Transmission for drive train having displacer

Abstract

The invention relates to a transmission (10) for a drive train (100) of a motor vehicle (K), comprising: a transmission housing (20); at least two drive elements (30, 40) which engage with each other and which are accommodated in a housing interior (22) of the transmission housing (20); at least one displacement body (60) which is designed to displace a lubricant (12) accommodated in the housing interior (22) for lubricating the at least two drive elements; and a lubricant exchange opening (24) via which lubricant (12) can be exchanged between the housing interior (22) and a peripheral region (P) surrounding the housing interior (22). The at least one displacement body (60) has at least one lubricant guide region (62) which is designed to guide the lubricant (12) at least in some regions along the displacement body (60) and in the housing interior (22) towards the lubricant exchange opening (24). Another aspect of the invention relates to a motor vehicle (K) having a drive train (100) comprising a drive motor (110) and a transmission (10) to be driven by means of the drive motor (110).

Description

Technical Field

[0001] The present invention relates to a transmission for a drive train of a motor vehicle, the transmission comprising: a transmission housing; at least two drive elements meshing with each other and accommodated in an interior of the transmission housing; at least one displacement body configured to displace lubricant accommodated in the interior of the housing for lubricating the at least two drive elements; and a lubricant exchange opening via which lubricant can be exchanged between the interior of the housing and a peripheral area surrounding the interior of the housing. Another aspect of the present invention relates to a motor vehicle having such a transmission. Background Art

[0002] Such a displacement body is used to reduce the amount of lubricant carried in the transmission, wherein, by displacement, a high lubricant level can be achieved in the transmission even with a low lubricant amount. For example, DE 10 2010 010 816 A1 discloses a transmission comprising at least a functional component and a transmission housing, wherein the displacement body is arranged between the functional component and the transmission housing and is designed as a hollow body.

[0003] EP 1389697 A2 discloses a transmission for a motor vehicle. The transmission includes at least one gear set for power transmission and a housing in which the gear set is mounted. The transmission contains a fluid lubricant and a gas for the gear set. The nominal amount of lubricant in the housing is selected such that at least one lower gear of the gear set is immersed in the lubricant even under unfavorable operating conditions. A displacement body for the lubricant is arranged in the housing and is at least largely immersed in the lubricant. The displacement body is a portion of the housing cover that faces the interior of the housing. Summary of the Invention

[0004] The object of the present invention is to further develop a transmission having a displacement body and a motor vehicle of the type mentioned at the outset in such a way that an improved movement of the lubricant is achieved.

[0005] This object is achieved by a transmission having the features of claim 1 and by a motor vehicle having the features of claim 10. Advantageous embodiments of the invention together with expedient developments are specified in the dependent claims.

[0006] A first aspect of the present invention relates to a transmission for a drive train of a motor vehicle, the transmission comprising: a transmission housing; at least two drive elements meshing with one another and accommodated in an interior of the transmission housing; at least one displacement body configured to displace lubricant accommodated in the interior of the housing for lubricating the at least two drive elements; and a lubricant exchange opening through which lubricant can be exchanged between the interior of the housing and a peripheral area surrounding the interior of the housing. The drive elements can preferably be elements for transmitting torque, such as meshing gears.

[0007] According to the present invention, the at least one displacement body includes at least one lubricant guide region configured to guide lubricant at least partially along the displacement body and within the housing interior toward the lubricant exchange opening. This is advantageous because the displacement body allows for targeted displacement of lubricant contained in the housing interior, typically in the form of transmission oil, and thus allows lubricant to reach machine elements to be lubricated and / or cooled by the lubricant, which may include the drive element, even when the lubricant content in the housing interior is low. The lubricant guide region enables, for example, targeted, low-resistance, and active lubricant extraction by means of a lubricant pump, without the displacement body constricting or blocking the lubricant exchange opening during extraction. This improves the movement of lubricant during lubricant exchange via the lubricant exchange opening. Preferably, the lubricant guide region can be configured to guide lubricant in a plurality of different spatial directions, which may be perpendicular to one another, for example, by having lubricant channels that are oriented at an angle to one another and interconnected. These lubricant channels can be designed, for example, as corresponding through-openings for guiding the lubricant or as corresponding grooves for guiding the lubricant. Particularly preferably, the lubricant guiding area can be open in the direction of the housing interior, so that lubricant can be discharged from the housing interior or introduced into the housing interior unhindered via the lubricant guiding area and the lubricant exchange opening.

