MECHANICAL ARRANGEMENT, GEARBOX MOTOR AND ASSOCIATED MOUNTING METHOD

Description

[0001] The present invention relates to an assembly of a plastic barrel on a metal casing of a mechanical device comprising a shaft. The metal casing corresponds for example to a casing of a geared motor, in particular of a wiping device of a motor vehicle.

[0002] The output shafts of geared motors in wiping systems, particularly for the rear windows of motor vehicles, generally include a relatively long output shaft to allow passage through the bodywork. It is therefore necessary to use a shaft guide barrel which is fixed to the geared motor housing containing the reduction mechanism.

[0003] Such barrels exist in the state of the art, but they are generally expensive and / or difficult to manufacture or to fix on the housing of the geared motor. Document EP o 635 651 A1 shows such a device forming part of the state of the art.

[0004] It is therefore necessary to provide a solution that allows for an inexpensive barrel that is easy to attach to the housing. In addition, the assembly of the barrel and the housing must prevent the introduction of dirt or moisture into the housing in order to preserve the life of the reduction mechanism.

[0005] To this end, the present invention relates to a method for fixing a plastic barrel intended to guide an output shaft of a mechanical device on a housing of said mechanical device, said housing comprising a chimney limited by an upper edge and a base, said chimney being arranged to partially surround the output shaft, the plastic barrel comprising a lateral protuberance, the method comprising at least the following steps: a first end of the plastic barrel is inserted into the chimney of the housing until the lateral protrusion comes into axial abutment against the upper edge of the chimney, the first end of the plastic barrel is at least partially deformed to form an axial counter-abutment.

[0006] According to another aspect of the present invention, the housing is for example a metal housing or a plastic housing whose hardness may be different from the hardness of the plastic of the barrel.

[0007] According to another aspect of the present invention, the base of the chimney is at least partially flared towards the interior of the housing and the deforming step comprises plastically deforming flaring the first end of the plastic barrel.

[0008] According to another aspect of the present invention, the deforming step comprises a heating step.

[0009] According to another aspect of the present invention, the heating temperature is between 150 and 180°.

[0010] According to another aspect of the present invention, the deforming step comprises a step of applying ultrasound.

[0011] According to another aspect of the present invention, the plastic drum is made of polyamide which can be loaded, i.e. reinforced with fiberglass for example.

[0012] According to another aspect of the present invention, the chimney of the housing comprises at least one recess and the deforming step comprises deforming the plastic barrel in said at least one recess to form an anti-rotation lug.

[0013] According to another aspect of the present invention, the mechanical device is a geared motor of a wiping device.

[0014] The present invention also relates to an assembly of a housing as described above and a plastic barrel, the plastic barrel comprising a lateral protuberance forming a stop and delimiting a first end intended to be inserted into the chimney of the housing around the output shaft, the first end of the plastic barrel having been deformed at least partially to form an axial counter-stop.

[0015] According to another aspect of the present invention, the lateral protrusion has a collar shape.

[0016] According to another aspect of the present invention, the collar comprises an end portion curved towards the first end.

[0017] According to another aspect of the present invention, the collar forms a water deflector to prevent the introduction of droplets into the housing.

[0018] According to another aspect of the present invention, the chimney comprises an at least partially annular counter-form configured to cooperate with the lateral protuberance.

[0019] According to another aspect of the present invention, the first end of the plastic barrel is flared to cooperate with the flared base of the chimney.

[0020] According to another aspect of the present invention, the first end of the plastic barrel is deformed to fit into the recess and form an anti-rotation lug.

[0021] The present invention also relates to a geared motor comprising an electric motor, a reducer comprising an output shaft, a housing as described previously at least partially enclosing the electric motor and the reducer and a plastic barrel forming an assembly with the housing as described previously.

