Drive train for motor vehicle

Abstract

The invention relates to a drive train for a motor vehicle, comprising a shaft assembly (200) which is guided through a coolant and / or lubricant space (212) of a reservoir, the shaft assembly (200) is surrounded at least in a longitudinal section by a pipe element (218) and is rotatably mounted relative to the first housing element (224) by a first bearing (221) and is rotatably mounted relative to the second housing element (230) by a second bearing (227), a sealing element (233) being arranged between the shaft assembly (200) and the first housing element (224), a collecting space (236) is formed spatially between the first bearing (221) and the sealing element (233), which collecting space is fluidically connected to at least one inflow (239) for the coolant and / or lubricant, and wherein the pipe element (218) is designed to receive the coolant and / or lubricant in its interior (242) and to at least indirectly guide it to an outflow (257).

Description

Technical Field

[0001] The invention relates to a drive train for a motor vehicle. The invention also relates to a motor vehicle having a plurality of axles, wherein at least one of the axles comprises such a drive train. Background Art

[0002] Drive trains for motor vehicles are known, in which an output shaft, for example, which is led from a differential to the wheels to be driven, is led through an oil tank or oil reservoir. The output shaft is surrounded by a protective tube, which separates the oil space inside the oil tank from the output shaft and the bearings supporting the output shaft and thus forms a dry space for the output shaft. The protective tube can be press-fitted into the housing or housing parts on both sides, wherein the dry space is sealed off from the oil space by a press fit and / or Christmas tree seals and / or O-rings. Due to the oil level inside the oil tank, which fluctuates constantly during operation, churning losses and friction losses caused by contact between the output shaft rotating during operation and the oil in the oil tank are prevented by the protective tube. Summary of the invention

[0003] The object of the present invention is to provide a drive train for a motor vehicle which has improved installation and removal conditions. The invention achieves this object by means of the subject matter of the independent claims. The dependent claims reflect preferred embodiments.

[0004] According to the present invention, a drive train for a motor vehicle comprises a shaft assembly which is guided through a coolant and / or lubricant space of a reservoir, wherein the shaft assembly is surrounded by a tube element at least in a longitudinal section and is supported rotatably relative to a first housing element via a first bearing and is supported rotatably relative to a second housing element via a second bearing, wherein a sealing element is arranged between the shaft assembly and the first housing element, wherein a collecting space is spatially constructed between the first bearing and the sealing element, wherein the collecting space is fluidically connected to at least one inlet for coolant and / or lubricant, and wherein the tube element is constructed to receive coolant and / or lubricant from the collecting space in its internal space and to guide it at least indirectly to an outlet.

[0005] The tube element is used as a protective tube to prevent contact between the shaft assembly and the coolant or lubricant in the coolant and / or lubricant space of the reservoir. The tube element thus prevents losses that could slow down the motor vehicle during operation. The tube element is arranged on the first housing element on the one hand and on the second housing element on the other hand. Preferably, a press-fit seat is provided between the tube element and the respective housing element. The inner space of the tube element is sealed relative to the coolant and / or lubricant space of the reservoir by means of a press-fit seat or an optional sealing element, such as an O-ring. The tube element forms a dry space that prevents the shaft assembly from running or rotating in the oil in the coolant and / or lubricant space and thus generating oil stirring losses. The tube element is only configured to accommodate the coolant or lubricant at the first end as a line or outlet groove and to divert the coolant or lubricant at the opposite end.

[0006] In order to allow the coolant or lubricant to reach the outflow portion from the collecting space, the inner space of the pipe element has a drop, in particular a constant drop. For this purpose, the inner diameter of the pipe element can increase from one end, i.e., the end facing the inflow portion, toward the other end, i.e., the end facing the outflow portion. In this sense, the pipe element can be configured in the form of a funnel, wherein the coolant or lubricant can flow from the end with a smaller diameter to the end with a larger diameter.

[0007] The inlet through which the coolant or lubricant at least indirectly enters the collecting space is arranged in the upper region of the drive train, in particular in the upper region above the shaft assembly with respect to the direction of gravity, so that the coolant or lubricant can flow into the system from above at least partially by gravity. The inlet can be a hole, a pipe, a line, a hose or an opening.

