Electric drive module having a motor assembly with an inverter that includes a liquid-cooled snubber

Abstract

The present invention provides an electric drive module that includes a housing assembly, an electric motor, and an inveter. The electric drive module includes: a positive busbar, a ground busbar, a plurality of phase busbars, and an inverter having a plurality of power semiconductor devices coupled to at least one of the phase busbars, and one or more first heat sinks, each of the power semiconductor devices having a power terminal, the power terminal of each of the power semiconductor devices being mounted to the one or more first heat sinks, and a snubber having a plurality of snubber circuit elements, and a plurality of second heat sinks, and one or more cooling chambers configured to receive fluid and communicate the fluid to the one or more first heat sinks or the one or more second heat sinks.

Description

ELECTRIC DRIVE MODULE HAVING A MOTOR ASSEMBLY WITH ANINVERTER THAT INCLUDES A LIQUID-COOLED SNUBBERFIELD

[0001] The present disclosure relates to an electric drive module having a motor assembly with an Inverter that Includes a liquid-cooled snubber.BACKGROUND

[0002] Electric drive modules can include an electric motor, a battery for supplying electrical current to the electric motor, and power electronics that can condition and regulate the supply of electrical current to the electric motor. Electric drive modules can be used in vehicles to at least partially propel the vehicles. It can be helpful to increase the operational efficiency of the power electronics used with the electric drive modules.SUMMARY

[0003] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of Its features.

[0004] In one form, the present disclosure provides an electric drive module that includes a housing assembly, an electric motor, and an inverter. The electric motor is received in the housing assembly and has a stator and a rotor that is rotatable relative to the stator about a rotary axis. The stator has a plurality of sets of field windings and a plurality of phase leads. Each of the phase leads iselectrically coupled to a corresponding one of the sets of windings. The inverter has a retaining member, an end plate, a plurality of first and second busbars, a circuit board assembly, a plurality of power semiconductor devices, one or more first heat sinks, and one or more snubbers. The retaining member is received between the housing assembly and an axial end of each of the sets of field windings. The end plate is fixedly and sealingly coupled to the retaining member. The first and second busbars and the circuit board assembly are received in the retaining member on a first side of the end plate. Each of the power semiconductor devices has a plurality of device terminals and a power terminal. A first one of the device terminals of each of the power semiconductor devices is electrically coupled to the second busbar. The power terminal is electrically coupled to a second one of the device terminals and to the first busbar. The power semiconductor devices are arranged within the retaining member such that the power terminals are disposed on a second side of the end plate that is opposite the first side. The device terminals of the power semiconductor devices extend through the end plate and are electrically coupled to the circuit board assembly. The power terminal of each of the power semiconductor devices is mounted to the one or more first heat sinks. Each of the one or more first heat sinks has a plurality of first fins that are disposed in a first region that is adjacent to the axial ends of the sets of field windings. An inlet port is formed through the end plate and is configured to receive a liquid cooling fluid therethrough. The snubber has a plurality of snubber circuit elements and a plurality of second heat sinks. Each of the snubber circuit elements has a resistor and a capacitor and is electrically coupled to the first and secondbusbars. Each of the second heat sinks is mechanically and thermally coupled to at least a portion of an associated one of the snubber circuit elements. Each of the second heat sinks has a plurality of second fins that are disposed in a second region that is adjacent to the axial ends of the sets of field windings. The inlet port is coupled in fluid communication with the first and second regions.

[0005] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.DRAWINGS

[0006] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0007] Figure 1 is a section view of an exemplary electric drive module constructed in accordance with the teachings of the present disclosure;

[0008] Figure 2 is a section view taken through a portion of the electric drive module of Figure 1 illustrating a motor assembly and an inverter in more detail;

[0009] Figure 3 is an enlarged portion of Figure 2;

[0010] Figure 4 is an exploded perspective view of a portion of the electric drive module of Figure 1 illustrating portions of the motor assembly and the inverter in more detail;

[0011] Figure 5 is a perspective view of a portion of the inverter, illustrating a heat-sinked power semiconductor in more detail;

