Patent Description:
A solution of integration (referred to as a powertrain) of a motor, a reducer, and a motor control unit (MCU) is adopted for a power drive system of an electric vehicle, to make the structure more compact and the weight lighter. In addition, in the powertrain, the inside of the motor is cooled by oil, the heated oil is cooled by a heat exchanger, and a component such as a power device in the MCU is cooled by a liquid cooling cold plate.

In the existing powertrain, the heat exchanger is externally disposed on a housing of the motor, hot oil in the motor is introduced into an internal circulation channel of the heat exchanger, cold water is introduced into an external circulation channel, and the oil exchanges heat with the water for cooling. The heat exchanger cools the oil in the motor alone, and an external cooling surface of the heat exchanger is exposed to the air, and is not fully used. In addition, the entire powertrain is not compact in structure and occupies relatively large space.

<CIT> discloses a cooling housing and a motor controller having the cooling housing. The housing includes adjacent side walls one and two. Two guide tubes are installed on the first side wall, and a cooling water path for fluid circulation is provided in the second side wall. Both ends of the cooling water path are connected to the two guide tubes respectively. The cooling water path is divided into a plurality of flow channels, and the flow channels located at both ends of the cooling water path are channel-shaped. A number of heat-conducting columns are provided in at least one of the remaining flow channels, and each heat-conducting column extends from the inside of the housing into the corresponding flow channel.

<CIT> discloses a motor comprising a motor body and an oil cooling mechanism. The oil cooling mechanism comprises: a stator cooling oil tank provided on a first inner wall of a housing opposite to a stator; a winding cooling oil tank provided on the upper part of a second inner wall of the housing opposite to an end winding, the winding cooling oil tank communicating with the stator cooling oil tank; an oil inlet channel provided on the upper part of the housing, the oil inlet channel communicating with the stator cooling oil tank; and an oil outlet channel provided on the lower part of the housing, an annular space between the oil outlet channel and the stator cooling oil tank communicating with an annular space between the housing and the end winding.

To overcome the foregoing problems existing in a conventional technology, this application provides a powertrain and an electric vehicle, so that an external cooling surface of a heat exchanger can be fully used to improve utilization efficiency of the heat exchanger and heat dissipation of a motor control unit, a structure is more compact, and space is saved. The invention is set out by the appended claims.

Therefore, the following technical solutions are used in embodiments of this application:
According to a first aspect, an embodiment of this application provides a powertrain, including: a motor control unit including a housing and a first functional unit disposed in the housing and capable of generating heat during operation; and a heat exchanger disposed in the housing, where the heat exchanger includes a first circulation channel for a first cooling medium to circulate and a second circulation channel for a second cooling medium to circulate, wherein the first circulation channel is arranged to cool the second circulation channel, where the first circulation channel has a first external cooling surface, and the first circulation channel conducts heat with the first functional unit at the first external cooling surface; and the first circulation channel has a second external cooling surface, and the first circulation channel conducts heat with an inner surface of the housing at the second external cooling surface.

Optionally, a first heat conduction interface material is disposed between the first external cooling surface and the first functional unit; and/or a second heat conduction interface material is disposed between the second external cooling surface and the inner surface of the housing.

Optionally, the motor control unit further includes a second functional unit disposed in the housing, the powertrain further includes a radiator disposed in the housing, and the radiator conducts heat with the second functional unit and the first functional unit.

Optionally, the second functional unit is a power module and includes at least one of a MOSFET, a GTO, and an IGBT. Optionally, a third heat conduction interface material is disposed between the radiator and the second functional unit; and/or a fourth heat conduction interface material is disposed between the radiator and the first functional unit.

Optionally, the first functional unit is disposed between the heat exchanger and the radiator; or the radiator is disposed between the heat exchanger and the first functional unit, and a part of the radiator conducts heat with the first external cooling surface.

Optionally, the first circulation channel is provided with a first outlet and a first inlet, the second circulation channel is provided with a third outlet and a third inlet, and the first outlet, the first inlet, the third outlet, and the third inlet extend out of the housing; and the radiator is provided with a second outlet and a second inlet, and the second outlet and the second inlet extend out of the housing.

Optionally, a pipeline of the radiator communicates with the first circulation channel, the second circulation channel is provided with a third outlet and a third inlet, the first circulation channel is provided with a fourth outlet, the radiator is provided with a fourth inlet, and the fourth outlet, the fourth inlet, the third outlet, and the third inlet extend out of the housing.

Optionally, the radiator and the heat exchanger are integrally made.

Optionally, the radiator includes a first cooling fin and a second cooling fin that are spaced and connected to each other, and the second functional unit is disposed between the first cooling fin and the second cooling fin.

