CN103930668B - Starter for explosive motor - Google Patents

Abstract

The invention relates to a starter head for an internal combustion engine and a starter equipped with the starter head. More specifically, the invention relates to a starter head for an internal combustion engine comprising a housing defining a reduction chamber and comprising a surface for mounting an electric motor M including a drive pinion, the starter head also comprising a reduction gears arranged in the reduction chamber and comprising an epicycloidal gear train comprising planetary gears rotated by the drive pinion of the electric motor and an outer ring having an axis Δ passed through A rotatable link (35) is connected to the housing. The reduction chamber comprises a cylindrical rotationally symmetrical bore with an axis of revolution Δ for receiving an outer ring having an outer cylindrical rotationally symmetrical form matching the cylindrical rotationally symmetrical shape of the receiving bore, the rotatable link means comprising at least one a torsional shock absorber mounted between the ring and the housing so as to dampen torque between the housing and the outer ring, and which is at least partially inserted into a recess provided in the housing, the recess including at least one shaft To the abutment, the abutment is adapted to form an obstacle in translation relative to the cushion and the mounting surface. The starter head includes a torsional damping pad mounted under axial compression in a recess between the axial abutment and the ring. Torque between the housing and the ring in the starter head is damped by the shock pads and rotation is stopped by at least one compressed shock pad.

Description

starters for internal combustion engines

technical field

The invention relates to the technical field of starters for internal combustion engines. In a preferred, but not exclusive application, the invention relates to motor vehicle internal combustion engine starters.

Background technique

A starter of this type usually includes an electric motor, which refers to means for driving an internal combustion engine. The drive means are mostly designed to be coupled to an on-board unit of the internal combustion engine during the starting phase of the internal combustion engine and to be decoupled therefrom when the internal combustion engine is running. For this purpose, the starter comprises an electromagnetic switch designed firstly to control the supply of power to the electric motor and secondly to control the coupling and decoupling of the drive means relative to the internal combustion engine. The drive means includes a launcher which is movable in rotation about itself and in axial translation between a rest position and a position for driving the internal combustion engine. The starter is shifted between its rest position and its drive position by a lever operated by a solenoid switch. Since starting of an internal combustion engine requires a relatively high level of torque, the drive means comprise a reduction gear arranged between the starter and the drive pinion of the electric motor.

In order to obtain a starter motor as compact as possible, it has been proposed to apply epicycloidal gear train reducers, as described, for example, in patent applications FR2937933 and WO2005/054664. The starter then comprises a starter head comprising a housing delimiting a reduction chamber and comprising means for mounting the electric motor. The starter head also includes a reduction gear arranged in the reduction chamber and comprising an epicycloidal gear train, in particular comprising planetary gears, designed to be rotated by the drive pinion of the electric motor, and an outer ring, Said outer ring has an axis Δ, which is connected to the housing by means for rotational connection.

This type of starter head and the starter incorporating it are very satisfactory in terms of their starter function when used for the first time. However, after a certain period of use of such a starter, it becomes apparent that the moving parts of the starter nose tend to degrade so that the starter no longer performs its function adequately and needs to be replaced. Based on the analysis, it was found that one of the causes of this failure was the constant shock maintained by the rotating parts of the retarder and starter during engine starting, especially when the detonation first occurred in the cylinder before the starter was decoupled. These shocks are caused in particular by various velocities that induce inertial torques.

It has therefore become increasingly apparent that there is a need for a new starter which is able to withstand these impacts without degradation in order to provide better reliability and a longer service life than starters of the prior art.

Contents of the invention

In order to achieve this object, the invention relates to a starter head for a starter of an internal combustion engine, comprising:

housing, delimiting the reduction chamber and comprising means for securing the electric drive motor including the drive pinion;

A reduction gear, which is arranged in the reduction chamber and includes an epicycloidal gear train including planetary gears designed to be rotated by a drive pinion of an electric motor, and an outer ring having Axis Δ, the outer ring is connected to the housing by means for rotational connection.

