Method for mounting a sealing ring of a propulsion electric motor of an motor vehicle

Abstract

The invention relates to a method for mounting a sealing ring (1) of an electric motor comprising a metal casing, a fitted sleeve in close contact with the casing and the ring, the method using a mounting tool (6) that comprises a radially expandable locking portion (7) operable between a retracted configuration and a deployed configuration and a support portion (8) for the ring, wherein the method includes placing the ring onto the support portion, inserting the anchoring portion into the duct and deploying it, heating the casing, inserting the sleeve provided with the tool and the ring into the casing, allowing the casing to cool, and retracting the locking portion in order to remove the tool. The invention also relates to a tool (6) intended for use in such a method and to a ring (1) intended to be mounted by such a method.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: METHOD FOR MOUNTING A RING

[0003] SEALING OF AN ELECTRIC MOTOR FOR PROPULSION OF A MOTOR VEHICLE

[0004]

[0001] The present invention claims priority from French application No. 2400207 filed on 10.01.2024, the content of which (text, drawings and claims) is incorporated herein by reference.

[0005]

[0002] The invention relates to a method for mounting a sealing ring of an electric motor for driving a motor vehicle, a mounting tool used in such a method and said ring.

[0006]

[0003] It is known to mount a sealing ring of an electric motor for propulsion of a motor vehicle, said motor comprising:

[0007] - a metal casing,

[0008] - a stator comprising a sleeve, defining a cylindrical conduit, and a plurality of coils of conductive wire mounted inside said sleeve and having a projecting portion extending beyond said sleeve and inscribed in axial view in a circle, said sleeve being fitted in adjusted contact in said casing,

[0009] - said ring, made of molded plastic material, covering said projecting part from the outside.

[0010]

[0004] One way of achieving the fitted contact between the casing and the sleeve is hot shrink fitting, which consists of heating said casing so as to expand it, inserting said sleeve into said casing, then allowing said casing to cool so that it shrinks and ensures a fitted fit of said sleeve into said casing.

[0011]

[0005] A known way of mounting the ring is to do so once the sleeve is fitted into the casing.

[0012]

[0006] However, constraints related to the geometry of the engine may make such a procedure unfeasible.

[0013]

[0007] One way of proceeding could be to insert the ring into the casing once heated, then insert the sleeve.

[0008] However, given the high temperature involved in achieving the expansion of the casing, such an approach proves complicated, as a manufacturing operator cannot do it manually.

[0014]

[0009] The object of the invention is to propose a method for mounting the sealing ring in a safe and ergonomic manner for the manufacturing operator.

[0015]

[0010] To this end, and according to a first aspect, the invention proposes a method for mounting a sealing ring of an electric motor for propulsion of a motor vehicle, said motor comprising:

[0016] - a metal casing,

[0017] - a stator comprising a sleeve, defining a cylindrical conduit, and a plurality of coils of conductive wire mounted inside said sleeve and having a projecting portion extending beyond said sleeve and inscribed in axial view in a circle, said sleeve being fitted in adjusted contact in said casing,

[0018] - said ring, made of molded plastic material, covering said projecting part from the outside, said method providing for the use of a tool for mounting said ring, said tool comprising:

[0019] - a radially extensible friction locking portion of said tool in said conduit, said locking portion being operable between a radially retracted configuration and a radially deployed configuration,

[0020] - and a support portion of said ring; said method comprising the following steps:

[0021] - place said ring on said support part,

[0022] - inserting said anchoring part in a first axial direction in the retracted configuration into said conduit until said ring is peripherally supported on an edge of said sleeve

[0023] - actuate said locking part in the deployed configuration so as to lock said tool in said conduit,

[0024] - heat said casing so as to expand it,

[0025] - inserting said stator provided with said tool and said ring into said casing in a second axial direction, opposite to said first direction, until said ring comes into peripheral abutment on a crown projecting radially inwards provided in said casing,

[0026] - allow said casing to cool so that it shrinks and ensures a snug fit of said sleeve,

[0027] - operate said locking part in the retracted configuration,

[0028] - remove said tool from said conduit.

[0029]

[0011] It is specified here that, throughout the description, the terms of circular reference (axial, radial, etc.) are taken with reference to the axis of rotation of the motor (reference X in the figures), corresponding in this case to the axis of symmetry of the sleeve.

[0030]

[0012] With such a method, the mounting of the sealing ring is carried out in a safe and ergonomic manner for the manufacturing operator.

[0031]

[0013] According to another aspect, the invention provides a tool for use in such a method, said tool comprising:

[0032] - a radially expandable locking portion operable between a radially retracted configuration and a radially expanded configuration,

[0033] - and a supporting part of a sealing ring.

