DRIVE BATTERY INSTALLATION ASSEMBLY AND MOUNTING METHOD

Abstract

An exemplary traction battery mounting assembly includes a traction battery and a damper that secures the traction battery to a vehicle frame in such a way that the traction battery, when mounted to the vehicle frame, can move relative to the vehicle frame. An exemplary traction battery mounting method includes securing a traction battery in a mounted position in which the traction battery is attached to a vehicle frame. The traction battery is movable relative to the vehicle frame when in the mounted position.

Description

TECHNICAL FIELD

[0001] This disclosure relates to attaching a traction battery to a frame of an electrified vehicle, and more particularly to a mounting assembly and method of attachment that allows some movement of the traction battery relative to the frame. GENERAL STATE OF THE ART

[0002] Electrified vehicles differ from conventional motor vehicles in that they are selectively powered using one or more electric motors. These motors can power the electrified vehicles instead of, or in addition to, an internal combustion engine. Examples of electrified vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell electric vehicles (FCVs), and battery electric vehicles (BEVs).

[0003] JP 2009-298207 A describes an electric vehicle with grounding means, wherein a humidifier, a voltage control unit, and a subframe are provided with an insulating surface, and said parts are brought into contact with each other at points where the insulation has been removed. Further prior art relating to the background of the invention is provided by JP 2001-294048 A, JP 2014-143042 A, and JP 2012-28023 A.

[0004] The traction battery can be used to selectively power the electric motors and other electrical loads of the electrified vehicle. The traction battery includes a plurality of interconnected battery cells that store energy to power these electrical loads. The traction battery can be rigidly mounted directly to the frame of the electrified vehicle and electrically grounded to the frame using a metallic wire.

[0005] The task is to arrange a drive battery of an electric vehicle movably on the frame of the vehicle.

[0006] This object is achieved by a drive battery mounting assembly according to claim 1 and by a drive battery mounting method according to claim 9. SUMMARY

[0007] A traction battery mounting assembly according to an exemplary non-limiting embodiment includes, among other things, a traction battery and a damper that secures the traction battery to a vehicle frame. The traction battery is capable of moving relative to the vehicle frame when secured to the vehicle frame.

[0008] In another example of the preceding assembly, the damper is so electrically conductive that the drive battery is electrically grounded to the vehicle frame via the damper.

[0009] In another example of any of the preceding assemblies, a damping portion of the damper is electrically conductive and compressible relative to a portion of the drive battery attached to the damper.

[0010] In another example of any of the foregoing assemblies, the damping portion includes an electrically conductive material distributed within an elastomeric material.

[0011] Another example of one of the foregoing assemblies includes an outer bushing, an inner bushing, and a damping portion of the damper. The damping portion attaches the outer bushing to the inner bushing.

[0012] In another example of any of the foregoing assemblies, one of the outer or inner bushings is attached directly to the traction battery and the other of the outer or inner bushings is attached directly to the vehicle frame.

[0013] In another example of one of the preceding assemblies, a wire electrically grounds the traction battery to the vehicle.

[0014] In another example of any of the foregoing assemblies, a first mount of the traction battery is directly attached to the damper and a second mount of the vehicle is directly attached to the damper.

[0015] In another example of any of the foregoing assemblies, the first bracket is completely spaced from the second bracket such that no portion of the first bracket contacts a portion of the second bracket when the damper secures the traction battery to the vehicle frame.

[0016] In another example of one of the preceding assemblies, the damper attaches the traction battery to an underbody of the vehicle.

[0017] A traction battery mounting method includes, among other things, securing a traction battery in an installed position, wherein the traction battery is attached to a vehicle frame. The traction battery is movable relative to the vehicle frame when in the installed position.

[0018] Another example of the foregoing method includes damping the movement of the traction battery relative to the vehicle frame when the traction battery is in the installed position.

[0019] In another example of any of the preceding methods, the traction battery is attached to the vehicle frame via a damper.

[0020] Another example of any of the preceding methods involves electrically grounding the traction battery to the vehicle frame via the damper.

[0021] Another example of any of the foregoing methods includes a path for grounding the traction battery that extends through a metallic material distributed within an elastomeric material of the damper.

[0022] In another example of any of the preceding methods, attaching comprises attaching a first mount of the traction battery directly to the damper and attaching a second mount of the vehicle directly to the damper.

[0023] In another example of any of the preceding methods, the damper includes a first bushing attached to the first bracket, a second bushing attached to the second bracket, and a damping portion connecting the first bushing and the second bushing.