[0008] The outflow is at least indirectly connected to the coolant and / or lubricant space of the reservoir. The outflow can be a hole, a tube, a line, a hose or an opening. The outflow is located below the inflow with respect to gravity, so that the coolant or lubricant conveyed through the inflow can reach the outflow without loss. Preferably, the outflow is arranged at the lowest point of the system in order to ensure a safe outflow of the coolant or lubricant.

[0009] In principle, any type of bearing is used as a bearing, which comprises at least one outer ring, at least one inner ring and a plurality of rolling bodies guided between the respective outer ring and the respective inner ring. At least one bearing can be a fixed bearing and at least one bearing can be a floating bearing. The bearing element configured as a fixed bearing is arranged to absorb axial forces in two directions. In addition to axial forces, the fixed bearing also absorbs radial forces and transmits them to adjacent components. The axial positioning of the supported component (here the shaft assembly) is precisely defined by the fixed bearing. This is particularly applicable under load. In addition, the operation of the respective components supported by the fixed bearing is relatively precise. The fixed bearing preferably has one or more rolling bearings, in particular ball bearings. Preferably, the respective fixed bearing is configured as a single-row deep groove ball bearing. The floating bearing is designed only for absorbing and transmitting radial forces relative to the fixed bearing. These floating bearings can be needle bearings or cylindrical roller bearings without retaining rings. Sliding bearings are also conceivable.

[0010] The sealing element is provided to seal a coolant and / or lubricant space, in particular an interior space of a drive train, from the external atmosphere. Preferably, the sealing element is a shaft sealing ring which is arranged on the shaft assembly or the first housing element and supported on the respective other component.

[0011] Preferably, the shaft assembly comprises a shaft and an output flange, wherein the bearing is arranged on the shaft, and wherein the sealing element is arranged on the output flange. In other words, the shaft assembly can be constructed in multiple parts, i.e., with a plurality of components that are connected or coupled to each other in a rotationally fixed manner, in order to transmit the drive power from an input side, such as a drive unit, a transmission stage, a differential, etc., to an output side, such as a wheel hub, a transmission ratio stage, etc.

[0012] Preferably, the shaft has means for receiving the output flange in a rotationally fixed manner. The output flange can be pressed into a sleeve-shaped section of the shaft. Alternatively or additionally, the rotationally fixed connection can be achieved via a drive toothing.

[0013] According to a first alternative embodiment, the inlet is arranged on the first housing element so that the coolant and / or lubricant flows directly into the collecting space. In other words, the collecting space is configured to accommodate the coolant and / or lubricant provided via at least one inlet directly connected to the collecting space, and is provided for at least indirectly cooling and / or lubricating at least the bearing and the sealing element. The inlet can be configured, for example, as a through hole on the first housing element. In this variant, the inlet can be connected upstream to a coolant and / or lubricant supply, such as a delivery unit, in particular a pump fluid, so that the bearing and the sealing element can be actively lubricated by actively delivering the coolant and / or lubricant to the collecting space. The pump can deliver the coolant and / or lubricant from the coolant and / or lubricant space of the reservoir to the collecting space via the inlet, wherein, after the mentioned components are cooled or lubricated, the coolant and / or lubricant can flow back into the reservoir via the outflow.

[0014] According to a second embodiment alternative, the inlet is designed as an opening in the tube element. For example, a passive supply of coolant and / or lubricant can be carried out via such an inlet. For example, an opening is understood to be a recess in the tube element, wherein, depending on the oil level in the coolant and / or lubricant space of the reservoir, the coolant or lubricant can flow from the reservoir to the component to be lubricated.

[0015] Preferably, the second bearing is arranged between the tube element and the outflow portion in the flow direction of the coolant and / or lubricant. In other words, the coolant or lubricant introduced into the interior of the tube element is first provided for cooling or lubricating the second bearing before it reaches the outflow portion, or from there to the outflow portion. Therefore, the tube element is arranged axially between the bearings. Therefore, the section of the housing element that accommodates the tube element is also arranged axially between the bearings.

