Oil recovery device of gearbox

Abstract

The invention relates to an oil recovery device (10) arranged in a gearbox (2), the gearbox (2) being lubricated by oil, the gearbox (2) comprising a motor (40) cooled and / or lubricated by the lubricating oil of the gearbox (2), the recovery device (10) comprising a settling tank (20) for settling the oil, the settling tank (20) comprising at least one discharge hole for discharging the oil to prevent the oil from spilling out of the settling tank (20).

Description

Technical Field

[0001] The invention relates to an oil recovery device installed in a gearbox. The invention also relates to a gearbox comprising such an oil recovery device. The invention also relates to a powertrain comprising such a gearbox or such an oil recovery device. The invention also relates to a vehicle comprising such a powertrain or such a gearbox or such an oil recovery device. Background Art

[0002] Vehicles, especially electric vehicles or hybrid vehicles, usually comprise an oil-lubricated gearbox. Usually, such a gearbox is mounted on an electric motor. Such an electric motor requires oil for cooling and lubrication. In order to ensure cooling and lubrication of the electric motor, oil is injected into the electric motor. The shaft of such an electric motor rotates at a very high speed, for example about 18,000 rpm. In order to optimize cooling and / or lubrication, the flow rate of the injection oil is high, for example about 6 L / min.

[0003] However, such a high rotation speed of the motor shaft combined with such a high flow rate of the oil results in a large volume of foam in the oil. However, the lubricating ability of the oil in foam form is not as good as that of the oil in liquid form. In particular, the gas bubbles have a different density than the oil and the gas bubbles reduce the heat dissipation performance of the oil. This leads to a risk of degradation and / or potential failure of the surfaces of the pinions and / or bearings and / or bearings of the gearbox which are not sufficiently lubricated and / or cooled by the foam-containing oil.

[0004] This situation is intolerable.

[0005] Invention

[0006] The object of the present invention is to provide an oil recovery device that overcomes the above-mentioned drawbacks. In particular, the present invention provides an oil recovery device that is easy to manufacture and easy to install in a gearbox. Summary of the invention

[0007] To achieve this object, the present invention relates to an oil recovery device installed inside an oil-lubricated gearbox, the gearbox comprising a motor, which is cooled and / or lubricated by the lubricating oil of the gearbox, the recovery device comprising an oil settling tank, the settling tank comprising at least one oil discharge hole to prevent oil from overflowing from the settling tank.

[0008] The recovery device may comprise at least one deflector intended to deflect oil splashing out of such a motor towards a settling tank.

[0009] The oil deflector may be made of plastic and / or composite material.

[0010] The invention also relates to an oil-lubricated gearbox comprising an electric motor which is cooled and / or lubricated by the lubricating oil of the gearbox, the gearbox comprising an oil recovery device as described above, at least one discharge hole being located at the bottom of the settling tank for discharging the oil without foam.

[0011] The oil settling tank can be installed under the motor.

[0012] The motors may include:

[0013] -stator,

[0014] a housing fixed relative to the gearbox, which housing may in particular serve to hold the stator in place,

[0015] - rotor,

[0016] - a shaft which ensures the rotation of the rotor relative to the stator, the shaft being able to have an axial duct (in particular a non-exposed axial duct) and at least one radial duct leading to the axial duct, so that oil passes through the axial duct and is radially ejected via the at least one radial duct in order to lubricate and / or cool the electric machine.

[0017] The housing of the motor may include at least one opening in its lower portion to facilitate the flow of oil from the inner wall of the housing to the settling tank.

[0018] The gearbox may comprise a first housing and a second housing, the first housing and the second housing may be designed to be fixed one on top of the other, the settling tank may be fixed to the first housing and / or the second housing, in particular by screws and / or centering pins and / or locating pins.

[0019] At least one deflector plate can be fixed to the first housing and / or the second housing, in particular by means of screws and / or centering pins and / or positioning pins.

[0020] The gearbox may include a first housing and a second housing, the first housing and the second housing may be fixed one on top of the other, and the settling tank may be held in place within the gearbox by being wedged between the first housing and the second housing.

[0021] The gearbox may include a first housing and a second housing, the first housing and the second housing may be fixed one on top of the other, and the at least one deflector may be retained within the gearbox by being wedged between the first housing and the second housing.

