Battery pack holding component and holding method

Abstract

An exemplary battery pack retention assembly includes, among other things, a conformable bracket for securing a battery array within the battery pack. The conformable bracket includes a platform configured to flex when the conformable bracket is secured. The flexure helps align a region of the conformable bracket with a heat exchange plate. An exemplary battery pack retention method includes, among other things, flexing the conformable bracket to reduce a gap between the battery array and the heat exchange plate. The flexure occurs when the battery array is secured within the battery pack.

Description

Technical Field

[0001] The present disclosure relates to battery pack retention assemblies, and more particularly, to utilizing conforming brackets to secure portions of a battery array of a battery pack. Background Art

[0002] Generally, electric vehicles differ from conventional motor vehicles in that they use one or more battery-powered electric motors to selectively propel the vehicle. In contrast, conventional motor vehicles rely solely on internal combustion engines to propel the vehicle. Electric vehicles may use electric motors in place of internal combustion engines or in combination with internal combustion engines.

[0003] Exemplary electric vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles, and battery electric vehicles (BEVs). The powertrain of an electric vehicle is generally equipped with a battery pack having battery cells that store electricity for powering a motor.

[0004] A battery pack may include one or more arrays of battery cells housed within a housing. The arrays may need to be secured. The battery pack may also include heat exchange plates for cooling the arrays, heating the arrays, or both. Summary of the Invention

[0005] An assembly according to an exemplary aspect of the present disclosure includes, among other things, a conformable bracket for securing a battery array within a battery pack. The conformable bracket includes a plurality of platforms configured to flex when the conformable bracket is secured. The flexure helps align regions of the conformable bracket with the heat exchange plate.

[0006] Another non-limiting embodiment of the aforementioned assembly includes a track member that secures the battery cell frame relative to the heat exchange plate. The track member is secured to the conformal bracket at track connection locations distributed axially along the longitudinal axis of the conformal bracket. Each track connection location is positioned within one of the plurality of platforms.

[0007] In a further non-limiting embodiment of any of the foregoing assemblies, the track member is separate and distinct from each battery cell frame.

[0008] In a further non-limiting embodiment of any of the foregoing assemblies, each track connection location includes a platform hole in one of the platforms. The platform hole is configured to receive a mechanical fastener that is otherwise received within the track hole of the track member. The mechanical fastener secures the track member to the platform of the conformable bracket.

[0009] In a further non-limiting embodiment of any of the foregoing assemblies, the heat exchange plate is sandwiched between the track member and the conformable bracket.

[0010] In a further non-limiting embodiment of any of the foregoing assemblies, the heat exchange plate includes a first plate, a second plate, and a coolant channel established between the first plate and the second plate. A portion of the first plate and the second plate are sandwiched between the track member and the conformal bracket.

[0011] A further non-limiting embodiment of any of the foregoing assemblies includes recesses of the conformable bracket, the recesses being axially aligned with the platform along a longitudinal axis of the bracket, and each recess being directly secured to the battery pack housing at a recess connection location.

[0012] In a further non-limiting embodiment of any of the foregoing assemblies, each recess includes a floor and sidewalls extending from the floor to the platform.

[0013] In a further non-limiting embodiment of any of the foregoing assemblies, the floor of the recess is welded to a region of the battery pack housing to secure the track member directly to the battery pack housing.

[0014] Another non-limiting embodiment of any of the foregoing assemblies includes a flange of the conformable bracket radially spaced from the platform relative to a longitudinal axis of the conformable bracket, the flange being directly secured to the battery pack housing at flange connection locations distributed axially along the conformable bracket.

[0015] In a further non-limiting embodiment of any of the foregoing assemblies, each flange connection location is axially aligned with one of the plurality of platforms.

[0016] A further non-limiting embodiment of any of the foregoing assemblies includes a track member that secures the battery cell frame relative to the heat exchange plate. The track member is secured to the conformal bracket at track connection locations distributed axially along the conformal bracket. Each track connection location is positioned within one of the plurality of platforms. Each flange connection location is axially offset from each rail connection location such that the flange connection location does not axially overlap with the rail connection location.