[0016] Preferably, the tube element has a first longitudinal section with a first inner diameter and / or a first change in inner diameter for guiding the coolant or lubricant. Depending on how the coolant or lubricant is fed to the cooling and / or lubricating system described herein, the coolant or lubricant either flows from the collecting space in the direction of the longitudinal section of the tube element, i.e. the longitudinal section of the tube element is arranged downstream of the first bearing, or the coolant or lubricant flows from the longitudinal section in the direction of the collecting space, i.e. the longitudinal section of the tube element is arranged upstream of the first bearing. It is also conceivable that the longitudinal section with the inner diameter or the change in inner diameter is selected in such a way as to be able to accommodate the coolant or lubricant in the region of the mentioned longitudinal section and to store the coolant or lubricant for lubricating the first bearing, regardless of the direction or side from which the coolant or lubricant is fed to the system, in particular even if the coolant or lubricant first reaches the receiving space through the inflow section and from there reaches the first bearing.

[0017] In this sense, it is advantageous if a first partition is arranged at the first inner diameter and / or the first inner diameter change of the first longitudinal section. The first partition limits the coolant or lubricant flow between two longitudinal sections of the tube element. The first partition can be designed as a tapering of the tube element or as a radially inwardly directed protrusion or a radially inwardly directed shoulder. Preferably, the first partition is arranged or shaped such that it separates the first longitudinal section having the first inner diameter or the first inner diameter change from a further longitudinal section of the tube element having at least one second inner diameter and / or a second inner diameter change.

[0018] If it is a longitudinal section with an inner diameter, the longitudinal section has a constant inner diameter. If it is a longitudinal section with an inner diameter change, the longitudinal section has a changing, preferably uniform, inner diameter change.

[0019] The invention includes the following technical teaching, namely, the first housing element comprises a bypass channel, which fluidically connects the collecting space with the inner space of the tube element. In this sense, at least a part of the coolant or lubricant is guided directly into the tube element via the bypass channel, instead of being guided into the first bearing, from which the coolant or lubricant reaches the outflow portion at least indirectly. Therefore, the bypass channel can be arranged on the first housing element in such a way that the bypass channel is arranged radially outside the first bearing and extends parallel to the rotation axis of the first bearing.

[0020] In one embodiment, a second partition is arranged in the bypass channel. The second partition can be configured to ensure that less coolant and / or lubricant flows out of the collecting space or is directed to the outflow than enters via the respective inflow. Thus, a throttled outflow can be achieved via the second partition. The second partition is therefore an outflow partition.

[0021] The motor vehicle according to the present invention is provided with a first axle and at least one second axle, wherein a drive train according to the first aspect of the present invention is arranged on at least one of the axles. Therefore, the axle with the drive train is a driven or drivable axle. It is also conceivable that such a drive train is provided for each axle so that each axle is a driven or drivable axle. Therefore, the drive train according to the present invention can be used for motor vehicles, in particular automobiles (for example, passenger vehicles weighing less than 3.5 tons), buses or cargo vehicles (for example, buses and cargo vehicles weighing more than 3.5 tons). If the drive machine of the respective drive train is an electric motor, the motor vehicle is in particular an electric vehicle or a hybrid vehicle. However, the motor vehicle can also be driven by an internal combustion engine. The drive power of the respective drive machine is transmitted to the wheels of the motor vehicle at least indirectly via the mentioned shaft assembly of the drive train.

[0022] A drive train according to the invention is effectively arranged on a driven axle, wherein the drive train transmits the driving power of the drive unit to at least one wheel of the driven axle via an optional transmission. If the drive train comprises a differential, two wheels of an axle can be driven. The mentioned axle assembly is drivingly connected to one of the wheels. The drive train is preferably installed in a front transverse structure so that the axle assembly is oriented substantially transversely to the longitudinal direction of the vehicle. Alternatively, the drive train can be arranged obliquely with respect to the longitudinal axis and the transverse axis of the vehicle, wherein the axle assembly is connected to the associated wheel of the axle arranged transversely to the longitudinal axis of the vehicle via at least one corresponding joint.