[0022] The invention also relates to a powertrain, in particular for a motor vehicle, comprising a gearbox as defined above or an oil recovery device as defined above.

[0023] The invention also relates to a vehicle, in particular a motor vehicle, comprising a gearbox as defined above, or an oil recovery device as defined above, or a powertrain as defined above. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] These objects, features and advantages of the invention will be explained in detail hereinafter in the description of an embodiment of an oil recovery device given by way of non-limiting example, with reference to the accompanying drawings, in which:

[0025] Figure 1 is a schematic diagram of a motor vehicle according to one embodiment of the invention.

[0026] Figure 2 It is a partial perspective view of a gear box according to one embodiment of the present invention.

[0027] Figure 3 FIG. 4 is another partial perspective view of a gear box according to an embodiment of the present invention.

[0028] Figure 4 4 is a partial cross-sectional view of a gearbox according to an embodiment of the present invention along a plane P perpendicular to the axis A.

[0029] Figure 5 1 is a partial cross-sectional view of a gearbox according to an embodiment of the present invention, taken along a plane B passing through an axis A.

[0030] Figure 6 is a perspective view of a motor of a gear box according to an embodiment of the present invention.

[0031] Figure 7 FIG. 1 is a perspective view of a guide plate of an oil recovery device according to an embodiment.

[0032] Figure 8 It is a perspective view of a sedimentation tank of the oil recovery tank according to this embodiment.

[0033] Fig. 9 FIG. 4 is another perspective view of the sedimentation tank of the oil recovery device according to this embodiment. DETAILED DESCRIPTION

[0034] The direction in which a vehicle, in particular a motor vehicle, moves in a straight line is defined as the longitudinal direction X. By convention, the direction perpendicular to the longitudinal direction, lying in a plane parallel to the ground, is called the transverse direction Y. The third direction, perpendicular to the other two, is called the vertical Z direction. Therefore, a direct reference system XYZ is used, where X is the longitudinal direction in the fore-aft direction of the vehicle, i.e. pointing to the rear, Y is the transverse direction pointing to the right, and Z is the vertical direction upwards. The front corresponds to the direction in which the vehicle usually moves in the longitudinal direction and is opposite to the rear.

[0035] Figure 1A vehicle 1, preferably a motor vehicle, is schematically shown. The vehicle comprises a powertrain 9. The powertrain 9 comprises, for example, an electric motor and / or an internal combustion engine. The powertrain 9 or the vehicle 1 comprises a gearbox 2. The gearbox 2 comprises an electric motor 40. The gearbox 2 is lubricated by oil. The electric motor 40 is also lubricated by oil. Advantageously, the lubricating oil of the gearbox 2 is used for lubricating and / or cooling the electric motor 40, which will be described below.

[0036] Especially Figure 2 , Figure 3 and Figure 4 As shown, the gearbox 2 comprises a lower part 7. "Lower part" refers to the area extending at the lowest point in the vertical direction Z of the gearbox, the gearbox being located in a vehicle placed on a surface substantially parallel to the XY plane.

[0037] like Figure 2 and Figure 3 As shown, the gearbox 2 comprises, for example, a first housing or shell or half-shell 3, and a second housing or shell or half-shell 4. One of the first housing 3 and the second housing 4 is attached to the other, or to each other. Preferably, a fastening device 8 is provided for assembling the housings 3 and 4 together. The fastening device 8 comprises, for example, a screw-nut system of the bolt type, or a screw that passes through one housing and engages with a threaded hole in the other housing, or a bolt that is screwed into one housing, passes through the other housing, and a nut that engages with these bolts.

[0038] The vehicle 1 , or the powertrain 9 , or the gearbox 2 comprises an oil recovery device 10 .

[0039] The oil recovery device 10 is installed in the gearbox 2. As a reminder, the gearbox 2 is lubricated by oil and includes a motor 40, which is cooled and / or lubricated by the lubricating oil of the gearbox 2. The motor 40 is, for example, sandwiched between two housings 3 and 4, such as Figure 5 shown.

