Powertrain with shaft having a central bore with simplified supply, for a system

Abstract

A powertrain equips a system and comprises a casing and a first equipment (EQ1) having a shaft (A1) having an axial direction and comprising a central bore (AC) that has to transport a lubricant and a portion (P1) housed in the casing (C2). This portion (P1) comprises a main cavity (CP) forming a loop on an exterior face (FE) of the shaft and communicating with the central bore (AC) via at least one first supply duct (CA1) making a non-zero angle with the axial direction. Moreover, the casing (C2) comprises a second supply duct (CA2) having a first end (E21) receiving the lubricant and a second end (E22) situated facing the main cavity (CP) in order to supply it with lubricant intended to be supplied to the central bore (AC) via the first supply duct (CA1).

Description

DESCRIPTION TITLE: SIMPLIFIED FEED CENTER BORE SHAFT POWERTRAIN FOR A SYSTEM The present invention claims priority from French application No. 2308749 filed on 08 / 17 / 2023, the content of which (text, drawings and claims) is incorporated herein by reference. Technical field of the invention

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

[0002] Some systems, such as for example certain vehicles (possibly of the automobile type), comprise a powertrain (or GMP) comprising equipment having a shaft having an axial direction and comprising a central (axial) bore for carrying a lubricant. For example, such equipment may be a gearbox or an electric motor. Also for example, the lubricant which is carried by the central bore may be intended to lubricate at least one bearing of the GMP shaft line or synchronization devices of the shaft line of a gearbox.

[0003] Currently, to introduce the lubricant into the central bore of the shaft, one end of the central bore includes an axial inlet into which is fitted a hollow tube extending in the axial direction of the shaft and which passes through a casing or a cover attached to a casing. It should be noted that this casing may be part of the equipment or other equipment of the GMP, such as for example a reducer.

[0004] The hollow tube is generally coupled to a feed channel defined in the aforementioned casing and receiving the lubricant.

[0005] The use of such a hollow tube, ensuring the interface between the feed channel and the central bore of the shaft, poses significant sealing problems due to the fact that this shaft has a degree of axial freedom and a manufacturing tolerance along its length and therefore the positioning of the hollow tube is very complex to achieve.

[0006] When the lubricant reaches the central bore of the shaft by gravity, a lubricant leak does not cause a loss of efficiency. But when the lubricant is injected into the supply channel by a pump (possibly via a water / lubricant heat exchanger), a lubricant leak causes a loss of efficiency on the powertrain's electrical balance.

[0007] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0008] For this purpose, it proposes in particular a powertrain suitable for equipping a system and comprising a casing and a first piece of equipment comprising a shaft having an axial direction and comprising a central bore intended to transport a lubricant and a part housed in the casing.

[0009] This powertrain is characterized by the fact that:

[0010] - that the part of the shaft comprises a main cavity forming a loop on an external face of the shaft and communicating with the central bore via at least a first supply channel making a non-zero angle with the axial direction, and

[0011] - that the casing comprises 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.

[0012] Thus, it is now possible to feed the central bore from at least one side and not from an axial end, which very advantageously makes it possible to avoid having to use a hollow tube unlike the prior art.

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

[0014] - the second end of the second feed channel can be installed perpendicular to the axial direction;

[0015] - in the presence of the first option, the second feed channel can be perpendicular to the axial direction;

[0016] - the shaft part may comprise at least two first supply channels communicating with the main cavity at separate locations and with the central bore at separate locations;

[0017] - each first feed channel may be perpendicular to the axial direction;

[0018] - the shaft part may comprise two auxiliary cavities defined on either side of the main cavity, each forming a loop on the external face and each housing a seal;

[0019] - the casing may be part of a second piece of equipment, may be fixedly secured to the first piece of equipment, and may include a passage housing the part of the shaft and communicating with the second supply channel;

[0020] - the first equipment may be an electric motor;

[0021] - in the presence of the last two options, the second equipment can be a reducer.

[0022] The invention also proposes a system comprising at least one powertrain of the type presented above.

