WO2019207223A1

WO2019207223A1 - Method for mounting a seal on a gearbox shaft

Info

Publication number: WO2019207223A1
Application number: PCT/FR2019/050629
Authority: WO
Inventors: Daniel Teixeira
Original assignee: Psa Automobiles Sa
Priority date: 2018-04-24
Filing date: 2019-03-20
Publication date: 2019-10-31
Also published as: FR3080425B1; FR3080425A1

Abstract

The invention relates to a method for mounting a seal (230), pre-mounted on a protection device (400), onto a cylindrical part comprising a sharp edge that risks damaging the seal, the method comprising: – a step, using a press (300), of slip-fitting, onto the part, the seal and the protection device arranged between the part and the seal, by sliding the protection device over the sharp edge; the protection device being then blocked in translation against a blocking wall of the part; the seal sliding on the protection device then on the part; – a step of linking the press and the protection device; – a step of withdrawing the press with the protection device; the linking step being carried out by rotation of the press with respect to the protection device creating a helical link.

Description

METHOD FOR MOUNTING A SEAL ON A GEARBOX SHAFT

The invention relates to the installation of seals in a motor vehicle and more particularly to the seals which, during their assembly, may be damaged by sharp edges on which the seals slide.

[0002] The gearboxes of motor vehicles comprise shafts transmitting to a component of the motor vehicle or receiving from the latter a rotational movement. The gearboxes comprise a housing, relative to which the shafts are rotating, usually filled with oil to meet the proper operation of said gearbox. In order to avoid the loss of oil and therefore premature degradation of the gearbox, a seal is arranged between the housing and each shaft. The seal is mounted on the gearbox after mounting the shaft in the housing. The seal is fitted on the shaft.

However, in order to transmit or receive the rotational movement, an end of the shaft coupled to the component of the motor vehicle comprises splines. These grooves comprise sharp edges which, when fitting the seal on the shaft, may damage the seal.

It is known, to overcome this problem, to pre-mount the seal on a ring-shaped protective device, the protective device, also called ogive, being intended, when fitting the seal of sealing, sliding on the shaft, between the seal and the shaft, protecting the seal edges sharp. The protection device and the seal are driven by a press bearing directly on the seal, around the protection device. The protective device is locked in translation, by increasing the diameter of the shaft, before the end of the fitting of the seal, so that the latter comes into contact with the shaft in its final position. Such a protective device must, however, at the end of operation, be removed manually from the tree by an operator.

DE102014016722A1 discloses such a method of fitting, on a shaft, a seal pre-mounted on a protective device. The protection device comprises a radial advance extending towards the press and configured to cooperate with a radial advance of the press extending towards the protection device. After locking the protection device in translation, the radial advance of the press passes beyond the radial advance of the protection device, on the side of the seal, the press continuing to press the seal until at its final position. The radial advances coming into contact with each other during the withdrawal of the press, allow the withdrawal of the protective device of the tree.

Alternatively, another document describes, instead of radial advances, magnets also allowing the removal of the protective device of the shaft.

Such methods of fitting the seal enable the removal of the protective device concomitantly with the withdrawal of the press.

[001 1] The objective is to propose an alternative technique to the removal of the protective device in concomitance with the withdrawal of the press.

For this purpose, it is proposed, in the first place, a method of mounting a seal on a cylindrical piece comprising at least one sharp edge likely to damage the seal, the seal of sealing being pre-mounted on a protection device, the seal and the protective device having a general annular shape complementary to the shape of the workpiece, the mounting method comprising: a primary fitting step, through a press, the protective device and the seal on the workpiece, by sliding the protective device, in a direction of depression, on the at least one sharp edge; the protective device being disposed between the workpiece and the seal; a step of secondary fitting, through the press, the seal on the workpiece; the protection device being locked in translation, in the direction of depression, against a blocking wall of the part; gasket sliding sealing, in the direction of depression, on the protection device and then on the part, beyond the at least one sharp edge; a step of connecting the press and the protection device; a step of removing the press, in a direction of withdrawal opposite to the driving direction, the press removing with it the protective device; the connecting step being carried out by rotating the press relative to the protection device, in a direction of connection, creating a helical connection between the press and the protection device.

