Patent Description:
The present disclosure relates generally to electric vehicles and, in particular embodiments, to powertrain components of electric vehicles.

Electric powertrains of electric vehicles, including electric powersport vehicles (e.g., all-terrain vehicles (ATVs), personal watercraft (PWC), and snowmobiles), typically include a battery system, one or more electrical motors, each with a corresponding electronic power inverter (sometimes referred to as a motor controller), and various auxiliary systems (e.g., cooling systems). Efficiencies in size, weight, and energy consumption of system components improve vehicle performance (e.g., responsiveness, range, and reliability) and cost, particularly for electric powersport vehicles where space and weight are at a premium.

Document <CIT> describes an electric motor and inverter assembly used in an electric vehicle or a hybrid electric vehicle to drive the vehicle's wheels to rotate. The electric motor and inverter assembly comprises: an electric motor, an end cover and a connecting cover; and an inverter, which includes a housing in which a power element and/or an electrical device is received.

The present disclosure relates to a drive unit housing as defined in claim <NUM>.

It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure, defined in the appended claims. The following detailed description, therefore, is not to be taken in a limiting sense.

Electric powertrains for electric vehicles, including electric powersport vehicles (e.g., motorcycles, all-terrain vehicles (ATVs), personal watercraft (PWC), (e.g., side-by-side) utility task vehicles (UTVs) and snowmobiles), typically include a battery system, one or more electrical motors, each with a corresponding electronic power inverter (sometimes referred to as a motor controller), and various auxiliary systems (e.g., cooling systems). Efficiencies in size, weight, and energy consumption of system components improve vehicle performance (e.g., responsiveness, range, and reliability) and cost, particularly for electric powersport vehicles where space and weight are at a premium.

<FIG> generally illustrates an electric vehicle <NUM> including an electric drive unit <NUM>, in accordance with examples of the present disclosure. Although illustrated as a snowmobile for example purposes, electric vehicle <NUM> could be other types of electric vehicles, including other types of powersport vehicles such as personal watercraft (PWC) and side-by-side vehicles. Electric vehicle <NUM> includes a seat <NUM>, which is shown as a straddle-seat, to accommodate an operator of electric vehicle <NUM>. Electric vehicle <NUM> employs an electric powertrain <NUM> including a battery system <NUM>, an electric motor <NUM>, and an electronic power inverter <NUM> for controlling electric motor <NUM>. Powertrain <NUM> is configured to propel the electric vehicle by driving one or more wheels (e.g., in the case of a motorcycle, ATV or UTV), by driving an endless track (e.g., in the case of a snowmobile) or by driving a propeller or impeller (e.g., in the case of a PWC).

In some examples, electric motor <NUM> may be a permanent magnet synchronous motor. Electric motor <NUM> may have a power output of between <NUM> and <NUM> horsepower. Alternatively, electric motor <NUM> may have a maximum output power of greater than <NUM> horsepower. In some examples, battery system <NUM> may include a rechargeable multi-cell lithium ion or other type of battery. Battery system <NUM> may include multiple battery modules each including multiple battery cells. The battery cells may be pouch cells, cylindrical cells and/or prismatic cells, for example. The battery modules may be housed within a battery enclosure for protection from impacts, water and/or debris. In some examples, battery system <NUM> may be configured to output electric power at a voltage of between <NUM>-<NUM> volts, or up to <NUM> volts, for example.

According to one example of the present disclosure, as will be described in greater detail herein, drive unit <NUM> includes a housing having a first compartment <NUM> and a second compartment <NUM> separated from one another by a shared wall <NUM>. In one example, as illustrated, inverter <NUM> is disposed in first compartment <NUM> and motor <NUM> is disposed in second compartment <NUM>. Together, housing <NUM> with motor <NUM> and inverter <NUM> disposed therein form drive unit <NUM> for electric vehicle <NUM>.