[0040] Especially Figure 2 As shown, the recovery device 10 includes an oil settling and recovery tank 20. Preferably, as Figure 3 , Figure 4 and Figure 5As shown, the settling tank 20 includes at least one oil discharge hole 21 to avoid oil overflowing from the settling tank 20. In the embodiment shown, three holes 21 are provided. Alternatively, one, two or more than three holes may also be suitable. For example, as shown, the hole 21 is provided in a conduit or a tube or a pipe extending from the bottom 22 of the settling tank 20. For example, the cross-section of the hole is circular. Alternatively, a single hole is provided in the groove. For example, the cross-section of such a hole is square, or rectangular, or some other shape. Therefore, it is advantageous that the oil discharge hole 21 of the settling tank is located at the bottom of the settling tank 20 so as to discharge the oil without foam (to be explained below). Preferably, one or more holes are located at the lowest point of the settling tank to allow the oil to be discharged so that there is no residual oil volume in the cavity of the settling tank. In any case, the oil discharge hole 21 is provided below the predetermined lower liquid level N of the oil in foam form ( Figure 4 ).

[0041] Especially Figure 2 , Figure 3 and Figure 4 As shown, the oil settling tank 20 is disposed below the motor 40 or at least partially below the motor 40 .

[0042] Preferably, the settling tank is a tank or a reservoir or an oil sump of the gearbox 2 .

[0043] For example, with one of the first housing 3 and the second housing 4 attached on top of the other, the settling tank 20 is held in place within the gearbox 2 by wedging or locking or clamping between the first housing 3 and the second housing 4 .

[0044] Alternatively, the settling tank 20 is fixed to the first housing 3 and / or the second housing 4, for example by means of screws 5 and / or centering pins and / or dowel pins. If one or more screws 5 are used, the lug or extension 23 is preferably integral with the settling tank, in particular as Figure 8 and Fig. 9 shown.

[0045] For example, Figure 2 , 3 , 4 and 5, the oil recovery device 10 further comprises at least one guide plate 30. The guide plate 30 is intended to deflect the oil splashed (in particular) from the motor 40 towards the sedimentation tank 20. Alternatively, a plurality of guide plates are provided in the gearbox 2 (variation not shown).

[0046] For example, with one of the first housing 3 and the second housing 4 attached to the top of the other, the deflector 30 is held within the gearbox 2 by being wedged or locked or clamped between the first housing 3 and the second housing 4 .

[0047] Preferably, the deflector 30 is fixed to the first housing 3. Alternatively, the deflector 30 is fixed to the second housing 4. Alternatively, the deflector 30 is fixed to both housings 3 and 4. For example, the fastening to one or both housings is ensured by one or more screws 6 and / or one or more centering pins 6' and / or one or more positioning pins. In the case of one or more pins, these pins are preferably integral with the deflector, such as Figure 7 shown.

[0048] In any case, the tank 20 and the baffle 30 are made of a material that can easily obtain complex shapes. Once the gearbox is closed after assembly, the tank 20 and the baffle 30 remain in place inside the housings 3 and 4.

[0049] like Figure 5 As shown, the motor 40 comprises, for example, a stator 41 and a housing 50 fixed relative to the gearbox 2. Preferably, the housing 50 comprises two parts or two shells or two half-shells 54 and 55, which clamp the stator 41 between them to hold the stator 41 in place. Thus, the housing 50 is used, for example, to hold the stator 41 in place. The motor also comprises a rotor 43. The motor also comprises a shaft 44 of axis A, which ensures that the rotor 43 rotates around or substantially around axis A relative to the stator 41. The shaft 44 comprises an axial conduit 45 or an axial hole, preferably with a circular cross-section. Advantageously, the axial conduit 45 is not open at the end. The shaft 44 also comprises at least one radial conduit 46 leading to the axial conduit 45, so that oil travels through the axial conduit 45 and is radially injected via the radial conduits 46 to lubricate and / or cool the motor 40. It should be noted that the motor 40 preferably comprises a tapping or supply conduit or oil inlet conduit or pipe 42, which is used to bring the oil flow into the axial conduit 45. Preferably, the outlet of the tap 42 corresponds to the axial duct 45 or extends opposite to the axial duct 45 or opens into the axial duct 45 .