[0023] For example, this system may constitute a vehicle, possibly of the automobile type. Brief description of the figures

[0024] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the attached drawing (obtained in CAD / CAM (“Computer Aided Design / Computer Aided Drawing”)), in which:

[0025] [Fig. 1] schematically and functionally illustrates, in a sectional view in a longitudinal and vertical plane, a part of an exemplary embodiment of a powertrain according to the invention. Detailed description of the invention

[0026] The invention aims in particular to propose a GM powertrain intended to be part of a system, comprising a first equipment EQ1 comprising a shaft A1 provided with a central bore AC having a simplified supply of lubricant to be transported.

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

[0028] Furthermore, it is considered in the following, by way of non-limiting example, that the GMP GM comprises a first piece of equipment EQ1 constituting an electric motor and associated with a second piece of equipment EQ2 constituting a reducer. But the invention is not limited to this type of GMP. Thus, the GM GMP could include a first EQ1 equipment constituting a gearbox, for example.

[0029] Figure 1 schematically illustrates a very small part of an exemplary embodiment of a GM powertrain (or GMP) according to the invention, suitable for equipping a system (here a motor vehicle). More precisely, in the example illustrated without limitation, the GM GMP comprises, as indicated above, an electric motor EQ1 associated with a reducer EQ2.

[0030] As illustrated at least partially in Figure 1, the first equipment EQ1 (here an electric motor) comprises a first shaft A1 having an axial direction da and comprising a central bore AC for transporting a lubricant.

[0031] It will be noted that in the example illustrated non-limitingly in Figure 1, the first shaft A1 is fixedly secured to a second shaft A2 forming part of the rotor of the electric motor EQ1. This central bore AC of the first shaft A1 communicates with a central bore AC' of the second shaft A2 which communicates with at least one internal channel opening to the outside of the second shaft A2 via a hole TL intended to supply at least one bearing of the electric motor EQ1 with lubricant from the first shaft A1.

[0032] In addition, the first shaft A1 comprises a part P1 which is housed in a casing C2, and more precisely, here, in a passage PA defined in the latter (C2) and communicating with a second supply channel CA2 (described later). It will be noted that in the example illustrated non-limitingly in Figure 1, the casing C2 is part of the second equipment EQ2 (here a reducer). But this is not obligatory. Indeed, the casing C2 could be part of the first equipment EQ1.

[0033] The part P1 of the first shaft A1 comprises a main cavity CP which makes a (closed) loop on an external face FE and which communicates with the central bore AC via at least a first supply channel CA1 making a non-zero angle with the axial direction da. The end (here left) of the central bore AC is therefore closed. Each first supply channel CA1 comprises a first end E11 opening into the main cavity CP and suitable for receiving the lubricant and a second end E12, opposite the first end E11 and opening into the central bore AC to supply it with lubricant.

[0034] Note that the loop has a circular shape when the local section of the part P1 of the first tree A1 where it is defined is circular.

[0035] The casing C2 comprises a second supply channel CA2 which has first E21 and second E22 opposite ends. The first end E21 is suitable for receiving the lubricant. The second end E22 is located opposite the main cavity CP to supply it with lubricant intended to supply the central bore AC via the (each) first supply channel CA1.

[0036] It will be noted that in the example illustrated non-limitingly in Figure 1 the lubricant is injected into the first end E21 of the second supply channel CA2 by a pump (not shown), via a water / lubricant type heat exchanger EAL. But, when the first equipment EQ1 is a gearbox, a pump can be dispensed with.

[0037] Thanks to this particular arrangement, the central bore AC can be fed from at least one side and not from an axial end, which very advantageously makes it possible to avoid having to use a hollow tube unlike in the prior art. This feeding is therefore simplified, as is the assembly of the GMP, and there are no longer any problems linked to the positioning of the hollow tube and the sealing at the latter.