Such a method of mounting a seal can effectively protect the seal during its mounting on the part, to remove manual steps to save time and quality.

Various additional features may be provided, alone or in combination: during the connecting step, the helical connection between the press and the protection device is effected by cooperation between a thread of the protective device and a tapping of the press; the threading and the tapping allowing a solidarization resistant without risk of damaging the press or the protective device; the linking step is performed by rotating, in the direction of connection, an inner portion of the press, an outer portion of the press being locked in rotation, in the direction of connection, so as not to damage the seal sealing by friction with the outer part; during the linking step, a recess of the press blocks, by abutment against a shoulder of the protection device, the translational protection device in the withdrawal direction so as to define a maximum position of the protective device in the press ; the mounting method comprises, after the step of removing, a step of separating the device for protecting the press made by rotating the press relative to the protection device, in a direction opposite to the direction of connection, eliminating the helical connection between the press and the device protection so as to allow the realization, once again, of the seal mounting method without the use of a manual operation while maintaining the integrity of the press and the protective device;

- The uncoupling step is performed by rotation, in said direction opposite to the connecting direction, of the inner part of the press, the outer portion of the press being locked in rotation in said opposite direction to the connection direction; the outer part protecting the individuals positioned close to the press during the rotation of the inner part;

during the primary fitting step, the at least one sharp edge on which the protection device slides extends in a direction defined by the driving direction so as to optimize the torque transmitted between the component and the component with which the piece is coupled;

- During the primary fitting step, the piece comprises several sharp edges distributed around the entire periphery of said piece and the protective device extends around the entire periphery of said piece.

It is proposed, secondly, a method of assembling a gearbox, the gearbox comprising: a housing, a shaft having an end provided with at least one sharp edge, said end of the gearbox; shaft protruding from the housing, and a seal disposed between the housing and the shaft, the method of assembling the gearbox comprising a step of fitting the seal on the shaft made according to the mounting method described above.

In a variant of the assembly method of the gearbox described above, at the end of the secondary fitting step: an inner lip of the seal is in contact with the shaft, an outer lip the seal is in contact with the housing, a support of the seal is in contact with the press, the seal having, in cross section, a generally U-shape.

The U-shaped allowing to marry to the maximum the housing and the shaft movable relative to each other.

The invention will be better understood, and other objects, features, details and advantages thereof will appear more clearly in the explanatory description which follows with reference to the accompanying drawings given solely by way of example illustrating a embodiment of the invention and in which: Figure 1 is a schematic perspective view of a motor vehicle comprising a motor and a gearbox, the gearbox comprising a housing, a shaft and a seal disposed between the housing and the shaft; Figure 2 is a schematic sectional view of the seal pre-mounted on a protection device; FIGS. 3 and 4 are diagrammatic views in section of a step of primary fitting, by means of a press, of the seal on the shaft, by convention the shaft not being shown in section; ; Figure 5 is a schematic sectional view of a step of secondary fitting, through the press, the seal on the shaft, by convention the shaft is not shown in section; Figure 6 is a schematic sectional view of a connecting step of the protection device and the press, by convention the shaft is not shown in section; Figure 7 is a schematic sectional view of a step of removing the press and the protection device, by convention the shaft is not shown in section; Figure 8 is a schematic representation of various steps of a method of mounting the seal on the shaft. In Figure 1 is shown a vehicle 1 automobile comprising a motor 100 and a gearbox 200 integral with the motor 100.

The gearbox 200 comprises: a housing 210, a shaft 220 having an end 221 projecting from the housing 210, said end 221 cooperating with the motor 100 and a seal 230 disposed between the housing 210 and the housing 210; tree 220.

The seal 230 avoids the loss of oil in the housing 210 for the proper operation of the gearbox 200.

