Battery pack and electric drive system

Abstract

The present disclosure provides a battery pack and an electric drive system, the battery pack comprising a battery module, the battery module comprising a battery and a battery support, further comprising a battery outer box, the battery outer box being provided with an opening; a heat dissipation component, the heat dissipation component being provided with a heat dissipation part, the heat dissipation part comprising an annular heat dissipation fin, the annular heat dissipation fin being gap-fitted with the opening; and an annular sealing element, the annular sealing element being sleeved on the annular heat dissipation fin, the annular sealing element being provided with a groove structure clamped with an end of the annular heat dissipation fin, a first sealing protrusion arranged on an inner side of the groove structure, and a second sealing protrusion arranged on an outer periphery of the annular sealing element; wherein the first sealing protrusion is interference-fitted with a side wall of the annular heat dissipation fin, and the second sealing protrusion is interference-fitted with an inner wall of the opening. The electric drive system comprises the battery pack and a motor, wherein the battery pack supplies power to the motor.

Description

Technical Field

[0001] This disclosure relates to a battery pack and an electric drive system. Background Technology

[0002] With the booming development of the construction machinery industry, battery-powered electric work machines are increasingly widely used due to their advantages such as environmental friendliness and high efficiency. These electric work machines often have stringent requirements for continuous operation, meaning that once the battery is fully discharged during operation, it must be quickly switched to charging mode within a very short time, and the charging time must be minimized to ensure the continuity and efficiency of the operation.

[0003] Effective thermal management is crucial for the stable performance of batteries. During rapid charging and continuous operation, batteries generate a significant amount of heat. If this heat cannot be dissipated effectively and promptly, it will severely impact battery life and performance, and may even pose safety hazards. Therefore, optimizing the battery's physical structure to improve its heat dissipation is one of the most fundamental and critical measures to enhance battery thermal management capabilities.

[0004] However, existing battery heat dissipation structures have revealed many significant shortcomings in practical applications. Their heat dissipation efficiency cannot meet the rapid heat dissipation requirements of electric work machinery during high-efficiency operation, resulting in excessively high battery temperatures and performance degradation after prolonged high-intensity operation, which in turn affects the normal operation of the entire work machinery.

[0005] Furthermore, in improving battery heat dissipation capabilities, a crucial and unavoidable issue arises: ensuring the battery's airtight seal. The battery's seal directly impacts its dust and water resistance. If alterations to the heat dissipation structure compromise the seal, dust and moisture can easily penetrate the battery in the complex and ever-changing working environments of engineering machinery, damaging it, shortening its lifespan, and even causing safety accidents. Therefore, how to improve heat dissipation capabilities while maintaining the battery's airtight seal has become a critical challenge that urgently needs to be addressed in the field of battery design and manufacturing. Utility Model Content

[0006] This disclosure provides a battery pack and an electric drive system.

[0007] According to one aspect of this disclosure, a battery pack is provided, comprising: The battery casing has an opening. A heat dissipation component is provided with a heat dissipation section, the heat dissipation section including annular heat dissipation fins, the annular heat dissipation fins being clearance-fitted with the opening; and An annular seal is fitted onto the annular heat dissipation fins and has a groove structure that engages with the end of the annular heat dissipation fins, a first sealing protrusion located inside the groove structure, and a second sealing protrusion located on the outer periphery of the annular seal. The first sealing protrusion is interference-fitted with the sidewall of the annular heat dissipation fin, and the second sealing protrusion is interference-fitted with the opening.

[0008] According to one aspect of the technical solution of this disclosure, the battery pack generates heat during operation, and the heat dissipation component dissipates heat through a heat dissipation section. The annular heat dissipation fins are fitted with the opening in the battery casing with a clearance fit, allowing the heat dissipation component to protrude from the battery casing. Simultaneously, the internally arranged heat dissipation fins increase the heat dissipation area, accelerating heat dissipation. An annular seal is fitted onto the annular heat dissipation fins, and its groove structure engages with the end of the annular heat dissipation fins for initial positioning. The annular seal fills the gap between the opening and the annular heat dissipation fins. The first sealing protrusion is interference-fitted with the sidewall of the annular heat dissipation fins, and the second sealing protrusion is interference-fitted with the inner wall of the opening, thereby forming a double seal between the annular heat dissipation fins and the opening in the battery casing. Further tightening during assembly increases the sealing area, preventing external moisture, dust, and other contaminants from entering the battery pack.