[0050] Especially Figure 5 and Figure 6 As shown, the lower portion 52 of the housing 50 of the motor 40 includes at least one opening 51. Preferably, as Figure 6 As shown, each half-shell or flange 54 and 55 comprises at least one opening 51. Advantageously, the opening 51 or hole is arranged at the lowest point of the half-shells 54 and 55. In any case, the opening 51 allows the oil to drain by flowing out from the inner wall 53 of the shell 50. By gravity, the oil drains towards the settling tank 20 arranged below the opening 51.

[0051] Advantageously, the oil recovery device is made of plastic material and / or composite material. Thus, the settling tank and / or the guide plate are made of plastic and / or composite material.

[0052] Alternatively, the deflector and the settling tank are formed as a single component by integrally casting together.Alternatively, the deflector is attached to the settling tank to form a single component.

[0053] Especially Figure 4 As shown, the settling tank 20 recovers a large amount of oil containing foam. By rotating the motor, the foam is generated and may be ejected due to the high rotation speed of the motor and / or the high flow rate of the injected oil. In addition to the walls of the housings 3 and 4, an additional guide plate 30 deflects the ejected oil toward the settling tank 20. Preferably, the protruding ribs 11 ( Figure 3 and Figure 4 ) to ensure the continuity of the oil projections between the housing 4 of the gearbox 2 and the guide plate 30, or to direct the oil projections, or to promote the flow of the oil projections. More protruding shapes or cavities may also be provided to control the gravity outflow of the oil. For example, Figure 2 , Figure 3 and Figure 7 As shown, the step 31 provided on the guide plate 30 promotes the interlocking, association or complementarity of the shapes between the guide plate 30 and the housing 3 .

[0054] Thus, the spray oil, in particular the spray oil in foam form, is directed and diverted to the settling tank 20. The settling tank is filled with oil. More specifically, the foam rises and is suspended above the oil layer. In other words, the foam floats on the upper part of the oil layer. Advantageously, the volume generated in the settling tank 20 is a stationary area, in particular an area that is not disturbed by the axis of rotation of the gearbox. Advantageously, the oil and foam in the accommodation chamber of the settling tank 20 are not affected by the movement of the shaft and / or pinion and / or bearing of the rest of the gearbox.

[0055] Due to the presence of the drain hole 21, the oil flows out of the settling tank 20. The drain hole is set at the bottom, so that only the oil without foam is discharged. It should be noted that the drain holes can be set above the lowest liquid level of the settling tank as long as they are below Figure 4 The lower liquid level N of the foam shown is sufficient.

[0056] For example, there is a cavity between the liquid level of the discharge hole 21 and the bottom of the settling tank for storing residues, such as debris and / or other waste present in the settled liquid oil. This prevents these residues from being sucked up by the pump and re-injected into the shaft 44. For example, a residue collection device, such as a magnetic collection device, is provided at the bottom of such a cavity.

[0057] It should be noted that the volume of the settling tank 20 is defined to be able to recover the oil flowing out of the motor while accommodating a certain volume of foam in the upper part without overflowing. The cross-section of the discharge hole 21 is dimensioned to avoid any overflow of the tank 20. In addition, the length of the pipe (if any) including the discharge hole 21 is short. In fact, the hole 21 is preferably arranged close to the oil layer to prevent the oil flow leaving the settling tank 20 from generating foam again.

[0058] Due to the oil recovery device, the gearbox 2 and / or the motor 40 are not lubricated and / or cooled by the oil in the form of foam. Only liquid oil is re-injected into the tap 42. In other words, the oil does not contain foam to ensure the cooling and / or lubrication of the motor by axial injection (via axial pipe 45) in the rotating shaft 44 of the motor 40 and radial diffusion via radial holes or pipes 46 arranged in the shaft. This brings optimal lubrication and / or cooling. Therefore, due to the very high rotation speed of the shaft 44 (for example, about 18000rpm) and / or the high flow rate of the injected oil (for example, about 6L / min), it is harmless to generate foam in the oil. This is because the oil falls back into the settling tank 20 by gravity (especially due to the guide plate 30), which can separate the oil in the form of foam from the oil in the form of liquid. Since the oil foam HM is lighter than the liquid oil HL, the foam is retained and stagnated at the top of the settling tank. Therefore, the foam oil is not discharged through one of the discharge holes 21 of the settling tank 20 located at the bottom or substantially bottom of the settling tank. In other words, the oil discharged from the settling tank is decanted, ie, foam-free, so that the oil refilled at the level of the tap 42 is in a liquid state. As a result, its lubrication and / or cooling capacity is optimal for the motor 40 mounted in the housing 50.

