ARRAY FRAME DESIGN FOR ELECTRIFIED VEHICLE BATTERY ARRAYS
A battery array includes a frame body extending along a longitudinal axis and including a top surface, a bottom surface, and frame arms that connect between the top surface and the bottom surface. In some embodiments, the array frame includes at least one lifting arm that extends from the top surface and establishes an engagement area for engaging and lifting the frame body. In other embodiments, the array frame includes a recessed groove for accommodating a tension strap.
This is a divisional of U.S. patent application Ser. No. 14/446,444, which was filed on Jul. 30, 2014.
TECHNICAL FIELDThis disclosure relates to a battery array for an electrified vehicle. The battery array includes unique array frame designs for housing battery cells of the battery array.
BACKGROUNDElectrified vehicles, such as hybrid electric vehicles (HEV's), plug-in hybrid electric vehicles (PHEV's), battery electric vehicles (BEV's), or fuel cell vehicles differ from conventional motor vehicles because they are powered by electric machines (i.e., electric motors and/or generators) instead of or in addition to an internal combustion engine. High voltage current for powering these types of electric machines is typically supplied by a high voltage battery assembly.
Electrified vehicle battery assemblies typically include multiple battery arrays. Each battery array includes a plurality of battery cells. The battery cells must be secured relative to one another. The battery array must also be secured to arrest movement once mounted within the battery assembly.
SUMMARYA battery array frame according to an exemplary aspect of the present disclosure includes, among other things, a frame body extending along a longitudinal axis and including a top surface, a bottom surface and frame arms that connect between the top surface and the bottom surface. At least one of the top surface and the bottom surface is rotationally symmetric about an axis that is transverse to the longitudinal axis.
In a further non-limiting embodiment of the foregoing battery array frame, the top surface includes a first side and a second side that each include an alternating pattern of rigid snap arms and flexible snaps arms.
In a further non-limiting embodiment of either of the foregoing battery array frames, the top surface includes opposing ends that each include a lifting arm.
In a further non-limiting embodiment of any of the foregoing battery array frames, the lifting arm includes a lip and a recess inboard of the lip.
In a further non-limiting embodiment of any of the foregoing battery array frames, the recess is disposed between the lip and one of the frame arms.
In a further non-limiting embodiment of any of the foregoing battery array frames, at least one of the top surface and the bottom surface includes a recessed groove that accommodates a tension strap.
In a further non-limiting embodiment of any of the foregoing battery array frames, the bottom surface includes at least one recessed groove disposed outboard of a thermal fin embedded within the frame body.
In a further non-limiting embodiment of any of the foregoing battery array frames, a thermal fin is embedded in the frame body. The thermal fin includes a body and a leg that extends from the body to a position outside of the frame body.
In a further non-limiting embodiment of any of the foregoing battery array frames, the bottom surface includes feet, and a center of the bottom surface is elevated above the feet.
A battery array frame according to another exemplary aspect of the present disclosure includes, among other things, a frame body extending along a longitudinal axis and including a top surface, a bottom surface and frame arms that connect between the top surface and the bottom surface. At least one lifting arm extends from the top surface and establishes an engagement area for engaging and lifting the frame body.
In a further non-limiting embodiment of the forgoing battery array frame, the top surface extends between opposing ends, and each of the opposing ends includes a lifting arm that extends along the longitudinal axis.
In a further non-limiting embodiment of either of the foregoing battery array frames, the at least one lifting arm extends upwardly from the top surface of the array frame.
In a further non-limiting embodiment of any of the foregoing battery array frames, the at least one lifting arm protrudes outboard of the frame arms.
In a further non-limiting embodiment of any of the foregoing battery array frames, at least one of the top surface and the bottom surface is rotationally symmetric about an axis that is transverse to the longitudinal axis.
In a further non-limiting embodiment of any of the foregoing battery array frames, at least one of the top surface and the bottom surface includes a recessed groove that accommodates a tension strap.
A battery array frame according to another exemplary aspect of the present discourse includes, among other things, a frame body extending along a longitudinal axis and including a top surface, a bottom surface and frame arms that connect between the top surface and the bottom surface. At least one of the top surface and the bottom surface includes a recessed groove and a tension strap received within the recessed groove such that the tension strap is seated flush with the top surface or the bottom surface.
In a further non-limiting embodiment of the foregoing battery array frame, at least one lifting arm extends from the top surface and establishes an engagement area for engaging and lifting the frame body.
In a further non-limiting embodiment of either of the foregoing battery array frames, at least one of the top surface and the bottom surface is rotationally symmetric about an axis that is transverse to the longitudinal axis.
