Double-sealed battery pack

Abstract

Present invention relates to a battery pack that includes a first and second sub-housings (502, 504), each with a mating surface (502a, 504a) featuring a groove and tongue, respectively. A first O-ring (506) is positioned within the groove. Two-stepped bosses (512) with second O-rings (508) are formed in the first sub-housing, with corresponding orifices and flanged bosses in the second sub-housing. Brass inserts are over-moulded in the second sub-housing. Fasteners traverse the orifices, bosses, and are secured in the inserts, compressing the O-rings and coupling the sub-housings to form a sealed internal cavity for housing battery cells and related components.

Description

DOUBLE-SEALED BATTERY PACKTECHNICAL FIELD

[0001] The present subject matter pertains, in general, to a battery pack, and more specifically, to a battery pack housing featuring coupling means designed to unify or establish a watertight seal between the sub-housings of the battery pack.BACKGROUND

[0002] The dynamic realm of electric vehicles (EVs) is characterized by the widespread integration of advanced battery packs as fundamental energy storage units. Generally, a battery pack includes dedicated space to securely hold various components, namely, battery cells, battery management systems, thermal management systems, voltage regulators. The battery pack further includes a housing which may be understood as a structural enclosure designed to act as a protective shield for the components accommodated therein from external elements like dust and water. The housing may be made up of a resin or reinforced plastic composites. The inherent design of the housing is such that it is formed by coupling complementary sub-housings, creating an internal cavity for accommodating the battery cells, electrical and electronic components like battery management systems, thermal management systems, voltage regulators. During the coupling, a portion where the complementary sub-housings contact each other is generally referred to as a coupling portion. To enhance protection for the internal components against the ingression of dust and water through the coupling portion, sealing materials, such as silicon gel are often applied around the coupling portion.BRIEF DESCRIPTION OF DRAWINGS

[0003] The detailed description is described with reference to the accompanying figures. In the figures, the left- most digit(s) of a reference number identifies the figure in which the reference number first appears.

[0004] Figure 1 illustrates a top view of interior region of a first sub-housing of a battery pack, in accordance with an example of the present subject matter;

[0005] Figure 2 illustrates perspective view of a two-stepped boss provided in the interior region of the first sub-housing, in accordance with an example of the present subject matter;

[0006] Figure 3 illustrates a perspective view of an interior region of a second sub-housing of a battery pack, in accordance with an example of the present subject matter;

[0007] Figure 4 illustrates a perspective view of a flanged boss provided in the interior region of the second sub -housing, in accordance with an example of the present subject matter;

[0008] Figure 5 illustrates an exploded view of a battery pack, in accordance with an example of the present subject matter;

[0009] Figure 6 illustrates both concealed and exposed views of a path traversed by a fastener, in accordance with an example of the present subject matter; and

[0010] Figure 7 illustrates compression of a first O-ring when the sub-housings are fastened, in accordance with an example of the present subject matter.

[0011] The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and / or implementations consistent with the description; however, the description is not limited to the examples and / or implementations provided in the drawings.DETAILED DESCRIPTION

[0012] Despite the technological strides in battery pack designs, the ingress of external elements, notably dust and water, remains a significant challenge, posing threats to the integrity and longevity of various internal components of the battery pack. Particularly, dust, composed of tiny particles, has the potential to settle on electronic components, introducing issues, such as overheating, reduced conductivity or interference with electrical pathways. Water ingress, on the other hand, poses additional hazards, including corrosion of metal components and short circuits, ultimately impacting the overall performance and safety of the battery pack.

[0013] In the conventional technologies, when the complementary subhousings contact each other, to prevent ingress of dust and water into the battery pack through the coupling portion, the coupling portion is sealed by applying a sealant such as the silicon gel. This is followed by fastening the sub-housings using mechanical fasteners, such as screws. However, this approach has inherent disadvantages. Firstly, manual application of the sealant is not feasible due to several reasons. For example, manual application of the sealant can lead to inconsistencies in application, resulting in uneven attachment of the coupling portion. As a result, the effectiveness of the sealing may be compromised, leaving vulnerable spots allowing ingress of dust and water. Moreover, the manual application of the sealant is time-consuming and labor-intensive, requiring skilled workers to apply the sealant accurately. Additionally, the manual application of the sealant poses health risks to workers, such as skin irritation from prolonged exposure to chemicals present in the sealant.