[0034]

[0014] According to one embodiment, the blocking part comprises

[0035] - a base having a first sector in an arc of a circle intended, when the tool is inserted into the conduit, to match the shape of said conduit and a second sector intended to be moved away from said conduit

[0036] - said second sector is provided with a locking blade actuated radially outwards by a spring, so as to put said locking part in the deployed configuration, said blade cooperating with a cam allowing it to be actuated radially inwards, so as to put said locking part in the retracted configuration.

[0037]

[0015] According to one embodiment:

[0038] - the cam is mounted in rotation by means of a first axial finger sliding in a first radially elongated slot provided in the base

[0039] - the blade is mounted radially sliding by means of a second axial finger secured to said base and radially spaced outwards from said first slot, said second finger sliding in a second radially elongated slot provided in said blade, said blade being further provided with an orifice for receiving said first finger, said cam bearing on said second finger

[0040] - the spring is a spiral traction spring mounted between said fingers.

[0041]

[0016] According to one embodiment, the locking part and the support part are connected to each other by an axially extending connecting rod, so as to keep them at a distance from each other.

[0042]

[0017] The invention finally proposes a sealing ring intended to be mounted by such a method, said ring being provided with a plurality of tabs projecting radially inwards intended to be received by a plurality of respective receiving zones provided on the support part.

[0043]

[0018] According to one embodiment, the ring is provided with two annular seals made of elastomer material intended to ensure sealing at the edge of the sleeve and at the crown.

[0044]

[0019] According to one embodiment, the legs are provided with axial projections intended to allow the ring to be locked in the nominal angular position.

[0045]

[0020] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which:

[0046] - [Fig.1] is a principle representation in partial axial section of an engine during assembly, the sealing ring assembly tool being arranged in the sleeve duct, the locking part being in the deployed configuration,

[0047] - [Fig.2] is a schematic perspective representation of a tool for mounting a sealing ring according to one embodiment, in exploded view (A) and in non-exploded view with representation of the ring mounted on the support part of said tool (B).

[0048]

[0021] A method of mounting a sealing ring 1 of an electric motor for propulsion of a motor vehicle will now be described with reference to the figures, said motor comprising:

[0049] - a metal casing 2,

[0050] - a stator comprising a sleeve 3, defining a cylindrical conduit 4, and a plurality of coils of conductive wire mounted inside said sleeve and having a projecting part 5 protruding from said sleeve and inscribed in axial view in a circle, said sleeve being fitted in adjusted contact in said casing,

[0051] - said ring, made of molded plastic material, covering said projecting part from the outside, said method providing for the use of a tool 6 for mounting said ring, said tool comprising:

[0052] - a radially extensible part 7 for locking by friction of said tool in said conduit, said locking part being actuable between a radially retracted configuration and a radially deployed configuration,

[0053] - and a support part 8 of said ring, said method comprising the following steps:

[0054] - place said ring on said support part,

[0055] - inserting said anchoring part in a first axial direction S1 in the retracted configuration into said conduit until said ring is peripherally supported on an edge 9 of said sleeve,

[0056] - actuate said locking part in the deployed configuration so as to lock said tool in said conduit,

[0057] - heat said casing so as to expand it,

[0058] - inserting said stator provided with said tool and said ring into said casing in a second axial direction S2, opposite to said first direction, until said ring is in peripheral abutment on a crown 10 projecting radially inwards provided in said casing,

[0059] - allow said casing to cool so that it shrinks and ensures a snug fit of said sleeve,

[0060] - operate said locking part in the retracted configuration,

[0061] - removing said tool from said conduit, in particular in said first direction.

[0022] A tool 6 intended to be used in such a method is now described, said tool comprising:

[0062] - a radially extensible locking part 7 actuable between a radially retracted configuration and a radially deployed configuration,

[0063] - and a support part 8 of a sealing ring 1.

[0064]

[0023] According to the embodiment shown, the blocking part 7 comprises:

[0065] - a base 11 having a first sector 12 in an arc of a circle intended, when the tool 6 is inserted into the conduit 4, to match the shape of said conduit and a second sector 13 intended to be moved away from said conduit,

[0066] - said second sector is provided with a locking blade 14 actuated radially outwards by a spring 15, so as to put said locking part in the deployed configuration, said blade cooperating with a cam 16 allowing it to be actuated radially inwards, so as to put said locking part in the retracted configuration.