In a further non-limiting embodiment of any of the foregoing battery array frames, the tension strap includes detents that extend toward the top surface or the bottom surface.
In a further non-limiting embodiment of any of the foregoing battery array frames, the recessed groove extends between a first side and a second side of the top surface or the bottom surface and is disposed between a rigid snap arm and a flexible snap arm that extend from the first side or the second side.
The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.
The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
This disclosure describes a battery array of an electrified vehicle. A plurality of array frames may be stacked and connected to one another to build the battery array. The array frames may include multiple design features for connecting adjacent array frames together. For example, the array frames may include retention features such as rigid and flexible snap arms that engage snap arms of adjacent array frames to build the battery array. The array frames may additionally include recessed grooves that accommodate tension straps, and lifting arms that establish tool engagement areas for lifting and handling the battery arrays. These and other features are discussed in greater detail in the paragraphs that follow.
In one embodiment, the powertrain 10 is a power-split powertrain system that employs a first drive system and a second drive system. The first drive system includes a combination of an engine 14 and a generator 18 (i.e., a first electric machine). The second drive system includes at least a motor 22 (i.e., a second electric machine), the generator 18, and a battery assembly 24. In this example, the second drive system is considered an electric drive system of the powertrain 10. The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels 28 of the electrified vehicle 12.
The engine 14, such as an internal combustion engine, and the generator 18 may be connected through 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 14 to the generator 18. 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.
The generator 18 can be driven by the engine 14 through the power transfer unit 30 to convert kinetic energy to electrical energy. The generator 18 can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft 38 connected to the power transfer unit 30. Because the generator 18 is operatively connected to the engine 14, the speed of the engine 14 can be controlled by the generator 18.
The ring gear 32 of the power transfer unit 30 may be connected to a shaft 40, which is connected to vehicle drive wheels 28 through 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 also be suitable. The gears 46 transfer torque from the engine 14 to a differential 48 to ultimately provide traction to the vehicle drive wheels 28. The differential 48 may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels 28. In one embodiment, 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.
The motor 22 can also be employed to drive the vehicle drive wheels 28 by outputting torque to a shaft 52 that is also connected to the second power transfer unit 44. In one embodiment, the motor 22 and the generator 18 cooperate as part of a regenerative braking system in which both the motor 22 and the generator 18 can be employed as motors to output torque. For example, the motor 22 and the generator 18 can each output electrical power to the battery assembly 24.
The battery assembly 24 is an example type of electrified vehicle battery assembly. The battery assembly 24 may include a high voltage battery pack that includes a plurality of battery arrays capable of outputting electrical power to operate the motor 22 and the generator 18. Other types of energy storage devices and/or output devices can also be used to electrically power the electrified vehicle 12.
In one non-limiting embodiment, the electrified vehicle 12 has two basic operating modes. The electrified vehicle 12 may operate in an Electric Vehicle (EV) mode where the motor 22 is used (generally without assistance from the engine 14) for vehicle propulsion, thereby depleting the battery assembly 24 state of charge up to its maximum allowable discharging rate under certain driving patterns/cycles. The EV mode is an example of a charge depleting mode of operation for the electrified vehicle 12. During EV mode, the state of charge of the battery assembly 24 may increase in some circumstances, for example due to a period of regenerative braking. The engine 14 is generally OFF under a default EV mode but could be operated as necessary based on a vehicle system state or as permitted by the operator.
The electrified vehicle 12 may additionally be operated in a Hybrid (HEV) mode in which the engine 14 and the motor 22 are both used for vehicle propulsion. The HEV mode is an example of a charge sustaining mode of operation for the electrified vehicle 12. During the HEV mode, the electrified vehicle 12 may reduce the motor 22 propulsion usage in order to maintain the state of charge of the battery assembly 24 at a constant or approximately constant level by increasing the engine 14 propulsion usage. The electrified vehicle 12 may be operated in other operating modes in addition to the EV and HEV modes within the scope of this disclosure.
In one embodiment, the battery cells 56 are pouch cells for a high voltage battery assembly. One non-limiting example of a suitable pouch battery cell is a lithium-ion polymer battery. However, other types of battery cells are also contemplated.