As will be described in greater detail below, by disposing motor <NUM> and inverter <NUM> together within housing <NUM>, drive unit <NUM> provides a volumetrically efficient form factor (e.g., a generally longitudinal form factor, such as a cylindrical form factor, for instance) which consumes less space within electric vehicle <NUM>. Additionally, drive unit <NUM> provides shortened electrical conductor lengths between output terminal of inverter <NUM> and input terminals of motor <NUM> which reduces electrical inductance and line losses (relative to separately housed motor-inverter combinations). Accordingly, drive unit <NUM>, in accordance with the present disclosure, provides efficiencies in both space and performance relative to conventional, separately housed motor-inverter combinations.

<FIG> is a block and schematic diagram generally illustrating one example of electric vehicle <NUM>, where, in addition to including electric powertrain <NUM> employing drive unit <NUM>, electric vehicle <NUM> further includes a thermal management system <NUM>. In one example, thermal management system <NUM> manages the temperatures (e.g., cooling) of electric powertrain <NUM> components, including battery system <NUM>, motor <NUM>, and inverter <NUM>. Thermal management system <NUM> may be a closed-loop cooling system and/or an open-loop cooling system. The thermal management system <NUM> may utilize a liquid-to-liquid cooling system (e.g., in the case of a PWC), a snow-to-liquid cooling system (e.g., in the case of a snowmobile), an air-to-liquid cooling system (e.g., using a radiator), or a combination thereof. In accordance with examples of the present disclosure, as will be described in greater detail below, housing <NUM> of drive unit <NUM> includes a network of fluid circulation pathways <NUM> through which the thermal transfer fluid is circulated, as indicated arrows <NUM>, to manage the temperatures of motor <NUM> and inverter <NUM>.

<FIG> illustrate perspective views of drive unit <NUM>, according to examples of the present disclosure. <FIG> is an exploded view illustrating portions of drive unit <NUM>, according to one example. In some examples, housing <NUM> includes a first housing section <NUM> forming a first compartment <NUM> for housing inverter <NUM>, and a second housing section <NUM> forming a second compartment <NUM> for housing electric motor <NUM>. First and second housing sections <NUM> and <NUM> may each include at least some walls or other structural components of housing <NUM>. While first and second housing sections <NUM> and <NUM> form first and second compartments <NUM> and <NUM>, respectively, first and second housing sections <NUM> and <NUM> might not fully enclose first and second compartments <NUM> and <NUM>.

In one example, a perimeter of housing <NUM> is confined within a generally longitudinal form factor <NUM> (graphically represented by dashed lines in <FIG>), where first and second housing sections <NUM> and <NUM>, respectively forming first and second compartments <NUM> and <NUM>, are disposed longitudinally relative to one another within the form factor. In one example, as illustrated, form factor <NUM> is generally cylindrical in shape with first and second housing sections <NUM> and <NUM> being disposed longitudinally relative to one another along a longitudinal axis <NUM> of generally cylindrical form factor <NUM>. Shared wall <NUM> is generally circular in shape. In one example, longitudinal axis <NUM> of form factor <NUM> generally coincides with a longitudinal axis of a shaft <NUM> (i.e., a rotor shaft) of motor <NUM> (which extends from second housing section <NUM>). In examples, as described below, first and second housing sections <NUM> and <NUM> are separable from one another.

In one example, first housing section <NUM> includes shared wall <NUM>, which provides a base for first housing section <NUM> and which is disposed transversely to longitudinal axis <NUM> of form factor <NUM>. Shared wall <NUM> may be integrally formed with first housing section <NUM>. In one example, shared wall <NUM> is substantially circular in shape, but any suitable shape may be employed. First housing section <NUM> further includes a perimeter sidewall casing <NUM>. In one example, as illustrated, perimeter sidewall casing <NUM> is ring- or band-shaped to form a generally tubular or circumferentially extending perimeter sidewall. In one example, the ring- or band-shaped perimeter sidewall casing <NUM> may be formed of a partial or continuous curved wall section, or may be formed from multiple straight wall sections extending from shared wall <NUM> that together form the ring- or band-shaped sidewall casing <NUM>. In one example, perimeter sidewall casing <NUM> extends orthogonally from shared wall <NUM> and longitudinally relative to form factor <NUM>, where shared wall <NUM> and circumferentially extending sidewall <NUM> together are generally can- or cup-shaped to form first compartment <NUM> for housing inverter <NUM>. An end cover <NUM> is separably coupled to sidewall casing <NUM> to enclose first compartment <NUM>.