[0067]

[0024] According to the embodiment shown:

[0068] - the cam 16 is mounted in rotation by means of a first axial finger 17 sliding in a first radially elongated slot 18 provided in the base 11,

[0069] - the blade 14 is mounted radially sliding by means of a second axial finger 19 secured to said base and radially spaced outwards from said first slot, said second finger sliding in a second radially elongated slot 20 provided in said blade, said blade being further provided with an orifice 21 for receiving said first finger, said cam bearing on said second finger,

[0070] - spring 15 is a spiral traction spring mounted between said fingers.

[0071]

[0025] According to the embodiment shown, the locking part 7 and the support part 8 are connected to each other by a connecting rod 22 extending axially, so as to keep them at a distance from each other.

[0072]

[0026] Finally, a sealing ring 1 is described, intended to be mounted by such a method, said ring being provided with a plurality of tabs 23 projecting radially inwards, intended to be received by a plurality of respective receiving zones 24 provided on the support part 8.

[0073]

[0027] It is observed that with such an arrangement, the removal at the end of assembly of the tool 6 from the conduit 4 requires imparting an axial rotation to said tool to release the tabs 23 from the receiving zones 24.

[0028] According to the embodiment shown, the ring 1 is provided with two annular seals 25 - here nested - made of elastomer material intended to ensure sealing at the level of the edge 9 of the sleeve 3 and at the level of the crown 10.

[0029] According to the embodiment shown, the tabs 23 are provided with axial projections 26 intended to allow the ring 1 to be locked in the nominal angular position.

Claims

CLAIMS 1. Method for mounting a sealing ring (1) of an electric motor for driving a motor vehicle, said motor comprising: - a metal casing (2), - a stator comprising a sleeve (3), defining a cylindrical conduit (4), and a plurality of coils of conductive wire mounted inside said sleeve and having a projecting part (5) protruding from said sleeve and inscribed in axial view in a circle, said sleeve being fitted in adjusted contact in said casing, - said ring, made of molded plastic material, covering said projecting part from the outside, said method being characterized in that it provides for the use of a tool (6) for mounting said ring, said tool comprising: - a radially extensible locking part (7) by friction of said tool in said conduit, said locking part being actuable between a radially retracted configuration and a radially deployed configuration, - and a support part (8) of said ring, said method comprising the following steps: - place said ring on said support part, - inserting in a first axial direction (S1) said anchoring part in retracted configuration into said conduit until said ring is peripherally supported on an edge (9) of said sleeve, - actuate said locking part in the deployed configuration so as to lock said tool in said conduit, - heat said casing so as to expand it, - inserting said stator provided with said tool and said ring into said casing in a second axial direction (S2), opposite to said first direction, until said ring is peripherally abutted on a crown (10) projecting radially inwards provided in said casing, - allow said casing to cool so that it shrinks and ensures a snug fit of said sleeve, - operate said locking part in the retracted configuration, - remove said tool from said conduit.

2. Tool (6) intended to be used in a method according to claim 1, characterized in that it comprises: - a radially extendable locking portion (7) operable between a radially retracted configuration and a radially extended configuration, - and a support part (8) of a sealing ring (1).

3. Tool (6) according to claim 2, characterized in that the locking part (7) comprises: - a base (11) having a first sector (12) in an arc of a circle intended, when the tool is inserted into the conduit (4), to match the shape of said conduit and a second sector (13) intended to be moved away from said conduit, - said second sector is provided with a locking blade (14) actuated radially outwards by a spring (15), so as to put said locking part in the deployed configuration, said blade cooperating with a cam (16) allowing it to be actuated radially inwards, so as to put said locking part in the retracted configuration.

4. Tool (6) according to claim 3, characterized in that: - the cam (16) is mounted in rotation by means of a first axial finger (17) sliding in a first radially elongated slot (18) provided in the base (11), - the blade (14) is mounted radially sliding by means of a second axial finger (19) integral with said base and radially spaced outwards from said first slot, said second finger sliding in a second radially elongated slot (20) provided in said blade, said blade being further provided with an orifice (21) for receiving said first finger, said cam bearing on said second finger, - the spring (15) is a spiral traction spring mounted between said fingers.

5. Tool (6) according to any one of claims 2 to 4, characterized in that the locking part (7) and the support part (8) are connected to each other by a connecting rod (22) extending axially, so as to keep them at a distance from each other.

6. Sealing ring (1) intended to be mounted by a method according to claim 1, characterized in that it is provided with a plurality of tabs (23) projecting radially inwards intended to be received by a plurality of respective receiving zones (24) provided on the support part (8).

7. Ring (1) according to claim 6, characterized in that it is provided with two annular seals (25) made of elastomer material intended to ensure sealing at the edge (9) of the sleeve (3) and at the crown (10).

8. Ring (1) according to any one of claims 6 or 7, characterized in that the legs (23) are provided with axial projections (26) intended to allow said ring to be locked in the nominal angular position.

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