FR2764946A1 - STARTER FOR MOTOR VEHICLE WITH IMPROVED SEAL - Google Patents

Abstract

The invention relates to a motor vehicle starter (100), of the type comprising on the one hand a casing (110) in which an X axis starter (120) is guided in axial translation and in rotation about its X axis by via a bearing (130) interposed between the launcher and the casing, the launcher emerging outside the casing through an opening (112) provided in a transverse wall (111) of the casing, and on the other hand a seal (140) positioned in the housing at said opening, said seal comprising an annular body (141) of axis X which carries a lip (142) coming into contact with said launcher (120). According to the invention, the seal produced in one piece is provided at least on one end face (141a) of its body with a rib (143) which extends along said body and of thickness (e) less than the thickness (E) of the body, said bearing directly maintaining said seal by compression against said housing.

Description

1 2764946

  The present invention relates to a starter for

motor vehicle.

  It relates more particularly to a starter of the type comprising on the one hand a casing in which an X-axis launcher is guided in axial translation and in rotation about its X axis by means of a bearing interposed between the launcher and the casing, the launcher emerging outside the casing through an opening provided in a transverse wall of the casing, and on the other hand a seal positioned in the casing at the level of said opening, said seal comprising an annular body of X axis which carries a lip

coming into contact with said launcher.

  The seal prevents the penetration of dust or water loaded with corrosive elements which could lead to deterioration of the surfaces

  friction between the bearing and the starter.

  The fixing of this seal in the starter housing must be sufficiently effective so that it is not rotated in its housing by means of the friction forces which

  act on the lip in contact with the launcher.

  Thus, in a starter of this type, already known, the fixing of a seal is effected by overmolding of said seal on a metal carcass force-fitted into said opening provided in the transverse wall.

of the housing.

  According to another already known technical solution, an elastic washer held by claws in the housing, axially compresses the periphery of the seal

  seal and the rotatable on.

  These two aforementioned solutions of the prior art have the main drawback of resorting to the use of additional parts for immobilizing the seal in the casing of the

2 2764946

  starter. This makes the assembly of said seal complex and

  generates an additional manufacturing cost of the starter itself.

  The present invention therefore proposes a new starter as defined above, in which the mounting of the seal provided at the front outlet of the launcher is simple and economical, while making it possible to immobilize it in rotation in the housing.

crankcase.

  More particularly, according to the invention, the seal made in one piece, is provided at least on one front face of its body with a rib which extends along said body and of thickness less than 1 body thickness, said bearing directly holding said compression seal

against said housing.

  Thus, advantageously in the starter according to the invention, the fixing of the seal in the casing does not require the use of other parts since said seal is held directly by the

  bearing itself by compression against the casing.

  However, be aware that the value of the compression of the seal produced directly by the bearing can vary, because it is clear that the position of the bearing face of the bearing against the seal, and the dimensions of the internal housing of the housing. in which the gasket is placed, cannot be fully controlled due to dimensional manufacturing tolerances

  of the aforementioned various elements of the starter.

  The rib provided on the seal according to the invention then advantageously makes it possible to absorb the dimensional variations in the manufacture of the parts of the starter while ensuring, in the event of minimal crushing of the seal by the bearing, a force of crushing of the seal. sufficient to allow it to be stationary in rotation in the housing. In the event of maximum crushing of said seal by the bearing against the casing, said

3 2764946

  rib allows by deforming not to transmit excessive deformations towards the sealing lip producing an excessive tightening of the seal on the launcher where friction and heating of the latter causing its rapid wear and loss of sealing . According to other features of the invention, it can be provided that said rib of the seal is continuous or discontinuous along said seal body. The rib may be carried on the rear front face of said body, facing the bearing, so that said rib bears against said bearing. Of course according to alternative embodiments, said rib can be carried by the front end face of said seal body, so that it comes to bear against the internal face of the transverse wall of the casing. It is also possible according to the invention to have a rib on each of the front end faces and

rear of the seal body.

  The following description, next to the drawings

  attached, given by way of nonlimiting examples, will make it clear what the invention consists of and how

it can be done.

  In the accompanying drawings: - Figure 1 is a partial schematic view in longitudinal section of the starter according to the invention, and - Figure 2 is a schematic detail view of the seal and its positioning in the

  casing, of the starter of figure 1.

  In Figure 1 is partially shown a starter 100 for a motor vehicle, of the outgoing pinion type. Such a starter 100 comprises a casing 110 in which a launcher 120 of axis X is guided in axial translation and in rotation about its axis X by

4 2764946

  via a bearing 130 interposed between the

launcher 120 and the housing 110.

  This bearing 130 is for example a bearing of the needle bearing type or a sintered bronze bearing or else a rolled strip with a coating of

slip and anti-wear.