The array frame 54 includes a frame body 58 that extends along a longitudinal axis A (see
A thermal fin 66 may be partially embedded within the frame body 58 and extend between the top surface 60 and the bottom surface 62. In one embodiment, the thermal fin 66 is an aluminum thermal fin. However, other materials are additionally contemplated. The thermal fin 66 separates the battery cells 56 and may be in contact with side faces 55 of the battery cells 56. During certain conditions, the thermal fin 66 removes heat from the battery cells 56. In other conditions, the thermal fin 66 adds heat to the battery cells 56. The frame body 58 establishes pockets 76 on both sides of the thermal fin 66. The battery cells 56 may be received within the pockets 76 to house the battery cells 56 within the array frame 54.
In one embodiment, the thermal fin 66 includes a body 74 and a leg 72 that extends from the body 74. The body 74 may be embedded or molded into the frame body 58, while the leg 72 extends outside of the frame body 58. In another embodiment, the thermal fin 66 may be inserted into the frame body 58 such that one end of the body 74 is located within a groove 68 formed in the top surface 60 of the frame body 58, and an opposite end of the body 74 may extend through a passage 70 formed through the bottom surface 62 of the frame body 58. The leg 72 of the thermal fin 66 may be oriented transversely to the body 74 so it extends underneath the bottom surface 62 to the position outside of the frame body 58. The leg 72 may contact a cooling plate or a thermal interface material (not shown in
The frame body 58 may include a plurality of retention features 80 that are integrated into the top surface 60. The bottom surface 62 may similarly include a plurality of integrated retention features 88. The retention features 80, 88 may engage corresponding retention features of adjacent array frames to build a battery array, as discussed in greater detail below. In yet another embodiment, the frame arms 64 may include retention features similar to the retention features 80, 88.
Referring to
In one embodiment, the top surface 60 of the frame body 58 of the array frame 54 is rotationally symmetric about a vertical axis V that is transverse to the longitudinal axis A. In another embodiment, the bottom surface 62 is rotationally symmetric about the vertical axis V. In yet another embodiment, both the top surface 60 and the bottom surface 62 are rotationally symmetric about the vertical axis V. In this way, the array frames 54 can be provided in a repeating fashion to construct the battery array 78. The symmetry of the top surface 60 and/or the bottom surface 62 permits the use of common array end plates, thereby reducing cost and complexity of the battery array 78. In other words, unique left hand and right hand array end plates are not required to construct the battery array 78. In another embodiment, the battery array 78 may include an end plate 79 that is connectable to the array frame 54 (see
The top surface 60 of the frame body 58 includes a first side 84 and a second side 86 that both extend between opposing ends 96, 98 (see
In another non-limiting embodiment, the retention features 80 of the top surface 60 include a plurality of rigid snap arms 82A and a plurality of flexible snap arms 82B oriented in an alternating pattern along each of the first side 84 and the second side 86 of the top surface 60. Because the top surface 60 is rotationally symmetric about the vertical axis V, each flexible snap arm 82B of the first and second sides 84, 86 are aligned directly across the top surface 60 from a rigid snap arm 82A on the opposite side 84, 86. Thus, the array frames 54 provide a repeating design that simplifies assembly and reduces complexity of the battery array 78.
The rigid snap arms 82A and the flexible snap arms 82B of both the first side 84 and the second side 86 are oriented to engage corresponding features of an adjacent array frame 54 to connect the array frames 54 together. For example, as best illustrated in
In another embodiment, the flexible snap arms 82B extend in a plane P1 and the rigid snap arms 82A extend in a different plane P2. The plane P1 is offset from the plane P2, and in some embodiments is located vertically above the plane P2 to provide an engagement area for these features to snap together. In addition, because the flexible snap arms 82B are exposed at a location that is external to the rigid snap arms 82A, the array frames 54 can be accessed and disassembled if necessary.