[0017] In a further non-limiting embodiment of any of the foregoing assemblies, the battery array is a battery array of an electric vehicle.

[0018] A method of securing a portion of a battery pack according to an exemplary aspect of the present disclosure includes, inter alia, bending a conformable bracket to reduce a gap between a battery array and a heat exchange plate. The bending occurs when securing the battery array within the battery pack.

[0019] Another non-limiting embodiment of the foregoing method includes supporting a platform of the conformable support with a recessed portion of the conformable support, wherein the recessed portion is directly secured to the battery pack housing, and wherein the platform is spaced apart from the battery pack housing.

[0020] In a further non-limiting embodiment of any of the foregoing methods, at least one platform of the plurality of platforms is disposed axially relative to a longitudinal axis of the conformable stent between axially adjacent recesses.

[0021] A further non-limiting embodiment of any of the foregoing methods includes securing a rail member to the platform to secure the battery array to the heat exchange plate.

[0022] A further non-limiting embodiment of any of the foregoing methods includes sandwiching a portion of the heat exchange plate between the rail member and the conformal bracket when securing the battery array to the battery pack housing.

[0023] A further non-limiting embodiment of any of the foregoing methods includes securing the track member to the platform using mechanical fasteners and securing the battery pack housing to the recess using welds.

[0024] The embodiments, examples and alternatives of the preceding paragraphs, claims or the following description and drawings, including any of their aspects or corresponding features, may be made independently or in any combination. Features described in conjunction with one embodiment are applicable to all embodiments, unless these features are incompatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The various features and advantages of the disclosed examples will become apparent to those skilled in the art based on the detailed description. The accompanying drawings of the detailed description can be briefly described as follows:

[0026] Figure 1 A schematic diagram showing a powertrain of an electric vehicle;

[0027] Figure 2 Shown Figure 1 A partial schematic perspective view of a battery array of a battery pack within a powertrain;

[0028] Figure 3 Shown from Figure 1 a cross-sectional view of a battery pack of a powertrain;

[0029] Figure 4 Shown Figure 3 There is no cross-sectional view of the battery array;

[0030] Figure 5 Shown Figure 3 A close-up perspective view of Area-V in the

[0031] Figure 6 Shows the front edge of the conformal bracket fixed to the battery pack Figure 7 The VI-VI line in the Figure 3 a cross-sectional view of a selected portion of a battery pack;

[0032] Figure 7 Shown after the conformable bracket is fixed in the battery pack Figure 6 sectional view of

[0033] Figure 8 Shown from Figure 2 A top view of one of the conformal supports of the battery pack;

[0034] Figure 9 Shown along Figure 8 A perspective cross-sectional view of the conformable stent taken along line IX-IX in FIG.

[0035] Figure 9A Shown Figure 9 A cross-sectional view of a conformable support having different areas connected to the heat exchange plate. DETAILED DESCRIPTION

[0036] The present disclosure generally relates to securing a battery array within a battery pack. In particular, the present disclosure relates to a retention assembly and method for securing a battery array of a battery pack to, for example, a housing of the battery pack using a conformable bracket.

[0037] The conformable brackets conform to the battery pack, which in some examples can reduce or eliminate gaps between components of the battery pack. Examples of such gaps can include gaps between heat exchange plates and fins or battery cells of a battery array.

[0038] Figure 1 A powertrain system 10 for an electric vehicle, in this example a hybrid electric vehicle (HEV), is schematically illustrated. Although described as an HEV, it should be understood that the concepts described herein are not limited to hybrid electric vehicles (HEVs) and can be extended to other types of electric vehicles, including but not limited to plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), fuel cell vehicles, and the like.