[0022] Other characteristics and advantages of the invention will emerge from the following description, given by way of example and without limitation, with reference to the appended drawings in which: there figure 1 represents a schematic perspective view of a geared motor according to the present invention, the figure 2 represents a schematic perspective view of a barrel according to the present invention, the figure 3 represents a schematic perspective and sectional view of a part of a housing of a geared motor according to the present invention, the figure 4 represents a schematic perspective and sectional view of an assembly comprising a housing of a geared motor and a barrel according to the present invention, the figures 5 , 6 And 7 represents schematic perspective and sectional views of different stages of an assembly according to the present invention, the figure 8 represents a flowchart of the different stages of assembly of the barrel on the housing according to the present invention.

[0023] In all figures, identical elements have the same reference numbers.

[0024] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment or that the features apply only to a single embodiment. Single features of different embodiments may also be combined or interchanged to provide other embodiments.

[0025] There figure 1 represents a perspective diagram of a geared motor 1 intended for a rear window wiping device of a motor vehicle.

[0026] The geared motor 1 comprises an electric motor 3, a reduction mechanism (not shown) arranged in a housing 5 and connected to the electric motor 3. The housing 5 is for example a metal housing or a plastic housing and may comprise fixing lugs 7 to allow fixing to a bodywork element for example. Silentblocs 9 may be arranged at the level of the fixing lugs 7 to produce vibration and acoustic decoupling with the bodywork element.

[0027] The geared motor 1 also comprises a plastic barrel 11 intended to guide an output shaft 12 of the geared motor 1. The plastic barrel 11 is for example made of polyamide which may or may not be loaded, i.e. reinforced with glass fiber in particular or any other type of fiber making it possible to reinforce the polyamide. In the case of a plastic housing, the material of the housing and the barrel may be different and the hardnesses of the two materials may be different.

[0028] There figure 2 represents the barrel 11 alone. The barrel 11 has a generally cylindrical shape and comprises a first end 11a called the internal end intended to be inserted into the housing 5 at the level of a chimney 5a of the housing 5 and a second end 11b. The barrel 11 also comprises a lateral protuberance 11c which delimits the part of the barrel intended to be inserted into the chimney 5a of the housing 5. The lateral protuberance 11c has a general collar shape. The collar can be curved with a first portion which extends in an annular manner around the cylinder then a second portion which extends parallel to the barrel 11 in the direction of the first end 11a, the first and second portions being connected by an intermediate bent portion.

[0029] The first end 11a is intended to be deformed after its introduction into the chimney 5a of the housing 5 to ensure the fixing of the barrel 11 on the housing 5. The figure 2 therefore represents the barrel 11 after its deformation. Before its introduction into the chimney 5a of the housing 5, the first end 11a has a cylindrical shape (see figure 5 ).

[0030] As shown in the figure 3 , the chimney 5a extends between an upper edge or end portion 51 and a base 52. The upper edge 51 is carried by a cylindrical portion 53 of a first diameter D1. The base 52 comprises a proximal portion 54 of a second diameter D2 greater than the first diameter D1 and a flared intermediate portion 55 intended to receive the end 11a of the barrel. The upper edge 51 comprises for example a circumferential material recess 57 intended to receive the second portion of the lateral protuberance 11c and forming an annular counter-form. The flared intermediate portion 55 may also comprise one or more recesses 56, for example three, arranged on a portion of the internal circumference of the chimney 5a and intended to receive anti-rotation lugs 110. The recesses 56 may be distributed regularly around the periphery of the chimney 5a.Indeed, as will be better described in the remainder of the description, the barrel 11 is intended to be deformed after its introduction into the chimney 5a so that the presence of recess(es) 56 causes an irregular deformation of the first end 11a of the barrel 11 on its circumference leading to the formation of anti-rotation lug(s) 110 at the level of the recess(es) 56 which makes it possible to prevent any rotation of the barrel 11 relative to the chimney 5a. The fact that the chimney 5a is flared makes it possible to block a translation of the barrel 11 by creating a counter-stop, the stop being created by the contact between the lateral protuberance 11c and the upper edge 51 of the chimney 5a.