[0024] Another example of any of the foregoing methods includes electrically grounding the traction battery to the vehicle frame via a metallic wire extending from the traction battery to the vehicle frame. SHORT DESCRIPTION OF THE CHARACTERS

[0025] The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures attached to the detailed description may be briefly described as follows: Fig. 1 illustrates a schematic view of an exemplary powertrain for an electrified vehicle. Fig. Figure 2 illustrates a side view of an electrified vehicle incorporating the powertrain of Fig. 1, and having selected portions cut out and expanded to show a traction battery of the electrified vehicle. Fig. Figure 3 shows a perspective close-up view of a mounting assembly which supports the drive battery of Fig. 2 attached to a vehicle frame in a built-in position. Fig. Figure 4 illustrates a sectional view of the attachment assembly at line 3-3 in Fig. 3. Fig. 4A illustrates a close-up view of a damping portion in a damper of the mounting assembly. Fig. Figure 5 illustrates a perspective view of a damper of the mounting assembly of Fig. 3. DETAILED DESCRIPTION

[0026] This disclosure is directed to attaching a traction battery to a frame of an electrified vehicle. When the traction battery is attached to the frame, a damper allows some movement of the traction battery relative to the frame. In some embodiments, the traction battery is grounded to the frame via the damper. These and other features are explained in more detail in the following paragraphs of this detailed description.

[0027] Fig. Figure 1 schematically illustrates a powertrain 10 for an electrified vehicle. Although depicted as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEVs and could extend to other electrified vehicles, including, but not limited to, plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell vehicles, among others.

[0028] The powertrain 10 includes a battery pack 14 having a plurality of battery assemblies 18, an internal combustion engine 20, an electric motor 22, and a generator 24. The electric motor 22 and generator 24 are types of electrical machines. The electric motor 22 and generator 24 may be separate or may take the form of a combined motor-generator.

[0029] In this embodiment, the powertrain 10 is a power-split powertrain employing 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 28. The first drive system includes a combination of the internal combustion engine 20 and the generator 24. The second drive system includes at least the electric motor 22, the generator 24, and the traction battery 14. The electric motor 22 and the generator 24 are parts of an electric drive system of the drive 10.

[0030] The engine 20 and the generator 24 may be connected by a power transfer unit 30, such as a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, may be used to connect the engine 20 to the generator 24. In one non-limiting embodiment, the power transfer unit 30 is a planetary gear set including a ring gear 32, a sun gear 34, and a carrier assembly 36.

[0031] The generator 24 can be driven by the internal combustion engine 20 through the power transmission unit 30 to convert kinetic energy into electrical energy. Alternatively, the generator 24 can serve as an electric motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft 38 connected to the power transmission unit 30.

[0032] The ring gear 32 of the power transfer unit 30 is connected to a shaft 40, which is connected to the vehicle drive wheels 28 via a second power transfer unit 44. The second power transfer unit 44 may include a gear set having a plurality of gears 46. Other power transfer units may be used in other examples.

[0033] The gears 46 transfer torque from the internal combustion engine 20 to a differential 48 to ultimately provide traction to the vehicle drive wheels 28. The differential 48 may include a plurality of gears that facilitate the transmission of torque to the vehicle drive wheels 28. In this example, the second power transfer unit 44 is mechanically coupled to an axle 50 through the differential 48 to distribute torque to the vehicle drive wheels 28.

[0034] The electric motor 22 can be selectively used to drive the vehicle drive wheels 28 by outputting torque to a shaft 52, which is also connected to the second power transfer unit 44. In this embodiment, the electric motor 22 and the generator 24 cooperate as part of a regenerative braking system in which both the electric motor 22 and the generator 24 can be used as electric motors for outputting torque. For example, the electric motor 22 and the generator 24 can each output electrical energy to recharge cells of the traction battery 14.

[0035] With reference to the Fig. 2 and Fig. 3, the drive battery 14 of the drive train 10 is now attached to a frame 58 of a vehicle 60 with at least one mounting assembly 62.

[0036] The vehicle 60 includes the powertrain 10. The vehicle 60 is an HEV. In another example, the vehicle 60 may be an all-electric vehicle.

[0037] The frame 58 is part of a chassis of the vehicle 60. When the drive battery 14 is attached to the frame 58, the drive battery 14 is attached to an underbody of the vehicle 60 and is located outside a passenger compartment of the vehicle 60. Fig. 3 shows the drive battery 14 in an installed position in which the drive battery 14 is attached to the frame 58.