Said end 221 of the shaft 220 projecting from the housing 210 comprises at least one groove 222 for transmitting a rotational movement produced by the motor 100. The at least one groove 222 comprises at least one sharp edge.

In the embodiment shown, the grooves 220, and therefore the sharp edges, are distributed over the entire periphery of the shaft 220.

According to the illustrated embodiment, as can be seen in Figures 3 to 7, in a method 1000 for mounting the seal 230, a press 300 engages the seal 230 on the shaft 220 , by the end 221 of the shaft 220, projecting from the housing 210, comprising the at least one sharp edge.

Thus, before mounting the seal 230 on the shaft 220, so as not to damage the seal 230 when mounting the latter, the seal 230 is pre-mounted on a protective device 400, also called ogive, as shown in Figure 2.

In the embodiment shown, the seal 230 comprises an inner lip 231, an outer lip 232 and a support 233 connecting the inner lip 231 and the outer lip 232. The seal 230 has, in cross section, a generally U-shape. The inner lip 231 is intended to be in contact with the shaft 220. The inner lip 231 is in contact with a skirt 410 of the protection device 400 when the seal 230 is pre-mounted on the device 400 protection.

The external lip 232 is intended to be in contact with the housing 210.

The support 233 is intended to be in contact with the press 300, during assembly of the seal 230 on the shaft 220.

According to the embodiment shown, the protection device 400 comprises a shoulder 420 blocking the insertion of the seal 230 on the protection device 400 during pre-assembly.

The protection device 400 comprises a primary helical linkage means 430 intended to cooperate with a secondary helical linkage means 321 of the press 300.

According to the illustrated embodiment, the shoulder 420 substantially separates the primary helical connecting means 430 and the skirt 410 of the protection device 400. In different embodiments, the primary helical connecting means 430 is disposed on the skirt 410.

In the illustrated embodiment, the primary helical connecting means 430 is a tapping and the secondary helical connecting means 321 is a thread. The tapping and threading extend over a limited length, respectively, of the protection device 400 and the press.

According to the illustrated embodiment, the seal 230 and the protection device 400 and the shaft 220 have forms of revolution. The seal 230 and the protective device 400 have an annular shape, complementary to the cylindrical shape of circular section of the shaft 220, so that the seal 230 and the protective device 400 are fitted on the 220. The protective device 400 extends over the entire periphery of the shaft 220. The shoulder 420 has a substantially annular shape extending outwardly of the protection device 400 and arranged substantially in the middle of the device. 400 of protection. In the embodiment shown, the press 300 has a general shape of circular cross section tube. The press 300 preferably has an internal diameter substantially equal to the outer diameter of the shaft 220 improving the guiding of the press 300 relative to the shaft 220 during assembly of the seal 230.

In the illustrated embodiment, the press 300 comprises: an outer portion 310 intended to be in contact with the support 233 of the seal 230, when mounting the seal 230 on the shaft 220 and an inner portion 320 comprising the secondary helical connecting means 321 and rotatable relative to the outer portion 310.

The method 1000 for mounting the seal 230 on the shaft 220 is shown schematically in Figure 8 and is illustrated in Figures 3 to 7.

The mounting method 1000 comprises a step 1001 primary fitting of the seal 230 on the shaft 220, shown in Figures 3 and 4, until the contact with the skirt 410 of the protection device 400 with a wall 223 blocking the shaft 220, the protective device 400 thus abuts against the wall 223 blocking. During step 1001 of primary fitting, the support 233 of the seal 230 is in contact with the external part 310 of the press 300, the latter pushing the seal 230 and the protection device 400 the along the end 221 protruding from the shaft 220, in a direction 2 of depression. The skirt 410 of the protective device 400 is disposed between the shaft 220 and the seal 230 protecting the latter against potential damage caused by the sharp edge or edges of the end 221 of the shaft 220.

In the illustrated embodiment, the sharp edges are arranged in a direction defined by the direction of penetration 2 corresponding to the direction in which the shaft 220 extends. In different embodiments, the sharp edges are perpendicular, oblique or in different directions with respect to said direction along which the shaft 220 extends.

