatever the state of the coupling system.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it.

BRIEF DESCRIPTION OF THE DRAWINGS These figures are given for illustrative purposes only but in no way limitative of the invention. They show: Figure 1a shows a side view of the principle (perpendicular to the X axis) of a starter according to an example of the invention; Figure 1b shows a side view of a section of a part of a starter of the type of Figure 1 has at rest; Figure 1c shows a side view of a section of a portion of the starter of Figure 1b in the active state; Figure 1d shows a front view (along the x-axis) in section of the starter of Figure 1b according to section BB of Figure 1a; Figure 1 e shows a sectional view of a starter detailed contactor according to the first example; Figure 2 shows a sectional view of a starter according to a second example;

Description of embodiments of the invention

Identical, similar or analogous elements of an example of an embodiment retain the same references from one figure to another. Figure 1A shows a side view of a starter 1 according to an example of the invention.

The starter 1 comprises a cylinder head 3 and a contactor 5 on the cylinder head 3. The starter further comprises a front flange 7 and a rear flange 9 mounted respectively on the front and the rear of the cylinder head 3. The flanges may also be monobloc with the cylinder head 3 but are preferably removable to access the interior of the starter. The front flange 7 comprises an opening 71 in which we can see the drive wheel 1 1 starter 1.

Figure 2 shows another embodiment of a starter without the front flange 7. The front of the starter is then the drive wheel.

In the remainder of the description, the front face of a workpiece means the face facing the front end of the starter (the front flange in the case of Figure 1 or the drive wheel in the case of Figure 2) and the back side means the face of the part facing the other end of the starter (rear flange) in the direction of the X axis of the drive wheel.

The drive wheel 1 1 may be a pulley or in this case a toothed wheel. The drive wheel January 1 is mounted on a drive shaft January 1 shown dashed in Figure 1a and more clearly in Figures 1b and 1c.

The elements, devices or systems shown in dashed lines in Figure 1 are inside the cylinder head and are shown schematically.

The drive wheel 1 1 and drive shaft 1 1 1 are part of an integral assembly hereinafter referred to as the drive wheel assembly. This drive shaft 1 1 1 is rotatably mounted relative to the yoke 3 through a front bearing 73 (shown in Figures 1b and 1c), in this case a roller bearing. This front bearing 73 is mounted on a support piece 75 fixed to the front flange 7.

The support piece 75 is, in this case, a part of the yoke 3 entering inside the front flange 7 and surrounding the drive shaft 1 January. The drive shaft is carried by means of a bearing, in this case roller by this part 75, the latter carrying the drive wheel.

The starter further comprises a reducing system 13 shown in dotted line in FIG. The reducing system is described below in the following description. The starter further comprises an electric motor 14 comprising a rotor 141, a stator 143 surrounding the rotor 141. The rotor 141 is mounted on a rotor shaft 145 whose one end is mounted in a bearing 91, said rear bearing. The rear bearing 91 is in this case a ball bearing. This rear bearing 91 is mounted in the flange 9 of the starter 1. The electric motor further comprises on its rotor shaft 145 between the rear bearing 91 and the rotor 141 a manifold 147. On this collector 147 is mounted brushes 149, in this case two brushes 149a and 149b in two doors ballais to provide the current to the rotor. It could include more than 2 like 4, 6, 8 or 10 brooms. At least one of the brushes is electrically connected to an electrical terminal 21a of the contactor 5, for example via a wire and the other brush is connected to the mass, for example to the carcass (shown schematically in Figure 1a). The brushes 149a and 149b rub against the collector 147 when the rotor 141 is rotated to feed the rotor.

The contactor 5 of the starter 1 comprises in addition to the terminal 21a connected to the brush 149a, a terminal 21b intended to be connected via an electrical connection element to a positive power supply V + of the vehicle, in particular a battery, not shown. Figures 1a, 1b, 1c, 1d and 2 show the contactor in a simplified and incomplete manner. The contactor 5 is a contactor that can be identical to that of the starters described above. Figure 1 e represents only a contactor 5 more fully. A normally open contact (not shown) located between a terminal V + of the power supply and the terminal 21b controls the power supply of the contactor 5 to start the electric motor.

The contactor 5 comprises a contact plate 53 (shown in Figure 1 e) movable to electrically connect the terminals 21b and 21a to supply the electric motor. The switch 5 is also able to actuate a movable member, in this case a range 55, between a deactivated position also called rest position and an activated position also called active position. The contactor 5 also comprises a movable core 57 from a rest position to a final position, a fixed coil 59 (shown in FIG. 6) and a movable control rod 61.