Optionally, the first functional unit includes a bus capacitor.

According to a second aspect, an embodiment of this application provides an electric vehicle including the powertrain according to the first aspect.

In the foregoing technical solution, because the heat exchanger is disposed in the housing of the motor control unit, and the first circulation channel of the heat exchanger for the cooling medium to circulate has the first external cooling surface and/or the second external cooling surface, so that the first external cooling surface can be in heat conduction and contact with the first functional unit to cool the first functional unit, and the second external cooling surface can be in heat conduction and contact with the inner surface of the housing to cool the housing. Compared with a solution in which an oil-water heat exchanger is externally disposed on a motor housing, the foregoing solution of this application in which the heat exchanger is integrated into the motor control unit (that is, the heat exchanger is disposed in the housing of the motor control unit) enables the external cooling surface of the heat exchanger to be fully used to improve utilization efficiency of the heat exchanger and heat dissipation of the motor control unit, a structure is more compact, and space is saved.

Other features and advantages of this application are described in detail in the subsequent part of description of embodiments.

The following briefly describes the accompanying drawings used to describe embodiments or the conventional technology.

The following describes the technical solutions in embodiments of this application with reference to accompanying drawings in embodiments of this application.

In descriptions of this application, locations or location relationships indicated by terms "center", "up", "down", "in front of", "behind", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and the like are based on locations or location relationships shown in the accompanying drawings, and are merely intended for ease of describing this application and simplifying descriptions, instead of indicating or implying that a mentioned apparatus or component needs to be provided on a specific location or constructed and operated on a specific location, and therefore shall not be understood as limitations on this application.

In the descriptions of this application, it should be noted that, unless otherwise clearly specified and limited, terms "mount", "link", and "connect" should be understood in a broad sense, for example, may mean a fixed connection, may be a detachable connection, or may be a butt joint connection or an integrated connection. Persons of ordinary skill in the art can understand specific meanings of the foregoing terms in this application based on specific cases.

In the descriptions of this specification, the described specific features, structures, materials, or characteristics may be combined in a proper manner in any one or more of embodiments or examples.

<FIG> is a schematic diagram of a structure of a powertrain according to Embodiment <NUM> of this application. As shown in <FIG>, the powertrain includes a motor control unit <NUM> and a heat exchanger <NUM>. The motor control unit <NUM> includes a housing <NUM> and a first functional unit <NUM> disposed in the housing <NUM> and capable of generating heat during operation. The heat exchanger <NUM> is disposed in the housing <NUM>, and the heat exchanger <NUM> includes a first circulation channel <NUM> for a first cooling medium to circulate and a second circulation channel <NUM> for a second cooling medium to circulate. The first cooling medium may be water, and the second cooling medium may be oil for circulating inside a motor to cool the motor. In this case, the heat exchanger <NUM> may be an oil-water heat exchanger. The first circulation channel <NUM> may be disposed around the outside of the second circulation channel <NUM>, so that the first circulation channel <NUM> can sufficiently cool the second circulation channel <NUM>. In addition, in the heat exchanger <NUM>, a path indicated by a solid arrow is a flow path of the first cooling medium such as water in the first circulation channel <NUM>, while a path indicated by a dashed arrow is a flow path of the second cooling medium such as oil in the second circulation channel <NUM>, and the flow path of the cooling water is opposite to that of the oil, to fully exchange heat. The first circulation channel <NUM> may have a first external cooling surface P1, and the first circulation channel <NUM> is in heat conduction and contact with the first functional unit <NUM> at the first external cooling surface P1. In this way, the first external cooling surface P1 may be used to cool the first functional unit <NUM>, to dissipate heat generated by the first functional unit <NUM> as quickly as possible, thereby preventing the first functional unit <NUM> from overheating and ensuring normal operation of the first functional unit <NUM>. Alternatively, the first circulation channel <NUM> may have a second external cooling surface P2, and the first circulation channel <NUM> is in heat conduction and contact with an inner surface of the housing <NUM> at the second external cooling surface P2. In this way, the second external cooling surface P2 may be used to cool the housing <NUM>, to dissipate heat generated by the housing <NUM> as quickly as possible, thereby preventing the housing <NUM> from overheating, dissipating the heat inside the housing <NUM> as quickly as possible, and lowering an ambient temperature inside the housing <NUM>, thereby ensuring that a device such as the first functional unit <NUM> in the housing <NUM> can operate normally.

It may be understood that the first circulation channel <NUM> may have both the first external cooling surface P1 and the second external cooling surface P2. For example, in <FIG>, the first external cooling surface P1 and the second external cooling surface P2 may be two opposite surfaces of the heat exchanger <NUM>. In addition, in case of need, the first circulation channel <NUM> may have more cooling surfaces.