According to the invention, a starter head for a starter of an internal combustion engine is characterized in that:

a reduction chamber comprising a cylindrical bore with an axis of revolution Δ for receiving an outer ring having an outer cylindrical form of revolution complementary to the cylindrical form of revolution of the receiving bore;

Means for rotationally connecting, comprising at least one torsional damping shock absorber fitted between the ring and the housing so as to dampen torque between the housing and the ring and at least partially engaged in the arranged in a receiving portion in the housing, said receiving portion comprising at least one axial stop designed to block translation of the damping shock absorber;

The application of means for the rotational connection between the outer ring and the housing, said means comprising at least one damping shock absorber, advantageously makes it possible to absorb the The shock caused by the sudden change in torque and speed caused by the engine to form the inertia torque. Thus, the energy induced by these changes in rotational speed and torque is dissipated by the damper, thereby preventing the teeth of the starter, the teeth of the different toothed wheels making up the reducer, or the teeth of the pinion driving the electric motor. fracture. It should be noted that, considering the complementary form of the outer ring and the receiving hole, the fact that the ring is movable in rotation relative to the housing means that, in the absence of means for rotationally connecting, the outer ring will be in the receiving portion swivel movement so as to be able to rotate about 360°.

According to a characteristic of the invention, the torsional damping shock absorber is fitted axially compressively in the reception between the axial stop and the ring, which makes it possible to prevent excessive displacement of the shock absorber(s), And thus stop it/they from wearing out.

According to a feature of the invention, the torque between the housing and the ring is damped by a damper and the rotation is stopped at least by such a compressed damper. This makes it possible to avoid an overly violent torque between the ring and the housing causing a shock that would destroy all starter equipment.

According to a feature of the invention, the starter head also comprises at least one axial support surface forming an axial stop designed to prevent relative axial translation of the outer ring and the fitting surface.

In addition, the presence of an axial stop (which prevents the axial translation of each damper parallel to the axis of rotation Δ of the reducer) avoids the damper(s) under the force to which it is subjected (The force is caused by sudden changes in torque and rotational speed) Excessive displacement. This perfect wedging of the damper helps to ensure a firm hold of the damper so as to prevent detachment from the ring. This thus increases the reliability of the retarder and the starter head according to the invention and thus of the starter incorporating them.

According to the invention, the damping shock absorber can be made of any suitable material. However, the damping shock absorber is preferably made of an elastically deformable polymeric material designed to withstand the mechanical stresses, as well as the chemical aggression and temperature conditions typical of the environment of an internal combustion engine.

According to a feature of the invention, designed to ensure damping efficiency of changes in torque and rotational speed, the means for rotationally connecting comprise at least three damping shock absorbers, each engaged at least partially in a Each of the receiving portions comprises at least one axial stop designed to prevent translation of a corresponding damping damper of the reducer assembly towards the end of the housing surrounding the pinion.

According to another characteristic of the invention, each damping shock absorber is limited in axial translation in two directions, firstly by an axial stop of the housing and secondly by the outer ring. Such an adaptation mode allows simple fixing of each damping damper by reducing the number of components, so as to limit the manufacturing costs of the starter according to the invention.

According to one embodiment of the invention, the housing comprises a starter chamber arranged opposite to the reduction chamber and the fitting surface, and the starter head comprises in the starter chamber an output shaft having an axis Δ, which is rotated by the reducer , and supports a starter comprising a pinion designed to cooperate with the starter ring of the heat engine.

According to a variant of this embodiment, the outer ring comprises a flange supporting the guide carrier of the output shaft. The incorporation of the flange in the outer ring makes it possible to reduce the number of parts of the starter head according to the invention.

According to a feature of this variant, the flange separates the retarder chamber from the starter chamber. The separation thus achieved makes it possible to protect the epicycloidal gear train reducer assembly and optionally delimit it in a greased reduction chamber.

According to another feature of this variant, the means for the rotational connection are arranged in the deceleration chamber. This feature makes it possible in particular to reduce the volume of the deceleration chamber by utilizing the part of the starter chamber that is not used for the movement of the starter.

The invention also relates to a starter for a heat engine comprising a starter head according to the invention, an electric motor mounted on a housing, and a drive pinion driving a reduction gear

According to a feature of the invention, the starter comprises a disc for closing the reduction chamber, arranged between the housing and the electric motor. Such a closing disc advantageously facilitates the assembly of the starter and ensures the positioning of the epicycloid gear train reducer.