[0014] To address the foregoing limitations associated with the manual application of the sealant, robots are often programmed to apply the sealant across the coupling portion. However, programming robots come with their own sets of challenges. One such challenge is the learning curve associated with robot programming. Learning curve refers to the time and effort involved in training and calibration of the robots to apply the sealant accurately and effectively. An incorrect parameter setting and / or programming logic of the robots can impact the effectiveness of the sealing.

[0015] In addition to the limitations with the application of the sealant, removal of cured sealant has further challenges. For example, the sealant once applied and cured forms a permanent bond between the sub-housings of the battery pack. In such cases, replacement of malfunctioning internal electrical components, such as battery cells, may require dismantling and removing the sub-housings of the battery pack. This entails a labor-intensive process, often requiring chiseling or scrapping of the sub-housings, leading to increased time and effort for maintenance or component replacement.

[0016] Hence, to avert such complications, it becomes imperative to provide an alternative mechanism for sealing the coupling portion for protecting the internal components accommodated in the battery pack, against the external factors, such as dust and water.

[0017] To this end, the present subject matter discloses a battery pack formed by connecting complementary sub-housings, each featuring coupling means designed to unify or establish a watertight seal between the sub-housings.

[0018] In an example, the present subject matter discloses a battery pack. The battery pack comprises a first sub-housing and a second sub-housing. Each subhousing includes raised side walls and a base. The side walls and the base of a subhousing together form a dedicated space or interior cavity to accommodate components, such as battery cells and other electrical and electronic components. During the coupling process of the sub-housings, a first sub-housing is connected to a second sub-housing. The portion where the first sub-housing comes into contact with the second sub-housing, during the coupling, forms a coupling portion. Particularly, the coupling portion is formed by connecting a mating surface provided on the first sub-housing to a complementary mating surface provided on the second sub-housing. Further, the mating surface of the first sub-housing is provided with a groove, while a corresponding tongue or tab is provided in the mating surface of the second sub-housing. The groove provided on the mating surface of the first sub-housing is used to accommodate a first O-ring. This groove- and-tongue configuration aids in aligning the sub-housings during assembly and the O-ring provided therein contributes towards providing an initial seal when the sub-housings of the battery pack are connected at the coupling portion.

[0019] In an implementation, an interior of the side walls of the first subhousing is provided with a plurality of two-stepped bosses raised from the base contiguous to the mating surface. Each of the plurality of two-stepped bosses is designed with a transition region where a first step transitions to a second step. The first sub-housing further includes a second O-ring placed at the transition region such that the transition region is enveloped by the second O-ring. A plurality oforifices, each aligned coaxially with a corresponding two-stepped boss are formed on exterior of the base.

[0020] The second sub-housing includes a plurality of flanged bosses raised from the base and formed interior of the side walls of the second sub-housing contiguous to the mating surface of the second sub-housing, corresponding to the two-stepped bosses formed in the first sub-housing. Each flanged boss has a flanged portion and a terminal portion. The flanged portion may be understood as an end portion of the flanged boss contiguous to the mating surface. Further, the termina portion may be understood as an end portion of the flanged boss proximate to the base of the second sub-housing and opposite to the flanged portion. Additionally, a plurality of inserts, each made from brass for durability and electrical conductivity, are over-moulded in the second sub-housing proximate and aligned with the terminal portion of the flanged bosses. Although brass inserts are disclosed herein, inserts made from any other metal exhibiting similar properties or comparatively higher effect like brass may also be used.

[0021] To secure the first and the second sub-housings together, a plurality of fasteners are employed. Each fastener traverses through an orifice, a two-stepped boss, a flanged boss, and is finally seized or anchored in a corresponding brass insert. In this fastening mechanism, the torque applied to the fasteners is converted into a compression force. This force results in the simultaneous compression of the first O-ring positioned in the groove provided on the first sub-housing by the tongue or tab provided in the second sub-housing and the second O-ring positioned at the transition region of the each of the two stepped boss of the first sub-housing by the flanged portion of the corresponding flanged boss on the second subhousing. As a result, the fasteners enhance the seal and coupling of the first and second sub-housings together to define the internal cavity.

[0022] The internal cavity formed by the coupled sub-housings serves as a receptacle for the battery cells, as well as electrical and electronic components.