[0038] Generally, the mounting assembly 62 includes a mount 66 of the traction battery 14, a mount 70 of the frame 58, and a damper 74. In some non-limiting embodiments, the traction battery 14 is attached to the frame 78 with four separate mounting assemblies. In such examples, the traction battery 14 may have a generally rectangular profile, with a separate mounting assembly located at each corner of the traction battery 14.

[0039] The traction battery 14 holds the battery assemblies 18 within a housing 82. In some examples, the housing 82 is made of a metallic material. In other examples, the housing 82 is made of a polymeric material.

[0040] The bracket 66 is rigidly attached to the housing 82 of the traction battery 14. In one non-limiting embodiment, the bracket 66 and the housing 82 are metallic, and the bracket 66 and the housing 82 are welded together. In another non-limiting embodiment, the housing 82 is made of a polymeric material, and the bracket 66 is attached to the housing 82 using one or more mechanical fasteners, such as threaded fasteners.

[0041] The frame 58, which includes the bracket 70, is metallic. The bracket 70 may be rigidly connected to the remaining portions of the frame 58, for example, via welds. In a further non-limiting embodiment, the bracket 70 is attached to the frame 58 using one or more mechanical fasteners, such as threaded fasteners.

[0042] The damper 74 of the mounting assembly 62 isolates the traction battery 14 from at least some of the forces imparted to the traction battery 14 by the frame 78. For example, when the frame 78 vibrates due to the vehicle 60 traveling over rough terrain, the vibration loads on the traction battery 14 are damped due to the damper 74. The damping extends the duration of transmitted shock forces and thus reduces a peak load.

[0043] With reference to the Fig. 4-5 with continued reference to the Fig. 2 and Fig. 3, in one exemplary, non-limiting embodiment, the damper 74 includes an outer bushing 84, an inner bushing 88, and a damping portion 92 between the outer bushing 84 and the inner bushing 88. The outer bushing 84 and the inner bushing 88 are each cylindrical in this example. The damping portion 92 secures the outer bushing 84 to the inner bushing 88.

[0044] A radially outer surface 96 of the outer bushing 84 is rigidly attached to the bracket 66 of the traction battery 14, and a radially inner surface 98 of the outer bushing 84 is bonded to the damping portion 92. The bracket 66 may be welded to the radially outer surface 96, for example, with welds 102.

[0045] A radially outer surface 106 of the inner bushing 88 is bonded to the damping portion 92, and a radially inner surface 108 provides a bore 112. A mechanical fastener 116 extends through the bore 112 to engage a weld nut 120 of the bracket 70. The weld nut 120 is rigidly connected to the remaining portions of the frame 70, for example, with welds 122.

[0046] The mechanical fastener 116 is tightened to secure the damper 74 to the bracket 70. When secured, the inner bushing 88 directly contacts the bracket 70. When secured, the outer bushing 84 and the damping portion 92 are spaced from the bracket 70.

[0047] In an exemplary, non-limiting embodiment, the damping portion 92 is electrically conductive. For example, the damping portion 92 may be made of high-carbon rubber, which is both elastomeric and electrically conductive.

[0048] In other non-limiting embodiments, the damping portion 92 is electrically conductive because the damping portion 92 includes an elastomeric material 100 and a conductive material 104 embedded within the elastomeric material 100. In such an example, the elastomeric material 100 may be a silicone 100A and the conductive material 104 may be an aligned metal wire 104A embedded within the silicone ( Fig. 4A). Other exemplary damping sections 92 may include metal-coated filled silicones or silicones having a wire mesh embedded therein.

[0049] The damping portion 92 is compressible relative to the outer bushing 84 and the inner bushing 88. The elastomeric material 100 allows the outer bushing 84 to move and flex relative to the inner bushing 88. Because the outer bushing 84 and the bracket 66 are rigidly connected, the outer bushing 84 moves along with the bracket 66. Because the inner bushing 88 and the bracket 70 are rigidly connected, the inner bushing 88 moves along with the bracket 70.

[0050] The damping portion 92 may allow the outer bushing 84 to rotate relative to the inner bushing 88 about an axis A of the bore 112. The damping portion 92 may allow the outer bushing 84 to tilt relative to the inner bushing 88 and the axis A.