[0008] The present invention is based on the recognition that in conventional vehicle transmissions, in particular transmissions designed to be driven by an electric motor as the drive motor, a large volume of air is present in the corresponding housing interior. Accordingly, in conventional systems, large amounts of lubricant must be introduced into the housing interior in order to supply the machine elements to be lubricated and / or cooled.

[0009] The use of the displacement body with its lubricant guide area allows, on the one hand, the displacement of lubricant in the housing interior to such a machine element even when the lubricant amount in the housing interior is small, and, on the other hand, allows a reliable exchange of lubricant with improved lubricant movement due to the lubricant guide area.

[0010] In order to ensure sufficient cooling of a lubricant-, in particular oil-, cooled transmission (which may, for example, be associated with an electric motor of a motor vehicle's drive train), it is advantageous to provide a sufficient lubricant volume flow at the main intake line of a lubricant pump, which may preferably be designed as a pressure pump, in particular a pressure oil pump. This can be achieved in the case of motion-controlled electric motors (also referred to as electric motors) by means of an active lubricant intake pump, which actively draws lubricant from a defined area of ​​the electric motor during dynamic driving maneuvers of the motor vehicle (lateral / longitudinal dynamics, i.e., high lateral and / or longitudinal accelerations), whereby the lubricant can be delivered back to the vicinity of the main intake line.

[0011] The basic principle of the present invention is to reduce the air volume by means of a displacement body in the transmission area. This displacement body is intended to reduce the lubricant volume in the transmission, i.e., in the transmission housing interior. This reduces the volume potentially available for lubricant accumulation (oil accumulation) in this area of ​​the electric machine. This significantly improves the lubricant availability at the active suction points of the transmission, especially under transverse dynamic conditions, by at least largely avoiding air dead volumes, when the displacement body is arranged in the housing interior. A core objective of the present invention is to reduce the lubricant volume of one or more electric machines while optimizing the lubricant supply at the active suction points, thereby saving costs and weight for the electric machine(s), based on the principle of volume displacement by means of a filler body.

[0012] In an advantageous embodiment of the present invention, the at least one displacement body is distinct from the machine element. This advantageously allows for a particularly weight-optimized design of the displacement body. The displacement body can therefore not assume the tasks of torque transmission, fixing, supporting, bracing, and / or housing functions within the housing interior. Thus, for example, the displacement body does not need to support a drive shaft or other machine element, nor does it need to contribute to torque transmission by meshing with a toothing, to name a few. The term "machine element" may be understood to include, for example, a rotating shaft, a shaft, a bearing, a gear, a shifting element (such as a clutch element or a claw), or a fastening element (such as a screw).

[0013] In another advantageous embodiment of the present invention, the displacement body fills at least 20%, preferably at least 40%, and particularly preferably at least 60% of the housing interior. This is advantageous because the displacement body can be dimensioned specifically to meet requirements. The greater the percentage of the housing interior occupied by the displacement body, the more reliable the lubricant supply to the machine elements (e.g., the drive elements of a transmission) is, even at high longitudinal and lateral accelerations during vehicle operation. Conversely, at lower longitudinal and lateral accelerations, it is sufficient for the displacement body to occupy only a small portion of the housing interior (e.g., between 20% and 40%). This allows the displacement body to be dimensioned accordingly and saves weight. Overall, the displacement body can, for example, occupy 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60% of the housing interior.