The control rod 61 has its front end fixed to the movable core 57 and its rear end connected to the contact plate 53. The contactor 5 comprises a contact spring 610 compressed between the contact plate 53 and a shoulder of the control rod 61. This contact spring 610 makes it possible to ensure the displacement of the movable core 57 to its rest position after the contact plate 53 comes into contact with the terminals 21b and 21a in order to connect them electrically. The switch 5 further comprises a return spring 571. This return spring 571 makes it possible to return the mobile core 57 to its rest position when the coil is no longer powered. The operating principle is explained below in the description. The fork 55 (visible in Figures 1b and 1c) has its upper end connected to a rod 572 (visible in Figure 1 e) by pivot connection. In Figures 1b and 1c, the connection between the rod 573 and the fork 55 is not shown. The rod 572 is mounted in the movable core 57. In the contactor 5 shown in FIG. 1e, the control rod 572 is connected to the movable core 57 by means of a magnetic bonding spring 573. This magnetic bonding spring 573 allows to ensure the magnetic bonding of the movable core 57 in the final position after coupling the crown to the cylinder head 3.

The fork 55 at its other fork-shaped lower end (visible in Figure 1 d), connected to a pusher plate 551 by pivot connection. The pusher plate 551 is visible, in particular in Figure 1 d. Each of the two teeth of the fork comprises two lugs 553a, 553b forming a pivot connection with the push plate 551. Between these two ends, the fork 55 is pressed against a fixed portion of the yoke 3 to form a lever. Between these two ends, the fork 55 is pressed against a fixed portion of the yoke 3 to form a lever.

According to an example not shown, the rod 572, the movable core 57 and the control rod 61 are fixed together (in this case, the rod 572 and the control rod are monobloc). In this case, it is necessary a resilient means of magnetic bonding, allowing magnetic bonding of the movable core 57 in its final position after moving the fork 55 in the activated position. For example, the magnetic bonding spring 573 may be located between the lower end of the fork 55 and the push plate 551. In another example, the fork 55 may be arranged to deform elastically ensuring the function of the magnetic bonding spring 573.

When the coil 59 is electrically powered, for example by means of a contact or switch controlled externally of the starter, the movable core 57 is drawn back to the final position. Its movement simultaneously drives the control rod 61, the rod 572, the contact plate 51 towards the rear and the upper end of the fork 55 to move the push plate 551 forward. Moving the movable core 57 rearward electrically connects, at first, the terminals 21a and 21b to supply the electric motor through the contact plate 51 and in a second step positions the upper end of the fork 55 in the activated position and finally in a third time the positioning of the movable core 57 in the final position (magnetic bonding).

The fork 55 is arranged so that the displacement of its upper end backward moves its lower end forward thus moving the pusher plate 551 to the drive wheel January 1. The range 55 therefore moves from its deactivated position to its activated position respectively when the coil is supplied with electricity and vice versa when it is no longer powered. The reducing system 13 comprises at least one epicyclic reduction gear 130 comprising two so-called planetary coaxial shafts. A first sun gear is a sun gear 131 secured to the rotor shaft 145. In this case, the sun gear 131 and the rotor shaft 145 are in one piece. The second sun gear forms a ring 133 serrated on its inner periphery. It furthermore comprises at least one satellite 135 engrained in the two planetaries, in this case three stellites, two of which are only visible in FIGS. 1b and 1c, numbered 1351 and 1352. FIGS. 1b, 1c, 1d represent schematically the reducing system 13.

Each satellite 135 is coupled through a pivot link with a satellite gate 137. This pivot link allows the satellite to rotate around its own axis. The satellites 135 are engrained in both the crown and the sun wheel. The satellites 135 turn on the one hand each around their axis and on the other hand around their axes in common corresponding to the axis X of the rotor shaft 145, of the sun gear 131. The displacement of the satellites 135 rotates the satellite gate 137 along its axis X in rotation. The satellite gate 137 comprises a hole along its housing axis X to accommodate the end of the shaft of the sun gear 131 in order to carry each other. The satellite gate 137 and the front end of the shaft of the sun wheel 131 have a pivot connection through a bearing, in this case a roller. The starter shown comprises two epicyclic reducers, but could include one or more, for example 3 or 4. The reduction ratio of the first satellite carrier on the sun wheel can be understood between 1/2 and 1/10, and the total ratio of the two reducers between 1/9 to 1/64. In the starter shown, the ratio is 1/20.