In one example, second housing section <NUM> includes a perimeter sidewall casing <NUM> separably coupled to shared wall <NUM>, such as via a number of fasteners <NUM> (e.g., screws or bolts) arranged about perimeter sidewall casing <NUM> of first housing section <NUM>. In one example, perimeter sidewall casing <NUM> is ring- or tube-shaped to form a generally tubular or circumferentially extending perimeter sidewall. In one example, perimeter sidewall casing <NUM> extends orthogonally from shared wall <NUM> and longitudinally relative to form factor <NUM> with shared wall <NUM> serving as a base for second housing section <NUM>, and with shared wall <NUM> and perimeter sidewall casing <NUM> together being drum-shaped to form second compartment <NUM> for housing motor <NUM>. An end cover <NUM> is separably coupled to an end of perimeter sidewall casing <NUM> opposite shared wall <NUM> to enclose second compartment <NUM>. Alternatively, end cover <NUM> may be integrally formed with sidewall casing <NUM> of the second housing section <NUM>, such that the shared wall <NUM> acts as an endplate for enclosing the second compartment <NUM>.

While shared wall <NUM> is described as being part of first housing section <NUM>, in other examples, shared wall <NUM> may be part of second housing section <NUM>. In other examples, shared wall <NUM> may be separable from both first and second housing sections <NUM> and <NUM>.

In one example, end cover <NUM> includes positive and negative DC connection terminals <NUM> and <NUM> extending there through for electrical connection of capacitors of inverter <NUM> (see <NUM> in <FIG>) to battery system <NUM> (see <FIG> and <FIG>). In one example, end cover <NUM> includes an electrical connector <NUM> for low voltage and control signal connection to control circuitry of inverter <NUM> (see <NUM> in <FIG>).

In one example, as will be described in greater detail below, first housing section <NUM> respectively includes inlet and outlet fluid ports <NUM> and <NUM> (see <FIG>) for connecting fluid pathways of thermal management system <NUM> to fluid pathways within housing <NUM> of drive unit <NUM> for cooling of motor <NUM> and inverter <NUM>. Inlet <NUM> may receive a fluid from thermal management system <NUM>, and outlet <NUM> may discharge the fluid back into thermal management system <NUM>. It is noted that in other examples, inlet and outlet fluid ports <NUM> and <NUM> may be reversed, and that in other examples, more than one inlet and/or outlet port may be employed. In one example, as illustrated, sidewall casing <NUM> includes recesses <NUM> and <NUM> in which inlet and outlet fluid ports <NUM> and <NUM> are respectively disposed so that inlet and outlet fluid ports <NUM> and <NUM> are disposed within the confines of form factor <NUM>.

In one example, as illustrated by <FIG>, a number of channels <NUM> extend circumferentially about sidewall casing <NUM> of second housing section <NUM>. When a casing sleeve <NUM> is disposed about the circumference of sidewall casing <NUM>, channels <NUM> become fluid pathways <NUM> (see <FIG>) extending about the circumference of second housing section <NUM>, where such fluid pathways <NUM> are part of the network of fluid pathways <NUM> through which fluid <NUM> is circulated by thermal management system <NUM> (see <FIG>) to cool motor <NUM>. In some examples, fluid pathways <NUM> may form a continuous spiral around sidewall casing <NUM>. In other examples, fluid pathways <NUM> may be separate pathways disposed in parallel with one another. In other examples, fluid pathways <NUM> may be a continuous pathway employing a switchback configuration. Any number of suitable implementations may be employed.