[0014] In another advantageous embodiment of the present invention, the displacement body at least partially surrounds at least one of the drive elements. This is advantageous because the displacement body can thereby occupy a particularly large portion of the housing interior and / or the lubricant can be directed particularly precisely and specifically to the locations to be lubricated, such as teeth or bearings, using the displacement body. Preferably, the displacement body can be arranged at least partially between the outer circumference of at least one of the drive elements and the region of the transmission housing closest to this outer circumference.

[0015] Preferably, the displacement body can at least largely, preferably completely, circumferentially surround at least one of the drive elements. The expression "largely circumferentially surround" is understood to mean that the displacement body circumferentially surrounds more than 50% of the circumference of the respective drive element. If the drive element is designed, for example, as a shaft or gear, the displacement body can extend along the drive element, preferably at a central angle exceeding 180° relative to the drive element's axis of rotation, for example, at a central angle of 181° or more.

[0016] In another advantageous embodiment of the present invention, the transmission includes at least one additional displacement body, which is different from the displacement body and, like the displacement body, at least partially surrounds at least one of the drive elements. Advantageously, the displacement body and the additional displacement body can together almost completely surround the at least one drive element, so that the displacement body and the additional displacement body together occupy a particularly large portion of the housing interior. Consequently, the required lubricant volume in the housing interior can also be reduced.

[0017] In another advantageous embodiment of the present invention, the displacement body and / or additional displacement body includes at least one recess for at least partially inserting at least one drive element in the drive element. This is advantageous because the displacement body and / or additional displacement body can thereby almost completely surround the respective drive element, since the displacement body can extend along the circumference of the drive element over a central angle of 360° with respect to the rotation axis of the drive element. This can be achieved, for example, if the displacement body has a cylindrical recess, into which the drive element, for example, configured as a gear, is inserted and thus circumferentially surrounded. Preferably, a gap can be provided between the displacement body and the additional displacement body, thereby improving the circulation of the lubricant within the housing interior.

[0018] In another advantageous embodiment of the present invention, the lubricant guide area comprises a through-opening for guiding the lubricant and / or a groove for guiding the lubricant. This is advantageous because the lubricant can be guided to the lubricant exchange opening in a targeted manner with low flow resistance. For this purpose, the through-opening and the lubricant exchange opening can particularly preferably overlap.

[0019] In another advantageous embodiment of the invention, the displacement body is formed from a non-metallic material, in particular from plastic. This is advantageous because the displacement body can thereby be designed to be particularly light.

[0020] In another advantageous embodiment of the present invention, the transmission includes a lubricant pump that is connected to the lubricant exchange opening for drawing lubricant from the housing interior. This is advantageous because the lubricant pump allows for targeted drawing of lubricant from the housing interior. The displacement body can form lubrication gap regions between the displacement body and the housing wall of the transmission housing. Drawing lubricant can achieve high lubricant flow rates in these lubrication gap regions, which can, for example, result in a high heat transfer coefficient at the housing wall and / or facilitate improved removal of potential contaminants (such as wear products). The lubricant pump can preferably be designed as a lubricant suction pump.

[0021] A second aspect of the present invention relates to a motor vehicle having a drive train including a drive motor and a transmission according to the first aspect of the present invention to be driven by the drive motor. In this motor vehicle, improved lubricant movement can be achieved while carrying a small amount of lubricant. The drive motor can be an electric motor. However, it is also conceivable in principle for the drive motor to be designed as an internal combustion engine.

[0022] Preferred embodiments and their advantages mentioned with respect to one of the aspects apply correspondingly to the respective other aspects of the invention and vice versa.

[0023] The features and feature combinations mentioned above in the description and the features and feature combinations mentioned below in the description of the figures and / or shown individually in the figures can be used not only in the respectively indicated combination but also in other combinations or alone without departing from the scope of the present invention.

[0024] Further advantages, features and details of the invention are apparent from the claims, the following description of preferred embodiments and with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be explained again below with the aid of specific embodiments.

