CN112955645A

CN112955645A - Flywheel for a starter of a motor vehicle, corresponding flywheel starter and starter

Info

Publication number: CN112955645A
Application number: CN201980040307.5A
Authority: CN
Inventors: J.维罗特; R.哈雅西; W.肖
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2018-06-25
Filing date: 2019-06-25
Publication date: 2021-06-11
Also published as: FR3082890B1; WO2020002826A1; FR3082890A1

Abstract

The invention relates to a flywheel (7) for a starter drive, comprising: -a driver (6) comprising a socket (61), the socket (61) having an internal ramp (62), the internal ramp (62) forming housing shells (64), each housing shell being adapted to house a roller (71) and a spring (72), -a rotary element (5) driven by the driver (6) via the roller (71), -a disc (9) for closing the driver, and-an assembly cover (8) for holding the disc (9) on the driver, the closing disc (9) comprising on an inner end face (92) mounted opposite the driver (6) at least one protrusion (91) forming a protrusion adapted to be plugged into a cavity (64, 66) of the driver such that the closing disc (9) is rotatably fixed to the driver.

Description

Flywheel for a starter of a motor vehicle, corresponding flywheel starter and starter

Technical Field

The present invention relates to a flywheel for a starter, in particular for a motor vehicle, in which a closing washer is integral with the driver so as to form an anti-rotation system. The invention also relates to a starter and a starter equipped with a flywheel of this type.

The invention finds application in the field of motor vehicles having a heat engine, and in particular, in the field of starters for motor vehicles having a heat engine.

Background

The starter is used in a known manner for the purpose of providing the pulses required to start the heat engine of the vehicle. To this end, the starter comprises an electric motor that is electromagnetically controlled and that is mechanically connected to the heat engine.

Fig. 1 shows an example of a starter according to the prior art in a partially schematic view in longitudinal section. The starter 1 comprises a starter 3 equipped with a pinion 4, the pinion 4 being designed to mesh with a crown 2 of the heat engine of the vehicle. The motor 12 of the starter 1 is designed to rotate the pinion 4. The starter 1 further comprises a contact 13, which contact 13 is designed to axially displace the starter 3 towards the crown by means of a fork 14.

The starter 3 comprises a flywheel 7, which flywheel 7 is fitted around the output shaft 5 extending along the longitudinal axis X. The flywheel 7 comprises a drive 6, in which drive 6a roller 71 is arranged. The output shaft 5 forms an internal track for the flywheel 7. The drive 6 comprises a bush 61 extending axially in the direction of the pinion 4, said bush 61 being configured on its inside to form an internal ramp in which a roller 71 and a spring 72 acting on said roller are housed. The inner track and the inner ramp of the freewheel 7 constitute the rolling surface of the roller 71. Grease is present within the drive 6 to assist the rolling of the roller 71.

As shown in fig. 2, the roller 71, the spring 72 and the grease are held inside the bush 61 of the driver 6 by a closing washer 9, which closing washer 9 ensures the seal between said driver 6 and the assembly cover 8. The closing washer 9 is in the form of a disc provided with an opening 93 in the centre thereof to allow the output shaft 5 to pass through. The assembly cover 8 comprises a disc 81, which disc 81 is open in its centre and is positioned around the output shaft 5 transversely with respect to the longitudinal axis X of the actuator 3. The assembly cover 8 further comprises a rim 82 having an annular form extending from the disc 81 in a direction substantially parallel to the longitudinal axis X. The assembly cover 8 covers at least partially the closing washer 9 and the end face of the bush 61 facing said washer.

According to the first technique of the prior art shown in fig. 2, the cover 8 is assembled on the driver 6 by a pressing process with striations provided on the inner wall of the rim 82 of the cover 8, thus retaining the closing washer on the driver 6. A disadvantage of this type of extrusion process is that it requires further machining and the use of multiple machines, which results in higher production costs.

According to the second technique of the related art, which is lower in cost than the first technique, the cover 8 is crimped on the driver 6. The closing washer 9 is then equipped with a seal to ensure sealing against the grease in the interior of the drive 6. At present, however, vehicles with heat engines are increasingly equipped with so-called stop and start systems which ensure automatic stopping and restarting of the engine of the vehicle in order to save fuel and reduce pollution. The result of these stop and start systems is, among other things, a significant increase in the number of start cycles, which can create thermal shock and, as a result, creep of the flywheel seals. However, when the seal creeps, the crimping of the cover 8 onto the driver is less effective and under the action of the rotating force, the closing washer 9 can rotate, leading to premature failure of the flywheel.