Reference is now made to <FIG>, which illustrates end cover <NUM> being removed from sidewall casing <NUM> of first housing section <NUM>, and showing first and second housing compartments <NUM> and <NUM>. Motor <NUM> includes a rotor <NUM> and a stator <NUM> which are disposed within second compartment <NUM> of second housing section <NUM>. As will be described in greater detail below (see <FIG>), an end <NUM> of shaft <NUM> facing shared wall <NUM> is hollow to enable circulation of thermal transfer fluid there through to cool motor <NUM>. A set of electrical input leads <NUM> extend from stator <NUM> for connection to inverter <NUM> within compartment <NUM> of first housing section <NUM>.

In one example, first compartment <NUM> of first housing section <NUM> includes a first compartment portion <NUM> for housing capacitors of inverter <NUM>, and a second compartment portion <NUM> for housing electronic control and switching components (e.g., insulated-gate bipolar transistors (IGBTs)) of inverter <NUM> (see <NUM> and <NUM> in <FIG>). In one example, a set of one or more openings <NUM> extend through shared wall <NUM> to enable electrical connection between input leads <NUM> of stator <NUM> and output terminals of inverter <NUM>. In one example, input leads <NUM> from stator <NUM> extend through openings <NUM> into second compartment portion <NUM> for connection to output terminals of inverter <NUM>. In other examples, output terminals of inverter <NUM> may extend through openings <NUM> into second housing section <NUM> for connection to input leads <NUM> of stator <NUM>.

<FIG> is a perspective view illustrating first housing section <NUM> with end cover <NUM> removed. In one example, input power leads <NUM> of stator <NUM> extend through the set of openings <NUM> in shared wall <NUM> and terminate at a set of terminals <NUM> (illustrated as terminals 96a, 96b, and 96c) in second compartment portion <NUM>. Sensor wiring <NUM> extends from motor <NUM> through shared wall <NUM> to inverter control electronics. By aligning the set of openings <NUM> through shared wall <NUM> (see also <FIG>) with input leads <NUM> of stator <NUM> and with terminals <NUM>, the lengths of conductor pathways between inverter <NUM> and stator <NUM> are reduced which, in-turn, reduces electrical inductances and power loss, thereby improving the electrical efficiency of drive unit <NUM>.

As discussed in further detail elsewhere herein, housing <NUM> includes a network of fluid pathways <NUM> (also referred to as a fluid network) extending therethrough for cooling of motor <NUM> and inverter <NUM>. In one example, in addition to inlet and outlet ports <NUM> and <NUM>, fluid network <NUM> includes a fluid chamber <NUM> in shared wall <NUM> having a fluid inlet <NUM> and a fluid outlet <NUM> connecting fluid chamber <NUM> with other portions of the fluid network <NUM>. It is noted that a cover over fluid chamber <NUM> is not shown in <FIG>. In one example, a network of power switches (e.g., IGBTs) is mounted to shared wall <NUM> over fluid chamber <NUM> so as to be cooled by fluid circulated there through.

<FIG> is a cross-sectional view of housing <NUM>, according to one example, where sidewall casing <NUM> of first housing section <NUM> contiguously and integrally extends from shared wall <NUM>, and which together with end cover <NUM> forms first compartment <NUM>. First compartment <NUM> includes first compartment portion <NUM> for housing capacitors of inverter <NUM>, and second compartment portion <NUM> for housing control and switching electronics of inverter <NUM>. In one example, shared wall <NUM> includes a bearing pocket <NUM> facing second compartment <NUM>, where bearing pocket <NUM> is to receive end <NUM> of shaft <NUM> of electric motor <NUM> and through which thermal transfer fluid circulates, as described below.

Sidewall casing <NUM> and end cover <NUM> of second housing section <NUM> together with shared wall <NUM> form second compartment <NUM>. End cover <NUM> includes a bearing pocket <NUM> to receive an opposing end of shaft <NUM> of motor <NUM> and an aperture <NUM> from which shaft <NUM> extends. Gaskets <NUM> and <NUM> respectively form seals between shared wall <NUM> and sidewall casing <NUM> to seal second compartment <NUM>, and between end cover <NUM> and sidewall casing <NUM> to seal first compartment <NUM>.