[0038] For example, and as illustrated non-limitingly in FIG. 1, the second end E22 of the second supply channel CA2 can be installed perpendicular to the axial direction da. In this case, it (E22) is perpendicular to the external face FE of the first shaft A1 and to the main cavity CP. This makes it possible to minimize leaks because the injection of lubricant into the main cavity CP is done in the axis of the latter (CP) and not at an angle.

[0039] However, it could be envisaged, for example due to a lack of space, that the second end E22 of the second supply channel CA2 is installed at an angle other than 90° relative to the axial direction da.

[0040] Also for example, and as illustrated non-limitingly in Figure 1, the entirety of the second supply channel CA2 may be perpendicular to the axial direction da. However, it could be envisaged, for example due to a lack of space, that the second supply channel CA2 is defined at an angle other than 90° relative to the axial direction da.

[0041] Also for example, and as illustrated non-limitingly in Figure 1, the part P1 of the first shaft A1 may comprise at least two first supply channels CA1 which communicate with the main cavity CP at separate locations and with the central bore AC of the first shaft A1 at separate locations. It will be noted that the number of first supply channels CA1 may take any value greater than or equal to one. Thus, it may be equal to two, three, four, or even more. This depends in particular on the desired lubrication level and / or flow rate.

[0042] Also for example, and as illustrated non-limitingly in Figure 1, the (each) first supply channel CA1 may be perpendicular to the axial direction da. But this is not an obligation. Indeed, the (each) first supply channel CA1 could be defined at an angle other than 90° relative to the axial direction da.

[0043] Also for example, and as illustrated non-limitingly in figure 1, the part P1 of the first shaft A1 can comprise two auxiliary cavities CVA which are defined on either side of the cavity main cavity CP, each making a (closed) loop on the external face FE, and each housing a seal JE. This advantageously prevents part of the lubricant circulating in the main cavity CP from escaping from the latter (CP) and exiting through the passage PA of the casing C2. It will be understood that the presence of the two seals JE allows the lubricant to remain between the latter (JE) and therefore to be transferred into the (each) first supply channel CA1, without leakage.

[0044] Note that each loop can have a circular shape when the local section of the part P1 of the first tree A1 where it is defined is circular.

Claims

CLAIMS

1. Powertrain (GM) suitable for equipping a system and comprising a casing (C2) and a first equipment (EQ1) comprising a shaft (A1) having an axial direction and comprising a central bore (AC) for transporting a lubricant and a part (P1) housed in the casing (C2), characterized in that said part (P1) comprises a main cavity (CP) forming a loop on an external face (FE) of the shaft and communicating with said central bore (AC) via at least a first supply channel (CA1) making a non-zero angle with said axial direction, and in that said casing (C2) comprises a second supply channel (CA2) having a first end (E21) suitable for receiving said lubricant and a second end (E22) located opposite said main cavity (CP) to supply it with lubricant intended to supply said central bore (AC) via said first supply channel (CA1).

2. Powertrain according to claim 1, characterized in that said second end (E22) is installed perpendicular to said axial direction.

3. Powertrain according to claim 2, characterized in that said second supply channel (CA2) is perpendicular to said axial direction.

4. Powertrain according to one of claims 1 to 3, characterized in that said part (P1) of the shaft (A1) comprises at least two first supply channels (CA1) communicating with said main cavity (CP) at separate locations and with said central bore (AC) at separate locations.

5. Powertrain according to one of claims 1 to 4, characterized in that each first supply channel (CA1) is perpendicular to said axial direction.

6. Powertrain according to one of claims 1 to 5, characterized in that said part (P1) of the shaft (A1) comprises two auxiliary cavities (CVA) defined on either side of said main cavity (CP), each forming a loop on said external face (FE) and housing each a seal (JE).

7. Powertrain according to one of claims 1 to 6, characterized in that said casing (C2) is part of a second equipment (EQ2), is fixedly secured to said first equipment (EQ1), and comprises a passage (PA) housing said part (P1) of the shaft (A1) and communicating with said second supply channel (CA2).

8. Powertrain according to one of claims 1 to 7, characterized in that said first equipment (EQ1) is an electric motor.

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

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

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