[0009] According to at least one embodiment of the battery pack of the present disclosure, the annular seal is provided with a sealing body, and a first sealing surface and a second sealing surface are respectively provided on both sides of the sealing body, the first sealing protrusion is provided on the first sealing surface, and the second sealing protrusion is provided on the second sealing surface.

[0010] According to at least one embodiment of the battery pack of this disclosure, a sealing rib may also be provided on the opening, extending in the opposite direction to the second sealing protrusion. The sealing rib is integrally interference-fitted with the annular seal. The sealing rib can play an auxiliary sealing role, increasing the sealing effect of the second sealing surface.

[0011] In this embodiment, during installation, due to differences in thickness, the thicker portion experiences less deformation and greater resilience under pressure, allowing the second sealing protrusion to better interfere with the opening and enhance the sealing effect. When installing the annular seal, the first sealing protrusion and the sidewall of the annular heat sink fin achieve an interference fit seal through the first sealing surface; during assembly, the second sealing protrusion and the inner wall of the opening achieve an interference fit seal through the second sealing surface, clearly defining the functional positions and sealing methods of the different sealing protrusions.

[0012] According to at least one embodiment of the battery pack of the present disclosure, a recess is provided on the outer side of the annular seal, the recess being located on the outer side of the sealing body.

[0013] In the technical solution of this embodiment, when the annular seal is compressed and deformed by pressure, the pit can provide a certain space for deformation, avoiding damage or displacement of the seal due to excessive deformation, and at the same time, it can make the seal fit the sealing surface better.

[0014] According to at least one embodiment of the battery pack of the present disclosure, the annular seal is provided with a limiting protrusion, the limiting protrusion being located inside the battery casing.

[0015] In the technical solution of this embodiment, during installation, the annular seal is sleeved on the annular heat dissipation fins, and the limiting protrusion is installed on the inner side of the battery outer casing to achieve axial limiting of the annular seal and prevent it from moving along its axis during operation.

[0016] According to at least one embodiment of the battery pack of the present disclosure, the battery outer casing is provided with a cavity, and a battery module is disposed in the cavity; the battery pack further includes a thermally conductive insulating layer, which is made of a flexible insulating material and has a thermal conductivity greater than that of air, and the thermally conductive insulating layer is attached to the outside of the battery connecting piece; the heat dissipation component is disposed on the outside of the thermally conductive insulating layer, the heat dissipation component penetrates the battery outer casing and is provided with a heat dissipation structure extending to the outside of the battery outer casing.

[0017] According to at least one embodiment of the battery pack of the present disclosure, the battery outer casing includes a mountable battery housing and a battery cover; the heat dissipation component is provided with a heat dissipation section, which passes through the connection between the battery housing and the battery cover, and is provided with a heat dissipation structure extending to the outside of the battery outer casing; wherein the battery housing, the battery cover, and the heat dissipation section are provided with a through connection structure, so that the battery housing, the battery cover, and the heat dissipation section are fixed at the same connection point by the same fastener.

[0018] According to one aspect of the technical solution disclosed herein, the battery outer casing is assembled from a battery housing and a battery cover; the heat dissipation part of the heat dissipation component penetrates through the connection between the battery housing and the battery cover, extending to the outside through an opening. The battery housing, battery cover, and heat dissipation part are fixed by the same fastener, achieving an integrated connection. This design simplifies assembly: reducing the number of fasteners, lowering assembly time and cost; it also strengthens the structure: the heat dissipation part, as the core connection point, improves module rigidity and enhances vibration resistance; simultaneously, it integrates heat dissipation: the heat dissipation part is directly exposed to the outside, shortening the heat path. Another benefit is that using the same fastener connection also ensures a tight seal between the annular heat dissipation fins, annular seal, and battery outer casing, allowing for uniform pressure on the annular seal and reducing the possibility of failure and displacement.