[0023] The above and other features, aspects, and advantages of the subject matter will be better explained with regard to the following description and accompanying figures. It should be noted that the description and figures merelyillustrate the principles of the present subject matter along with examples described herein and should not be construed as a limitation to the present subject matter. It is thus understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and examples thereof, are intended to encompass equivalents thereof. Further, for the sake of simplicity, and without limitation, the same numbers are used throughout the drawings to reference like features and components.

[0024] Figure 1 illustrates a top view of an interior region of a first sub-housing 100 of a battery pack, in accordance with an example of the present subject matter.

[0025] As illustrated therein, the first sub-housing 100 is provided with a mating surface 102 on one side of the first sub-housing 100. In an example, the first subhousing 100 may be made from resin or reinforced plastic composites. The mating surface 102 in an example is formed by spanning the entire perimeter of the first sub-housing 100 taking the shape of the first sub-housing 100. The mating surface 102 is provided with a groove 104. The groove 104 is a running channel spanning the mating surface 102 for positioning a first O-ring (not shown in the figure). In an example, the dimensions of the groove 104 is comparable to the dimensions of the first O-ring to be positioned in the groove 104 or vice versa. As further illustrated therein, contiguous to the mating surface 102, the first sub-housing 100 is provided with a plurality of two-stepped bosses 106 at different places strategically selected in the interior side walls of the first sub-housing 100. The first sub-housing 100 is provided with plurality of orifices (not shown in figure) at the side opposite to the mating surface such that the orifices or openings correspond to the two-stepped bosses.

[0026] It may be noted that the sub-housings forming the battery pack illustrated herein is curve shaped. However, to optimize space utilization, thermal cooling and weight distribution, the shape of the sub-housings, thereby the shape of the battery pack may vary. A few of the possible shapes may include, but may not be limited to rectangular, T-shaped, L-shaped, curved, and trapezoidal.

[0027] Figure 2 illustrates a perspective view of two-stepped boss provided in the interior region of the first sub-housing in accordance with an example of the present subject matter.

[0028] As illustrated therein, the two-stepped boss 200 is contiguous to the mating surface 208. The stepped boss as known in the art is a protruding feature having a through hole with certain transitions such that a fastener, such as screws, can pass or slide through it. As depicted in FIG. 2, the two-stepped boss 200 includes a first step 202 and a second step 204. A region on the two-stepped boss 200 where the first step 202 transitions to the second step 204 is called as a transition region 206. A second O-ring (not shown in the figure) is placed on the transition region such that it spans a certain area of transition region 206 and the first step 202. In other words, the second O-ring is positioned such that the transition region 206 is enveloped by the second O-ring. In an example, the transition region 206 is meticulously designed to match the dimensions of the second O-ring 206 to be positioned therein to render effective sealing on coupling the sub-housings.

[0029] Figure 3 illustrates a perspective view of an interior region of a second sub-housing 300 of a battery pack, in accordance with an example of the present subject matter.

[0030] As illustrated therein, the shape of the second sub-housing 300 is complimentary to the shape of the first sub-housing 100 (illustrated in Figure 1) such that the first and the second sub-housings 100 and 200 are coupled together to form a unified battery pack defining an internal cavity. In an example, the second sub-housing 300 may be made from resin or reinforced plastic composites. The internal cavity may define a space for accommodating battery cells, electrical and electronic components like battery management systems, thermal management systems, voltage regulators. The second sub-housing 300 also includes a mating surface 302 on one side of the second sub-housing 300. The mating surface 302, in an example, is formed by spanning the entire perimeter of the second sub-housing 300 taking the shape of the second sub-housing 300. In an example, the mating surface 302 is complimentary to the mating surface 102 (shown in Figure 1)provided on the first sub-housing 100. The mating surface 302 is provided with a tongue or tab 304 spanning the mating surface 302. When the sub-housings are connected, the first O-ring positioned in the groove (shown in Figure 1) provided on the first sub-housing gets compressed by the tongue 304. As a result, the first O-ring is deformed to cover the region of the groove to render effective sealing between the first sub-housing and the second sub-housing. In an example, the dimensions of the tongue 304 is comparable to the dimensions of the groove and the first O-ring or vice versa considering the effective sealing.