In the embodiment shown, the wall 223 blocking the shaft 220 defined on the shaft 220 a diameter greater than the diameter of the end 221 and the diameter of the device 400 of protection. As shown in Figure 5, the mounting method 1000 comprises a step 1002 of secondary fitting of the seal 230 on the shaft. The support 233 of the seal 230 remains in contact with the external portion 310 of the press 300, the latter pushing the seal 230, in the direction of depression 2. The protection device 400 is, for its part, locked in translation in the direction of depression so that the seal 230 slides on the protection device 400 to its final position, between the housing 210 and the housing. 220 shaft of the gearbox 200.

When the sealing gasket 230 is disposed in its final position, as shown in Figure 5, the primary helical connection means 430 of the protection device 400 is in contact with the secondary helical connecting means 321 of the part 320 internal of the press 300.

The method 1000 for mounting the sealing gasket 230 comprises a step 1003 for connecting the internal portion 320 of the press 300 and the protection device 400, shown in FIG. 6. During the connection step 1003 , the inner portion 320 is rotated in a connecting direction 3, so that the primary helical connecting means 430 and the secondary helical connecting means 321 cooperate and create a helical connection solidarisant the inner portion 320 of the press 300 and the protection device 400. The protective device 400 is thus moved in a direction of withdrawal 4 opposite to the direction of depressing.

In the embodiment shown, the outer portion 310 of the press 300 comprises a recess 311, extending towards the inner portion 320 of the press 300, intended to block, by contact between the recess 311 and the shoulder 420 of the protection device 400, the protection device 400 in translation in the direction 4 of withdrawal.

In step 1003 of the connection, the outer portion 310 of the press 300, in contact with the seal 230, is immobile in rotation relative to the seal 230. Thus, the seal 230 is not damaged by friction due to relative movement between the outer portion 310 and the seal 230.

According to a different embodiment, the press 300 includes only the outer portion 310 provided with the means 321 secondary helical link. In a variant, the outer portion 310 comprises a bearing in contact with the seal 230 of so as not to damage the sealing gasket 230 during the rotation of the outer portion 310 creating the helical connection.

As illustrated in FIG. 7, the assembly method 1000 includes a step 1004 for removing the press 300 and the device 400 for protecting the shaft 220. The press 300 is moved in the direction 4 of withdrawal pulling with it the protective device 400 secured to the internal portion 320 of the press 300 through the helical link.

The method 1000 for mounting the seal comprises a step 1005 of uncoupling the device 400 for protecting the press 300. The internal portion 320 of the press is rotated so that the means 430 of primary helical connection and the means 321 secondary helical link deletes the helical connection solidarisant the inner portion 320 of the press 300 and 400 protection device. The protection device 400 is thus automatically disconnected from the press 300.

By automatic is heard without manual intervention of an operator on the 400 protection device.

In the embodiment shown, the internal portion 320 of the press is rotated, during the step 1005 of uncoupling, in a direction opposite to the direction 3 of connection.

According to different embodiments, the step 1005 of uncoupling is performed by tearing the 400 protection device. In a variant, the protection device 400 is composed of several parts that can be brought closer so that the protection device 400 is no longer integral with the press 300.

Such a method of mounting the sealing gasket 230 on the shaft 220 of the gearbox 200 makes it possible to effectively protect the seal 230 during its assembly. The press 300 required to implement this mounting method 1000 is simple to design and manufacture.

The assembly method 1000 also allows, by eliminating manual steps, to save time on the assembly of a vehicle 1 automobile and more particularly a box 200 speeds and to improve quality by avoiding problems. risks of forgetting the realization of manual steps.