[0026] Figure 1 shows an overview of a motor vehicle and its drive train, which comprises a drive motor and a transmission to be driven by means of the drive motor, shown in schematic section; and

[0027] Figure 2 Shown in Figure 1 Magnified view of the framed area A. DETAILED DESCRIPTION

[0028] Figure 1 A schematic diagram shows a motor vehicle K having a drive train 100 comprising a drive motor 110 and a transmission 10 to be driven by means of the drive motor 110 . Figure 2 Shown in an enlarged view Figure 1 The framed partial area A. In the present case, the drive motor 110 is designed as an electric drive motor and is connected to the transmission 10 in a torque-transmitting manner. Figure 1 The corresponding arrows in 1 represent the driving end 18 and the output end 19.

[0029] The transmission 10 includes a transmission housing 20 having a housing wall 21; drive elements 30, 40 meshing with one another and accommodated in a housing interior 22 of the transmission housing 20; a displacement body 60 and an additional displacement body 70, each of which is configured to displace lubricant 12 accommodated in the housing interior 22 for lubricating the drive elements. Furthermore, a lubricant exchange opening 24 is provided, via which lubricant 12 can be exchanged between the housing interior 22 and a peripheral region P surrounding the housing interior 22. The displacement body 60 includes a lubricant guide region 62, which is configured to guide lubricant 12 at least partially along the displacement body 60 and within the housing interior 22 toward the lubricant exchange opening 24.

[0030] In addition to the displacement body 60, an additional displacement body 70 is provided. Both the displacement body 60 and the additional displacement body 70 are different from the machine element and can each be formed from a non-metallic material. In the present variant of the transmission 10, the displacement body 60 and the additional displacement body 70 are formed from plastic. By means of the displacement body 60 and the additional displacement body 70, a corresponding lubrication gap area 16 is formed between the displacement body and the housing wall 21 of the transmission housing 20. The displacement body 60 and the additional displacement body 70 displace the lubricant contained in the housing interior 22, so that a high lubricant level is obtained even when the amount of lubricant contained in the housing interior 22 is small. Furthermore, the displacement ensures that even when acceleration a (which is greater than 0.05 mm) occurs during driving of the motor vehicle K, the lubricant level is maintained. Figure 1 Even at high values ​​(indicated by arrows in FIG), sufficient lubricant reaches the corresponding machine element to be lubricated (such as the corresponding rolling bearing of the drive elements 30 , 40 or the transmission 20 ). The acceleration a can be a longitudinal acceleration and / or a transverse acceleration.

[0031] The displacement body 60 and the additional displacement body 70 different from the displacement body 60 can together fill at least 20%, preferably at least 40%, and particularly preferably at least 60% of the housing interior 22. The remaining portion of the housing interior is filled by the drive elements 30, 40, which are in the present case designed as gears, and further machine elements, such as rolling bearings, as schematically shown in FIG. Figure 1 Visible in.

[0032] The displacement body 60 and the additional displacement body 70 each partially surround the two drive elements 30, 40. For this purpose, the displacement body 60 and the additional displacement body 70 have corresponding recesses 64, 74 for at least partially inserting at least one of the drive elements 30, 40. The recesses 64, 74 can, for example, be formed at least partially cylindrically or at least partially hollow-cylindrically, whereby a lubrication gap of at least partially uniform thickness can be formed in the region of the toothing of the drive element 30, 40, which is currently configured as a gearwheel, along which a lubrication gap can be formed. As a result, a uniform distribution of lubricant can be achieved at least partially on the outer circumference of the drive element 30, 40. The displacement body 60 and the additional displacement body 70 can here surround the drive elements 30, 40 from opposite directions and therefore on different sides. As a result, on the one hand, the respective drive element 30, 40 can be located between the displacement body 60 and the additional displacement body 70, and on the other hand, a gap 76 can remain between the displacement body 60 and the additional displacement body 70, as shown from the figure. Figure 1 The gap 76 ensures that the lubricant reaches the drive elements 30 , 40 and can flow away from them again. This ensures that the lubricant is exchanged directly at the drive elements 30 , 40 .