[0023] Features and advantages of the drive train according to the invention can be transferred to the motor vehicle according to the invention and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will now be described in detail with reference to the accompanying drawings, in which:

[0025] Figure 1 A highly schematic illustration of a motor vehicle according to the invention is shown;

[0026] Figure 2 Shown in accordance with Figure 1 A partial longitudinal section of a drive train of a motor vehicle according to the present invention; and

[0027] Figure 3A partial longitudinal section through a drive train of a motor vehicle according to the invention is shown according to an alternative embodiment. DETAILED DESCRIPTION

[0028] Figure 1 A motor vehicle 100 is shown with two axles 105, 110, wherein a drive train 115 according to the invention is arranged on the first axle 105 in a driving manner. The motor vehicle 100 is an electric vehicle, wherein the motor vehicle 100 is driven purely electrically. The first axle 105 can be the front axle and the rear axle of the motor vehicle 100 and forms the driven axle of the motor vehicle 100. In this case, the drive train 115 is arranged, for example, on a non-steerable rear axle of the motor vehicle 100.

[0029] The drive train 115 comprises a drive unit 120 designed as an electric motor and a gear 125 operatively connected thereto, wherein the design and arrangement of the drive unit 120 and the gear 125 are not shown or explained in detail in the following figures. In any case, the drive unit 120 or the electric motor has a battery (not shown here) to supply it with electrical energy and power electronics (also not shown) for controlling and regulating the drive unit 120. By energizing the stator (not shown here), a rotor (also not shown) arranged rotatably relative to the stator is set in a rotational motion relative to the stator. The drive power generated in this way is conducted via the gear 125 to the differential 130, wherein the drive power is converted by the differential 130 and divided or distributed to a first output shaft 135 and a second output shaft 140, which are in turn connected to the wheels 145 of the first axle 105 in a driving manner.

[0030] Figure 2 and Figure 3 A partial section of the drive train 115 is schematically shown. In the present case, the first output shaft 135 is shown in the form of a shaft assembly 200, wherein the shaft assembly 200 comprises a shaft 203 and an output flange 206. The shaft 203 is arranged on the differential side and is drivingly connected to an output member 209 of the differential 130. The output flange 206 is arranged on the hub side or wheel side as an output member of the drive train 115. The shaft 203 accommodates the output flange 209 axially and rotationally fixedly, for example, by means of a drive toothing.

[0031] The shaft assembly 200 axially guides a coolant and / or lubricant space 212 of a reservoir 215 of a cooling and / or lubricating system of the drive train 115, wherein the shaft 203 of the shaft assembly 200 is surrounded by a tube element 218 over a section of its longitudinal extension. The tube element 218 separates the coolant or lubricant space 212 from its interior space 242 and thus provides controlled and desired cooling or lubrication conditions in the interior space 242 separated from the coolant and / or lubricant space 212 by the tube element 218.

[0032] Furthermore, the shaft 203 is rotatably supported relative to the first housing element 224 via a first bearing 221 and is rotatably supported relative to the second housing element 230 via a second bearing 227. The pipe element 218 is pressed onto the first housing element 224 at the end shown on the left and onto the second housing element 230 at the end shown on the right, and seals off the interior space 242 relative to these housing elements. If the sealing effect is not sufficient, a sealing element may also be provided.

[0033] The bearings 221, 227 are radial ball bearings and are axially fixed relative to the respective housing element 224, 230 or the shaft 203. On the side of the first bearing 221 opposite to the second bearing 227, a sealing element 233 is arranged between the output flange 206 and the first housing element 224. The sealing element 233 is designed in the form of a shaft sealing ring.

[0034] The space between the sealing element 233 and the first bearing 221 is understood as a collecting space 236, which is set up to accommodate a coolant or lubricant and is provided for cooling or lubricating the component to be lubricated. Here, the component to be lubricated is understood to be at least two bearings 221, 227 and the sealing element 233.

[0035] according to Figure 2 , the collecting space 236 constructed around the outlet flange 206 is directly fluidically connected to an inlet 239 for coolant and / or lubricant, which is constructed as a through-hole on the first housing element 224. The inlet 239 is in turn fluidically connected to a pump (not shown here), which actively transports the coolant or lubricant via the inlet 239 into the collecting space 236. The flow direction is indicated by the first dashed arrow FL1. A partition 240 is arranged in the inlet 239 in order to control the inflow into the collecting space 236.