[0031] As further illustrated therein, contiguous to the mating surface 302, the second sub-housing 300 is provided with a plurality of flanged bosses 306 at different places strategically selected in the interior side walls of the second subhousing 300. In an example, the places of flanged bosses 306 selected strategically correspond to the places of two stepped bosses provided on the first sub-housing 100 such that fasteners, such as screws, traversing orifices and two-stepped bosses provided on the first sub-housing 100 enter corresponding flanged bosses 306.

[0032] Figure 4 illustrates a perspective view of a flanged boss provided in an interior region of the second sub -housing, in accordance with an example of the present subject matter.

[0033] As illustrated therein, the flanged boss 400 is provided contiguous to the mating surface 402. As is known in the art, a flanged boss is a protruding feature having a through hole. Each flanged boss 400 has a flanged portion 404 and a terminal portion. The flanged portion may be understood as an end portion of the flanged boss contiguous to the mating surface. Further, the terminal portion may be understood as an end portion of the flanged boss proximate to the base of the second sub-housing and opposite to the flanged portion. The dimensions of the flanged portion 404 is comparable to the dimensions of the transition region of the two-stepped boss provided on the first sub-housing 100 and the second O-ring positioned on the transition region considering the effective sealing. Thus, in an example, when the sub-housings 100 and 200 are coupled together, the second O- ring on the transition region gets compressed by the flanged portion 404. As a result, the second O-ring is deformed to cover the transition region, renderingeffective sealing. Further, the brass insert 406 provided at the terminal portion of the flanged boss 400 is used for anchoring a fastener traversing orifice, two-stepped boss, flanged boss while coupling the sub-housings.

[0034] Figure 5 illustrates an exploded view of a battery pack, in accordance with an example of the present subject matter.

[0035] As illustrated therein, a battery pack 500 has a first sub-housing 502 and a second sub-housing 504. The first sub-housing 502 and the second sub-housing 504 may be similar to the first sub-housing 100 and the second sub-housing 200, respectively. Accordingly, the first sub-housing 500 is provided with a mating surface 502a complementary to a mating surface 504a formed on the second subhousing 504.

[0036] The battery pack 500 includes a first O-ring 506 positioned in the groove formed on the first mating surface 502a. An interior of the side walls of the first sub-housing 502 is provided with a plurality of two-stepped bosses 512 raised from the base, contiguous to the first mating surface. Each of the plurality of two-stepped bosses is designed with a transition region where a first step transitions to a second step. Further, second O-rings 508 are positioned on each of the plurality of two- stepped bosses 512 at the transition region. A plurality of fasteners 510 is used to couple the sub-housings 502 and 504. To effectuate coupling, each of the fasteners are slid through corresponding orifice, two-stepped boss on the first sub-housing 502 and the corresponding flanged boss in the second sub-housing 504 and is finally anchored in the brass insert provided in the corresponding flanged boss. The coupling so effectuated causes the torque applied to the fasteners result in the simultaneous compression of O-rings i.e., the first O-ring 506 positioned in the groove of the first sub-housing is compressed by the tongue formed on the second sub-housing and the second O-ring positioned at a transition region of the two- stepped boss on the first sub-housing is compressed by the flanged portion of the corresponding flanged boss on the second sub-housing. It may be noted that the orifices, two-stepped bosses, flanged bosses, brass inserts is aligned linearly or coaxial to facilitate sliding operation of the fastener.

[0037] Figure 6 illustrates a schematic view 600 illustrating a concealed view and an exposed view of a path traversed by a fastener, in accordance with an example of the present subject matter.

[0038] As illustrated therein, the schematic view 600 depicts an exposed view 602 and a concealed view 604 of a path traversed by a fastener in battery pack 600. The exposed view 602 depicts a fastener 602a traversing through an orifice (not shown in the figure), a two-stepped boss (not shown in the figure) on the first subhousing 600a which is anchored or seized in the brass insert 602d on the second sub-housing 600b. The exposed view 602 further depicts the compression of first O-ring 602b and the second O-ring 602c.

[0039] In this fastening mechanism, the torque applied to the fasteners is converted into a compression force. This force results in the simultaneous compression of the first O-ring 602b positioned in the groove provided on the first sub-housing by the tongue or tab provided in the second sub-housing and the second O-ring 602c positioned at the transition region of the each of the two stepped boss of the first sub-housing by the flanged portion of the corresponding flanged boss on the second sub-housing, thereby enhancing the sealing and coupling the first and second sub-housings together to define the internal cavity for accommodating internal components such as battery cells.