<FIG> is a cross-sectional view of drive unit <NUM>, according to one example. DC capacitors <NUM> of inverter <NUM> are disposed in first compartment portion <NUM>, while power switching network <NUM> and control electronics <NUM> of inverter <NUM> are disposed in second compartment portion <NUM>. Input power leads <NUM> from stator <NUM> of motor <NUM> extend through shared wall <NUM> and terminate at terminals <NUM> in second compartment portion <NUM>. Motor <NUM> is disposed within second compartment <NUM> with hollow end <NUM> of shaft <NUM> disposed within bearing pocket <NUM> of shared wall <NUM>.

<FIG> is a perspective view illustrating portions of first housing section <NUM> facing second (motor) compartment <NUM> including shared wall <NUM> and sidewall casing <NUM>, according to one example. In one example, as illustrated, sidewall casing <NUM> contiguously extends from shared wall <NUM> such that shared wall <NUM> and sidewall casing <NUM> form a single base component for first housing section <NUM>. A plurality of ribs, such as rib <NUM>, extend from an inner surface of sidewall casing <NUM> to support a central hub <NUM> including bearing pocket <NUM> for supporting hollow end <NUM> of shaft <NUM> of motor <NUM>. Also illustrated is the set of openings <NUM> through shared wall <NUM>, illustrated as openings 94a-94c arrayed along an arc to align with input leads <NUM> of stator <NUM> (see <FIG>). While three openings 94a-94c are shown in the Figures, this is exemplary only. In one example, shared wall <NUM> may include a single opening <NUM> for input leads <NUM> and terminals <NUM>, or any other suitable number of openings <NUM>.

In one example, end wall <NUM> includes a portion of the network of fluid pathways <NUM> through which a thermal transfer fluid is circulated to cool components of motor <NUM> and inverter <NUM>. The network <NUM> of fluid pathways, which will be described in greater detail below (see <FIG>) includes inlet and outlet ports <NUM> and <NUM>, as well as fluid chamber <NUM> having inlet and outlet <NUM> and <NUM> (see <FIG>). In one example, network <NUM> further includes a tube <NUM> which extends within hub <NUM> and, as will be described below (see <FIG>), extends into hollow end <NUM> of shaft <NUM> to form inlet and outlet fluid pathways within shaft <NUM> to enable circulation of thermal transfer fluid therein to cool motor <NUM>.

<FIG> is a schematic diagram generally illustrating the circulation of thermal transfer fluid within hollow end <NUM> of shaft <NUM>. As illustrated, tube <NUM> extends into hollow end <NUM> of shaft <NUM> from bearing pocket <NUM> (disposed within hub <NUM>) to form an inlet fluid pathway <NUM> within tube <NUM>, and an outlet fluid pathway <NUM> between the outer wall of tube <NUM> and inner wall of shaft <NUM>. In this way, tube <NUM> and hollow end <NUM> of shaft <NUM> form fluid pathways in shaft <NUM>. In one example, inlet and outlet fluid pathways <NUM> and <NUM> are respectively in fluid communication with fluid pathways <NUM> and <NUM> of the network of fluid pathways <NUM> (see <FIG> below).

<FIG> and <FIG> are perspective views illustrating portions of network <NUM> of fluid pathways, according to one example, for circulating thermal transfer fluid through housing <NUM> to cool components of motor <NUM> and inverter <NUM>. <FIG> and <FIG> illustrate network <NUM> as respectively viewed from second (motor) compartment <NUM> and first (inverter) compartment <NUM>.

In one example, as illustrated, thermal transfer fluid is received via inlet port <NUM> and travels through pathways <NUM> to inlet fluid pathway <NUM> within tube <NUM> inside shaft <NUM> (see <FIG>). Fluid then travels through outlet fluid pathway <NUM> and exits shaft <NUM> via fluid pathway <NUM>, which is concentrically disposed about end <NUM> of shaft <NUM>. Fluid then travels through a fluid pathway <NUM>, which forms a fan-like, semicircular path along or within shared wall <NUM> proximate to first compartment portion <NUM> of first compartment <NUM> to cool DC capacitors <NUM> of inverter <NUM> (see <FIG>).