The ring 133 is closed at least partly on a lateral side, in this case the rear side (the face), by the push plate 551. That is to say that the push plate 551 closes part of the space between the crown and the sun wheel 131 in which the satellites are mounted. Preferably, and as shown in FIG. 1 d, the pusher plate 551 closes the entire portion of this opening in order to prevent the grease between the ring gear and the sun gear from coming out of the reducer. The pusher plate 551 is mounted in translation on the rotor shaft 147 or the sun gear 131.

The crown 133 comprises at its other lateral side, a front side portion 1331 forming a cap, closing the other end of the opening to also prevent the fat from coming out. This lateral portion comprises a first shoulder 1335 surrounding the satellite door 137. Preferably, a bearing, in this case needle, is disposed between the satellite door 137 and the shoulder 1335 of the crown 133. This shoulder 1335 on the door satellite makes it possible to wear the crown 133. According to another embodiment, the ring 133 is directly carried by the cylinder head, with a radial clearance included in the range 0 and 1 mm, excluding the terminal or by means of a bearing, to allow the crown 133 to rotate relative to the cylinder head 3.

The front lateral portion 1331 comprises a second shoulder 1333 extending forwardly of the starter 1. This second shoulder 1333 could be the same as the first shoulder 1335. Having two shoulders makes it possible to lighten the starter and can allow to use less material. The starter further comprises on this shoulder 1333, a friction clutch, in this case disks. The clutch thus comprises discs 139, translating along the X axis. Part of the discs 139 are internal discs 139A and the other part of the discs are external discs 139B. The internal disks 139A and external disks 139B are respectively mounted on the outer periphery of the shoulder 1333 and in the inner periphery of a part integral with the cylinder head 3. In this case, the external disks 139B are mounted on the inner periphery of the the breech 3. In this case, the number of internal disks 139A is three and the number of external disks 139B is three. They are mounted alternately, that is to say that the two friction faces of an inner disc 139A placed between two discs are each opposite a friction face of an adjacent outer disc 139B. The internal disks 139A has a through opening between its two largest faces whose inner periphery substantially corresponds to the outer periphery of the shoulder 1333. The internal disks 139A are arranged to be integral in rotation with the shoulder 1333 and therefore the and are arranged to translate on the surface or surfaces forming the outer periphery of the shoulder 1333.

The external discs 139B comprise an outer periphery substantially corresponding to the inner periphery of the integral part of the cylinder head, in this case the cylinder head. The external disks 139B are arranged to be integral in rotation with the yoke 3 and to translate on an inner peripheral surface of the yoke 3 partially surrounding the shoulder 1333.

Each inner disk 139A and outer 139B comprises, for example lugs respectively on its inner and outer periphery corresponding to a notch respectively on the shoulder 1333 and the yoke 3. These notches extend along the axis X.

These lugs and notches make it possible to ensure the function of making the inner and outer disks respectively of the crown and the yoke integral in rotation, but also of their translations with respect to the crown and the yoke respectively along the X axis. , according to other embodiments, the lugs may also be on the cylinder head or shoulder of the crown and the notches on the discs. The first disc (front disc) at its front face vis-à-vis a friction face integral with rotation of the cylinder head 3. In this case, the first disc is an outer disc 139B having its front friction face against a rear side face of a second fixed ring 133B, integral in rotation with the yoke 3, a second epicyclic reduction gear 130B described below. According to another example, not shown, the face vis-à-vis the front face of the first disc could be the rear face of an internal radial shoulder of the yoke 3.

The discs 139 are made of a friction material, such as bronze and steel, which makes it possible to provide a friction-resistant torque (predetermined torque) between the yoke 3 and the crown 133, when the latter is compressed against the discs (compression predetermined). In the coupled state, the starter is arranged so that the discs 139 are compressed against each other such that the slip start torque is greater than the maximum torque transmitted from the electric motor 14 to the ring gear 133 for starting the engine. desired. By slip starting torque is meant the torque necessary to make a slip (a rotation) between the internal and external disks.

