POWERTRAIN ASSEMBLY WITH INTERFACE PIECE FOR SUPPLYING LUBRICANT THROUGH A CENTRAL BORE OF A SHAFT

Abstract

A powertrain equips a system and comprises: a) a first component (EQ1) having an axial direction and including a central bore (AC) for carrying lubricant and an inlet portion (PA) carrying a bearing (RA) and defining an open internal housing (LI), b) a housing (C2) including a supply channel (CA) having a first end (E21) receiving the lubricant and a second end (E22) opening into a passage (PC), and c) an interface part (PI) including a hollow tube (TC) having a first sub-part (SP1) housed fixedly and sealed in this internal housing (LI) and a second sub-part (SP2) housed in this passage (PC) and provided with an external flange (CEP) bearing against the bearing (RA) to position the shaft (A1) relative to the latter and an inlet (EL) supplied with lubricant by the second end (E22). Figure 1

Description

Title of the invention: POWER ENGINE WITH INTERFACE PIECE FOR SUPPLYING LUBRICANT TO A CENTRAL BORE OF A SHAFT Technical field of the invention

[0001] The invention relates to powertrains comprising equipment including a shaft, and more specifically to the supply of lubricant to such a shaft. Prior art

[0002] Certain systems, such as certain vehicles (possibly automobiles), comprise a powertrain (or PWM) including equipment having an axial direction and a central bore for carrying lubricant and an intake portion carrying a bearing, comprising a portion of this central bore and housed in a casing. For example, such equipment may be a gearbox or an electric motor. Also, for example, the lubricant carried by the central bore may be intended to lubricate at least one bearing of the PWM shaft line or of the synchronizing devices of the shaft line of a gearbox. Also, for example, the casing may be part of the equipment or of other equipment of the PWM, such as a reduction gear.

[0003] To bring the lubricant into the central bore of the shaft, it has been proposed that the external face of the intake part of the shaft include a main cavity forming a loop and communicating with the central bore via at least one first supply channel making a non-zero angle with the axial direction, and that the housing include a second supply channel having a first end suitable for receiving the lubricant and a second end located opposite the main cavity to supply it with lubricant intended to supply the central bore via the (each) first supply channel.

[0004] Such an arrangement does not allow for precise positioning of the shaft relative to the bearing. Furthermore, this arrangement is not compatible with a reduction in the axial length of the shaft, for example, to achieve a reduction in mass.

[0005] Furthermore, when the lubricant reaches the central bore of the shaft by gravity, a lubricant leak does not induce a loss of efficiency. However, when the lubricant is injected into the supply channel by a pump (possibly via a water / lubricant type heat exchanger), a lubricant leak induces a loss of efficiency on the electrical balance of the powertrain.

[0006] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0007] In particular, it proposes for this purpose a powertrain suitable for equipping a system and comprising a casing and a first equipment including a shaft having an axial direction and comprising, on the one hand, a central bore for transporting a lubricant and, on the other hand, an intake part carrying a bearing, including a part of the central bore.

[0008] This powertrain is characterized by the fact that:

[0009] - that the intake part of the shaft defines an open internal housing,

[0010] - that it comprises an interface piece having a hollow tube having a first a sub-part housed fixedly and in a sealed manner within the internal housing and a second sub-part housed partially within a passage in the casing and equipped with an external flange bearing against the bearing to position the shaft relative to the latter and an inlet, and

[0011] - that the housing includes a supply channel having a first end of its own to receive the lubricant and a second end opening into the passage to supply the inlet of the interface part with lubricant intended to supply the central bore via the hollow tube.

[0012] Thanks to this interface piece, it is now possible not only to position the shaft relative to the bearing, but also to supply lubricant in a sealed manner to the central bore.

[0013] The powertrain according to the invention may include other features which may be taken separately or in combination, and in particular:

[0014] - the internal housing can be opened at the level of an inlet face and can include an internal thread located away from the latter. In this case, the first sub-part may be provided with an external thread screwed onto the internal thread;

[0015] - in the presence of the first option, the external thread can be fitted with a paste sealing contributing to the sealing;

[0016] - the second sub-part can be provided, before the outer collar and on one face external, with an annular groove housing a sealing segment;

[0017] - the feed channel can be perpendicular to the axial direction;

[0018] - the housing can be part of a second piece of equipment, and can be fixedly attached to the first equipment;

[0019] - the first piece of equipment may be an electric motor;

[0020] - in the presence of the last two options, the second piece of equipment can be a reducer.