According to a variant of this feature, the disc for closing achieves the blocking of the axial translation of the outer ring.

It should be appreciated that different features, variants and embodiments of the invention may be related to each other in various combinations (to the extent that they are not contradictory or mutually exclusive).

In addition, various other features of the invention will become more apparent by reference to the description provided in the accompanying drawings, which illustrate a non-limiting embodiment of a starter head according to the invention and a starter incorporating such a reduction gear .

Description of drawings

1 is a schematic diagram of a starter for a heat engine according to the present invention;

Figure 2 is a partial perspective view in axial section of the starter head according to the invention shown in Figure 1;

Figure 3 is a sectional view according to the plane III-III in Figure 1 of a component epicycloid gear train reducer designed to equip the starter shown in Figure 1;

Figure 4 is a perspective view showing a detail of Figure 3 on an enlarged scale.

detailed description

As shown in Figure 1, a starter D according to the invention for a heat engine comprises a starter head 1 on which is fixed an electric motor M controlled by a magnetic switch C which also controls the integrated Starter L in damping system 1. Embodiments of starters of this type and their component elements are known to those skilled in the art, so that only the features necessary for understanding the invention will be described. Further information on the details of embodiments of starters can be found in documents FR2934933, FR2843427, and WO2005/054664, which information will not be described below.

The starter head 1 according to the invention comprises a housing 2 on which an electric motor M is fastened. The housing 2 includes fixing lugs 3 designed to allow the starter D to be fixed on the thermal engine it is designed to start. The housing 2 also includes means 9 for fixing the electric motor M. As shown in FIG.

As shown in FIG. 2 , the housing 2 is hollow and delimits a reduction chamber 4 adjacent a surface 5 for the assembly of the electric motor M on the housing 2 . The reduction box 4 extends opposite the surface 5 through an actuator cavity 6 in which the actuator L is located.

The starter head 1 also includes a reduction gear 10 disposed in the reduction cavity 4 . As shown in FIG. 3 , the speed reducer 10 includes an outer ring 11 having a substantially symmetrical form around the axis of rotation Δ. The circumferential outer surface 12 of the ring 11 is smooth and cylindrical with an axis of revolution Δ, while the circumferential inner surface 13 of the outer ring 11 is toothed. The toothed inner surface 13 of the outer ring 11 cooperates with three planetary gears 14 movable in rotation according to axes parallel to the axis Δ. The planet gears 14 mesh with planet gears 15 which are coaxial with the outer ring 11 . The planetary gear 15 has a receptacle 16 for receiving a drive pinion 17 of the electric motor M. As shown in FIG. The receptacle 16 has a shape complementary to that of the pinion 17, so that, when the pinion 17 is engaged in the receptacle 16, the planetary gear 15 is integral with the drive shaft of the motor, which has an axis Δ and is shown in the drawing not shown in

As is known to those skilled in the art, the planetary gears 14 are integral with a disc 18 connected in rotation to an output shaft 19 coaxial with the axis Δ. The output shaft 19 extends into the starter chamber 6 while being supported by means 20 for guiding the rotation arranged in the wall of the housing 2 opposite the reducer 10 . The output shaft 19 supports a starter L, which is rotatably connected to the output shaft 19 and can be positioned at rest R (shown in solid line in FIG. 1 ) and in position E for driving the internal combustion engine (in FIG. 1 shown in dashed lines) to move in translation on the output shaft. In the drive position E, the starter L is designed to cooperate with a starter ring (not shown in the figures) which extends partly into the starter chamber by means of the window 21 of the housing 2 . The starter L is displaced between a rest position R and an actuation position E by means of a lever 22 operated by an electromagnetic switch C. As shown in FIG.

In order to ensure the guidance of the rotation of the disc 18 and the output shaft 19 , at the level of its surface facing the starter chamber 6 , the outer ring 11 comprises a flange 25 supporting a guide carrier 26 of the output shaft 19 . The flange 25 also helps to separate the retarder chamber 11 from the starter chamber 6 in order to protect the retarder assembly 10 .