[0012] Figure 6 is an enlarged portion of Figure 4 illustrating a positive busbar, a ground busbar and a plurality of phase busbars in more detail;

[0013] Figure 7 is a perspective view of a portion of the inverter that illustrates a snubber;

[0014] Figure 8 is a top perspective view of the snubber;

[0015] Figure 9 is a schematic illustration of a portion of the snubber electrically coupled to the positive busbar and the ground busbar;

[0016] Figure 10 is a perspective view of a portion of the snubber illustrating a snubber circuit element in more detail;

[0017] Figure 11 is a bottom perspective view of the snubber;

[0018] Figure 12 is a section view taken through a portion of the snubber to show a cooling chamber in the snubber;

[0019] Figure 13 is a perspective view of a portion of the inverter illustrating chamber outlets in the snubber that are formed by a snubber housing;

[0020] Figure 14 is a section view taken through the inverter and a portion of the motor assembly and illustrating a cooling channel in fluid communication with an annular plenum 252;

[0021] Figure 15 is a section view similar to that of Figure 14 but depicting an alternate configuration where portions of the cooling channels are employed to direct cooling fluid outwardly of the snubber; and

[0022] Figure 16 is an alternately configured inverter in which elements of a snubber are disposed circumferentially between heat-sinked power semiconductors.

[0023] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0024] With reference to Figure 1 , an exemplary electric drive module constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. The electric drive module 10 can generally include a housing assembly 12, a motor assembly 14, a transmission 16, one or more output members 20 and optionally a differential assembly 22. The motor assembly 14 can include an electric motor 30 and a motor controller 32 that includes an inverter 36. In the example provided, the electric drive module 10 is constructed similar to that which is disclosed in U.S. Patent Application Publication No. 2022 / 0393522 except as noted herein.

[0025] With reference to Figure 2, the electric motor 30 includes a stator assembly 40 and a rotor assembly 42. The stator assembly 40 can have a stator body 50, a plurality of sets of field windings 52 and a plurality of phase leads 54. The stator body 50 is fixedly coupled to the housing assembly 12 and defines a plurality of stator body cooling channels 60 that extend longitudinally through the stator body 50. In the example shown, each of the stator body cooling channels 60 extends in a straight line between and through the opposite axial ends of the stator body 50, but it will be appreciated that the stator body cooling channels 60 could be configured differently(e.g., to extend helically about the stator body 50 and / or could enter into and / or exit from the stator body 50 in a manner that is different from that which is depicted here). Each of the sets of field windings 52 is wrapped about the stator body 50 such that the opposite axial ends of each set of field windings 52 extends from a corresponding axial end of the stator body 50. A cap 64 can be coupled to the sets of field windings 52 and can shroud or cover the wires that form the sets of field windings 52. The cap 64 is formed of an electrically insulating material but also has relatively good thermally conductive properties. Optionally, the cap 64 can be an encapsulant that is molded onto the wires of the sets of field windings 52.

[0026] The rotor assembly 42 is received in a rotor bore that is formed in the stator assembly 40 and includes a rotor body 70 and a motor output shaft 72. The rotor assembly 42 is rotatable relative to the stator assembly 40 about a motor axis 76. Each of the phase leads 54 is mechanically and electrically coupled to a corresponding one of the sets of field windings 52. Optionally, the phase leads 54 can be sealingly coupled to the cap 64 that covers or shrouds the wires that form the sets of field windings 52. In the example provided, the phase leads 54 are partly encapsulated in the encapsulant material that forms the cap 64.

[0027] With reference to Figures 3 and 4, the inverter 36 of the motor controller 32 (Fig. 1) includes an inverter mount 80, a plurality of power semiconductors 82, a plurality of busbars (i.e. , a positive busbar 90, a ground busbar 92, and a plurality of phase busbars 94a, 94b and 94c), a plurality of insulating layers (not specifically shown), an inverter circuit board 98 and a snubber 100. The inverter 36 controls the amplitude and frequency of electric power that is supplied to the electric motor 30. More specifically, the inverter 36 employs the power semiconductors 82, which canbe MOSFET’s, LGBT’s or JFET’s, for example, to control the switching of DC electricity (provided via the positive busbar 90) to create three AC electric outputs, with each AC electric output provided to a given one of the phase busbars 94a, 94b and 94c (for powering a respective one of the sets of field windings 52).