[0039] The powertrain 10 includes a battery pack 14, a motor 18, a generator 20, and an internal combustion engine 22. The motor 18 and the generator 20 are types of electric machines. The motor 18 and the generator 20 may be separate or may be in the form of a combined motor-generator.

[0040] In this embodiment, powertrain 10 is a power-split powertrain that utilizes a first drive system and a second drive system. The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels 26 of an electric vehicle. The first drive system includes a combination of an engine 22 and a generator 20. The second drive system includes at least a motor 18, a generator 20, and a battery pack 14. The motor 18 and generator 20 are part of the electric drive system of powertrain 10.

[0041] The engine 22 (an internal combustion engine in this example) and the generator 20 can be connected by a power transfer unit 30 (e.g., a planetary gear set). Of course, other types of power transfer units, including other gear sets and transmissions, can be used to connect the engine 22 to the generator 20. In one non-limiting embodiment, the power transfer unit 30 is a planetary gear set that includes a ring gear 32, a sun gear 34, and a carrier assembly 36.

[0042] Generator 20 can be driven by engine 22 through power transfer unit 30 to convert kinetic energy into electrical energy. Generator 20 can alternatively be used as a motor to convert electrical energy into kinetic energy, thereby outputting torque to shaft 38 connected to power transfer unit 30. Because generator 20 is operatively connected to engine 22, the speed of engine 22 can be controlled by generator 20.

[0043] Ring gear 32 of power transfer unit 30 may be connected to shaft 40, which is connected to vehicle drive wheels 26 via a second power transfer unit 44. Second power transfer unit 44 may include a gear set having a plurality of gears 46. Other power transfer units are also suitable.

[0044] Gear 46 transfers torque from engine 22 to differential 48 to ultimately provide traction to vehicle drive wheels 26. Differential 48 may include a plurality of gears capable of transferring torque to vehicle drive wheels 26. In this example, second power transfer unit 44 is mechanically coupled to shaft 50 through differential 48 to distribute torque to vehicle drive wheels 26.

[0045] The motor 18 can also be used to drive the vehicle drive wheels 26 by outputting torque to a shaft 52, which is also connected to the second power transfer unit 44. In one embodiment, the motor 18 and the generator 20 cooperate as part of a regenerative braking system, in which both the motor 18 and the generator 20 can function as motors to output torque. For example, both the motor 18 and the generator 20 can output power to the battery pack 14.

[0046] In the continued reference Figure 1 Now refer to Figure 2 The exemplary battery pack 14 provides relatively high-voltage batteries that store generated electricity and output the electricity to operate the motor 18, the generator 20, or both. The battery pack 14 includes at least one battery array 60 having a plurality of individual battery cells 64, each of which is held within a support structure 68 and disposed on a heat exchange plate 72. The battery array 60 may include, for example, 30 to 50 individual battery cells 64.

[0047] The support structure 68 includes, among other things, a battery cell frame 76 surrounding the perimeter of each battery cell 64. In this example, each frame 76 supports two individual battery cells 64. The frames 76 are a polymer material, but other materials are also contemplated.

[0048] The frame 76 and the battery cells 64 are held between opposing end walls 80. The frame 76 and the battery cells 64 are positioned adjacent to the heat exchange plate 72. Fins 82 are positioned between the battery cells 64. The fins 82 extend from between the battery cells 64 to a position adjacent to the heat exchange plate 72. The fins 82 can conduct heat energy between the heat exchange plate 72 and the battery cells 64. The fins 82 can directly contact the heat exchange plate 72. The fins 82 can be made of aluminum, for example.

[0049] Thermal interface material may be positioned where the fins 82 interface with the heat exchange plate 72. The thermal interface material facilitates thermal energy transfer between the fins 82 and the heat exchange plate.

[0050] In this example, the heat exchange plate 72 includes a first plate 84, a second plate 88, and a plurality of coolant channels 92 established between the first plate 84 and the second plate 88. Coolant can circulate through the coolant channels 92 and then move from the battery array 60 to transfer thermal energy from the battery array 60. The heat exchange plate 72 can be, for example, a metal or a metal alloy.