[0019] According to at least one embodiment of the battery pack of the present disclosure, the through connection structure includes: a bottom connecting post disposed on the battery housing, a through hole disposed on the heat dissipation part, and a top connecting hole disposed on the battery housing cover; wherein the through hole is coaxially disposed with the connecting post and the connecting hole.

[0020] In this embodiment, the coaxial design ensures accurate assembly and avoids stress concentration. Simultaneously, the even distribution of fastening force prevents seal failure caused by battery box deformation.

[0021] A battery pack according to at least one embodiment of the present disclosure further includes a power socket and a waterproof sealing cover, the waterproof sealing cover sealing the power socket.

[0022] According to at least one embodiment of the battery pack of the present disclosure, the battery outer casing is provided with a cavity, and a battery module is disposed in the cavity; the battery pack further includes a thermally conductive insulating layer, which is made of a flexible insulating material and has a thermal conductivity greater than that of air, and the thermally conductive insulating layer is attached to the outside of the battery connecting piece; the heat dissipation component is disposed on the outside of the thermally conductive insulating layer, the heat dissipation component penetrates through the battery outer casing and is provided with a heat dissipation structure extending to the outside of the battery outer casing.

[0023] According to another aspect of this disclosure, an electric drive system is provided, including the battery pack described above, and also including a motor, wherein the battery pack supplies power to the motor. Attached Figure Description

[0024] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0025] Figure 1 This is a schematic diagram of the structure of a battery pack according to one embodiment of the present disclosure.

[0026] Figure 2 This is an exploded view of a battery pack according to one embodiment of the present disclosure.

[0027] Figure 3 This is an assembly diagram of a battery module according to one embodiment of the present disclosure.

[0028] Figure 4 This is a schematic diagram of the structure of a thermally conductive insulating layer according to one embodiment of the present disclosure.

[0029] Figure 5 This is an exploded view of a heat dissipation substrate mounting structure according to one embodiment of the present disclosure.

[0030] Figure 6This is a schematic diagram of a heat dissipation component according to one embodiment of the present disclosure.

[0031] Figure 7 This is a cross-sectional view of a battery pack according to one embodiment of the present disclosure.

[0032] Figure 8 This is a side view of a battery pack according to one embodiment of the present disclosure.

[0033] Figure 9 This is a schematic diagram showing the connection between an annular seal and a battery casing and a heat dissipation component according to one embodiment of the present disclosure.

[0034] Figure 10 This is a schematic cross-sectional view of an annular seal according to one embodiment of the present disclosure.

[0035] Figure 11 This is a schematic diagram of the structure of a waterproof sealing cap according to one embodiment of the present disclosure.

[0036] Figure 12 This is a perspective view of a battery charger according to one embodiment of the present disclosure.

[0037] Figure 13 This is a schematic diagram of the structure of a battery charger according to one embodiment of the present disclosure.

[0038] Figure 14 This is a front view of a battery charger according to one embodiment of the present disclosure.

[0039] Figure 15 This is a side view of a battery charger according to one embodiment of the present disclosure.

[0040] Figure 16 This is a schematic diagram of the internal structure of a liquid-cooled motor according to one embodiment of the present disclosure.

[0041] Figure 17 This is a schematic diagram of the structure of a flow guiding component according to one embodiment of the present disclosure.

[0042] Figure 18 This is a schematic diagram of the external structure of a liquid-cooled motor according to one embodiment of the present disclosure.

[0043] Figure 19 This is a schematic diagram of a liquid-cooled motor according to one embodiment of the present disclosure, which includes an air pipe and an air filter.

[0044] Figure 20 This is a cross-sectional view of an air filter element according to one embodiment of the present disclosure.