[0033] The lubricant guide area 24 comprises at least one through-opening 26 for guiding the lubricant 12 and additionally or alternatively a groove (not shown in detail) for guiding the lubricant 12. The through-opening 26 is formed by channels oriented at an angle, in particular at right angles, to one another, which extend through the displacement body 60.

[0034] In order to discharge the lubricant from the housing interior 22 via the lubricant guide area 24, the transmission 10 includes a lubricant pump 14, which is connected to the lubricant exchange opening 24 for sucking the lubricant 12 from the housing interior 22. The lubricant exchange opening is a suction point of the transmission 10, wherein lubricant (here oil) can be actively sucked in at this suction point by means of the lubricant pump 14. The suction by means of the lubricant pump 14 generates a lubricant volume flow 13, which is Figure 2 Indicated by corresponding arrows.

[0035] Reference Signs List

[0036] 10 transmission

[0037] 12 Lubricant

[0038] 13 Lubricant volume flow

[0039] 14 Lubricant pump

[0040] 16 Lubrication gap area

[0041] 18 drive end

[0042] 19 output terminals

[0043] 20 Transmission housing

[0044] 21 Shell wall

[0045] 22 Shell internal space

[0046] 24 lubricant exchange openings

[0047] 26 through openings

[0048] 30 driving elements

[0049] 40 driving elements

[0050] 60 replacement body

[0051] 62 Lubricant guide area

[0052] 64 recesses

[0053] 70 additional replacement bodies

[0054] 74 concavity

[0055] 76 gap

[0056] 100 drive system

[0057] 110 drive motor

[0058] K Motor Vehicle

[0059] P peripheral area

[0060] aAcceleration

Claims

1. A transmission (10) for a drive train (100) of a motor vehicle (K), comprising: - Transmission housing (20), - at least two drive elements (30, 40) meshing with each other and accommodated in the housing interior (22) of the transmission housing (20); - at least one displacement body (60) configured to displace the lubricant (12) contained in the housing interior (22) for lubricating the at least two drive elements; and a lubricant exchange opening (24), via which the lubricant (12) can be exchanged between the housing interior (22) and a peripheral region (P) surrounding the housing interior (22), The invention is characterized in that the at least one displacement body (60) has at least one lubricant guide area (62) which is designed to guide the lubricant (12) at least partially along the displacement body (60) and in the housing interior (22) toward the lubricant exchange opening (24).

2. The transmission (10) according to claim 1, characterized in that The at least one displacement body (60) is different from the machine element.

3. The transmission (10) according to claim 1 or 2, characterized in that The displacement body (60) fills at least 20%, preferably at least 40%, and particularly preferably at least 60% of the housing interior (22).

4. A transmission (10) according to any one of the preceding claims, characterized in that The displacement body (60) at least partially surrounds at least one of the drive elements (30, 40).

5. The transmission (10) according to any one of the preceding claims, characterized in that The transmission (10) comprises at least one additional displacement body (70) which is different from the displacement body (60) and, like the displacement body (60), surrounds at least one of the drive elements (30, 40) at least in sections.

6. The transmission (10) according to claim 5, characterized in that The displacement body (60) and / or the additional displacement body (70) comprises at least one recess (64, 74) for at least partially inserting at least one drive element of the drive elements (30, 40).

7. A transmission (10) according to any one of the preceding claims, characterized in that The lubricant guiding area (24) comprises a through-opening (26) for guiding the lubricant (12) and / or a groove for guiding the lubricant (12).

8. A transmission (10) according to any one of the preceding claims, characterized in that The displacement body (60) is formed from a non-metallic material, in particular plastic.

9. A transmission (10) according to any one of the preceding claims, characterized in that The transmission (10) comprises a lubricant pump (14) which is connected to a lubricant exchange opening (24) for sucking lubricant (12) from a housing interior (22).

10. A motor vehicle (K) having a drive train (100) comprising a drive motor (110) and a transmission (10) according to any one of the preceding claims, to be driven by means of the drive motor (110).

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