[0051] In the continued reference Figure 1 and Figure 2 Now refer to Figures 3 to 5 The battery array 60 is housed within a housing 100, which in this example has a tray 104 and a cover 108. The housing 100 may be a metal or metal alloy. Other examples may use other materials, such as polymer-based materials.

[0052] The battery array 60 is secured to the housing 100 by a pair of conformable brackets 112. One conformable bracket 112 is positioned along each side of the battery array 60. In this example, the conformable bracket 112 is secured to the tray 104, and the other portion of the conformable bracket 112 is secured to the track member 116. The conformable bracket 112 may be a metal or metal alloy. Other examples may use other materials, such as polymer-based materials.

[0053] The track member 116 includes an overhang 118 or lip that grips laterally extending feet 119 of the frame 76 to retain the battery array 60 when the track member 116 is secured to the conformal bracket 112 .

[0054] When the battery array 60 is secured within the housing 100 by the conformal brackets 112 , the outer peripheral edge portions 126 of the first and second plates 84 , 88 are sandwiched between the track members 116 and the conformal brackets 112 .

[0055] When the battery array 60 is fixed in the housing 100 by the adapter bracket 112, a portion of the fins 82 extends to a position adjacent to the heat exchange plate 72. The thermal interface material 114 located between the portion of the fins 82 and the heat exchange plate 72 helps promote thermal conductivity between the fins 82 and the heat exchange plate 72.

[0056] In the past, dimensional variations in the heat exchanger plates could cause gaps between the heat exchanger plates and other parts of the battery array. For example, the generally flat surface of a rigid structure used to secure the battery array would interface with the wavy surface of a relatively flexible heat exchanger plate. The generally flat surface would initially contact the peaks of the relatively wavy surface. As the rigid structure and the relatively flexible heat exchanger plate pressed against each other during securement, the rigid structure forced the relatively flexible heat exchanger plate to deform.

[0057] Deformation of the relatively flexible heat exchange plate can result in increased gaps or spaces between the heat exchange plate and other parts of the battery array (e.g., gaps between the heat exchange plate and the fins used for heat conduction). Among other factors, these gaps or spaces can lead to less efficient heat transfer between the fins (or battery cells) and the heat exchange plate. These gaps or spaces may require the use of additional thermal interface materials to fill these gaps or spaces.

[0058] The exemplary conformable bracket 112 includes features that allow the conformable bracket 112 to flex and conform to irregularities (e.g., waves) within the heat exchange plate 72 when the conformable bracket 112 is secured. Conforming to irregularities in the heat exchange plate 72 can reduce deformation of the heat exchange plate 72 during securing. Among other things, reducing deformation of the heat exchange plate 72 can promote good thermal contact between the heat exchange plate 72 and other areas of the battery array 60, which can improve thermal conductivity.

[0059] See also Figure 6 , shows a portion of one of the conformal brackets 112 before the track member 116 is secured and clamps the peripheral edge portions 126 of the first and second plates 84, 88 of the heat exchange plates 72. As shown, a gap G exists between the conformal bracket 112 and the second plate 88. In this example, the gap G is exaggerated for clarity of the drawing.

[0060] See also Figure 7 , shows the same conformal bracket 112 after securing the track member 116 to the first and second plates 84, 88 of the heat exchange plate. As shown, the conformal bracket 112 bends to conform to irregularities in the first and second plates 84, 88.

[0061] Now refer to Figure 5 、 89 and 9 describe some features of the conformable bracket 112 that facilitate conformity with the first plate 84 and the second plate 88. As shown, the conformable bracket 112 is disposed along the longitudinal axis L. A Extension, longitudinal axis L A Aligned with the longitudinal channels of the battery array 60. The conformable bracket 112 includes a plurality of platforms 120, a plurality of recesses 124 and a connecting flange 128.