[0045] The specific labels in the attached figures are as follows: 100 Motor housing 101 Motor Cover 110 Inner cavity 111 Stator Coil 120 Vent 130 heat dissipation fins 140 Liquid Maintenance Hole 141 Sealing bolt 200 rotor 210 End Cap 211 Guide vanes 220 Magnetic Yoke 221 Magnet 230 Output Shaft 231 Rotating part 232 Output Section 300 Coolant 400 fan 401 outer cover 500 trachea 510 First U-shaped bend 520 Second U-shaped bend 600 Air Filter Assembly 610 volumetric chamber 611 outer wall 620 First air valve 630 Second air valve 640 partition shaft 641 First Passage 642 Second Channel 650 filter material 660 filter sponge 700 Support Frame 710 Shielding Structure 720 Overall casing 800 Battery Outer Box 810 cavity 820 battery module 821 Battery Connector 822 battery 823 Battery Bracket 824 positioning hole 825 Wire Harness Clearance Slot 830 opening 831 Sealing Rib 840 Battery Case 841 Bottom connecting column 842 Groove 850 Battery Box Cover 851 Top connection hole 860 vibration damping block 870 Battery Protection Board 880 Insulating and Thermally Conductive Layer 900 thermally conductive insulation layer 910 Surface Layer 920 filler layer 1000 heat dissipation components 1010 Heat Dissipation Unit 1011 Annular heat sink fins 1020 heat sink fins 1030 Connecting part 1031 Through Hole 1100 heat sink 1200 Fasteners 1300 elastic buffer 1400 Waterproof Sealing Cap 1410 Perforated Tail 1500 Annular Seal 1510 Groove Structure 1520 First sealing protrusion 1530 Second sealing protrusion 1540 First sealing surface 1550 Second sealing surface 1560 pit 1570 limiting bump 1600 charger 1601 Cooling Fan 1610 Charger Frame Detailed Implementation The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0046] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.

[0048] Existing battery heat dissipation structures are inadequate, failing to meet the rapid heat dissipation requirements of electric work machinery during high-efficiency operation, thus affecting the normal operation of the machinery. Furthermore, improving heat dissipation capacity must ensure battery sealing; otherwise, it can damage the battery, shorten its lifespan, or even cause accidents. Therefore, improving heat dissipation capacity while ensuring sealing is a key challenge in battery design and manufacturing.

[0049] To address the aforementioned technical problems, this embodiment provides a battery pack.

[0050] Figure 1 This is a schematic diagram of the structure of a battery pack according to one embodiment of the present disclosure. Figure 2 An exploded view of a battery pack according to one embodiment of the present disclosure. Figure 3 This is a schematic diagram of the assembly of a battery pack according to one embodiment of the present disclosure.

[0051] like Figures 1 to 3 As shown, the battery pack provided in this embodiment includes a battery module 820, which in turn includes a battery 822 and a battery bracket 823. The battery pack also includes a battery casing 800, a thermally conductive insulating layer 900, and a heat dissipation component 1000.

[0052] like Figure 1 and Figure 2 As shown, the battery outer casing 800 is provided with a cavity 810, and a battery module 820 is provided inside the cavity 810. The battery module 820 is provided with a battery connecting piece 821, which is mounted on the battery bracket 823 and is used to fix and connect each battery 822 so that the battery module 820 forms an initial battery pack.

[0053] like Figure 3 As shown, the thermally conductive insulating layer 900 is made of a flexible insulating material with a thermal conductivity greater than that of air. The thermally conductive insulating layer 900 is attached to the outside of the battery module 820 and the battery connecting piece 821. The heat dissipation component 1000 is disposed on the outside of the thermally conductive insulating layer 900.

[0054] like Figure 2 and Figure 3As shown, in one embodiment, the battery 822 is installed in the cavity 810 via a battery bracket 823. One side of the thermally conductive insulating layer 900 is tightly fitted to the battery bracket 823 and the battery connecting piece 821, and the other side is tightly fitted to the heat dissipation component 1000. The thermally conductive insulating layer 900 and the heat dissipation component 1000 are symmetrically arranged on both sides of the battery bracket 823 and the battery connecting piece 821, with the battery pack as the center, and are fastened to the battery bracket 823 by screws passing through both sides, forming a complete battery module 820. The thermally conductive insulating layer 900 may also be provided with positioning holes 824 and wire harness clearance grooves 825 that mate with the battery bracket 823.