[0028] The inverter mount 80 can include a base or end plate 110, a plurality of phase lead receptacles 112, a first side wall 114 and second side wall 116. The end plate 110 can have an annular configuration with a first axial side and a second axial side. The end plate 110 can define a plurality of semiconductor mounts (not specifically shown) that can be formed into the radially outer portion on the first axial side of the end plate 110 Each of the semiconductor mounts can define a plurality of semiconductor terminal apertures that extend through the end plate 110. The semiconductor mounts can be disposed in any desired arrangement, but in the particular example provided, the semiconductor mounts are disposed in a ring-shaped arrangement about the outer perimeter of the end plate 110. The semiconductor mounts can optionally include one or more partition walls 11 8 (Fig 7) that can be employed to separate and electrically insulate adjacent ones of the power semiconductors 82 from one another Each of the phase lead receptacles 112 defines an aperture, which is formed through the end plate 110, and can have a first portion, which is located on a central portion of the end plate 110 and which extends axially away from the first axial side of the end plate 110, and a second portion that extends axially away from the second axial side of the end plate 110. In the example shown, each of the phase lead receptacles 112 is a generally tobularstructure that is disposed on the central portion of the end plate 110. The phase lead receptacles 112 can be spaced circumferentially apart from one another. The first and second sidewalls 114and 116 can be fixedly coupled to the end plate 110 and can encircle the outer perimeter and the inner perimeter, respectfully, of the end plate11 0. The first side wall114 can extend from the first axial side of the end plate11 0 by a first distance and from the second axial side of the end plate11 0 by a second, relatively shorter distance. The second side wail 116 can extend from the first axial side of the end plate110 by a third distance that can be relatively larger than the first distance. A first seal groove 120 can be formed about the first side wail 114 and can be configured to receive a first seal 122 therein that seaiingiy engages the first side wail 114 and the housing assembly 12. A second seal groove 124 can be formed about the second side wall 116 and can be configured to receive a second seal 126 therein that seaiingiy engages the second side wall 116 and the cap 64

[0029] With reference to Figure 5, each of the power semiconductors 82 has a plurality of first pins or terminals 130 and a power terminal 132 that is electrically coupied to one of the first terminals 136 (e.g., first terminal 130a in the example shown). The power terminal 132 is fixedly and electrically coupled to a respective first heat sink 146 to form a heat-sinked power semiconductor assembly 142. The first heat sink 140 can be formed of a suitable thermally conductive material and can be electrically coupled to an associated one of the first terminals 130. As a non-limiting example, the first heat sink 140 could be formed of a metal material, such as aluminum, brass, bronze or copper. The first heat sink 140 can define a plurality of first fins 146 that can be employed to discharge heat into a flow of fluid passing through the first fins 146.

[0030] Returning to Figure 3, each of the heat-sinked power semiconductor assemblies 142 can be mounted in a respective one of the semiconductor mounts onthe inverter mount 80 such that each of the power semiconductors 82 is received into a corresponding one of the power semiconductor recesses in the end piate 110 and the first terminals 130 on each of the power semiconductors 82 are received through semiconductor terminal apertures in the end plate11 0. Configuration in the manner illustrated positions the power semiconductors 82 radially outwardly of the sets of field windings 52.

[0031] With reference to Figures 3 and 4, the positive and ground busbars 90 and 92 and the phase busbars and the insulating layers are stacked to form a busbar assembly in which an insulating layer is disposed between the positive busbar 90 and the ground busbar 92, and an insulating layer is disposed between the ground busbar 92 and each of the phase busbars 94a, 94b and 94c. The insulating layers are formed of an electrically insulating material and electrically insulate axially adjacent busbars from one another.