The top surface 60 of each array frame 54 may additionally include one or more recessed grooves 92 (see
In one non-limiting embodiment, the tension straps 94 include detents 57 (see
In another embodiment, the bottom surfaces 62 of the array frames 54 include a plurality of retention features 88. Similar to the retention features 80 of the top surface 60, the retention features 88 may include both rigid snap arms 89A and flexible snap arms 89B. The flexible snap arms 89B are located outside of, which in this embodiment is beneath, the rigid snap arms 89A so they are accessible to disassemble the array frames 54. In one non-limiting embodiment, the rigid snaps arms 89A are disposed directly across the bottom surface 62 from a flexible snap arm 89B. In another embodiment, the retention features 88 are provided only at the outside edges, such as within the outer quarters of the bottom surface 62 (see
In another embodiment, as shown in
In this embodiment, each of the opposing ends 96, 98 includes a lifting arm 91. The lifting arms 91 are disposed along the longitudinal axis A. In one embodiment, the lifting arms 91 extend outboard of, or laterally beyond, the frame arms 64 of the frame body 58. In other words, the lifting arms 91 jut outwardly from the array frame 54 beyond a periphery established by the frame arms 64. In another embodiment, the lifting arms 91 extend upwardly from the top surface 60 of the array frame 58 (see
Each lifting arm 91 may include a lip 93 and a recess 95. In one embodiment, the recess 95 is directly inboard of the lip 93. The recess 95 of each lifting arm 91 establishes an engagement area 97 for lifting and handling a battery array 78 that is constructed of a plurality of the array frames 54. Alternatively, the lifting arm 91 may eliminate the recess 95 and provide a substantially flat engagement area 97 (see
A lifting tool 99 may engage the engagement area 97 on each of the opposing ends 96, 98 of the array frame 54. For example, in one non-limiting embodiment, the recesses 95 of the lifting arms 91 of adjacent array frames 54 align to establish a uniform engagement area 97 for lifting and handling a battery array 78 (see, e.g.,
The battery array 178 of this embodiment is constructed of multiple array frames 154 that house battery cells 156. The array frames 154 are positioned side-by-side and can be connected to one another to build the battery array 178. Each array frame 154 includes a thermal fin 166 that is molded into or otherwise embedded within the array frame 154. The thermal fins 166 separate the battery cells 156 housed by each array frame 154.
In one embodiment, each thermal fin 166 includes a body 174 and a leg 172 that extends from the body 174. The leg 172 may be transverse to the body 174 so that it extends along an underside of the array frame 154 to a position outside of the array frame 154. In other words, unlike the body 174, the leg 172 is not encased or embedded within the array frame 154.
In one embodiment, the leg 172 of each thermal fin 166 is flexible between a first position P (see
In the first position P, the leg 172 of each thermal fin 166 may extend at an obtuse angle a relative to the body 174. Therefore, the leg 172 can flex to the second position P′ as the battery array 178 is moved into position atop the cooling plate 165. In the second position P′, the leg 172 of each thermal fin 166 may be substantially perpendicular to the body 174.
In another embodiment, the leg 172 of each thermal fin 166 additionally includes a bent end portion 167. Each bent end portion 167 may be tucked into a relief notch 169 formed in a surface 101 of an adjacent array frame 154 when the leg 172 is moved to the second position P′. This helps avoid damaging a thermal interface material that may be located on the cooling plate 165. In this embodiment, the surface 101 is a bottom surface of the adjacent array frame 154. Therefore, the battery array 178 may be stacked on the cooling plate 165 without the thermal fins 166 interfering with the stacking. In yet another embodiment, the leg 172 of each thermal fin 166 is spaced from the surface 101 in the first position P and abuts the surface 101 in the second position P′.
In another embodiment, shown in the top view of
In the additional embodiment of
The battery array 278 is positioned on a tray 201 of the battery pack 200. A cooling plate 265 may be positioned between the tray 201 and the bottom surface 262 of each array frame 254, in one embodiment. In another non-limiting embodiment, an extension 225 of the cooling plate 265 extends between a foot 219 of the bottom surface 262 of each array frame 254 and the tray 201. One or more walls 203 of the battery pack 200 may surround the battery array 278.
The battery array 278 may be retained to the tray 201 of the battery pack 200 using one or more retention clips 205. In one embodiment, multiple individual retention clips 205 may be periodically spaced along a length of the battery array 278 to retain the battery array 278 to the tray 201. The retention clips 205 are mounted to the tray 201, and in one embodiment are welded to the tray 201 as indicated by weld bead 207. Other mounting methodologies are also contemplated.
Each retention clip 205 may include a base 209 and a clip arm 211 that extends from an end 213 of the base 209 opposite from an end 215 that is received against the tray 201. The clip arm 211 may include an undulated shaped body. In one embodiment, the clip arms 211 include an extension 217 that engages the foot 219 of the bottom surface 262 of each array frame 254 to retain the battery array 278 to the tray 201. When received against the feet 219, the retention clips 205 arrest movement of the battery array 278 in the Z direction and at least partially in the X and Y directions. Therefore, the battery array 278 can be retained to the tray 201 without using threaded fasteners or the like.
Referring to
The retention clip 205 may be flexed in a first direction D1 to position it in the installation position IP′, and may be flexed in a second direction D2 to return the retention clip 205 back to the installed position IP. In one embodiment, the retention clip 205 is biased in the direction D2, or toward the installed position IP. Therefore, during installation of the battery array 278, the retention clip 205 is first moved to the installation position IP′ by applying a force in the first direction D1. Once the battery array 278 is in a desired position on the tray 201, the retention clip 205 may be returned to the installed position IP to retain the battery array 278 in place.