[0055] Figure 4 This is a schematic diagram of the structure of a thermally conductive insulating layer according to one embodiment of the present disclosure.

[0056] For example, such as Figure 4 As shown, the thermally conductive insulating layer 900 is a multi-layer composite structure with a thickness of 0.5-2 mm. The thermally conductive insulating layer 900 includes a surface layer 910 and a filler layer 920. The two surface layers 910 are the core layers that realize the functions of thermal conductivity and insulation. The main materials are uniformly coated high thermal conductivity silicone and other thermally conductive fillers (such as alumina, boron nitride, etc.), supplemented by a cloth base material (such as high-density fiberglass cloth) to achieve flexible insulation and thermal conductivity.

[0057] like Figure 3 and Figure 4 As shown, one surface layer 910 is attached to the outer surface of the battery connector 821, and another surface layer 910 is attached to the heat dissipation component 1000. The filler layer 920 is made of silicone blocks of different heights. Depending on the welding position of the battery connector 821 and the height difference between the outer side of the battery bracket 823 and the mounting surface of the heat dissipation component 1000, the filler layer 920 is fitted with silicone blocks of different heights. This completely eliminates the air gap between the battery connector 821 and the heat dissipation component 1000, allowing the heat from the positive and negative electrodes of the battery 822 to be directly conducted to the heat dissipation component 1000 through the battery connector 821.

[0058] like Figure 2 As shown, the battery casing 800 is provided with an opening 830, and the heat dissipation component 1000 has a heat dissipation part 1010 that penetrates the battery casing 800. The heat dissipation part 1010 is provided with a heat dissipation structure that extends to the outside of the battery casing 800.

[0059] Figure 6 This is a schematic diagram of a heat dissipation component according to one embodiment of the present disclosure.

[0060] like Figure 2 and Figure 6As shown, the battery module 820 includes a battery 822. As can be seen from the surface temperature characteristics of a cylindrical battery, the axial temperature conduction of the battery 822 is usually faster than the radial temperature, and the surface temperature of the positive electrode is usually slightly higher than that of the negative electrode during charging and discharging.

[0061] In some embodiments, the battery heat dissipation structure can be a heat dissipation component 1000, which is provided with a plurality of heat dissipation fins 1020 to increase the contact area between the heat dissipation component 1000 and the air. The heat dissipation fins 1020 extend along the axial direction of the battery 822 in the height direction, and their arrangement can follow the direction of the active heat dissipation measures.

[0062] In some implementations, the heat dissipation fins 1020 located outside the positive electrode region of the battery 822 are arranged at a higher density to optimize heat dissipation in the positive electrode region; this is to accommodate situations where the surface temperature of the positive and negative electrodes is higher than the circumferential side temperature and the surface temperature of the positive electrode is slightly higher than the surface temperature of the negative electrode during the charging and discharging process of the battery 822.

[0063] Meanwhile, the heat dissipation component 1000 may also be provided with reinforcing ribs to enhance the structural strength of the heat dissipation component 1000.

[0064] like Figure 2 and Figure 6 As shown, the heat dissipation structure includes annular heat dissipation fins 1011, which are uniformly spaced and fitted with openings 830 in the battery casing 800. The heat dissipation structure also includes partial heat dissipation fins 1020 disposed inside the annular structure. These internal heat dissipation fins 1020 are spaced vertically, their direction aligned with the flow direction of the active cooling measures. The height extension direction of the heat dissipation fins 1020 is the same as the axial direction of the battery 822, but with the difference that the heights of the heat dissipation fins 1020 inside and outside the annular heat dissipation fins 1011 are different. The heights of the annular heat dissipation fins 1011 and the internal heat dissipation fins 1020 are set so that they can just pass through the battery casing 800, contacting the active cooling measures and enabling them to take effect. To allow the heat dissipation component 1000 to be exposed, the battery casing 800 also has openings 830 on the battery body 840 and battery cover 850, shaped like the heat dissipation part 1010. A slight, uniform gap is left between the openings 830 and the annular heat dissipation fins 1011.