[0036] After the coolant or lubricant enters the collecting space 236, a portion of the coolant or lubricant is directed to the first bearing 221 and is directed through the first bearing 221, which is illustrated by the second dashed arrow FL2. The tube element 218 has a first longitudinal section 245 with a substantially constant first inner diameter 248, wherein the coolant or lubricant is collected at the first longitudinal section 245 after the first bearing 221. A first partition 251 is arranged as a radially inwardly directed projection at the end of the first longitudinal section 245 that is away from the first bearing 221. The first partition 251 is adapted to the cooling or lubrication requirements of the first bearing 221 and the sealing element 233 and defines a maximum liquid level inside the collecting space 236, which is shown here by a line 254. Excess coolant or lubricant, i.e. coolant or lubricant that exceeds the maximum liquid level, is directed over the first partition 251 into the interior space 242 of the funnel-shaped tube element 218. Therefore, the first bearing 221 and the sealing element 233 are supplied with coolant or lubricant as required. The tube element 218 is configured to receive the coolant or lubricant in its inner space 242 and first guide it to the second bearing 227 at the opposite end of the tube element 218, and the coolant or lubricant is then received by the outflow portion 257 and guided away, in particular back to the coolant and / or lubricant space 212. This is shown by the third dashed arrow FL3. Therefore, the second bearing 227 is arranged between the tube element 218 and the outflow portion 257 in the flow direction of the coolant and / or lubricant.

[0037] A bypass channel 260 is also formed on the first housing element 224, which is located on the opposite side of the inlet 239 with respect to the rotation axis of the shaft assembly 200 and additionally connects the collecting space 236 to the inner space 242 of the tube element 218. The coolant or lubricant that does not reach the first bearing 221 is guided into the inner space 242 of the tube element 218 via the bypass channel 260 in order to lubricate or cool the second bearing 227, in particular when the maximum liquid level defined by the first partition 251 is not exceeded.

[0038] In the bypass channel 260, a second partition 263 is also arranged, which as an outflow partition ensures a throttled outflow from the collecting space 236 into the interior 242 of the tube element 218 in order to lubricate or cool the second bearing 227 as required. In operation with continuous cooling or lubrication, the accumulation of coolant or lubricant in the collecting space 236 is ensured by the design of the inflow partition or inflow 239 relative to the second partition 263, in order to also ensure sufficient lubrication of the sealing element 233. A partial amount of coolant or lubricant flows via the bypass channel 260, the tube element 218, the inner periphery of which serves as an outflow groove, and the second bearing 227 to the outflow 257. If the pump or the cooling is deactivated and coolant or lubricant no longer enters the collecting space 236 via the inflow 239, the collecting space 236 is emptied via the bypass channel 260. This is advantageous for mounting or dismounting the output flange 206 , since no coolant or lubricant escapes from the system if the output flange 206 is dismounted and pulled out to the left.

[0039] Drive system 115 Figure 3 The alternative design shown in Figure 2 The exemplary embodiments shown are constructed substantially identically, so that only the differences are named and described below. In other respects, reference is made to the above-described embodiments.

[0040] according to Figure 3 , the bearings 221, 227 and the sealing element 233 are cooled or lubricated by means of a passive coolant or lubricant supply. Line 254 illustrates the liquid level in the reservoir 215, which is so high that the coolant or lubricant is introduced into the system through the inlet 300 designed as an opening or a hole, which in this case is arranged in the region of the first longitudinal section 245 of the tube element 218 and is arranged on the tube element 218 above the shaft 205 with respect to gravity, i.e. in the vertical direction, wherein the flow direction of the coolant or lubricant is indicated by the first dashed arrow FL1. Analogously to the above-described embodiment, the first longitudinal section 245 of the tube element 218 is bounded by a first partition 251, so that the coolant or lubricant flows from the annular space located between the shaft 203 and the inner diameter 248 of the first longitudinal section 245, which is designed on the first longitudinal section 245, to the left to the first bearing 221 and from there to the collecting space 236 (see the second dashed arrow FL2).