[0051] If the damping portion 92 is electrically conductive, the damping portion 92 may provide a portion of an electrical grounding path between the traction battery 14 and the frame 78. The electrical grounding path may extend from the mount 66 of the traction battery 14, through the outer bushing 84, through the conductive material 104 of the damping portion 92, through the inner bushing 88, to the mount 70 of the frame 78. Thus, if the damping portion 92 is electrically conductive, the traction battery 14 is electrically grounded to the frame 78 via the damper 74.

[0052] The bracket 66 is spaced from the second bracket 70 such that no portion of the bracket 66 contacts any portion of the bracket 70 when the damper 74 secures the traction battery 14 to the vehicle frame 58. Electrical grounding via the damper portion 92 allows spacing between the bracket 66 and the bracket 70 without requiring a separate grounding structure.

[0053] If the damping section 92 is not electrically conductive, a separate structure, such as a line 110 (in Fig. 3) can be used to electrically ground the traction battery 14 to the frame 78. The wire 110 can be, for example, a braided wire. If the damping section 92 is electrically conductive, the wire 110 can be omitted.

[0054] Features of some of the disclosed examples include mounting a traction battery to a vehicle frame using a mounting assembly that isolates the traction battery from at least some vehicle loads. In some embodiments, a damper that isolates the traction battery provides a portion of a ground for electrically grounding the traction battery to the vehicle frame. When the damper is used for grounding, a separate ground wire may not be necessary.

Claims

[1] A traction battery mounting assembly (62) comprising: a traction battery (14); and a damper (74) that secures the drive battery (14) to a vehicle frame (58) such that the drive battery (14) can move together relative to the vehicle frame (58) when it is secured to the vehicle frame (58), the damper (74) being electrically conductive such that the drive battery (14) is electrically grounded to the vehicle frame (58) via the damper (74). [2] The drive battery mounting assembly (62) of claim 1, wherein a damping portion (92) of the damper (74) is electrically conductive and compressible relative to a portion of the drive battery (14) attached to the damper (74). [3] The traction battery mounting assembly (62) of claim 2, wherein the damping portion (92) includes an electrically conductive material (104) distributed within an elastomeric material (100). [4] The drive battery mounting assembly (62) of claim 1, further comprising an outer bushing (84), an inner bushing (88), and a damping portion (92) of the damper (74), the damping portion (92) securing the outer bushing (84) to the inner bushing (88). [5] The traction battery mounting assembly (62) of claim 4, wherein one of the outer (84) or inner bushing (88) is attached directly to the traction battery (14) and the other of the outer bushing (84) or inner bushing (88) is attached directly to the vehicle frame (58). [6] The traction battery mounting assembly (62) of claim 1, further comprising a lead (110) electrically grounding the traction battery (14) to the vehicle (60). [7] The traction battery mounting assembly (62) of claim 1, further comprising a first mount (66) of the traction battery (14) directly attached to the damper (74) and a second mount (70) of the vehicle (60) directly attached to the damper (74), and wherein the first mount (66) is completely spaced from the second mount (70) such that no portion of the first mount (66) contacts a portion of the second mount (70) when the damper (74) secures the traction battery (14) to the vehicle frame (58). [8] The traction battery mounting assembly (62) of claim 1, wherein the damper (74) secures the traction battery (14) to an underbody of the vehicle (60). [9] A traction battery mounting method comprising: Securing a traction battery (14) in an installed position, wherein the traction battery (14) is attached to a vehicle frame (58), the traction battery (14) being movable relative to the vehicle frame (58) when in the installed position, the traction battery (14) being secured to the vehicle frame (58) via a damper (74), and further comprising electrically grounding the traction battery (14) to the vehicle frame (58) via the damper (74). [10] The drive battery mounting method of claim 9, further comprising damping movement of the drive battery (14) relative to the vehicle frame (58) when the drive battery (14) is in the installed position. [11] The traction battery mounting method of claim 9, wherein a path for grounding the traction battery (14) extends through a metallic material distributed within an elastomeric material (100) of the damper (74). [12] The traction battery mounting method of claim 9, wherein said mounting comprises mounting a first bracket (66) of said traction battery (14) directly to said damper (74) and mounting a second bracket (70) of said vehicle frame (58) directly to said damper (74), and wherein said damper (74) includes a first bushing (84) mounted to said first bracket (66), a second bushing (88) mounted to said second bracket (70), and a damping portion (92) connecting said first bushing (84) to said second bushing (88). [13] The traction battery mounting method of claim 9, further comprising electrically grounding the traction battery (14) to the vehicle frame (58) via a metallic lead extending from the traction battery (14) to the vehicle frame (58).

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