[0062] The platform 120 provides a plurality of rail connection locations 134. In this example, the rail connection locations 134 include holes 138 in the platform 120. When the battery array 60 is secured, mechanical fasteners 142 extend through the platform holes 138 and further secure the rail member 116 to the conformable bracket 112 via the rail holes 146.

[0063] In this example, the mechanical fasteners 142 are threaded fasteners that draw the track member 116 and the platform 120 relatively close together when the mechanical fasteners 142 are torqued to a fully tightened position. Although described as mechanical fasteners 142, other connection techniques may be used, including welding.

[0064] The peripheral edge portions 126 of the first and second plates 84, 88 of the heat exchange plates 72 extend transversely as shown and terminate before reaching the mechanical fasteners 142 and the recesses 124. In other examples, some of the peripheral edge portions 126 may extend further transversely to extend relative to the longitudinal axis L. A Axially positioned between axially adjacent mechanical fasteners 142 , axially adjacent recesses 124 , or both.

[0065] Each recess 124 includes a floor 150 and sidewalls 156. The sidewalls 156 extend from the floor 150 to the platform 120. In this example, the recesses 124 are frusto-conical.

[0066] Reference longitudinal axis L A , the platforms 120 and recesses 124 are axially aligned. Furthermore, the platforms 120 are alternated with the recesses 124 axially shifted along the conformable stent 112. That is, at least one of the recesses 124 is axially located between axially adjacent platforms 120 along the axial length of the conformable stent 112.

[0067] The recess 124 is fixed directly to the tray 104 by, for example, welds in the bottom plate 150 of the recess 124. The location of the weld in each recess 124 is determined by Figure 8 and 9 The "X" in the .

[0068] In this example, conformal bracket 112 is secured to tray 104 prior to installing battery array 60. The securing of recess 124 helps secure conformal bracket 112 to tray 104 as mechanical fasteners 142 are torqued downward to secure track member 116 and clamp first and second plates 84, 88.

[0069] The platform 120 is spaced a distance from the tray 104. In some examples, the platform 120 is spaced less than 7 mm from the tray 104.

[0070] When the mechanical fasteners 142 are torqued downward, the sidewalls 156 and the platform 120 may flex to allow the area A of the conformable bracket 112 to engage the heat exchange plate 72. TE flexing and conforming to irregularities within the heat exchange plates, which can reduce or eliminate the gap G. Reducing or eliminating the gap can desirably reduce deformation and stress induced in the heat exchange plates 72 when securing the heat exchange plates 72 to the conformal brackets 112. The thickness of the conformal brackets 112 can be varied as needed to provide the appropriate amount of flex or springback.

[0071] like Figure 9A As shown, in the example where the peripheral edge portions 126 of the first and second plates 84, 88 are further extended laterally to be positioned axially between the axially adjacent mechanical fasteners 142, the axially adjacent recesses 124, or both, the region A of the conformal bracket 112 that engages the heat exchange plate TE Extend laterally into these areas.

[0072] See again Figure 9 , the conformable bracket 112 is additionally secured to the pallet 104 at flange connection locations 160 on the attachment flange 128. In this example, the flange connection locations 160 are each represented by an "X" on the attachment flange 128. Spot welds, for example, may be used to secure the attachment flange 128 to the pallet 104 at the flange connection locations 160.

[0073] It is worth noting that the flange is relative to the longitudinal axis L A Radially spaced from both the platform 120 and the recess 124. Furthermore, the flange connection location 160 is axially aligned with the rail connection location 134, which has been found to be advantageous for region A. TE bends to conform to the heat exchange plate 72.

[0074] Some disclosed examples feature a retaining assembly that can secure the battery array within the battery pack without substantially bending or flexing the heat exchange plate. Essentially, the retaining assembly can conform to the heat exchange plate rather than the heat exchange plate conforming to the retaining assembly. This can, among other things, help reduce or eliminate gaps between the heat exchange plate and other components, thereby improving thermal conductivity. Furthermore, the required thermal interface material can be reduced.