[0041] After the coolant or lubricant reaches the collecting space 236, similarly to the first embodiment, the coolant or lubricant is guided into the inner space 242 of the pipe element 218 via the bypass channel 260, so that the coolant or lubricant reaches the second bearing 227 for cooling or lubrication as shown by the third arrow FL3 of the dotted line, and is then delivered to the outflow portion 257. The bypass channel 260 is arranged on the opposite side of the inflow portion 300 with respect to the rotation axis of the shaft assembly 200.

[0042] The first partition plate 251 and the second partition plate 263 inside the bypass channel 260 ensure that a certain liquid level is maintained in the collecting space 236 in order to ensure sufficient lubrication or cooling of the sealing element 233 and the first bearing 221 .

[0043] Reference numerals list

[0044] 100 Motor Vehicles

[0045] 105 First Axle

[0046] 110 Second Axle

[0047] 115 drive system

[0048] 120 drive unit

[0049] 125 transmission

[0050] 130 Differential

[0051] 135 first output shaft

[0052] 140 Second output shaft

[0053] 145 wheels

[0054] 200 shaft assembly

[0055] 203 axis

[0056] 206 output flange

[0057] 209 differential output member

[0058] 212 Coolant and / or lubricant space

[0059] 215 Storage

[0060] 218 tube element

[0061] 221 first bearing

[0062] 224 first housing element

[0063] 227 Second bearing

[0064] 230 second housing element

[0065] 233 Sealing element

[0066] 236 Collection Space

[0067] 239 Inflow

[0068] 240 partition

[0069] 242 Internal space of the tube element

[0070] 245 first longitudinal section of the tube element

[0071] 248 Inner diameter of the first longitudinal section

[0072] 251 First partition

[0073] 254 lines

[0074] 257 Outflow

[0075] 260 bypass channel

[0076] 263 Second partition

[0077] 300 Inflow

[0078] FL1 first arrow

[0079] FL2 second arrow

[0080] FL3 third arrow

Claims

1. A drive train (115) for a motor vehicle (100), comprising a shaft assembly (200) which is guided through a coolant and / or lubricant space (212) of a reservoir (215), wherein: The shaft assembly (200) is surrounded by a tube element (218) at least in a longitudinal section and is rotatably supported relative to a first housing element (224) via a first bearing (221) and is rotatably supported relative to a second housing element (230) via a second bearing (227), wherein a sealing element (233) is arranged between the shaft assembly (200) and the first housing element (224), wherein a collecting space (236) is spatially formed between the first bearing (221) and the sealing element (233), the collecting space being fluidically connected to at least one inlet (239, 300) for a coolant and / or a lubricant, and wherein the tube element (218) is designed to receive a coolant and / or a lubricant in its interior space (242) and to at least indirectly guide the coolant and / or the lubricant to an outlet (257).

2. The drive train (115) according to claim 1, wherein: The inlet (239, 300) is arranged on the first housing element (224) so ​​that the coolant and / or the lubricant flows directly into the collecting space (236).

3. The drive train (115) according to claim 1, wherein: The inflow (239, 300) is designed as an opening on the pipe element (218).

4. The drive train (115) according to any one of the preceding claims, wherein: The second bearing (227) is arranged between the pipe element (218) and the outflow portion (257) in the flow direction of the coolant and / or lubricant.

5. The drive train (115) according to any one of the preceding claims, wherein: The tube element (218) has a first longitudinal section (245) with a first inner diameter (248) and / or a first inner diameter change for conducting a coolant and / or a lubricant.

6. The drive train (115) according to claim 5, wherein: A first partition plate (251) is arranged on the first inner diameter (248) and / or the first inner diameter change of the first longitudinal section (245).

7. The drive train (115) according to any one of the preceding claims, wherein: The first housing element (224) comprises a bypass channel (260) which fluidically connects the collecting space (236) with the interior space (242) of the tube element (218).

8. The drive train (115) according to claim 7, wherein: A second partition plate (263) is arranged in the bypass channel (260).

9. The drive train (115) according to any one of the preceding claims, wherein: The shaft assembly (200) comprises a shaft (203) and an output flange (206), wherein the bearings (221, 227) are arranged on the shaft (203), and wherein the sealing element (233) is arranged on the output flange (206).

10. A motor vehicle (100), comprising a first axle (105) and at least one second axle (110), wherein: At least one of the axles (105, 110) has a drive train (115) according to one of the preceding claims.

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