In the foregoing technical solution, the heat exchanger <NUM> is disposed in the housing <NUM> of the motor control unit <NUM>, and the first circulation channel <NUM> of the heat exchanger <NUM> for the cooling medium to circulate has the first external cooling surface P1 and/or the second external cooling surface P2, so that the first external cooling surface P1 can be in heat conduction and contact with the first functional unit <NUM> to cool the first functional unit <NUM>, and the second external cooling surface P2 can be in heat conduction and contact with the inner surface of the housing <NUM> to cool the housing <NUM>. Compared with a solution in which an oil-water heat exchanger is externally disposed on a motor housing, the foregoing solution of this application in which the heat exchanger is integrated into the motor control unit (that is, the heat exchanger is disposed in the housing of the motor control unit) enables the external cooling surface of the heat exchanger to be fully used to improve utilization efficiency of the heat exchanger and heat dissipation of the motor control unit, a structure is more compact, and space is saved.

Still refer to <FIG>. To improve an effect of heat conduction between the first external cooling surface P1 and the first functional unit <NUM>, optionally, a first heat conduction interface material D1 is disposed between the first external cooling surface P1 and the first functional unit <NUM>. Similarly, to improve an effect of heat conduction between the second external cooling surface P2 and the housing <NUM>, a second heat conduction interface material D2 is disposed between the second external cooling surface P2 and the inner surface of the housing <NUM>.

In addition, the motor control unit <NUM> further includes a second functional unit <NUM> disposed in the housing <NUM>. The second functional unit <NUM> may be a power module, such as an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or a gate turn-off thyristor (GTO).

The powertrain further includes a radiator <NUM> disposed in the housing <NUM>, and the radiator <NUM> is in heat conduction and contact with the second functional unit <NUM> and the first functional unit <NUM>. A path indicated by a solid arrow in the radiator <NUM> is a flow path of a cooling medium. It should be noted that the first functional unit <NUM> may be a device other than the second functional unit. Optionally, the first functional unit <NUM> includes a bus capacitor.

In this case, the radiator <NUM> cools the second functional unit <NUM> and the first functional unit <NUM> (such as a capacitor) in the motor control unit <NUM> by using a cooling medium (such as water) to lower temperatures of the second functional unit <NUM> and the first functional unit <NUM>. The heat exchanger <NUM> exchanges heat with and cools the oil in the motor by using the cooling water in the first circulation channel <NUM>. In addition, the first external cooling surface P1 of the first circulation channel <NUM> of the heat exchanger <NUM> may cool and dissipate heat of the first functional unit <NUM> in the housing <NUM> of the motor control unit <NUM>, and the second external cooling surface P2 of the first circulation channel <NUM> of the heat exchanger <NUM> may dissipate heat of the housing <NUM> of the motor control unit <NUM>, thereby improving utilization efficiency of the heat exchanger <NUM>, improving heat dissipation of the motor control unit <NUM>, and lowering an internal ambient temperature of the motor control unit <NUM>. In addition, integrating the heat exchanger <NUM> into the motor control unit <NUM> may further improve an integration degree, make the structure more compact, and save space.

Further, the radiator <NUM> may include a first cooling fin <NUM> and a second cooling fin <NUM> that are spaced and connected to each other, and the second functional unit <NUM> is disposed between the first cooling fin <NUM> and the second cooling fin <NUM>. In this way, the first cooling fin <NUM> and the second cooling fin <NUM> may better cool and dissipate heat of the second functional unit <NUM>.

To improve an effect of heat conduction between the radiator <NUM> and the second functional unit <NUM>, a third heat conduction interface material D3 may be disposed between the radiator <NUM> and the second functional unit <NUM>. Similarly, to improve an effect of heat conduction between the radiator <NUM> and the first functional unit <NUM>, a fourth heat conduction interface material D4 may be disposed between the radiator <NUM> and the first functional unit <NUM>.

In addition, in the powertrain of Embodiment <NUM> shown in <FIG>, the first functional unit <NUM> is disposed between the heat exchanger <NUM> and the radiator <NUM>. In this case, the first circulation channel <NUM> may be provided with a first outlet C1 and a first inlet R1, the second circulation channel <NUM> may be provided with a third outlet E and a third inlet F, and the first outlet C1, the first inlet R1, the third outlet E, and the third inlet F extend out of the housing <NUM>. The radiator <NUM> may be provided with a second outlet C2 and a second inlet R2, and the second outlet C2 and the second inlet R2 extend out of the housing <NUM>.