  As can be seen in Figure 1, the rear end of the launcher 120 located in the housing 110, is mounted in a yoke 1 hinged on the movable core 2 of the contactor 3 arranged in said housing. Thus, in a known manner and which will not be described here in detail, the translational movement of said movable core is

  transmitted via said articulated yoke to the launcher 120.

  The front end of the launcher 120 emerges outside the casing 110 through a circular opening 112 provided in a front transverse wall 111 of the casing 110. At this outer front end of the launcher is provided a launcher pinion 121 which is intended to mesh with a toothed wheel (not shown) of a flywheel of an internal combustion engine of the vehicle equipped with the starter 100. This pinion 121 comes from

  training with the body of the launcher 120.

  As shown in more detail in Figure 2, in the starter 100, a seal 140 is positioned in the housing 110 at said circular opening 112 of the front transverse wall 111. This seal is placed in a housing delimited on the front side by the internal face 11la of said front transverse wall 111 of the casing 110, on the rear side situated in the casing, by the front frontal face 130a of the bar 130, and laterally by -a internal face 10la ′ of a part cylindrical llOa of the casing by

launcher 120 and bearing 130.

  The seal 140 produced in one piece by molding a plastic or elastomer, comprises an annular body 141 of axis X, then positioned

2764946

  around the launcher 120, this body 141 carrying a circular lip 142 coming into contact with said launcher 120 to avoid inadvertent intrusion into the casing 110 of dust or water charged with corrosive elements attacking the friction surfaces between the bearing 130

and the launcher 120.

  According to the embodiment shown in Figures 1 and 2, the seal 140 is provided on the rear end face 141a of its body 141 with a rib 143 which extends continuously or discontinuously along said body 141 , and has a thickness e less than the thickness E of the body 141. This rib 143 comes into contact with the front end face 130a of the bearing 130 and said bearing 130 then directly maintains the seal 140 by compression against the casing 110 More particularly, under the action of the bearing 130, the seal 140 is compressed against the internal face 11a of the front transverse wall 111 of the casing 110 and against the internal face 110a 'of the cylindrical part 110a behind the

housing 110.

  By means of this rib 143, which makes it possible to absorb the dimensional differences in manufacture of the various elements of the starter 100, the compression of the seal 140 by the bearing 130 is sufficient to immobilize said seal in rotation while in the housing. avoiding, in the event of excessive compression, a deformation of the lip 142 leading to a

  rapid wear thereof and loss of tightness.

  Of course, according to other alternative embodiments not shown, it is conceivable that this rib is carried by the front end face 141b of the body 141 of the seal 140, facing the internal face 11a of the front transverse wall 111 of the casing 110, so that it comes into contact with it. In

6 2764946

  in this case the bearing would then lean directly against the

  rear face of the seal body.

  We can also consider a rib on each

  front and rear face of the seal body.

  The height of each rib is such that

  the size of the seal 140 is optimal.

  The use of such a seal makes it possible to reduce the number of parts of the starter since it is not necessary to have recourse to an additional part to fix the seal in the casing, the latter being mounted further easily in said housing, which results in an advantageous reduction in the manufacturing cost

of the starter.

  The present invention is in no way limited to the embodiment described and shown in the figures, but the person skilled in the art will know how to make any variant

conforms to his spirit.

7 2764946

Claims (6)

  1. Motor vehicle starter (100), of the type comprising on the one hand a casing (110) in which a launcher (120) of X axis is guided in axial translation and in rotation about its X axis via a bearing (130) interposed between the launcher (120) and the casing (110), the launcher (120) emerging outside the casing (110) through an opening (112) provided in a transverse wall (111) of the housing (110), and on the other hand a seal (140) positioned in the housing (110) at the level of said opening (112), said seal (140) comprising an annular body (141) of axis X which carries a lip (142) coming into contact with said launcher (120), characterized in that the seal (140) made in one piece, is provided at least on one end face (141a) of its body (141) of a rib (143) which extends along said body (141) and of thickness (e) less than the thickness (E) of the body (141), said bearing (130) directly holding the said seal (140) by compression against said housing (110).   2. Starter (100) according to claim 1, characterized in that the rib (143) is continuous on along said body (141).   3.The starter (100) according to claim 1, characterized in that the rib (143) is discontinuous on along said body (141).   4.The starter (100) according to one of claims 1   to 3, characterized in. that the rib (> 13) is provided on the rear front face (141a) of said body (141), facing the bearing (130), so that said rib   (143) bears against said bearing (130). 8 2764946   5. Starter (100) according to one of claims 1   to 3, characterized in that the rib is provided on the front end face of said body, facing the internal face of said transverse wall of the casing, so   let it come to bear against the latter.   6.The starter (100) according to one of claims 1   to 3, characterized in that the front and rear front faces of the body of the seal bear a rib.