[0032] With reference to Figure 6, each of the positive and ground busbars 90 and 92 and each of the phase busbars 94a, 94b and 94c includes a first busbar portion 150a, 150b, 150c, respectively, and a second busbar portion 152a, 152b, 152c, respectively, that are fixedly and electrically coupled to one another. Each of the second busbar portions 152a, 152b, 152c can be generally similar in their construction to their associated first busbar portion 150a, 150b, 150c, respectively, and as such, only the first busbar portions 150a, 150b, 150c will be described in detail herein. Each of the first busbar portions 150a, 150b, 150c can be formed of an electrically conductive material, such as copper, and can include a body and a set of fingers 160a,160b and 160c, respectively.

[0033] The bodies of the positive busbar 90a and the ground busbar 92b can have an annular shape, while the body of each phase busbar 94a, 94b and 94c can be shaped as an annular segment. The bodies are sized to be received over the second side wai1l 1 6 (Fig. 3) of the inverter mount 80 (Fig. 3) and within the first side wall 114 (Fig. 3) of the inverter mount 80 (Fig. 3) and abutted against the end plate110 (Fig. 3). The outer circumference of the bodies can be disposed radially inwardly of the semiconductor terminal apertures in the inverter mount 80 (Fig. 3).

[0034] With reference to Figures 2 through 4, the bodies of the positive busbar90 and the ground busbar 92b can define a central aperture 180 (Fig. 6). a plurality of terminal apertures 182 (Fig. 6) and a cooling standpipe aperture 184 (Fig. 6) that are each formed therethrough. The terminal apertures 182 can be received over the phase lead receptacles 112, while the cooling standpipe apertures 184 can be received over a cooling standpipe 190 that is integrally formed with the inverter mount 80. The cooling standpipe 190 is configured to direct coolant through the inverter mount 80 to a coolant chamber 196 that is disposed between the inverter mount 80 and the cap64 Heat from the heat-sinked power semiconductor assemblies 142 and the sets of field windings 52 can be transmitted to the coolant in the coolant chamber 196 to thereby cool the inverter 36 and the electric motor 3Q. Each of the phase busbars94a, 94b and 94c can be mechanically and electrically coupled to an associated one of the phase leads 54.

[0035] Each of the sets of fingers 160a, 160b and 160c comprises a plurality of fingers that are configured to mechanically and electrically couple an associated one of the first terminals 130 of a corresponding one of the power semiconductors82 to an associated one of the positive busbar 90, the ground busbar 92 and the phasebusbars 94a, 94b and 94c. For example, the distal ends of ths fingers of each of the sets of fingers 160a, 160b and 160c can be fixedly and electrically coupled to the first terminals 130 by resistance welding or resistance soldering.

[0036] With reference to Figures 3 and 6, the positive busbar 90 can be received within the first side wall 114 in the inverter mount 80 such that the positive busbar 90 is abuted against the second side of the end plate 110 and each adjacent pair of fingers of the sets of fingers 160a is engaged to a first one of the first terminals 130 on a respective one of the power semiconductors 82. A first electrically insulating member can be disposed over the positive busbar 90. The ground busbar 92 can be received within the first side wall 114 in the inverter mount 80 such that the ground busbar 92 is abutted against a side of the first electrically insulating member that is opposite the positive busbar 90 and each adjacent pair of fingers of the sets of fingers 160b is engaged to a second one of the first terminals 130 on a respective one of the power semiconductors 82. A second eiectricaiiy insulating member can be disposed over the ground busbar 92. Each of the phase busbars 94a, 94b and 94c can be positioned within the first side wall 114 and abutted against the second insulator on a side of the second insulator that is opposite the ground busbar 92 and each adjacent pair of fingers of the sets of fingers 160c is engaged to a third or fourth one of the first terminals 130 on a respective one of the power semiconductors 82. The positive busbar 90. the ground busbar 92 and each of the phase busbars 94a, 94b and 94c can be oriented relative to the inverter mount 80 such that the phase lead receptacles 112 are received through each of the terminal apertures 182 and the coaling standpipe aperture 184 is received over the cooling standpipe end plate 110