<FIG> is a schematic diagram of a structure of a powertrain according to Embodiment <NUM> of this application. The powertrain of Embodiment <NUM> shown in <FIG> differs from the powertrain of Embodiment <NUM> shown in <FIG> in that a pipeline of the radiator <NUM> communicates with the first circulation channel <NUM> of the heat exchanger <NUM>. In this case, the flow path of the cooling medium in the first circulation channel <NUM> (the path indicated by the solid arrow) and the flow path of the oil in the second circulation channel <NUM> (the path indicated by the dashed arrow) are opposite to each other, to fully exchange heat. The second circulation channel <NUM> of the heat exchanger <NUM> may be provided with a third outlet E and a third inlet F, the first circulation channel <NUM> may be provided with a fourth outlet C, the radiator <NUM> may be provided with a fourth inlet R, and the fourth outlet C, the fourth inlet R, the third outlet E, and the third inlet F extend out of the housing <NUM>. In this way, after entering from the fourth inlet R on the radiator <NUM>, the cooling medium first circulates in the radiator <NUM> to cool and dissipate heat of the second functional unit <NUM> and the first functional unit <NUM> (such as a capacitor) in the motor control unit <NUM>, then enters the first circulation channel <NUM> of the heat exchanger <NUM> to exchange heat with the oil in the second circulation channel <NUM> of the heat exchanger <NUM>, and finally flows out from the fourth outlet C on the first circulation channel <NUM>. Compared with that of the powertrain of Embodiment <NUM>, in a cooling system of this solution, one outlet and one inlet are reduced, that is, a quantity of cooling interfaces is reduced, which facilitates installation and can reduce costs.

Still refer to <FIG>. In this case, the first cooling fin <NUM> and the second cooling fin <NUM> may have a same structure. In this way, the first cooling fin <NUM> and the second cooling fin <NUM> of the second functional unit <NUM> may be designed into a structure in a normalized manner, so that the first cooling fin <NUM> and the second cooling fin <NUM> can be manufactured in a same process, which reduces costs.

<FIG> is a schematic diagram of a structure of a powertrain according to Embodiment <NUM> of this application. As shown in <FIG>, the radiator <NUM> is disposed between the heat exchanger <NUM> and the first functional unit <NUM>, and a part of the radiator <NUM> may be in heat conduction and contact with the first external cooling surface P1. In this case, the radiator <NUM> and the heat exchanger <NUM> may be integrally made. That is, the radiator <NUM> and the heat exchanger <NUM> may be integrated together as a heat dissipation component. This can reduce a processing and manufacturing time, reduce a quantity of cooling interfaces and components, and make installation more convenient.

In addition, the powertrain of Embodiment <NUM> shown in <FIG> is similar to the powertrain of Embodiment <NUM> shown in <FIG> in that the radiator <NUM> communicates with the first circulation channel <NUM> of the heat exchanger <NUM>. However, in the powertrain of Embodiment <NUM> shown in <FIG>, because the radiator <NUM> may be directly disposed at the bottom of the heat exchanger <NUM>, the cooling medium may directly enter the first circulation channel <NUM> of the heat exchanger <NUM> from the radiator <NUM>, to exchange heat with and cool the oil in the second circulation channel <NUM> of the heat exchanger <NUM>. In the powertrain of Embodiment <NUM> shown in <FIG>, because the first functional unit <NUM> is disposed between the heat exchanger <NUM> and the radiator <NUM>, that is, the heat exchanger <NUM> and the radiator <NUM> are spaced, the cooling medium needs to pass through a pipeline after coming out of the radiator <NUM>, and then enters the first circulation channel <NUM> of the heat exchanger <NUM>.

Claim 1:
A powertrain, comprising:
a motor control unit (<NUM>) comprising a housing (<NUM>) and a first functional unit (<NUM>) disposed in the housing (<NUM>) and capable of generating heat during operation; and
a heat exchanger (<NUM>) disposed in the housing (<NUM>), wherein the heat exchanger (<NUM>) comprises a first circulation channel (<NUM>) for a first cooling medium to circulate and a second circulation channel (<NUM>) for a second cooling medium to circulate, wherein the first circulation channel (<NUM>) is arranged to cool the second circulation channel (<NUM>), wherein the first circulation channel (<NUM>) has a first external cooling surface (P1), and the first circulation channel (<NUM>) conducts heat with the first functional unit (<NUM>) at the first external cooling surface (P1); and the first circulation channel (<NUM>) has a second external cooling surface (P2), and the first circulation channel (<NUM>) conducts heat with an inner surface of the housing (<NUM>) at the second external cooling surface (P2).