The reduction chamber 4 comprises a cylindrical bore having an axis of revolution Δ and having a shape complementary to the shape of the outer surface 12 of the outer ring 11 . The ring is rotationally movable relative to the housing 2 . The outer ring 11 is fitted between an axial support surface 27 forming a stop, which is provided in the reduction chamber 4 , bounded between the reduction chamber and the starter chamber 6 , and a part of the closing disc 28 , Said closing disk 28 is placed between the housing 2 and the motor M. Closing the disc 28 and the axial support surface 4 makes it possible to limit the axial translation of the outer ring 11 and thus the axial deformation of the damper 36 . Closing disc 28 helps to restrain pinions 14 and 15 , as well as inner surface 13 of ring 11 , so as to protect reducer 10 . According to the embodiment shown, at the level of the central hole 29 the closing disc 28 comprises means for guiding the rotation of the rotor shaft of the electric motor.

In order to allow the transmission of the rotation of the drive pinion 17 to the planetary gears 14 and thus to the output shaft 19 , the outer ring 11 must be rotationally connected to the housing 2 . For this purpose means 35 are used for rotationally connecting the outer ring 11 with the housing 2 . The means 35 for rotational connection comprise at least one (six in the illustrated embodiment) damping shock absorbers 36 , only three of which are visible in FIG. 2 .

Each damping damper 36 engages in a receptacle 37 of the housing 2 provided in the wall of the starter chamber 6 at the level of its end located towards the deceleration chamber 4 . Each receiving portion 37 has a shape complementary to that of the corresponding damping shock absorber 36 and is open towards the interior of the starter chamber 6 . Each reception 37 is also open towards the reduction chamber 4 in order to allow the engagement of the corresponding shock absorber 36 according to a translational movement parallel to the axis Δ. According to another example described, the base of the receiving portion is inclined relative to the axis Δ (the base of the receiving portion means the surface of the receiving portion furthest from the axis Δ). Each receptacle 37 also includes two side walls 38 each defined by an interposed rib 39 separating the receptacle 37 from an adjacent receptacle. Each receptacle extends from the peripheral wall of the actuator chamber 6 , according to a substantially radial direction, towards the interior of said actuator chamber 6 .

The means 35 for connection also comprise a skirt 40 extending from the flange 25 into the interior of the actuator chamber 6 . The skirt 40 forms a one-piece assembly together with the flange 25 and the outer ring 11 . The skirt 40 comprises at least one radial rib 41 associated with each shock absorber 36 extending into the interior of said shock absorber 36 to connect it to the skirt 40 and thus to the outer ring 11 .

In order to ensure the blocking of the movement of the shock absorber in the axial direction (ie parallel to the axis Δ), each receiving portion 37 for receiving a damping shock absorber 36 comprises at least one axial stop 45 which The portion is designed to prevent the translation of the damper 36 parallel to the axis Δ toward the interior of the starter chamber 6 and relative to the deceleration chamber 4 . According to the example shown, the axial stops 45 are provided in the wall of the actuator chamber 6 while being separated from each other by cutouts 46 provided in the wall of the actuator chamber 6 . The cutouts 46 facilitate the circulation of the air flow for the cooling system 1 . In addition, these cutouts 46 make it possible to save material and thus reduce weight.

The damping damper 36 is also fixed axially by an outer ring 11 opposite the axial stop 45 relative to the damping damper 36 . Thus, each damping shock absorber 36 is preferably fixed in its receptacle 37 so that it is not easily displaced under the action of shocks caused by variations in the starting torque of the engine The invented starter is realized.

According to the example shown, the outer ring 11 is made of plastic material and the shock absorbers 36 are made of a viscoelastic material such as synthetic rubber and are overmoulded on the outer ring 11 in order to facilitate the starting of the handpiece 1 according to the invention. And the assembly of starter D.

It will be appreciated that this type of embodiment is not strictly necessary for the present invention and that various modifications may be made to the foregoing embodiments of the invention within the scope of the appended embodiments.