The clutch operates as follows: As the fork 55 moves from the deactivated position to the activated position, the push plate 551 pushes the crown 133 forward to compress it against one of the disks 139 (the last disk 139B) compressing simultaneously 139A internal disks and external 139B sets and the first disk with the fixed ring 133B of the second reducer 130B. The ring 133 is thus arranged to translate relative to the satellites 135. The translation distance is between 1 micrometer and 5mm. The serrations of the crown 133 and satellites 135 are arranged for proper operation. The compression of the discs 139 rotates the crown 133 to the yoke 3. When the yoke 55 is deactivated, it moves the pusher plate 551 rearwards, which displaces the crown 133 backwards decompressing the discs 139. Thus the ring 133 is uncoupled in rotation from the cylinder head 3. The second epicyclic gearbox 130B is identical to the first gearbox except for the elements described below. Its sun gear 131 B is secured to the satellite gate 137 of the first reducer. Its crown 133B is fixed to the yoke 3. Its satellite door 137B is coupled in rotation with the drive shaft January 1. The opening between the ring 133B and the sun gear 131 B is closed on each radial side.

Of course, according to an example not shown, the second reducer may be absent. The satellite gate 137 of the first gearbox can thus be directly coupled with the drive shaft January 1. According to another example not shown, it is the second gearbox 130B which is arranged to be able to go from a coupled state to a state uncoupled with the cylinder head 3.

According to another example not shown, the pusher plate 551 pushes all the epicyclic reduction gear 130. The sun gear 131 and the satellite gate 137 are each arranged to be able to translate along the X axis with respect to the rotating shaft integral with the solar wheel, in this case the drive shaft and the rotating shaft integral with the satellite gate 137, in this case the sun gear 131 B of the second gear 130B. For example, the sun gear 131 has a lug nested in a corresponding groove on the outer periphery of the rotor shaft 145, extending along the axis X. Of course, the groove may be on the sun gear 131 and the lug on the rotor shaft 145. In the same way, the satellite holder 137 may comprise a lug or a groove fit respectively with a groove or a lug of the coupled shaft, for example the sun gear 131 B of the second gear 130B.

Translating all the gearbox 130 makes it possible to eliminate the problems of translation of the crown 13 relative to the satellites 135.

According to another example not shown, the fork 55 is replaced by a movable member arranged to move from a so-called initial deactivated position to a so-called final activated position towards the crown 133 and forms in final position an antirotation stop at least in a direction of rotation of the ring 133 relative to the cylinder head 3. In the initial position, the movable member is not in contact with the ring 133, thus leaving it free to rotate.

Thus in this embodiment, the starter no longer has disks. The crown 133 therefore no longer needs the second shoulder and no need for a pusher plate. This makes it possible to reduce the axial distance of the starter but also to use a conventional crown. In addition, it reduces the power required for the clutch. Indeed, according to this embodiment, the effort required to engage does not position itself directly against the couple.

The movable member can move from its initial position to its final position perpendicular to the X axis to be in contact with the crown or move as in the example shown in the figures, that is to say say a movement like a lever. According to an example, the ring may comprise one or lugs intended to cooperate with the movable member (for example a finger moving toward the lug) to prevent rotation of the ring. For example, the lugs may be on the radial side, for example the rear side of the ring, so as to cooperate with the movable member to stop the rotation of the ring at least in the opposite direction of the start.

In one example, the lug may have a sawtooth shape including a sloping surface and a stop surface. The lugs and the movable member function as a pawl when the movable member is in the activated position. In this case, the saw tooth of the lug is oriented such that the slope of the sawtooth is arranged to let the crown rotate in the opposite direction of starting and the abutment surface of the lug is arranged to retain the crown in the starting rotation direction of the electric motor. In this example, the movable member is always controlled by an actuator, such as for example the contactor. Thus the ring is always free to rotate in both directions of rotation when the movable member is in the deactivated position. This embodiment has the advantage that the crown with the movable member operates as an overspeed freewheel between the crankshaft and the engine. Indeed, in overspeed, when the movable member is in the activated position, the heat engine drives the ring in rotation such that the slope of the sawtooth moves the movable member to its deactivated position by acting on the magnetic glue spring.

In another example, the ring comprises one or more notches on its outer cylindrical periphery. The movable member is arranged to enter the orifice to prevent rotation of the ring. The contact between the ring and the movable member can be carried out initially by friction, then by blocking when the movable member cooperates with the pin or notch.

The movable member may also be the fork shown in the figures.

Below will now be described the principle of operation of the starter shown in the figures.