[0065] like Figure 2 As shown, the heat dissipation component 1000 is also provided with a positioning hole 824 and a wire harness clearance groove 825 that cooperate with the battery bracket 823.

[0066] Figure 5 This is an exploded view of a heat dissipation substrate mounting structure according to one embodiment of the present disclosure.

[0067] like Figure 1 and Figure 5As shown, the battery pack also includes a battery protection board 870; the battery pack heat dissipation structure also includes a heat dissipation substrate 1100.

[0068] For example, the heat dissipation substrate 1100 is made of a hard material with high thermal conductivity, preferably aluminum alloy; the heat dissipation substrate 1100 is embedded in the battery outer casing 800, and its outer surface is provided with heat dissipation ribs and exposed outside the battery outer casing 800, while the inner surface is attached with an insulating thermally conductive layer 880; the battery protection board 870 is disposed in the battery cavity 810 and fixed on the heat dissipation substrate 1100 with the insulating thermally conductive layer 880 attached.

[0069] Specifically, in some embodiments, the cover 850 of the battery casing 800 is made of plastic. Considering the heat dissipation problem of the battery protection board 870, a heat dissipation structure is also provided on the battery cover 850. The heat dissipation structure can be a heat dissipation substrate 1100, which is integrally formed with the battery cover 850. Its thickness is equal to or greater than the thickness of the battery cover 850, and its embedding position is flush with or slightly higher than the inner surface of the battery cavity 810.

[0070] The outer surface of the heat dissipation substrate 1100 is provided with heat dissipation ribs and is directly exposed to the battery box cover 850, which can increase the contact area between the component and the air, thereby increasing the effective heat dissipation area; the battery protection board 870 is preferably made of aluminum substrate.

[0071] During assembly, an insulating and thermally conductive layer 880 is first attached to the inner surface of the heat dissipation substrate 1100. Then, a battery protection board 870 is attached and installed on the insulating and thermally conductive layer 880. Finally, the battery protection board 870 is threaded and fixed to the heat dissipation substrate 1100. This not only dissipates heat but also increases physical insulation, preventing the risk of leakage caused by accidental breakage of the insulation layer of the battery protection board 870.

[0072] To further dissipate heat through active cooling measures, the heat dissipation section 1010 and / or heat dissipation substrate 1100, which directly absorb heat from the battery and battery protection board 870, can be directly cooled or equipped with air cooling or water cooling measures. For example, coolant can be directly sprayed onto the heat dissipation section 1010 and / or heat dissipation substrate 1100, or a cooling fan 1601 can be added to the battery charger paired with the battery pack.

[0073] In the above technical solution, the principle of heat dissipation of the battery pack is as follows: Based on battery characteristics, the heat source during charging and discharging of a cylindrical battery is mainly located in the core area inside the battery 822. Due to the thermal conductivity of the wound structure, the axial thermal conductivity is generally 5-10 times higher than the radial thermal conductivity. Therefore, the heat distribution on the battery surface shows that the temperature of the positive and negative electrodes is greater than the radial circumferential plastic shell temperature. Accordingly, after fixing several batteries 822 inside the battery bracket 823 and welding battery connecting pieces 821 to initially assemble them, a thermally conductive insulating layer 900 is directly attached to the positions where the battery connecting pieces 821 are welded to the positive and negative electrodes of the battery 822 and to the positions where the battery connecting pieces 821 are placed and positioned in the battery bracket 823. A heat dissipation component 1000, serving as a structural support for the battery pack, is attached to the other side of the thermally conductive insulating layer 900. The thermally conductive insulating layer 900 can completely eliminate the air gap between the battery connector 821 and the heat dissipation component 1000, allowing the heat from the positive and negative poles of the battery 822 to be directly conducted to the heat dissipation component 1000 through the battery connector 821 and the thermally conductive insulating layer 900; and then through the opening 830 of the battery casing 800, the heat dissipation part 1010 of the heat dissipation component 1000 is directly exposed, conducting the heat to the external environment of the battery pack, so that the active cooling measures can directly and effectively dissipate heat from the originally sealed battery pack.