Claims (12)

1. a kind of explosive motor starts head, including：

Housing (2), defines velocity-reducing chamber (4), and including assembly surface (5), the assembly surface (5) be used to install include driving it is small Gear (16) and the electric notor (M) outside the velocity-reducing chamber；

Reduction gearing (10), it is arranged in velocity-reducing chamber (4), and including epicycloidal tooth train and outer shroud (11), epicycloidal tooth train Including multiple gears (14), gear (14) is designed to rotate by electric notor (M) driving pinion (16), outer shroud (11) tool There is axis of rotation (Δ), the outer shroud is connected to housing (2) by the device (35) for rotatably connecting,

Characterized in that,

Velocity-reducing chamber (4) includes the cylindrical hole with axis of rotation (Δ) and is used to receive outer shroud (11), and the outer shroud has with connecing The Outer cylindrical that the cylinder revolution shape of batter is complementary turns round shape, and wherein outer shroud can be relative to housing rotary motion；

Device (35) for rotatably connecting includes at least one torsion damping shock absorber (36), torsion damping shock absorber dress Fit between outer shroud and housing (2) and contact housing and outer shroud, to suppress the moment of torsion between housing (2) and outer shroud (11), and It is bonded in the acceptance division (37) being arranged in housing (2) at least in part, and the acceptance division stops including at least one axial direction Dynamic portion (45), the axial retention portion are designed as preventing torsion damping shock absorber (36) and assembly surface (5) axially opposite translation, Wherein torsion damping shock absorber is by being compressed axially in the acceptance division being assemblied between axial retention portion and outer shroud.

2. starting head as claimed in claim 1, the wherein moment of torsion between housing and outer shroud is suppressed by torsion damping shock absorber, And rotate at least through such torsion damping shock absorber compressed and be stopped.

3. the starting head as described in one in preceding claims, it is characterised in that the starting head is also included at least One axial support surface, the axial support surface form axial retention portion, and the axial retention portion is designed as preventing outer shroud and dress With surface (5) axially opposite translation.

4. head is started as claimed in claim 1 or 2, it is characterised in that the device for rotatably connecting includes at least three Individual torsion damping shock absorber (36), each torsion damping shock absorber are bonded on the reception being arranged in housing (2) at least in part In portion (37), each acceptance division (37) includes at least one axial retention portion (45), and the axial retention portion is designed as preventing torsion Damping shock absorber (36) and the relative translation of assembly surface (5).

5. head is started as claimed in claim 1 or 2, it is characterised in that each torsion damping shock absorber (36) passes through first The axial retention portion (45) of housing (2), axial translation is unable to along both direction secondly by outer shroud (11).

6. head is started as claimed in claim 1 or 2, it is characterised in that

Housing (2) includes starter chamber (6), and the starter chamber relatively positions relative to velocity-reducing chamber (4) and assembly surface (5)；

It includes the output shaft (19) with axis of rotation (Δ) in starter chamber (6), and the output shaft is by reduction gearing (10) Rotation, and starter (L) is supported, the starter includes little gear, and the little gear is designed as cooperating with the starter ring of heat engine.

7. head is started as claimed in claim 1 or 2, it is characterised in that outer shroud (11) includes support drawing for output shaft The flange (25) of guidance holder.

8. head is started as claimed in claim 7, it is characterised in that

Housing (2) includes starter chamber (6), and the starter chamber relatively positions relative to velocity-reducing chamber (4) and assembly surface (5)；

It includes the output shaft (19) with axis of rotation (Δ) in starter chamber (6), and the output shaft is by reduction gearing (10) Rotation, and starter (L) is supported, the starter includes little gear, and the little gear is designed as cooperating with the starter ring of heat engine,

And wherein, the flange (25) separates velocity-reducing chamber (4) from starter chamber (6).

9. head is started as claimed in claim 6, it is characterised in that the device (35) for rotatably connecting is arranged on startup In device chamber (6).

10. a kind of starter for heat engine, it includes the starting head as described in one in claim 1-9, and installation Electric notor on housing (2), and the driving pinion (16) of driving reduction gearing (10).

11. starter as claimed in claim 10, it is characterised in that it includes being used for the disk for closing velocity-reducing chamber (4), and the disk is set Put in housing (2) between electric notor.

12. starter as claimed in claim 11, it is characterised in that the closure disc is realized to the axial translation of outer shroud (11) Stop.