[0031] There figure 4 represents the barrel 11 in the assembled state in the chimney 5a of the housing 5 after deformation of the first end 11a of the barrel 11 to form an assembly between the housing 5 and the barrel 11. The lateral protuberance 11c bears on the upper edge 51 of the chimney 5a and fits by complementary shape around the circumferential material recess 57 formed on the upper edge 51 of the chimney 5a of the housing 5. The circumferential material recess 57 therefore acts as a counter-form of the lateral protuberance 11c of the barrel. Thus, by covering the upper edge 51 of the chimney 5a, the lateral protuberance 11c forms a moisture deflector making it possible to prevent the introduction of water drops at the connection between the barrel 11 and the housing 5, which makes it possible to protect the interior of the housing 5 and in particular the reduction mechanism.

[0032] The first end 11a of the barrel 11 is in contact with the flared intermediate portion of the chimney and is therefore also flared. In addition, the portions of the first end 11a facing the recesses 56 are deformed so as to be inserted at least partially into said recesses 56 and form anti-rotation lugs 110.

[0033] Furthermore, the second end 11b of the barrel 11 may comprise a narrower internal part to improve the guidance of the output shaft 12 of the gear motor 1. In addition, at the internal part of its second end 11b, the barrel 11 may comprise a groove 11d intended to receive a seal 13, for example an O-ring or an overmolded seal to ensure sealing between the barrel 11 and the output shaft of the gear motor 1.

[0034] Thus, in the assembled state, the chimney 5a partially surrounds the barrel 11, that is to say from the first end 11a to the lateral protuberance 11c of the barrel 11.

[0035] The different stages of the process allowing the assembly and fixing of the plastic barrel 11 on the housing 5 will now be described from the figures 5 à 7 and the organizational chart of the figure 8 .

[0036] The first step 101 concerns the insertion of the first end 11a of the plastic barrel 11 into the chimney 5a of the housing 5 as represented by the arrow in the figure 5 . Insertion is carried out until the lateral protrusion 11c comes into contact with the end of the chimney as shown in the figure 6 The lateral protuberance 11c is positioned so that the first end 11a of the plastic barrel 11 is located opposite the flared intermediate portion 55 of the chimney 5a when the lateral protuberance is in contact with the upper edge 51 of the chimney 5a.

[0037] The second step 102 concerns the plastic deformation of the first end 11a of the plastic barrel 11. This deformation corresponds for example to a flaring of the first end against the flared intermediate portion 55 of the chimney 5a to form an axial counter-stop and prevent any translation of the plastic barrel 11 relative to the chimney 5a, the stop being formed by the support of the lateral protuberance 11c on the upper edge 51 of the chimney 5a.

[0038] According to a first alternative 102a, the plastic deformation is carried out by means of a step of heating the first end 11a of the plastic barrel 11. In the case of a plastic barrel 11 made of polyamide (which may or may not be filled), the heating temperature is, for example, between 150 and 180°C. The deformation may be carried out by a conical or substantially conical element introduced from the inside of the housing 5 into the first end 11a of the plastic barrel 11. Pressure is applied to the conical element towards the second end 11b of the plastic barrel 11 while the plastic barrel 11 is held in position (the lateral protuberance 11c being in contact with the upper edge 51) in the housing 5, leading to the flaring of the first end of the plastic barrel 11.In the case where the chimney 5a comprises recesses 56, the conical element may comprise shapes complementary to the recesses 56 so that the plastic barrel 11 is deformed to come and position itself in the recesses 56 and form anti-rotation lugs 110.

[0039] According to a second alternative 102b, the plastic deformation of the first end 11a of the plastic barrel 11 is obtained by means of a step of applying ultrasound, for example via a sonotrode probe. The application of ultrasound allows local heating of the first end 11a of the plastic barrel 11 which then allows plastic deformation. A conical or substantially conical element similar to the conical element of the alternative 102a can be used to flare the first end 11a against the flared intermediate portion 55 of the chimney 5a of the housing 5. Once the first end 11a of the plastic barrel is flared, the plastic barrel is fixed to the housing and forms an assembly.