[0021] The invention also proposes a system comprising at least one powertrain of the type presented above.

[0022] For example, this system can constitute a vehicle, possibly of the automobile type. Brief description of the figures

[0023] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings, in which:

[0024] [Fig. 1] schematically illustrates, in a cross-sectional view in a longitudinal and vertical plane, part of an example embodiment of a powertrain according to the invention, and

[0025] [Fig.2] schematically illustrates, in a side view, an example of an embodiment of an interface part of a powertrain according to the invention. Detailed description of the invention

[0026] The invention aims in particular to provide a GM powertrain intended to be part of a system, comprising a first EQ1 equipment including an Al shaft with a central AC bore supplied with lubricant via an interface piece PI.

[0027] In what follows, the system is considered, by way of non-limiting example, to be a motor vehicle, such as a car. However, the invention is not limited to this type of system. It relates to any system comprising at least one powertrain (or powertrain) having at least one shaft with a central bore for transporting a lubricant. Thus, it relates in particular to all vehicles (land, sea (or river), or air), appliances (including household appliances), installations (including industrial installations), and buildings.

[0028] Furthermore, in what follows, by way of non-limiting example, the GM powertrain comprises a first piece of equipment EQ1 constituting an electric drive unit and associated with a second piece of equipment EQ2 constituting a gearbox. However, the invention is not limited to this type of powertrain. Thus, the GM powertrain could comprise a first piece of equipment EQ1 constituting a gearbox, for example.

[0029] Figure 1 schematically illustrates a very small part of an example embodiment of a GM powertrain (or GMP) according to the invention, suitable for equipping a system (here, a motor vehicle), and comprising an interface component PI. More specifically, in the example illustrated, which is not exhaustive, the GM powertrain comprises, as indicated above, an electric drive unit EQ1, shown only partially, and associated with a gearbox EQ2, shown only partially.

[0030] As illustrated at least partially in [Fig. 1], the first piece of equipment EQ1 (here an electric drive machine) comprises a shaft Al having an axial direction da and comprising a central bore AC for carrying a lubricant and an intake portion PA carrying on an external face a bearing RA and comprising a portion of the central bore AC.

[0031] It should be noted that the shaft Al can optionally be fixedly attached to another shaft forming part of the rotor of the electric drive machine EQ1. In this case, the central bore AC of the shaft Al communicates with a central bore of the other shaft which communicates with at least one internal channel opening outside this other shaft via a hole intended to supply at least one bearing of the electric drive machine EQ1 with lubricant from the shaft Al.

[0032] Furthermore, the inlet part PA of the Al tree defines an internal housing LI which is open at the level of an inlet face FA (here located on the left side).

[0033] Furthermore, the GM GMP includes a housing C2 having an AC supply channel comprising first E21 and second E22 ends at opposite ends. The first end E21 is designed to receive the lubricant. The second end E22 opens into a passage PC defined in the housing C2 to supply an EL inlet of the PI interface piece (described later) with lubricant intended to supply the central AC bore via this PI interface piece.

[0034] It should be noted that in the example illustrated, but not limited to, in [Fig. 1], the housing C2 is part of the second component EQ2 (here a gearbox). However, this is not mandatory. Indeed, the housing C2 could be part of the first component EQ1.

[0035] It should also be noted that in the example illustrated, but not limited to, in [Fig. 1], the lubricant is injected into the first end E21 of the AC supply channel by a pump (not shown), via a water / lubricant type heat exchanger. However, when the first piece of equipment EQ1 is a gearbox, the pump can be omitted.

[0036] As illustrated at least partially in Figures 1 and 2, the interface piece PI comprises a hollow tube TC having first sub-parts SP1 and second sub-parts SP2 that extend each other. The first sub-part SP1 is fixedly and securely housed in the internal housing LI, which means that when the shaft Al is rotated, the interface piece PI is rotated in the same way.

[0037] The second sub-part SP2 is partially housed within the PC passage of the housing C2 and is provided, on its outer face FE, with an external flange CEP (preferably annular) which bears against the bearing RA to position the shaft Al relative to the latter (RA). It will be understood that, since the interface piece PI is fixedly attached to the shaft Al, when its flange CEP contacts the bearing RA, this allows for very precise positioning of the shaft Al relative to the latter (RA). Furthermore, this advantageously prevents the inner race of the bearing RA from rotating relative to the shaft AL.

