Axle drive unit for a motor vehicle

Abstract

Axle drive unit for a motor vehicle (2) with a housing arrangement (10) in which a transmission unit and an electric motor are provided, which are operatively connected to a drive axle (6), wherein the housing arrangement (10) is mounted on the vehicle chassis via a bearing arrangement with bearing points, wherein the housing arrangement (10) has a heat exchanger unit (16) operatively connected to the electric motor and the transmission unit, characterized in that an electric motor housing (12) has a first supply connection (20) and a first return connection (22) and a transmission housing (14) has a second supply connection (24) and a second return connection (26), wherein the first return connection (22) is directly connectable to the second supply connection (24), wherein, viewed in the direction of coolant flow, power electronics for the electric motor are arranged upstream of the electric motor and the electric motor is arranged upstream of the transmission unit.

Description

[0001] The invention relates to an axle drive unit for a motor vehicle with a housing arrangement in which a transmission unit and an electric machine are provided, which are operatively connected to a drive axle, wherein the housing arrangement is mounted on the vehicle chassis via a bearing arrangement with bearing points according to the preamble of patent claim 1.

[0002] Such axle drive units are well known in the art. For example, DE 10 2010 061 217 A1 describes an axle drive unit in which an electric motor drives a drive axle, in particular a front axle, via a differential gear. The housing unit, which consists of an electric motor housing and a transmission housing, is mounted on the vehicle chassis via corresponding bearings. Furthermore, it is known, for example, from DE 10 2010 061 285 A1, to cool a transmission housing, and thus the transmission, via a heat exchanger system. With the increasing functionality of such axle drive units, the complexity and space requirements of such modules also increase, which, however, clearly contradicts the installation space options available in modern vehicles.

[0003] Furthermore, US 2012 / 0153718 A1 also belongs to the state of the art.

[0004] The object of the invention is therefore to provide an axle drive unit which ensures the complexity and functionality of the gear unit and electric machine provided in the housing arrangement while utilizing a small installation space.

[0005] This object is achieved according to the invention with the features of patent claim 1. Advantageous embodiments thereof are mentioned in the subclaims.

[0006] According to the invention, the housing arrangement has a heat exchanger unit that is operatively connected to the electric machine and the transmission unit.

[0007] This allows for optimal cooling of the electric motor and transmission unit in the smallest possible space. Effective cooling of the components is particularly necessary given the extremely tight installation space.

[0008] The heat exchanger unit advantageously includes a coolant piping system. To ensure optimal utilization of the coolant capacity, it is advisable to arrange the power electronics for the electric motor upstream of the electric motor, and the electric motor upstream of the transmission unit, as seen in the direction of coolant flow.

[0009] In an advantageous embodiment, an electric machine housing has a first supply connection and a first return connection, and a transmission housing has a second supply connection and a second return connection, wherein the first return connection can be directly connected to the second supply connection.

[0010] Advantageously, the drive axle is a front axle.

[0011] The invention is explained in more detail below with reference to the drawing, in which: Fig. 1 a schematic side view of a front area of ​​a motor vehicle, and Fig. 2 a perspective view of a drive unit according to the invention.

[0012] Fig. 1 shows a schematic side view of the front area of ​​a motor vehicle 2. A front wheel 4 is driven by a front axle 6, to which an axle drive unit 8 is operatively connected.

[0013] Fig.2 now shows the axle drive unit 8 according to the invention, which essentially has a housing arrangement 10 consisting of an electronics machine housing 12 and a transmission housing 14, which is shown here partially in section. Power electronics (not shown in detail) with an electric machine is arranged in the electronics machine housing 12 in a known manner. A differential gear (not shown in detail) is arranged in the transmission housing 14 in a known manner. The housing arrangement 10 further has a heat exchanger unit 16, which is operatively connected to both the electric machine housing 12 and the transmission housing 14. The heat exchanger unit 16 consists of a coolant line system 18, which is guided through both the electric machine housing 12 and the transmission housing 14. For this purpose, the electric machine housing 12 has a first supply connection 20 and a first return connection 22 for the coolant.The first return port 22 is connected to a second supply port 24 of the transmission housing 14. The coolant leaves the transmission housing via a second return port 26 and is returned, for example, to a coolant compressor (not shown).

[0014] In order to ensure optimum efficiency of the heat exchanger unit 16, the coolant line 18 is first guided past a power electronics unit for the electric machine arranged in the electric machine housing 12, then past the electric machine and is finally guided through the gear unit arranged in the gear housing 14.

[0015] The axle drive unit 8 according to the invention is particularly suitable for a front axle 6.

Claims

[1] Axle drive unit for a motor vehicle (2) with a housing arrangement (10) in which a transmission unit and an electric machine are provided, which are operatively connected to a drive axle (6), wherein the housing arrangement (10) is mounted on the vehicle chassis via a bearing arrangement with bearing points, wherein the housing arrangement (10) has a heat exchanger unit (16) operatively connected to the electric machine and the transmission unit, characterized by in that an electric machine housing (12) has a first supply connection (20) and a first return connection (22) and has a gear housing (14), a second supply connection (24) and a second return connection (26), wherein the first return connection (22) is directly connectable to the second supply connection (24), wherein, viewed in the flow direction of the coolant, power electronics for the electric machine are arranged upstream of the electric machine and the electric machine is arranged upstream of the gear unit. [2] Axle drive unit according to claim 1, characterized by that the heat exchanger unit (16) has a coolant line system (18). [3] Axle drive unit according to claim 1 or 2, characterized by that the drive axle (6) is a front axle.

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