Disclosure of Invention

In order to solve the above-mentioned problem of premature failure of the flywheel caused by the rotation of the closing washer, the applicant has proposed a starter flywheel in which the closing washer is equipped with an anti-rotation system.

According to a first aspect, the invention relates to a flywheel for a starter, comprising:

-a drive comprising a bushing provided with internal ramps forming receptacles, each receptacle being designed to receive a roller and a spring;

-a rotating element driven by a driver by means of a roller;

-a gasket for closing the driver; and

-an assembly cover for holding the gasket on the driver.

The flywheel is characterized in that the closing washer comprises, on an inner end face fitted to face the driver, at least one projection forming a projection designed to be fitted in a cavity in the driver, so that the closing washer rotates integrally with the driver.

By means of its anti-rotation system, this type of flywheel makes it possible to avoid any rotation of the washer with respect to the driver, thus reducing the risk of detecting a premature failure of the flywheel.

Advantageously, and according to some embodiments, the cavity in the driver is one of the housings of the internal ramp (which receive the roller and the spring), the projection being received between a wall of the housing and the spring.

These embodiments make it possible to avoid rotation of the closing washer without any modification of the driver.

According to other embodiments, the cavity in the driver is a non-through hole formed in the peripheral surface of the internal ramp.

The flywheel according to the invention may comprise one or more of the following features:

-forming said projections by embossing on the closing gasket;

-forming the protrusion by adding material on the closing washer;

the projection of the closing washer is as many as the accommodation comprised by the internal ramp of the driver;

it comprises a flat seal fitted between the outer face of the closing gasket and the assembly cover;

it comprises a flat seal fitted around the closing gasket between the bush and the assembly cover;

the closing washer comprises a circular periphery of a size complementary to the size of the bush of the driver.

According to a second aspect, the invention relates to a starter characterized in that it comprises a flywheel as defined previously.

According to a third aspect, the invention relates to a motor vehicle starter, characterized in that it comprises a starter equipped with a flywheel as defined previously.

Drawings

Other advantages and features of the invention will become apparent upon reading the description illustrated by the drawings in which:

fig. 1 shows a partial schematic view of a longitudinal section of a starter according to the prior art;

figure 2 is an exploded perspective view of a flywheel according to the prior art;

figure 3 shows a schematic longitudinal section of a flywheel according to the invention;

fig. 4 shows a perspective view of an example of a gasket for closing the flywheel in fig. 3;

fig. 5A, 5B, 5C show a top view, a side view and a perspective view of a flywheel whose closing washer is equipped with a first example of a projection;

fig. 6A and 6B show perspective views of a flywheel drive which is opened and closed, respectively, by a closing washer equipped with a second example projection;

figures 7A and 7B respectively show a partial schematic view in longitudinal section of a third example of the flywheel, and a top view of a closing washer of this third example of the flywheel;

fig. 8 presents in tabular and curvilinear form the results of a comparison test between the flywheel according to the prior art and the flywheel of fig. 4 and 5.

Detailed Description

Hereinafter, an embodiment of a starter flywheel in which a closing washer is integrated with a driver will be described in detail with reference to the accompanying drawings. This example illustrates the features and advantages of the present invention. It should be borne in mind, however, that the present invention is not limited to this example.

In the drawings, like elements are denoted by like reference numerals. For reasons of clarity of the drawing, no dimensional ratios between the elements represented are observed.

Fig. 3 shows a cross-sectional view of a flywheel according to the invention. The flywheel 7 comprises a driver 6, an output shaft 5, a closure washer 9 and an assembly cover 8. The drive 6 comprises a bush 61 extending along the axis X in the direction of the pinion of the starter (not shown in the figures). The bushing 61 is a hollow cylindrical part which fits around the output shaft 5 and is designed to rotate said output shaft. The bush 61 comprises, on its inner cylindrical wall, internal ramps 62, said internal ramps 62 forming receptacles 64, each receptacle 64 being designed to receive a roller 71 and a spring 72 acting on said roller. The bushing 61 comprises at its centre an internal track 63 formed by the output shaft 5. The internal ramp and the internal track constitute rolling surfaces for the flywheel, between which the roller 71 rolls and which, thanks to the presence of the grease inside the bushing 61, contribute to the rolling of the roller 71.