[0037] The first terminals 130 of the power semiconductors 82 are received into the inverter circuit board 98 and can be electrically coupled to other componentry of the inverter circuit board 98 in a desired manner. The phase leads 54 are received into the terminal receptacles end plate 110 and a seal (not specifically shown) that is disposed in a seal groove (not specifically shown) in each of the phase leads 54 forms a corresponding seal between the phase lead 54 and the inverter mount 80 that inhibits the flow of fluid therethrough Threaded fasteners 180 can be employed to secure each of the phase busbars 94a, 94b and 94c to an associated one of the phase leads 54.

[0033] With reference to Figures 7 through 10, the snubber 100 includes a plurality of snubber circuit elements 200, a plurality of second heat sinks 2Q2, and optionally one or more snubber mounts 204 onto which the snubber circuit elements 200 can be mounted. Each snubber circuit element 200 has a resistor 210 and a capacitor 212 and is electrically coupled to the positive and ground busbars 90 and 92. In the example provided: a) the snubber mount 204 comprises a plurality of snubber circuit boards 216, b) the resistor 210 and the capacitor 212 of each of the snubber circuit elements 200 are mounted on an associated one of the snubber circuit boards 216, and c) the snubber circuit boards 216, the resistors 210 and the capacitors 212 are adjacent to the second axial side of the end plate 110. Each of the resistors 210 can have a first leg 220 and a second leg 222, while each of the capacitors 212 can include a first leg 224 and a second leg 226 The first leg 220 of each resistor 210 is electrically coupled to the positive busbar 90, the second leg 222 of each resistor 210 is electrically coupled to the first leg 224 of an associated one of thecapacitors 212, and the second leg 226 of each capacitor 212 is electrically coupled to the ground busbar 92.

[0039] With specific reference to Figure 10, each of the second heat sinks 202 is mechanically and thermally coupled to at least a portion of an associated one of the snubber circuit elements 200 and includes a second heat sink body 230 and a plurality of second fins 232 that extend from the second heat sink body 230. in the example provided, the second heat sink body 230 of each of the second heat sinks 202 is mounted to the capacitor 212 of an associated one of the snubber circuit elements 200. it will be appreciated, however, that the second heat sinks 202 could be mounted to the resistor 210 of an associated one of the snubber circuit elements 200, or could be mounted to both the resistor210 and the capacitor 212 of an associated one of the snubber circuit elements 200.

[0040] With reference to Figures 8, 11 and 12, the snubber 100 can optionally include a snubber housing 240 that is coupled to the one or more snubber mounts 204. in one form, the snubber housing 240 can encapsulate portions of the snubber circuit elements 200 to inhibit contact between a cooling fluid that is circulated through the inverter 36 and the electrical components of the snubber 100.

[0041] With reference to Figures 11 through 14, a plurality of cooling channels 250 can optionally be formed into the snubber 100 to direct a flow of cooling fluid into or through the second heat sinks 202 in a desired manner. In the example shown, an annular plenum 252 is formed between the end plate 110 and the one or more snubber mounts 204, each of the one or more snubber mounts 204 defines one or more iniet ports 256 and the snubber housing 240 forms a plurality of cooling chambers 258. The annular plenum 262 is disposed in fluid communication with the cooling standpipe190 and is configured to receive cooling fluid therefrom. Each of the cooling chambers 258 houses a corresponding one of the second heat sinks 202 and defines a cavity or region 260 into which the second fins 232 extend, end a chamber outlet 264 that can discharge cooling fluid from the cooling chamber 258 into one or more desired areas, it will be appreciated that cooling fluid flowing through the cooling chambers 258 permits the heat that is conducted into the second heat sinks 202 from the snubber circuit elements 20Q to be rejected from the second fins 232 of the second heat sinks 202 into the cooling fluid.