Fluid then enters chamber <NUM> via inlet opening <NUM>, where fluid within chamber <NUM> cools the power switching network <NUM> and control electronics <NUM> of inverter <NUM> disposed within second compartment portion <NUM> of first compartment <NUM> (see <FIG>). Fluid then exits chamber <NUM> via outlet opening <NUM> and travels through a fluid pathway <NUM> to fluid pathways <NUM> circumferentially disposed about sidewall casing <NUM> of second housing section <NUM> to cool motor <NUM> (see, for example, <FIG> and <FIG>). Fluid then exits fluid pathways <NUM> to outlet port <NUM>.

In one example, the fluid pathways of network <NUM> of fluid pathways forms a continuous fluid pathway through housing <NUM> such that the components of drive unit <NUM> are cooled in series (e.g., shaft <NUM>, capacitors <NUM>, power switching network <NUM>, and motor stator <NUM>). In one example, the fluid pathways of shared wall <NUM> are disposed in series with the fluid pathways of perimeter sidewall <NUM> of second housing section <NUM> between inlet and outlet ports <NUM> and <NUM>. In one example, the fluid pathways of shared wall <NUM> and perimeter sidewall <NUM> of second housing section <NUM> are disposed in series with fluid pathways within hollow end <NUM> of shaft <NUM> of electric motor <NUM>.

By employing a single continuous cooling loop, the cooling system is simplified (relative to systems employing parallel pathways), such that the network of fluid pathways <NUM> of the present disclosure provides high efficiency and requires fewer parts relative to known systems. Additionally, disposing the network of fluid pathways <NUM> within the confines of housing <NUM> (i.e., within form factor <NUM>), including disposing inlet and outlet ports <NUM> and <NUM> on end cover <NUM> of first housing section <NUM> maintains the perimeter of drive unit <NUM> within the generally longitudinally extending form factor <NUM> (see <FIG>). As described above, such form factor is volumetrically efficient and provides improved ease of installation within electric vehicles (particularly electric powersport vehicles).

It is noted that the network of fluid pathways <NUM> specifically described herein is for illustrative purposes, and represents only one example implementation of fluid network <NUM>. In the example shown, the fluid pathways <NUM> travel from an inlet port <NUM>, to the shaft <NUM>, to the channels within the shared wall <NUM>, to the circumferentially disposed pathways <NUM> in the sidewall casing <NUM>, and finally to the outlet port <NUM>. In other examples, the configuration of the fluid pathways of fluid network <NUM> and the order in which components are cooled may be different from that illustrated herein. In another example, the fluid pathways <NUM> may travel from an inlet port <NUM>, to the channels within the shared wall <NUM>, to the shaft <NUM>, to the circumferentially disposed pathways <NUM> in the sidewall casing <NUM>, such that the inverter <NUM> components are cooled prior to the motor components. For example, fluid network <NUM> may be implemented such that thermal transfer fluid is first directed to cool DC capacitors <NUM> of inverter <NUM>, as such capacitors may have a narrow thermal tolerance. Any number of configurations are possible. Further, one or more pathways in the network of fluid pathways may be omitted in some examples. For example, a network of fluid pathways may omit fluid pathways in shaft <NUM>. The fluid pathways may travel from an inlet port <NUM>, to the channels within the shared wall <NUM>, to the circumferentially disposed pathways <NUM> in the sidewall casing <NUM>, and finally to the outlet port <NUM>.

Housing <NUM> may be made, in whole or in part, from metals, metal alloys, composites and/or plastics. Similarly, the channels/pathways of fluid network <NUM> may be made, in whole or in part, from metals, metal alloys, composites and/or plastics. It is further noted that the components of housing <NUM>, including the channels/pathways of fluid network <NUM> may be manufactured according to any know technique, including machining, casting, and 3D-printing, for example.