[0059] In other words, the generation of foam in the oil does not harm the motor. The generation of foam is a phenomenon caused by the entrapment of air in oil that is excessively stirred in a non-vacuum environment, and the generation of foam does not stop. In fact, as mentioned above, the foam is generated by the high speed rotation of the motor and the high flow rate of the oil through its shaft. The purpose of this solution is to decant enough oil so that the shaft of the motor can be supplied with liquid oil without foam, thereby providing optimal cooling and / or lubrication for the motor. The oil injected into the shaft 44 is in a liquid state, which ensures the characteristics of the oil in terms of lubrication and in terms of cooling (removing heat from the elements that receive the oil).

[0060] Preferably, a pumping device (not shown) pumps out the oil, for example at the outlet of one or more holes 21, i.e. at the bottom or level of the liquid oil layer HL, to lift the oil to a tap 42 (preferably located further up the gearbox). More precisely, as Figure 5As shown, the tap 42 enables the oil to be injected directly or substantially directly into the hole 45 of the hollow shaft 44 through the housing 3. In particular, due to the high rotational speed of the motor 40 (e.g. about 18,000 rpm) and the radial holes or ducts 46 in the shaft 44, the parts that need cooling and / or lubrication (in particular the bearings) receive the oil. This thus allows these elements to be lubricated and cooled. Under the effect of the rotational speed, and / or after the motor is cooled and lubricated, the oil is ejected towards the interior of the gearbox, or falls directly into the oil layer or tank by run-off, in particular downward along the inner wall of the housings 3 and 4.

[0061] The solution still allows the storage of gas bubbles of different density than the oil while waiting for the oil to reform into a liquid state. This prevents the gas bubbles from being directed to the element to be cooled or lubricated, since the heat removal capacity of the gas bubbles is less than that of the oil. Any risk of surface degradation and / or potential failure of the element (e.g. the gears or bearings of the gearbox) is thus avoided.

[0062] One or more baffles 30 can, for example, separate and / or separate the motor from the rest of the gearbox in order to direct the injection oil towards the settling tank 20. These baffles are designed according to the internal structure of the gearbox and / or according to the structural limitations of the gearbox. Alternatively, these baffles can be mounted directly in the walls of the housings 3 and 4.

[0063] Thus, the recovery device 10 makes it possible to overcome the drawbacks of electric motors mounted in gearboxes, in particular electric motors that are lubricated and / or cooled by the same oil layer as the rest of the gearbox. This solution is inexpensive, in particular since the recovery device can be made of plastic, for example. This type of material makes it easy to add ribs, walls and complex shapes to adapt to the internal shape of the housings 3 and 4 of the gearbox, which are usually cast. Optionally, at least one of the housings 3 and 4 comprises at least one rib 11, which can maximize the runoff and / or allow the nesting of components.

[0064] In addition, the solution also solves the problem of excessive foaming due to oil mixing in various types of gearboxes. In view of this, as mentioned above, partitions can be provided around the areas that promote foaming, for example in the housing of the box, for example by additional ribs in the casting, or additional partitions are added. Alternatively or additionally, other forms of promoting the guidance and recovery of oil by gravity runoff are provided, especially at the level of the guide plate. These additional components are kept inside the assembled gearbox, for example enclosed between the housings 3 and 4.

[0065] It should be noted that the decanted oil may be redirected to be delivered to various elements of the gearbox that require lubrication. Alternatively, the oil may flow from the aperture 21 to another tank or container or housing that receives a pinion or pulley or ring gear (e.g., a differential ring gear) so that the decanted oil lubricates the gearbox by splashing oil onto such a ring gear.

[0066] Particularly in the case of a one-piece guide plate and settling tank (variant not shown), positioning in the gearbox is easier and faster.