One non-limiting installation method is schematically illustrated in
In the embodiment illustrated in
For example, as shown in the additional embodiment of
During a non-limiting mounting procedure, the feet 219A may flex in a first direction D1 in response to contacting the clip arm 211A of the rigid retention clip 205A. Once the feet 219A have flexed far enough in the direction D1 that the ledges 227A are able to avoid interference with the clip arm 211A, the feet 219A may flex in a second direction D2 that is opposite of the first direction D1 to position the ledges 227A into the openings 223A and retain the array frame 254A, and thus the battery array 278A, to the tray 201A.
In yet another embodiment, rather than using multiple individual retention clips, a single retention clip assembly may be used to retain multiple battery arrays 278 to the tray 201. One such retention clip assembly 205A is illustrated in
In another embodiment, a stop block 235 may be received into a recess 299 of the retention clip assembly 205A. The stop block 235 may be received against the base 209A between the clip arms 211A of the retention clip assembly 205A. Alternatively, the stop block 235 elevation may be controlled by engaging the tops of the retention clips 205, or the tops of the feet 219. The stop block 235 can be positioned to arrest loads applied in the X direction. In one embodiment, the stop block 235 is made of either plastic or rubber materials. However, other materials are also contemplated within the scope of this disclosure.
The various battery array design features described above and illustrated with respect to
Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments.
It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure.
The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.
Claims
1. A battery array, comprising:
- an array frame including a frame body extending along a longitudinal axis and including a top surface, a bottom surface, and frame arms that connect between said top surface and said bottom surface; and
- at least one lifting arm that extends from said top surface and establishes an engagement area for engaging and lifting said frame body.
2. The battery array as recited in claim 1, wherein said top surface extends between opposing ends, and each of said opposing ends includes a lifting arm that extends along said longitudinal axis.
3. The battery array as recited in claim 1, wherein said at least one lifting arm extends upwardly from said top surface of said array frame.
4. The battery array as recited in claim 1, wherein said at least one lifting arm protrudes outboard of said frame arms.
5. The battery array as recited in claim 1, wherein at least one of said top surface and said bottom surface is rotationally symmetric about an axis that is transverse to said longitudinal axis.
6. The battery array as recited in claim 1, wherein at least one of said top surface and said bottom surface includes a recessed groove.
7. The battery array as recited in claim 6, comprising a tension strap received within said recessed groove.
8. The battery array as recited in claim 1, comprising a thermal fin embedded in said frame body.
9. The battery array as recited in claim 8, comprising a first battery cell positioned in a first pocket of said frame body and a second battery cell positioned in a second pocket of said frame body.
10. The battery array as recited in claim 9, wherein said second pocket is separated from said first pocket by said thermal fin.
11. The battery array as recited in claim 1, wherein said at least one lifting arm includes a lip and a recess inboard of said lip.
12. The battery array as recited in claim 1, comprising a lifting tool for engaging said engagement area.
13. A battery array, comprising:
- an array frame including a frame body;
- a lifting arm extending from a top surface of said frame body;
- a recessed groove formed in said top surface or a bottom surface of said frame body; and
- a tension strap received within said recessed groove.
14. The battery array as recited in claim 13, wherein said lifting arm establishes an engagement area for engaging and lifting said frame body.
15. The battery array as recited in claim 13, wherein at least one of said top surface and said bottom surface is rotationally symmetric about an axis that is transverse to a longitudinal axis of said frame body.
16. The battery array as recited in claim 13, wherein said tension strap includes detents that extend toward said top surface or said bottom surface of said frame body.
17. The battery array as recited in claim 13, wherein said recessed groove extends between a first side and a second side of said top surface or said bottom surface and is disposed between a rigid snap arm and a flexible snap arm that extend from said first side or said second side.
18. The battery array as recited in claim 13, wherein said tension strap is seated flush with said top surface or said bottom surface.
19. The battery array as recited in claim 13, wherein said recessed groove is positioned between opposing feet of said bottom surface of said frame body.
20. The battery array as recited in claim 19, wherein a center of said bottom surface is elevated relative to said opposing feet.
Type: Application
Filed: Jul 7, 2017
Publication Date: Oct 26, 2017
Inventors: Rohit Gunna (Novi, MI), Patrick Daniel Maguire (Ann Arbor, MI), Steve Droste (Ypsilanti, MI)
Application Number: 15/643,518