[0042] With reference to Figures 7 and 12, the chamber outlets 264 of the cooling chambers 258 direct cooling fluid into an annular volume 270 that is located radially between the snubber 100 and the heat-sinked power semiconductor assemblies 142 Cooling fluid in this annular volume can pass through a region into which the first fins 146 of the first heat sinks 140 extend to cool the heat-sinked power semiconductor assemblies 142 Thereafter, the cooling fluid can flow about an axial end of the sets of field windings 52 (Fig 2) and into the stator body cooling channels 60 (Fig. 2} in the stator assembly 40 (Fig. 2) to cool the stator assembly 40 (Fig. 2).

[0043] it will be appreciated that the snubber 100 could be configured somewhat differently to direct cooling fluid in a somewhat different manner. In the example of Figure 15, the snubber housing 240 cooperates with the end plate 110 of the inverter mount 80 and the cap 64 that covers the sets of field windings 52 to define a plurality of snubber cooling passages 250a that direct the cooling fluid away from the second heat sinks 202 to the first heat sinks 140 that are coupled to the power semiconductors 82. in this example, the chamber outlets 264 discharge cooling fluid into an annular volume 280 that supplies cooling fluid to portions 282 of the snubbercooling passages 250a that are disposed between the cap 64 and the end plate 110 The cooling passages 250a supply cooling fluid into the annular volume 27Q (Fig. 7), where it can How into the region where the first fins 146 of the first heat sinks 140 extend.

[0044] While the snubber 100 has been illustrated and described as being a discrete component that is located radially inwardly of the heat-sinked power semiconductors 82, it will be appreciated that the snubber 100 could be integrated into the inverter 36 (Fig. 2) in a somewhat different manner. For example, the snubber 100a could be integrated into the inverter 36a so as to position the second heat sinks 202 and the snubber circuit elements 200 within groups of associated heat-sinked power semiconductor assemblies 142 as is shown in Figure 16. in this example, each of the snubber circuit elements 200 is disposed between an associated pair of the power semiconductors 82 on the second axial side of the end plate 110.

[0045] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMSWhat is claimed is:1 . An electric drive module comprising: a housing assembly; an electric motor received in the housing assembly and having a stator and a rotor that is rotatable relative to the stator about a rotary axis, the stator having a plurality of sets of field windings and a plurality of phase leads, each of the phase leads being electrically coupled to a corresponding one of the sets of windings; an inverter having a retaining member, an end plate, a plurality of first and second busbars, a circuit board assembly, a plurality of power semiconductor devices, one or more first heat sinks, and a snubber, the retaining member being received between the housing assembly and an axial end of each of the sets of field windings, the end plate being fixedly and sealingly coupled to the retaining member, the first and second busbars and the circuit board assembly being received in the retaining member on a first side of the end plate, each of the power semiconductor devices having a plurality of device terminals and a power terminal, a first one of the device terminals of each of the power semiconductor devices being electrically coupled to the second busbar, the power terminal being electrically coupled to a second one of the device terminals and to the first busbar, the power semiconductor devices being arranged within the retaining member such that the power terminals are disposed on a second side of the end plate that is opposite the first side, wherein the device terminals of the power semiconductor devices extend through the end plate and are electrically coupled to the circuitboard assembly, the power terminal of each of the power semiconductor devices being mounted to the one or more first heat sinks, each of the one or more first heat sinks having a plurality of first fins, wherein the first fins of the first heat sinks are disposed in a first region that is adjacent to the axial ends of the sets of field windings, wherein an inlet port is formed through the end plate, the inlet port being adapted to receive a liquid cooling fluid therethrough, the snubber having a plurality of snubber circuit elements and a plurality of second heat sinks, each snubber circuit element having a resistor and a capacitor and being electrically coupled to the first and second busbars, each second heat sink being mechanically and thermally coupled to at least a portion of an associated one of the snubber circuit elements, each second heat sink having a plurality of second fins that are disposed in a second region that is adjacent to the axial ends of the sets of field windings, the inlet port being coupled in fluid communication with the first and second regions.

2. The electric drive module of Claim 1 , wherein the plurality of power semiconductor devices is disposed in an annular manner about the rotary axis, and wherein each of the snubber circuit elements is disposed between an associated pair of the power semiconductor devices.