[0067] It is noteworthy that the solution thus achieves the intended goal of providing an oil recovery device that prevents the injection of oil foam into the lubrication and / or cooling circuits of the gearbox and the motor, and has the following advantages:

[0068] - It can be used in gearboxes of other types of vehicles, such as agricultural machinery, construction machinery, ships or other equipment.

[0069] - The shape of this oil recovery device can be easily adapted to the internal configuration of any type of gearbox, especially due to its material.

Claims

1. An oil recovery device (10) arranged in an oil-lubricated gearbox (2), the gearbox (2) comprising a motor (40), the motor (40) being cooled and / or lubricated by lubricating oil of the gearbox (2), characterized in that: The recovery device (10) comprises an oil settling tank (20), and the settling tank (20) comprises at least one oil discharge hole (21) to prevent oil from overflowing from the settling tank (20).

2. The oil recovery device (10) according to the preceding claim, characterized in that The recovery device (10) comprises at least one guide plate (30) for guiding the injection oil from the motor (40) to the settling tank (20).

3. An oil recovery device (10) according to any one of the preceding claims, characterized in that The oil guide plate (10) is made of plastic and / or composite material.

4. An oil-lubricated gearbox (2), the gearbox (2) comprising an electric motor (40), the electric motor (40) being cooled and / or lubricated by the lubricating oil of the gearbox (3), characterized in that: The gearbox (2) comprises an oil recovery device (10) according to any one of the preceding claims, wherein the at least one discharge hole (21) is located at the bottom of the settling tank (20) in order to discharge the oil without foam.

5. Gearbox (2) according to the preceding claim, characterized in that The oil sedimentation tank (20) is arranged below the motor (40).

6. The gearbox (2) according to any one of claims 4 or 5, characterized in that: The motor (40) comprises: - a stator (41), - a housing (50) fixed relative to the gearbox (2), the housing (50) being used in particular to hold the stator (41) in place, - a rotor (43), - a shaft (44) ensuring the rotation of the rotor (43) relative to the stator (41), the shaft (44) having an axial duct (45), in particular an axial duct (45) without an open end, and at least one radial duct (46) leading to the axial duct (45), so that oil passes through the axial duct (45) and is radially injected via the at least one radial duct (46) to lubricate and / or cool the electric machine (40).

7. Gearbox (2) according to the preceding claim, characterized in that The housing (50) of the motor (40) comprises at least one opening (51) in its lower portion (52) in order to promote the flow of oil from the inner wall (53) of the housing (50) to the settling tank (20).

8. The gearbox (2) according to any one of claims 4 to 7, comprising a first housing (3) and a second housing (4), one of the first housing (3) and the second housing (4) being fixed on top of the other, characterized in that: The settling tank (20) is fixed to the first housing (3) and / or the second housing (4), in particular by means of screws (5) and / or centering pins and / or positioning pins.

9. Gearbox (2) according to the preceding claim in combination with claim 2, characterized in that The at least one deflector (30) is fixed to the first housing (3) and / or the second housing (4), in particular by means of screws (6) and / or centering pins (6') and / or positioning pins.

10. The gearbox (2) according to any one of claims 4 to 7, comprising a first housing (3) and a second housing (4), one of the first housing (3) and the second housing (4) being fixed to the top of the other, characterized in that: The settling tank (20) is held in place within the gearbox (2) by being wedged between the first housing (3) and the second housing (4).

11. The gearbox (2) according to any one of claims 4 to 7 in combination with claim 2, the gearbox (2) comprising a first housing (3) and a second housing (4), one of the first housing (3) and the second housing (4) being fixed on top of the other, characterized in that: The at least one deflector (30) is retained within the gearbox (2) by being wedged between the first housing (3) and the second housing (4).

12. A power assembly (9), in particular for a motor vehicle (1), characterized in that The powertrain (9) comprises a gearbox (2) according to any one of claims 4 to 11 or an oil recovery device (10) according to any one of claims 1 to 3.

13. A vehicle, in particular a motor vehicle (1), characterized in that It comprises a gearbox (2) according to any one of claims 4 to 11 or an oil recovery device (10) according to any one of claims 1 to 3 or a powertrain (9) according to the preceding claims.

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