The bush 61 is closed by a closing washer 9 (more simply, called a washer). The washer 9 is a thin circular part, for example made of metal, which is hollow at its centre 93 and is designed to fit around the output shaft 5 and to close the open area of the driver's bushing 61. The washer includes an inner end face 92 positioned to face the bushing and an outer end face 95, the outer end face 95 being positioned to face the disk 81 of the assembly cover 8. The washer 9 comprises a circular periphery of a size complementary to the circumference of the bush 61, so that once the washer 9 is fitted in front of the opening of the bush, the washer ensures that the roller 71, the spring 72 and the grease are retained inside said bush.

The assembly cover 8 ensures that the washer 9 is held against the bushing 61. The assembly cover 8 comprises a disc 81, which disc 81 is designed to fit around the output disc 5. A first rim 82 extends laterally from the disc 81, the first rim 82 having an annular form extending in a direction substantially parallel to the longitudinal axis X. A second rim 83 extends axially from the first rim 82 itself, the second rim 83 being in the form of a hollow disc extending in a direction substantially parallel to the disc 81. The assembly cover 8 at least partially covers the closing washer 9 and at least partially surrounds the bushing 61. Thus, the assembly cover 8 is crimped against the bush 61 of the driver 6.

In accordance with one or more embodiments, such as the embodiment shown in fig. 3, a seal 10 (e.g., a flat seal) is positioned between the disk 81 of the assembly cover 8 and the bushing 61 around the gasket 9 to ensure a good seal against grease. In certain other embodiments described below, the seal may be positioned differently.

According to the invention, the washer 9 is provided with a system ensuring the rotation prevention of said washer inside the flywheel 7. This anti-rotation system can be ensured by one or more projections which make it possible to achieve an integral rotation of the washer 9 with the driver 6 or the assembly cover 8.

According to some embodiments, at least one projection 91 is provided on the inner end face 92 of the washer 9, which projection is designed to be received in a cavity of the driver 6. In these embodiments, a plurality of projections may project from the inner end face of the washer, each projection being received in a different cavity of the driver 6. The cavity designed to receive the projection may be a natural cavity of the driver, i.e. a pre-existing cavity in the driver, such as e.g. a receptacle formed by the internal ramp 62. Fig. 4 shows an example of a washer 9, which washer 9 comprises five projections 91 projecting from a surface 92 of the washer 9, each of these projections 91 being designed to open into one of the receptacles 64 of the internal ramp 62 of the driver 6. Those skilled in the art will appreciate that a single tab 91 received in a single receptacle 64 is sufficient to constitute an anti-rotation system, however, the number of tabs may advantageously be the same as the number of receptacles 64 formed in the internal ramp 62.

Fig. 5A to 5C show different views of the projection 91 leading to the receptacle 64 of the internal ramp 62. Fig. 5A shows a top view of a part of the driver 6, wherein the internal ramp 62, the receptacle 64, the spring 72 and the projection 91 are shown in a transparent manner through the washer 9. Fig. 5B shows a side view of the receptacle 64, wherein the projection 91 is received between the spring 72 and the internal ramp 62 at the angle of the receptacle 9, as illustrated by transparency. Fig. 5C shows a perspective view of the receptacle 64 of fig. 5B, with the projection 91 received between the spring 72 and the internal ramp 62 at the angle of the receptacle 64, as shown in transparency.

In the example of fig. 4 and 5, the projections are distributed in a central region of the inner surface 92 of the washer in order to open into the receptacle 64 of the internal ramp 62 of the driver 6.

In certain variants, the projections 91 are lugs obtained on the surface of the gasket 9 by embossing of said gasket. According to other variants, the projection 91 is a stop, which is added to the end face of the gasket, for example by welding or gluing. Whether they are obtained by deformation or by adding material, when the projection 91 is received between the spring 72 and the internal ramp 62, they make the washer 9 integral with the driver 6 when the flywheel rotates.

Tests conducted on flywheels according to the embodiments of fig. 4 and 5 show an improvement of about 10 times the original torque, and thus to this extent the risk of premature flywheel failure is reduced. The results of these tests are shown in figure 8 and show that five samples of a flywheel according to the prior art (i.e. E1-E5) have an average torque of less than 8Nm, whereas the average torque of a flywheel according to the invention exceeds 48Nm under the same test conditions. The mean torque in the case of the present invention is multiplied by more than 10 compared to sample E1 where the mean torque is less than 4 n.m.