According to an operating principle, the starter is in the idle state, that is to say the range 55 in the deactivated state, the ring 133 in the uncoupled state, the mobile core 57 not attracted. In this state of rest, the rotation of the drive wheel 1 1, for example due to the motor in swinging phase, simultaneously drives in rotation the drive shaft 1 1, the satellite carrier 137B, the satellites 135B and the wheel solar 131 B of the second epicyclic reduction gear, the satellite carrier 137 and the ring gear 133 of the first epicyclic reduction gear 130. The sun gear 131 does not rotate because its resistant rotation torque is greater than the torque of the ring gear 133. During the starting, the contactor 5 is first fed, which feeds the coil 59. The coil creates a magnetic field attracting the movable core 57 towards the rear of the starter.

The displacement of the movable core displaces the movable member, in this case the fork 55, pulling its high end towards the rear which simultaneously moves the ring 133 towards the discs 139. During the movement of the ring 133 to its coupled state, the contact plate 53 comes into contact with two terminals for the passage of electricity to power the brushes of the electric motor. The contact plate 53 slides along the control rod 61 and compresses the spring 610 until the ring 133 arrives in the coupled state.

The coil 59 still attracts the movable core 57 by magnetization, which pulls the fork 55 and which by leverage compresses the ring gear 133 of the first gearbox 130 and the discs 139 against the other ring 133B. The electric motor being electrically powered, rotates the drive wheel, which can rotate the crankshaft of the engine by means of other organ such as a belt.

The fact of supplying the motor before the ring gear 133 is coupled makes it possible to prevent the opposite rotation (opposite direction to the starting) of the rotor 14. Moreover, this operating mode makes it possible to have a quick start and allows to interrupt a balancing phase of the heat engine smoothly. Indeed, during the phase where the electric motor rotates and the crown is not in the coupled state, the crown rotates and the drive wheel continues to rotate in the other direction, during the compression phase, the crown an increasing resistance torque that can gradually slow the reverse rotation and smoothly transmit the torque of the electric motor to the drive wheel.

According to another example of operation, the starter is arranged to put the crown in the coupled state before starting the electric motor. Coupling the crown while it is not rotating reduces its torque to move from the disengaged state to the engaged state. Thus, it reduces the power required for the movable member to couple the crown to the cylinder head. In addition it avoids premature wear of the discs. In fact, the fact of coupling the disks while the internal disks are not rotated by the electric motor makes it possible to reduce the friction during the clutch between the internal and external disks. In another example, the starter comprises a means other than the contactor and the fork to pass the ring from the uncoupled state to the coupled state. For example, the starter may comprise a magnetic coil attracting the ring, in this case forming the movable member, to the coupled state when it is powered. A spring can then be arranged to replace the crown in the uncoupled state when the coil is no longer powered.

In another example of a starter with a friction clutch, the starter has no fork and contactor. The movable member is the solar wheel of the epicyclic reduction gear, which comprises internal helical splines corresponding to external splines on the rotor shaft for moving the epicyclic reduction gear with respect to the rotor shaft from an initial position (uncoupled) at an end position (coupled) when the electric motor is powered. The starter further includes a spring between the ring gear and the cylinder head to move the gearbox to its uncoupled position. In this embodiment, it is preferable that the mobile epicyclic reduction gearbox is the second epicyclic reduction gear in order to have more torque and therefore greater thrust for the same spline angle. This spring has of course a low enough strength not to prevent the friction clutch from operating when the sun gear is advancing through the rotation of the rotor. This starter is advantageous over the starter described in the patent FR2858366 A1 described in the prior art of the description, because unlike the starter of the prior art, in the coupled state, that is to say when a start, the ring being stationary relative to the cylinder head, there is no loss of friction between the spring and the cylinder head. In the uncoupled state, there is no friction or negligible friction between the spring and the cylinder head and / or the crown, because the spring is not compressed. Preferably, the spring is fixed to the cylinder head and is sliding relative to the ring in the uncoupled position. Thus, the spring does not rotate and therefore can be less bulky than in the case where it is attached to the crown. For example, the spring is a plate half or quarter of a washer, having an end placed in a groove around the periphery of the crown to slide inside the groove when the crown rotates and having its other end in contact against a wall of the cylinder head. The washer is arranged to deform elastically when the reducer moves along the X axis forward with respect to the rotor shaft and therefore the cylinder head. In addition, this spring can make it possible to form a resistive torque between the crown and the yoke to enable the sun gear to be advanced on the drive shaft.