[0074] In some embodiments, the battery casing 800 includes a mountable housing 840 and a cover 850. The heat dissipation fins 1020 extend outwards from the battery axis to conduct heat away from the battery pack, rendering traditional battery pack fixing methods ineffective and difficult to assemble. Furthermore, it has been found that if the battery module 820 and the battery cover 850 are not fixedly connected, but only have flexible connections such as vibration damping blocks, the vibration frequencies of the battery module 820 and the battery cover 850 deviate, accelerating the failure of the flexible connections. This can easily lead to mutual wear between the battery cover 850 and the battery module 820.

[0075] Figure 7 This is a cross-sectional view of a battery pack according to one embodiment of the present disclosure.

[0076] like Figure 2 , Figure 6 and Figure 7 As shown, in order to solve this technical problem, in this embodiment, the heat dissipation component 1000 is provided with a connecting part 1030, which passes through the connection between the housing 840 and the cover 850.

[0077] The housing 840, cover 850, and connecting part 1030 are provided with a through-connection structure, so that the housing 840, cover 850, and connecting part 1030 are fixed at the same connection point by the same fastener 1200. The through-connection structure includes: a bottom connecting post 841 provided in the housing 840, a through hole 1031 provided in the connecting part 1030, and a top connecting hole 851 provided in the cover 850; the through hole 1031 is coaxially arranged with the connecting post 841 and the connecting hole 851. The fastener 1200 is set from bottom to top.

[0078] Furthermore, a groove 842 is provided at the bottom of the housing 840. The head of the fastener 1200 is hidden in the groove 842 at the bottom of the housing 840 during assembly, and the end of the fastener 1200 is sunk into the inside of the cover 850, so as to achieve high overall structural strength and a flat surface.

[0079] like Figure 2 As shown, the battery pack also includes an elastic buffer 1300, which is disposed between the battery module 820 and the battery housing 840 and battery cover 850 around, at the top and bottom, and is interference-fitted with them. The elastic buffer 1300 is a low-hardness polymer material, preferably a rubber pad or a silicone pad, and its thickness is determined by the specific gap, commonly 2-5mm, to absorb vibration energy and prevent the battery 822 from being damaged by mechanical vibration.

[0080] In the above technical solution, the principle behind the battery pack's structural stability is as follows: the battery housing 840, battery module 820, and battery cover 850 are securely connected as a single unit through a through-connection structure and fasteners 1200. This increases the fastening surface area, improves the overall connection strength of the battery pack, reduces the center of gravity shift during operation, and makes the overall system more stable. Simultaneously, a soft connection, including an elastic buffer 1300, is retained, allowing for slight relative displacement between the battery module 820 and the battery outer casing 800. This prevents wear and damage to the battery bracket 823 and the battery 822. Another advantage of the integrated connection between the battery module 820 and the battery outer casing 800 is the simplified structure, reducing assembly steps, components, and assembly errors. The fasteners 1200 are positioned from bottom to top, making them relatively concealed and providing dust and water protection, extending their lifespan, and increasing their reliability.

[0081] Figure 8 This is a side view of a battery pack according to one embodiment of the present disclosure. Figure 9 This is a schematic diagram showing the connection between an annular seal and a battery casing and a heat dissipation component according to one embodiment of the present disclosure. Figure 10 This is a schematic cross-sectional view of an annular seal according to one embodiment of the present disclosure.

[0082] like Figures 8 to 10As shown, in order to meet the sealing requirements between the battery casing 800 and the heat dissipation section 1010, in this embodiment, the battery pack further includes an annular seal 1500. The annular seal 1500 is sleeved on the annular heat dissipation fin 1011. The annular seal 1500 is provided with a groove structure 1510 that engages with the top end of the annular heat dissipation fin 1011, a first sealing protrusion 1520 disposed inside the groove structure 1510, and a second sealing protrusion 1530 disposed on the outer periphery of the annular seal 1500.