In some embodiments, the projections 91 are positioned at the periphery of the gasket 9, as shown in FIG. 6B, where they can be seen through the thickness of the gasket by a transparent illustration. Thus, the projection 91 is designed to be received into the cavity 66 provided in the circumferential surface of the internal ramp 62. Each of these cavities 66 is a non-through hole formed in the peripheral surface of the internal ramp facing the washer 9. In other words, in these embodiments, the projections 91 are distributed on the inner end face of the washer 9 in the region of the washer with the largest diameter arranged facing the inner ramp of the driver 6.

In the example of fig. 6A and 6B, the projection 91 is represented in a substantially cubic form; similarly, the cavities 66 in the circumference of the internal ramp have a substantially cubic form, so as to each be designed to receive a projection 91. These components are formed by the projection 91 and the cavity 66, respectively, so that the washer 9 can rotate integrally with the driver 6.

In these embodiments of fig. 6A-6B, a seal 10 (e.g., a flat seal) may be fitted between the outer end face of the gasket 9 and the assembly cover 8.

In other embodiments, such as shown in fig. 7A and 7B, the projection 91 is located on the contour of the gasket 9 and is received into the cavity 85 provided in the assembly cover 8. In these embodiments, the first rim 82 of the assembly cover 8 includes one or more indentations of complementary form and size to the form and size of the projections 91, such that each cavity 85 can receive a projection 91. These assembly of the projection 91 and the cavity 85 allows the washer 9 to rotate with the assembly cover 8.

In these embodiments, the gasket 9 is machined to include a circular groove 94 designed to receive the seal 10. This circular groove 94 is advantageously provided in the inner end face 92 of the washer, in the region of the wall facing the bushing 61 or the internal ramp. The seal 10 inserted into the groove 94 may be, for example, an O-ring seal.

The different embodiments just described make it possible to increase the torque considerably, thus reducing the risk of premature failure of the flywheel. The embodiments in fig. 4 and 5 also make it possible to do without any modifications to the drive 6.

While the flywheel has been described with a certain number of examples, modifications and embodiments, various changes, modifications and improvements therein will be apparent to those skilled in the art, and may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. Flywheel (7) for a starter comprising:

-a driver (6), the driver (6) comprising a bushing (61), the bushing (61) being provided with an internal ramp (62) to form receptacles (64), the receptacles (64) each being designed to receive a roller (71) and a spring (72);

-a rotating element (5), said rotating element (5) being driven by said driver (6) through said roller (71);

-a gasket (9), said gasket (9) being intended to enclose said driver; and

-an assembly cover (8), the assembly cover (8) being used to fix the gasket (9) on the driver,

characterized in that the closure washer (9) comprises, on an inner end face (92) fitted to face the driver (6), at least one projection (91) forming a projection designed to fit in a cavity (64, 66) in the driver, so that the closure washer (9) rotates integrally with the driver.

2. A flywheel according to claim 1, characterized in that the cavity in the driver is a non-through hole (66) formed in the peripheral surface of the internal ramp (62).

3. A flywheel according to claim 1, characterized in that said cavity in the driver is one of the housings (64) of the internal ramp to receive a roller (71) and a spring (72), said projection (91) being received between the wall of the housing (64) and the spring (72).

4. A flywheel according to any of claims 1 to 3, characterized in that said projections (91) are formed by embossing said closing washer.

5. A flywheel according to any of claims 1 to 3, characterized in that said projection (91) is formed by adding material to said closing washer.

6. A flywheel according to any of claims 1 to 5, characterized in that said closing washer (9) comprises as many projections (91) as the internal ramps of the driver comprise receptacles.

7. A flywheel according to any of claims 1 to 6, characterized in that it comprises a flat seal (10) fitted between the outer end face of the closing washer (9) and the assembly cover (8).

8. A flywheel according to any of claims 1 to 6, characterized in that it comprises a flat seal (10) mounted around said closing washer (9) between said bushing (61) and said assembly cover (8).

9. A flywheel according to any of claims 1 to 8, characterized in that said closing washer (9) comprises a circular periphery of a size complementary to the size of said bush (61) of the driver.

10. Motor vehicle starter, characterized in that it comprises a starter equipped with a flywheel (7) according to any one of claims 1 to 9.