[0040] Figure 7 illustrates compression of first O-ring when the sub-housings are fastened in accordance with an example of the present subject matter.

[0041] As illustrated therein, the battery pack 700 comprises a first sub-housing 702a (or 702b) and a second sub-housing 704a (or 704b). Figure 7(a) depict the state of first O-ring before compression or before coupling of sub-housings and figure 7(b) depicts the compressed state of first O-ring as a result of coupling of sub-housings.

[0042] The first sub-housing 702a (or 702b) has a groove 706a (or 706b) and the first O-ring 710a (710b) is positioned in the groove 706a (or 706b). The second sub-housing 704a (704b) has a tongue or tab 708a (708b) formed therein. When the sub-housings are coupled the first O-ring 710a is compressed by the tongue 708a and the first O-ring reaches a deformed state 710b. It may be noted that thedeformed or compressed state of the first O-ring 710a (or 710b) covers the entire region of the groove with the reduce in cross sectional diameter of the first O-ring. In other words, the flattened shape of the O-ring enhances seal integrity reducing the likelihood of ingress of contaminants such as dust and water.

[0043] Thus, in the present subject matter the first O-ring on the mating surface of the first sub-housing forms a seal directly with the corresponding mating surface of the second sub-housing. The second O-rings, enveloping the bosses on the interior regions ensure additional sealing. As the fasteners slide through the bosses compressing both the O-rings simultaneously, they create a dual sealing mechanism, effectively preventing water and dust ingress into the internal cavity, thus ensuring the battery pack’s protection.

[0044] Further, by simply removing the fasteners coupling the first and second sub-housings, the battery pack can be easily disassembled, granting access to individual components for maintenance or replacement. This modular design allows for targeted repairs, minimizing downtime and cost by only replacing the affected part rather than the entire unit. Moreover, the robust sealing system preserves component integrity during both operation and maintenance, ensuring long-term reliability and performance.

[0045] The present subject matter has been disclosed in connection with certain examples but is not limited to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the present subject matter.

Claims

I / We Claim:

1. A battery pack, comprising: a first sub-housing (100) and a second sub-housing (300), wherein the first sub-housing and the second sub-housing each comprising a mating surface (102, 302); a groove (104) formed in the first sub-housing mating surface and a corresponding tab (304) formed in the second sub-housing mating surface; a first O-ring (506) positioned in the groove; a plurality of bosses (106) formed at multiple interior regions contiguous to the first sub-housing mating surface, each of the boss is enveloped by a second O-ring (508); a plurality of fasteners (510), wherein each of the fasteners, results in the simultaneous compression of the first O-ring and the corresponding second-ring when fastened to effect coupling of the first sub-housing and the second sub-housing, defining an internal cavity.

2. The battery pack as claimed in claim 1, wherein the boss is a two-stepped boss and the second O-ring envelops the two-stepped boss at a transition region (206), wherein the transition region is where first step (202) of the two-stepped boss transitions to second step (204).

3. The battery pack as claimed in claim 1, wherein the first sub-housing comprises a plurality of orifices formed in an exterior region.

4. The battery pack as claimed in claim 1, wherein the second sub-housing comprises a plurality of flanged bosses (306, 400) corresponding to the plurality of bosses, formed at multiple interior regions contiguous to the second sub-housing mating surface.

5. The battery pack as claimed in claim 1, wherein the second sub-housing comprises a plurality of inserts (602d), each over-moulded in the second sub-housing at a terminal portion, distinct from a flanged portion (404) of each of the flanged bosses.

6. The battery pack as claimed in claim 1, wherein the orifices, bosses, flanged bosses and inserts are coaxial, facilitating the traversal and seizing of the fastener in the corresponding insert.

7. The battery pack as claimed in claim 1, wherein the simultaneous compression of the first O-ring and the second O-ring comprises the first O-ring compressed by the tab and the second O-ring compressed by the flanged portion of the corresponding flanged boss.

8. The battery pack as claimed in claim 1, wherein the internal cavity is to serve as receptacle for battery cells, electrical and electronic components.

9. The battery pack as claimed in claim 5, wherein the inserts are made from brass.

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