[0075] In some examples, the retaining assembly is a stent having a relatively small width (approximately fifty-five millimeters) and height (approximately seven millimeters) to facilitate incorporation of the conformable stent into a relatively tight packaging envelope.

[0076] The foregoing description is illustrative and not restrictive. Variations and modifications to the disclosed examples may become apparent to those skilled in the art, and such variations and modifications do not necessarily depart from the essence of this disclosure. Therefore, the scope of legal protection afforded to this disclosure can only be determined by studying the following claims.

Claims

1. A battery pack holding assembly comprising: a conformable bracket securing the battery array within the battery pack, the conformable bracket comprising a plurality of platforms configured to flex when the conformable bracket is secured so that regions of the conformable bracket align with heat exchange plates; as well as A track member is fixed to the plurality of battery cell frames relative to the heat exchange plate, the track member being fixed to the conformal bracket at a plurality of track connection positions axially distributed along the longitudinal axis of the conformal bracket, each of the track connection positions being positioned within one of the plurality of platforms, the heat exchange plate being sandwiched between the track member and the conformal bracket.

2. A battery pack retention assembly according to claim 1, wherein the plurality of rail connection locations each include a platform hole within one of the plurality of platforms, the platform hole being configured to receive a mechanical fastener, the mechanical fastener being further received within the rail hole of the rail member, the mechanical fastener securing the rail member to the platform of the conformal bracket.

3. The battery pack retention assembly of claim 1 , wherein the heat exchange plate comprises a first plate, a second plate, and a coolant channel established between the first plate and the second plate, wherein a portion of the first plate and the second plate are sandwiched between the rail member and the conformal bracket.

4. The battery pack retaining assembly according to claim 1 further includes a plurality of recesses in the conformal bracket, the plurality of recesses being axially aligned with the plurality of platforms along the longitudinal axis of the conformal bracket, and the plurality of recesses are each directly fixed to the battery pack housing at the recess connection position. 5 . The battery pack holder assembly of claim 4 , wherein each of the plurality of recesses includes a bottom plate and side walls extending from the bottom plate to the platform. 6 . The battery holder assembly of claim 5 , wherein the bottom plate of the plurality of recesses is welded to an area of the battery housing to secure the conformal bracket directly to the battery housing.

7. A battery pack retaining assembly according to claim 5, wherein the conformal bracket further includes a flange, which is radially spaced a certain distance from the multiple platforms relative to the longitudinal axis of the conformal bracket, and the flange is directly fixed to the battery pack housing at multiple flange connection positions distributed axially along the conformal bracket. 8 . The battery pack retention assembly of claim 7 , wherein each of the plurality of flange connection locations is axially aligned with one of the plurality of platforms.

9. The battery pack retention assembly of claim 7, wherein each of the flange connection locations is axially offset from each of the plurality of rail connection locations such that the flange connection locations do not axially overlap with the rail connection locations.

10. A method of securing a battery pack portion, comprising: When the battery array is fixed in the battery pack, the conformable bracket is bent to reduce the gap between the battery array and the heat exchange plate. fixing a rail member to a plurality of platforms of the conformable bracket to fix the battery array to the heat exchange plate, When securing the battery array to the battery pack housing, a portion of the heat exchange plate is sandwiched between the rail member and the conformal bracket.

11. The method according to claim 10, further comprising: The plurality of platforms of the conformal bracket are supported by a plurality of recesses of the conformal bracket, the plurality of recesses being directly secured to the battery pack housing, and the plurality of platforms being spaced a distance from the battery pack housing.

12. The method according to claim 11, wherein At least one of the plurality of platforms is axially disposed relative to a longitudinal axis of the conformable stent between axially adjacent recesses within the plurality of recesses.

13. The method of claim 11, further comprising securing the track member to the plurality of platforms using a plurality of mechanical fasteners and securing the battery pack housing to the plurality of recesses using a plurality of welds.

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