In one example, the form factor <NUM> of the housing <NUM> of the drive unit <NUM> that is suitable for a powersport vehicle <NUM> may have a length of <NUM> to <NUM> and a diameter or width of <NUM> to <NUM>. In one example, the thickness of the shared wall <NUM> may be between <NUM> and <NUM>, which provides a sufficient thickness to accommodate channel <NUM> and chamber <NUM>. It should be understood that the form factor <NUM> and shared wall <NUM> thickness may have any suitable dimensions, and that these dimensions may vary depending on the application and power requirements of the drive unit <NUM>.

<FIG> is a flow diagram illustrating a method <NUM> for cooling components of a drive unit, according to one example of the present disclosure. The method <NUM> may be performed by a drive unit housing such as housing <NUM>, for example. Block <NUM> includes receiving a fluid via an inlet port of the housing. For example, block <NUM> may include inlet <NUM> receiving a fluid. Block <NUM> includes circulating the fluid. In some examples, the fluid is circulated through fluid pathways formed in the housing to cool an electrical inverter and/or an electrical motor. For example, block <NUM> may include circulating the fluid through fluid pathways formed in a shared wall (e.g., shared wall <NUM>) of the housing to cool the electrical inverter. The shared wall may separate a first compartment of the housing in which the electrical inverter is disposed and a second compartment of the housing in which the electric motor is disposed. Alternatively or additionally, block <NUM> may include circulating the fluid through fluid pathways formed in a perimeter sidewall of the housing (e.g., perimeter sidewall casing <NUM>) to cool the electric motor. Alternatively or additionally, block <NUM> may include circulating the fluid through fluid pathways formed in a rotor shaft (e.g., shaft <NUM>) of the electric motor to cool the electric motor. Block <NUM> includes discharging the fluid via an outlet port of the housing, such as outlet port <NUM>, for example.

Claim 1:
A drive unit housing (<NUM>) for an electric vehicle (<NUM>) comprising:
a first housing section (<NUM>) defining a first compartment (<NUM>) to house an electrical inverter (<NUM>), the first housing section (<NUM>) including:
a tubular perimeter casing (<NUM>) defining a circumference of the first compartment (<NUM>) and having first and second open ends, and
a cover plate (<NUM>) separably coupled to the tubular perimeter casing (<NUM>) to cover the second open end;
a second housing section (<NUM>) defining a second compartment (<NUM>) to house an electric motor (<NUM>), the first and second housing sections (<NUM>,<NUM>) separably coupled to one another with the first and second compartments (<NUM>,<NUM>) separated by a shared wall (<NUM>), the shared wall (<NUM>) coupled to and closing the first open end, and the shared wall (<NUM>) being generally circular in shape, wherein:
perimeters of the first and second housing sections (<NUM>,<NUM>) are confined within a generally longitudinal form factor (<NUM>) being cylindrical in shape, with the first and seconc housing sections (<NUM>,<NUM>) being disposed axially to one another along a longitudinal axis (<NUM>) of the longitudinal form factor (<NUM>), and
the shared wall (<NUM>) includes one or more openings (<NUM>) extending therethrough to provide electrical connection of the electric motor (<NUM>) to the electrical inverter (<NUM>); and
a network of fluid pathways (<NUM>) extending through the drive unit housing (<NUM>) for cooling of the electric motor (<NUM>) and the electrical inverter (<NUM>), the network of fluid pathways (<NUM>) including an inlet port (<NUM>) and an outlet port (<NUM>), wherein the tubular perimeter casing (<NUM>) of the first housing section (<NUM>) defines recesses (<NUM>,<NUM>) such that the inlet port (<NUM>) and the outlet port (<NUM>) are disposed within the recesses (<NUM>,<NUM>), and therefore do not protrude outside of the longitudinal form factor (<NUM>) or past the cover plate (<NUM>), thereby protecting the inlet port (<NUM>) and outlet port (<NUM>) from unintended damage.