[0038] Furthermore, this second sub-part SP2 includes an inlet EL which is supplied in the PC passage of the housing C2 by the second end E22 of the CA supply channel (as described above). Thus, the lubricant flowing in the CA supply channel can enter the hollow tube TC through the inlet EL of its second sub-part SP2, and then reach the central bore AC of the shaft AL

[0039] The interface piece PI therefore not only allows the shaft Al to be positioned relative to the bearing RA, but also provides a sealed supply of lubricant to the central bore AC. Furthermore, since the lubricant supply is now axial, rather than radial, this makes it possible to reduce the axial length of the shaft Al, for example to achieve a reduction in mass.

[0040] For example, and as illustrated, but not limited to, in [Fig. 1], the internal housing LI can be open at its inlet face FA and can include an internal thread FLI that is offset from this inlet face FA. In this case, the first sub-part SP1 of the interface piece PI can be provided with an external thread FLE that is screwed onto this internal thread FLI. This screwing contributes to sealing, and this sealing can be further enhanced by applying a sealant to the external thread FLE. For example, this sealant can be similar to that commonly used on crankshaft bolts used to securely fasten the flywheel to an internal combustion engine. It should be noted that the sealing can be further enhanced by giving the external thread FLE thread-locking properties.

[0041] However, in an alternative embodiment, the first sub-part SP1 of the interface piece PI could be fixedly attached to the intake portion PA of the shaft Al by welding or bonding. But such an alternative does not allow for disassembly.

[0042] Also, for example, and as illustrated non-limitingly and at least partially in Figures 1 and 2, the second sub-part SP2 of the interface part PI can be provided, before the external collar CEP (and therefore here on the left) and on its external face FE, with an annular groove GA housing a sealing segment SE.

[0043] This advantageously prevents part of the lubricant that exits through the second end E22 in front of the inlet EL from escaping through the passage PC of the housing C2, defined to allow the housing of the second sub-part SP2 of the interface part PI, and ending up (here) in the first equipment EQ1.

[0044] Also, for example, and as illustrated non-limitingly in [Fig. 1], the entire AC power channel can be perpendicular to the axial direction da. However, it could be envisaged, for example due to a lack of space, that the AC power channel be defined at an angle other than 90° with respect to the axial direction da.

Claims

Demands

1. Powertrain (PW) suitable for equipping a system and comprising a housing (C2) and a first piece of equipment (EQ1) having an axial direction shaft (Al) and comprising i) a central bore (AC) for carrying a lubricant and ii) an intake portion (PA) carrying a bearing (RA) and comprising a portion of said central bore (AC), characterized in that said intake portion (PA) defines an open internal housing (LI), in that it comprises an interface piece (PI) comprising a hollow tube (TC) having a first sub-part (SP1) housed fixedly and in a sealed manner in said internal housing (LI) and a second sub-part (SP2) housed partially in a passage (PC) of said housing (C2) and provided with an external flange (CEP) bearing against said bearing (RA) for positioning said shaft (Al) relative to the latter (RA) and an inlet (EL),and in that said housing (C2) comprises a supply channel (CA) having a first end (E21) adapted to receive said lubricant and a second end (E22) opening into said passage (PC) to supply said inlet (EL) with lubricant intended to supply said central bore (AC) via said hollow tube (TC).

2. Powertrain according to claim 1, characterized in that said internal housing (LI) is open at the level of an intake face (FA) and includes an internal thread (FLI) distant from the latter (FA), and in that said first sub-part (SP1) is provided with an external thread (FLE) screwed onto said internal thread (FLI).

3. Powertrain according to claim 2, characterized in that said external thread (FLE) is provided with a sealing paste participating in said sealing.

4. Powertrain according to any one of claims 1 to 3, characterized in that said second subpart (SP2) is provided, before said outer flange (CEP) and on an outer face (FE), with an annular groove (GA) housing a sealing segment (SE).

5. Powertrain according to any one of claims 1 to 4, characterized in that said supply channel (CA) is perpendicular to said axial direction.

6. Powertrain according to any one of claims 1 to 5, characterized in that said casing (C2) is part of a second piece of equipment (EQ2) and is fixedly attached to said first piece of equipment (EQ1).

7. Powertrain according to any one of claims 1 to 6, characterized in that said first equipment (EQ1) is an electric motive machine.

8. Powertrain according to the combination of claims 6 and 7, characterized in that said second equipment (EQ2) is a reducer.

9. System, characterized in that it comprises at least one powertrain (MT) according to any one of claims 1 to 8.

10. System according to claim 9, characterized in that it constitutes a vehicle.

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