Electric vehicle axle assembly and motor vehicle transmission system having such electric vehicle axle assembly

Abstract

An electric axle assembly (1) for a motor vehicle drivetrain and a drivetrain having at least one such electric axle assembly (1), the electric axle assembly comprising: a drivable axle (2); a motor (3), wherein the axle (2) is connected to or is connectable to the motor (3) in a drive-effective manner; a coolant sump (4) having a liquid coolant; and an elevated container (5), wherein the liquid coolant is capable of being delivered from the coolant sump (4) to the elevated container (5), wherein the elevated container (5) is fluidly connected to a cooling system (7) via a switchable valve (6) for cooling the motor (3).

Description

Technical Field

[0001] This invention relates to an electric axle assembly for a motor vehicle drivetrain, comprising: a drivable axle; a motor, wherein the axle is connected to or is connectable to the motor in a drive-effective manner; a coolant sump having liquid coolant; and an elevated container, wherein liquid coolant can be delivered from the coolant sump to the elevated container. Furthermore, this invention also relates to a motor vehicle drivetrain having at least one such electric axle assembly. Background Technology

[0002] The auxiliary drive system of a motor vehicle is towed while idling for most of its service life. In the case of electrically assisted motor vehicle axles, it is necessary to cool the motor associated with the axle when needed. Typically, the motor is cooled by means of a liquid coolant, such as engine oil, but the delivery of this liquid coolant causes towing losses. Summary of the Invention

[0003] The object of this invention is to provide an improved electric axle device for motor vehicle powertrains. Furthermore, the object of this invention is to provide an improved motor vehicle powertrain with such an electric axle device, characterized in particular by reduced drag loss and subsequent optimization of the effective mileage of the motor vehicle during electric operation.

[0004] This requirement is met by the drivetrain for a motor vehicle and the electric vehicle axle device for the drivetrain of a motor vehicle according to the present invention. Advantageous embodiments of the invention are described below.

[0005] The electric axle device for a motor vehicle drivetrain according to the present invention comprises: a drivable axle; a motor, wherein the axle is connected to or is connectable to the motor in a drive-effective manner; a coolant sump having liquid coolant; and an elevated container, wherein liquid coolant can be delivered from the coolant sump to the elevated container.

[0006] According to the present invention, the elevated container can be fluid-efficiently connected to a cooling system via a switchable valve for cooling a motor.

[0007] In a favorable embodiment variation, the axle can be connected to the motor via a switching unit in a drive-efficient manner. Here, the valve can also be switched via the switching unit.

[0008] The switching unit preferably works in conjunction with the valve in an effective regulating manner, such that in the first operating state of the switching unit, that is, when the motor is effectively connected to the axle in a driving manner, the valve is open, and in the second operating state of the switching unit, that is, when the motor is not effectively connected to the axle in a driving manner, the valve is closed.

[0009] In an alternative implementation variation, the valve is configured to be magnetically switchable.

[0010] The drivetrain for a motor vehicle according to the present invention includes at least one electric vehicle axle device according to the present invention.

[0011] By means of the electric axle device according to the present invention, and subsequently the configuration of the motor vehicle's drivetrain, it is feasible to minimize drag loss as much as possible with a simple construction that reduces components and costs, thereby enabling optimized operation of the electric axle device. By using at least one such electric axle device in the motor vehicle's drivetrain, increased effective mileage can be achieved by reducing drag loss at the axle level, especially in electric operation. Attached Figure Description

[0012] The invention is described below with reference to the accompanying drawings.

[0013] Figure 1 A schematic diagram of a first embodiment of an electric vehicle axle device is shown.

[0014] Figure 2 A schematic diagram of a second embodiment of the electric vehicle axle device is shown. Detailed Implementation

[0015] Figure 1 and Figure 2 Examples of electric axle devices 1 for motor vehicle transmissions according to the present invention are schematically shown. Each of the two electric axle devices 1 includes a driveable axle 2, a motor 3, a coolant oil pan 4, a high-level container 5, a valve, and a cooling system 7.

[0016] The motor 3 is connected to or can be connected to the axle 2 via the transmission device 11 in a driving-effective manner.

[0017] Liquid coolant is present in the coolant pan 4. In this case, the liquid coolant should be understood as engine oil.

[0018] Liquid coolant can be transferred from the coolant sump 4 to the upper container 5. According to... Figure 1 and Figure 2 In both embodiments, this is done via a rotating gear 10 (“final drive”) and a suitable guide device (not shown), which is partially immersed in the coolant sump 4.