In another example, the friction clutch is cone. In this case, there is no more disc. For example, the outer surface of the crown is tapered and the yoke includes a complementary conical portion to mate with the yoke.

In another example, the starter further comprises a member between the ring gear and the electric motor increasing the resistance torque of the rotor relative to the cylinder head in the opposite direction of rotation. For example, a free wheel can replace the bearing between the rear flange and the rotor shaft.

Claims

claims

Combustion engine permanent motor starter (1), in particular of a motor vehicle, comprising:

- a cylinder head (3),

an electric motor (14) comprising:

A rotor (141) mounted on a rotor shaft (145),

A stator (143) around the rotor (141),

- a drive wheel assembly comprising a drive wheel (1 1) rotatable about its axis, and mounted on a drive shaft (1 1 1),

an epicyclic reduction gear (130) comprising:

Two so-called planetary shafts, one of which forms a sun gear (131) connected to the rotor shaft (145), and the second forms a ring gear (133),

At least one satellite (135) between the two planetaries,

A satellite door (137) coupled in rotation with the shaft

drive (1 1 1),

- A movable member (55) in translation between a rest position and an active position, arranged to act on the ring (133) to pass

• an uncoupled state, in which the ring (133) is free in

rotation with respect to the cylinder head (3),

In a coupled state, in which the ring gear (133) is integral in rotation with the yoke (3) in at least the opposite direction to the starting torque,

and wherein the ring is in the rest position when the starter is not electrically powered.

Starter (1) according to the preceding claim, comprising a clutch device friction between the ring (133) and the yoke (3), the movable member (55) being arranged to enable and disable the clutch device for respectively coupling and uncoupling the ring (133) with the cylinder head (3).

Starter (1) according to claim 2, wherein the friction clutch is discs (139) comprising at least one inner disc (139A) integral in rotation with the crown (133) and at least one outer disc (139B) making facing the inner disk (139A) and integral in rotation with the cylinder head (3) and wherein in the coupled state the disks (139) are compressed against each other such that the slip starting torque is greater than the maximum torque transmitted from the electric motor (14) to the ring gear (133) for starting a heat engine.

4. The starter (1) according to claim 2, wherein the friction clutch device is conical clutch, wherein the ring (133) comprises a frustoconical first friction surface and the cylinder head (3) or a piece integral with the cylinder head (3) comprises a second frustoconical surface of complementary friction vis-à-vis the first friction surface.

Starter (1) according to one of claims 2 to 4, wherein the movable member (55) is arranged to press the crown (133) against the clutch device to activate it and decompresses the crown (133) to deactivate the clutch.

Starter (1) according to one of claims 2 to 4, wherein the movable member (55) is arranged to move a member integral in rotation with the yoke (3), presses this member against the ring (133) by the the clutch device to activate it and move this member to deactivate the clutch.

Starter (1) according to claim 2 or 3, wherein the movable member activates the clutch by acting directly on the clutch device.

Starter (1) according to one of claims 2 to 7, wherein the movable member is a fork (55), the starter further comprising an actuator, including a contactor, adapted to actuate the fork (55) to activate and deactivate the clutch device.

Starter (1) according to one of claims 1 to 7, wherein the movable member (55) is the sun gear (131), the sun gear (131) moving any epicyclic reducer (130).

10. Starter (1) according to the preceding claim, wherein the sun gear (131) comprises internal helical grooves corresponding to external splines on the rotor shaft (145) for moving the reducer. epicyclic (130) with respect to the rotor shaft (145) of a position

uncoupled to a coupled position.

1 1. Starter (1) according to one of the preceding claims, wherein

the movable member (55) moves a member of the epicyclic reduction gear (130) to move its crown (133).

12. The starter (1) according to claim 1, wherein the movable member (55) is arranged to move from its initial position to its final position towards the crown (133) so as to form in the final position an anti-rotation stop less in a direction of rotation of the ring gear (133) relative to the cylinder head (3) and in the initial position to release the ring gear (3) in rotation.

13. Starter (1) according to the preceding claim, wherein the ring (3) comprises lugs intended to cooperate with the movable member (55) to form the stop.

14. Starter (1) according to any one of the preceding claims, wherein the ring (133) is mounted directly pivotally relative to the yoke (3).

15. Motor vehicle comprising a starter according to any one of the preceding claims.