[0040] Step 203 consists of placing the mechanical device, for example a geared motor 1, in the housing 5 and the output shaft 12 of the mechanical device 1 in the plastic barrel 11 as shown in the figure 7 .

[0041] The present invention is not limited to a geared motor 1 of a device for wiping a rear window of a motor vehicle but also extends to other types of mechanical devices comprising an output shaft, a housing and a plastic barrel for guiding the output shaft fixed to the housing.

[0042] Thus, the use of a plastic barrel 11 makes it possible to perform the function of guiding the output shaft 12 while limiting the weight and cost price of the barrel 11. In addition, the fixing of the plastic barrel 11 to the housing 5 which can be made of a material different from the barrel 11, for example metal, is simple and quick and also makes it possible to limit the risks of introducing humidity inside the housing 5 and therefore to preserve the mechanism of the geared motor 1.

Claims

1. A method for attaching a plastic barrel (11) intended to guide an output shaft (12) of a mechanical device to a housing (5) of said mechanical device, said housing (5) comprising a chimney (5a) delimited by an upper edge (51) and a base (52), said chimney (5a) being arranged to partially surround the output shaft (12), the plastic barrel (11) comprising a lateral protuberance (11c), the method comprising at least the following steps: - inserting a first end (11a) of the plastic barrel (11) into the chimney (5a) of the housing (5) until the lateral protuberance (11c) axially abuts against the upper edge (51) of the chimney (5a), characterized in that - at least partially deforming the first end (11a) of the plastic barrel (11) in order to form an axial counter-abutment.

2. The method as claimed in claim 1, wherein the base (52) of the chimney (5a) is at least partially flared towards the inside of the housing (5) and the deformation step comprises flaring the first end (11a) of the plastic barrel (11) by plastic deformation.

3. The method as claimed in claim 1 or 2, wherein the deformation step comprises a step of heating or applying ultrasound.

4. The method as claimed in claim 3, wherein the deformation step comprises a heating step and the heating temperature is, in particular, between 150 and 180°.

5. The method as claimed in any one of the preceding claims, wherein the plastic barrel (11) is made of polyamide.

6. The method as claimed in any one of the preceding claims, wherein the chimney (5a) of the housing (5) comprises at least one recess (56) and the deformation step comprises deforming the plastic barrel (11) into said at least one recess (56) in order to form an anti-rotation lug (110).

7. The method as claimed in any one of the preceding claims, wherein the mechanical device is a gear motor (1) of a wiper device.

8. Assembly of a housing (5) for a mechanical device comprising a chimney (5a) configured to at least partially surround an output shaft (12) of the mechanical device, said chimney (5a) comprising a base (52) comprising a substantially conical inner shape flared towards the inside of said housing (5) and a plastic barrel (11), the plastic barrel (11) comprising a lateral protuberance (11c) forming an abutment and delimiting a first end (11a) intended to be inserted into the chimney (5a) of the housing (5) around the output shaft (12) of the mechanical device, characterized in that the first end (11a) of the plastic barrel (11) have been at least partially deformed to form an axial abutment.

9. Assembly as claimed in the preceding claim, wherein at least one recess (56) is provided in the base (52) of the chimney (5a) of the housing (5) in order to receive an anti-rotation lug (110).

10. Assembly according to claim 8 or 9, wherein the lateral protuberance (11c) is flange-shaped.

11. The assembly as claimed in the preceding claim, wherein the flange comprises a part that is curved towards the first end (11a) of the plastic barrel (11).

12. The assembly as claimed in claims 8 to 11, wherein the chimney (5a) comprises an at least partially annular mating shape configured to cooperate with the lateral protuberance (11c).

13. The assembly as claimed in one of claims 8 to 12, wherein the first end (11a) of the plastic barrel (11) is flared to cooperate with the flared base (52) of the chimney (5a).

14. A gear motor (1) comprising an electric motor (3), a reduction gear comprising an output shaft (12), a housing (5) at least partially containing the electric motor (3) and the reduction gear and a plastic barrel (11) forming an assembly with the housing as claimed in one of claims 8 to 13.