[0019] Cooling system 7 is used to cool motor 3.

[0020] In both of these variant implementations, the high-level container 5 can be fluid-efficiently connected to the cooling system 7 via a switchable valve 6 for cooling the motor 3. Coolant then flows back from the motor 3's cooling system 7 to the coolant sump 4.

[0021] exist Figure 1 An exemplary first embodiment variant of the electric vehicle axle device 1 according to the present invention is schematically shown. In this first embodiment variant, a connecting unit 8 is provided on the intermediate shaft 9 of the transmission device 11. The motor 3 can be connected to the axle 2 in a driving-effective manner via the connecting unit 8.

[0022] Furthermore, the switching unit 8 is connected to the switchable valve 6 in an adjustable manner. More precisely, the switching unit 8 and the valve 6 work together in an adjustable manner such that in the first operating state of the switching unit 8, that is, in the operating state where the motor 3 and the axle 2 are connected in a driving manner, the valve 6 is opened, and in the second operating state of the switching unit 8, that is, in the operating state where the motor 3 is not connected to the axle 2 in a driving manner, the valve 6 is closed.

[0023] If motor 3 is decoupled from axle 2 via switching unit 8 during idling, intermediate shaft 9 and gear 10 still rotate with axle 2. This rotation causes gear 10 to transport coolant from coolant sump 4 to high-level container 5. By using valve 6, which is switched off in a corresponding manner (i.e., closed) via switching unit 8 in the second operating state of switching unit 8, it is possible to prevent coolant from flowing back from high-level container 5 to coolant sump 4 via cooling system 7, thereby reducing drag loss in the second operating state of switching unit 8, as more coolant accumulates in high-level container 5, thus splashing a reduced amount of coolant onto gear 10.

[0024] If the motor 3 is recoupled to the axle 2 (first operating state of the switching unit 8), the valve 6 is opened via the switching unit 8, and coolant is once again supplied from the high-level container 5 to the cooling system 7 for cooling the motor 3.

[0025] exist Figure 2 The diagram schematically illustrates an exemplary second embodiment of the electric vehicle axle device 1 according to the invention. In this embodiment, the switching unit 8 is omitted, and the motor 3 is permanently connected to the axle 2 in a drive-effective manner. The valve 6 is magnetically operable.

[0026] If motor 3 is idling in this situation, coolant is continuously transported from the coolant sump 4 through gear 10 and the high-level container 5 to the cooling system 7 of motor 3, resulting in very high drag losses. By using a valve 6 that is magnetically switched off when motor 3 is idling, it is possible to prevent coolant from flowing back from the high-level container 5 through the cooling system 7 to the coolant sump 4, thereby reducing drag losses when motor 3 is idling, as more coolant accumulates in the high-level container 5 and splashes onto gear 10 with a reduced amount of coolant.

[0027] If motor 3 drives axle 2, then valve 6 can be magnetically opened, thereby cooling motor 3 via cooling system 7.

[0028] List of reference numerals in the attached diagram:

[0029] 1 Electric vehicle axle assembly

[0030] 2 Axles

[0031] 3 motors

[0032] 4. Coolant oil pan

[0033] 5 high container

[0034] 6 valves

[0035] 7 Cooling System

[0036] 8 Connecting Units

[0037] 9. Intermediate Shaft

[0038] 10 Gears

[0039] 11. Transmission Unit

Claims

1. An electric vehicle axle device (1) for a transmission system of a motor vehicle, the electric vehicle axle device comprising: - Driveable axle (2); - Motor (3), wherein the axle (2) can be connected to the motor (3) in a drive-effective manner via a connection unit (8); - A coolant sump (4) containing liquid coolant; and - An elevated container (5), wherein the liquid coolant can be transported from the coolant sump (4) to the elevated container (5). The high-level container (5) is characterized in that it can be fluid-efficiently connected to a cooling system (7) via a switchable valve (6) for cooling the motor (3). The valve (6) can be switched via the switching unit (8) in such a way that the switching unit (8) and the valve (6) work together in an effective regulating manner, such that in the first operating state of the switching unit (8), that is, in the operating state in which the axle (2) is connected to the motor (3) in an effective driving manner, the valve (6) is open, and in the second operating state of the switching unit (8), that is, in the operating state in which the axle (2) is not connected to the motor (3) in an effective driving manner, the valve (6) is closed.

2. A drivetrain for a motor vehicle, the drivetrain comprising at least one electric vehicle axle device (1) according to claim 1.

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