3. The electric drive module of Claim 1 , wherein the snubber circuit elements and the second heat sinks are disposed on the second side of the end plate.

4. The electric drive module of Claim 3, wherein each snubber circuit element has a first terminal and a second terminal, the first and second terminals extending through the end plate, the first terminal being mechanically coupled to the first bus bar, the second terminal being mechanically coupled to the second bus bar.

5. The electric drive module of Claim 4, wherein each of the first terminals is a leg of an associated one of the resistors.

6. The electric drive module of Claim 1 , wherein the snubber further comprises one or more snubber mounts and a snubber housing, the snubber circuit elements being fixedly coupled to the one or more snubber mounts, the snubber housing being coupled to the one or more snubber mounts and cooperating with the one or more snubber mounts to house the snubber circuit elements, the snubber housing at least partly forming the second region.

7. The electric drive module of Claim 6, wherein a plurality of cooling channels fluidly couple the first and second regions, the cooling channels being at least partly formed by the snubber housing.

8. The electric drive module of Claim 7, wherein each of the cooling channels is formed by a void space that is disposed between the end plate and the snubber housing.

9. The electric drive module of Claim 6, wherein the snubber circuit elements are offset in a radial direction from the power semiconductors and wherein the snubber housing defines a plurality of outlets that are configured to discharge fluid from the second region toward the first region.

10. The electric drive module of Claim 9, wherein the snubber circuit elements are located radially inward of the power semiconductors.

11. An electric drive module comprising: a housing assembly; an electric motor received in the housing assembly and having a stator and a rotor that is rotatable relative to the stator about a rotary axis, the stator having a plurality of sets of field windings and a plurality of phase leads, each of the phase leads being electrically coupled to a corresponding one of the sets of windings; a positive busbar; a ground busbar; a plurality of phase busbars electrically coupled to the plurality of phase leads; an inverter, having a plurality of power semiconductor devices coupled to at least one of the phase busbars, and one or more first heat sinks, each of the power semiconductor devices having a power terminal, the power terminal of each of the power semiconductor devices being mounted to the one or more first heat sinks:a snubber having a plurality of snubber circuit elements and a plurality of second heat sinks, each snubber circuit element having a resistor and a capacitor and being electrically coupled to the positive busbar and the ground busbar, each second heat sink being mechanically and thermally coupled to at least a portion of an associated one of the snubber circuit elements, each second heat sink having a heat sink body; and one or more cooling chambers configured to receive fluid and communicate the fluid to the one or more first heat sinks or the one or more second heat sinks.

12. The electric drive module recited in Claim 11 , wherein the fluid flows through the one or more second heat sinks.

13. The electric drive module recited in Claim 11 , further comprising a snubber housing that receives the plurality of snubber circuit elements.14 The electric drive module recited in Claim 11 , further comprising one or more chamber outlets in the one or more cooling chambers that direct fluid into an annular volume positioned between the snubber and the plurality of power semiconductor devices.

15. The electric drive module recited in Claim 11 , further comprising one or more cooling channels formed into the snubber to direct a flow of cooling fluid over or through the second heat sinks.

16. The electric drive module recited in Claim 15, wherein the one or more cooling channels comprises an annular plenum formed between an end plate and a snubber mount carrying the plurality of snubber circuit elements.

17. The electric drive module recited in Claim 11 , wherein the one or more first heat sinks include a first heat sink body and a plurality of first fins.

18. The electric drive module recited in Claim 11 , wherein the one or more second heat sinks include a second heat sink body and a plurality of second fins.

18. The electric drive module recited in Claim 11 , wherein the one or more second heat sinks are mounted to a capacitor of the snubber circuit elements.

19. The electric drive module recited in Claim 11 , wherein the snubber is positioned radially-inwardly of the power semiconductor devices.

20. The electric drive module recited in Claim 11 , wherein the power semiconductor devices are positioned adjacent to the snubber circuit elements around a circumference of an inverter mount.

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