Claims

1. Method (1000) for mounting a seal (230) sealing on a cylindrical piece comprising at least one sharp edge likely to damage the seal (230) sealing, the seal (230) sealing being pre-mounted on a protection device (400), the sealing gasket (230) and the protection device (400) having an annular general shape complementary to the shape of the part, the method (1000) of mounting comprising: a step (1001) of primary fitting, by means of a press (300), of the device (400) of protection and the seal (230) of sealing on the workpiece, by sliding of the device (400) of protection following a direction (2) of depression on the at least one sharp edge; the protection device (400) being disposed between the workpiece and the sealing gasket (230); a step (1002) secondary fitting, through the press (300), the seal (230) sealing the workpiece; the protection device (400) being locked in translation, in the depressing direction (2), against a wall (223) for blocking the workpiece; the sealing seal (230) sliding, in the direction (2) of depression, on the device (400) of protection and on the piece, beyond the at least one sharp edge; a step (1003) for connecting the press (300) and the protection device (400); a step (1004) for withdrawing the press (300), in a direction (4) of withdrawal opposite to the direction (2) of depression, the press (300) withdrawing with it the device (400) of protection; the method (1000) of mounting being characterized in that the step (1003) of connection is carried out by rotation of the press (300) relative to the device (400) of protection, in a direction (3) of connection, creating a helical link between the press (300) and the protection device (400).

2. Method (1000) for mounting a seal (230) sealing according to the preceding claim, characterized in that, during the step (1003) of connection, the helical connection between the press (300) and the protection device (400) is provided by cooperation between a thread of the device (400) of protection and a tapping of the press (300).

3. Method (1000) for mounting a seal (230) sealing according to any one of the preceding claims, characterized in that the step (1003) of connection is carried out by rotation, according to the direction (3) connection, an inner portion (320) of the press (300), an outer portion (310) of the press (300) being locked in rotation in the direction (3) of connection.

4. Method (1000) for mounting a seal (230) sealing according to any one of the preceding claims, characterized in that, during the step (1003) of connection, a recess (311) of the press (300) blocks, by abutment against a shoulder (420) of the device (400) of protection, the device (400) for protection in translation along the direction (4) withdrawal.

5. Method (1000) for mounting a seal (230) sealing according to any one of the preceding claims, characterized in that it comprises, after the step (1004) of withdrawal, a step (1005) detaching the device (400) for protecting the press (300) made by rotating the press (300) relative to the protection device (400) in a direction opposite to the connecting direction (3), eliminating the helical connection between the press (300) and the protection device (400).

6. Method (1000) for mounting a seal (230) sealing according to the preceding claim, characterized in that the step (1005) of uncoupling is performed by rotation, in said opposite direction to the direction (3) of connection, the portion (320) internal of the press (300), the portion (310) external of the press (300) being locked in rotation in said opposite direction to the direction (3) of connection.

7. Method (1000) for mounting a seal (230) sealing according to any one of the preceding claims, characterized in that, during the step (1001) of primary fitting, the at least one edge vivid on which slides the device (400) of protection extend in a direction defined by the direction (2) of depression.

8. Method (1000) for mounting a seal (230) sealing according to any one of the preceding claims, characterized in that, during the step (1001) of primary fitting, the piece comprises several edges vividly spread over everything the periphery of said piece and the device (400) of protection extends around the entire periphery of said piece.

9. A method of assembling a gearbox (200), the gearbox (200) comprising: - a housing (210), a shaft (220) having an end (221) provided with at least one edge live, said end (221) of the shaft (220) protruding from the housing (210), and a seal (230) sealing between the housing (210) and the shaft (220), the method of assembly of the gearbox (200) being characterized in that it comprises a step of fitting the seal (230) sealing on the shaft (220) made according to the method (1000) of mounting according to one any of the preceding claims.

10. A method of assembling a gearbox (200) of speeds according to the preceding claim, characterized in that, at the end of the step (1002) secondary fitting: a lip (231) internal seal (230) sealing is in contact with the shaft

(220), an outer lip (232) of the seal (230) sealing is in contact with the housing

(210), - a support (233) of the sealing gasket (230) is in contact with the press (300), the sealing gasket (230) having, in cross-section, a generally U-shape.