[0083] The first sealing protrusion 1520 is interference-fitted with the outer wall of the annular heat dissipation fin 1011, and the second sealing protrusion 1530 is interference-fitted with the inner wall of the opening 830. Both achieve sealing through elastic deformation. The cross-section of the annular seal 1500 is generally asymmetrical, and its thickness is different on both sides of the groove structure 1510. The thicker part has a first sealing surface 1540 and a second sealing surface 1550 on its two sides, respectively. The first sealing protrusion 1520 is located on the first sealing surface 1540, and the second sealing protrusion 1530 is located on the second sealing surface 1550.

[0084] like Figure 9 As shown, a sealing rib 831 extending in the opposite direction to the second sealing protrusion 1530 can also be provided on the opening 830. The sealing rib 831 is also interference-fitted with the annular seal 1500. The sealing rib 831 can play an auxiliary sealing role and increase the sealing effect of the second sealing surface 1550.

[0085] The thicker part serves as the sealing body. The first sealing protrusion 1520 and the second sealing protrusion 1530 are located on both sides of the thicker part, respectively. This arrangement is intended to balance the internal and external deformation of the annular seal 1500 at the bend, preventing excessive compression on the compressed side from bending and warping, and excessive stretching on the stretched side from deformation and cracking.

[0086] like Figure 9 As shown, the annular seal 1500 has a recess 1560 on the outside of the thicker sealing body. The recess 1560 is located in the area where the seal is subjected to the greatest compression deformation when tightened.

[0087] The annular seal 1500 is also provided with several limiting protrusions 1570, which are evenly distributed on the sealing body and perpendicular to the two sealing surfaces. The limiting protrusions 1570 are located inside the battery outer casing 800, and the height of the protrusions is higher than the second sealing surface 1550 to prevent the seal from being displaced and coming out of the sealing position under stress during assembly and equipment operation.

[0088] In the above technical solution, the annular seal 1500 of the battery pack achieves a reliable seal between the heat dissipation section 1010 and the battery outer casing 800 by setting sealing protrusions and a special cross-sectional design on the double sealing surfaces. The limiting protrusion 1570 ensures that the annular seal 1500 does not shift under vibration conditions.

[0089] On the other hand, the battery housing 840, battery cover 850 and heat dissipation part 1010 of heat dissipation component 1000 are connected at the same connection point using the same fastener 1200, which also makes the annular heat dissipation fins 1011 of heat dissipation component 1000, annular seal 1500 and battery outer casing 800 tightly sealed, so that the annular seal 1500 is subjected to uniform pressure from top to bottom, reducing the possibility of its failure and displacement.

[0090] During installation, the groove structure 1510 of the annular seal 1500 is fitted onto the top of the annular heat sink fin 1011, with the first sealing protrusion 1520 on the inner side of the groove facing the outer side of the annular heat sink fin 1011. The battery module 820 is placed into the battery housing 840. In the horizontal and near-horizontal directions, the lower half of the annular seal 1500 contacts the battery housing 840. Under the action of gravity, the first sealing protrusion 1520 on the first sealing surface 1540 of the lower half interacts with the outer side of the annular heat sink fin 1011 to press and seal. The second sealing protrusion 1530 on the second sealing surface 1550 interacts with the battery housing 840 to press and seal. The limiting protrusion 1570 is installed and locked inside the cavity 810 of the battery housing 840 for limiting. Then, the battery housing cover 850 is assembled, and the annular seal 1500... The upper half of the ring seal 1500 contacts the battery box cover 850. The first sealing protrusion 1520 on the first sealing surface 1540 contacts the outer side of the annular heat dissipation fin 1011, and the second sealing protrusion 1530 on the second sealing surface 1550 contacts the battery box cover 850. After the fasteners 1200 connecting the battery box 840, battery module 820 and battery box cover 850 are tightened, the first sealing surface 1540 and the second sealing surface 1550 of the upper half of the annular seal 1500 press against each other, forming a seal between the annular heat dissipation fin 1011 and the battery box cover 850. Furthermore, in the vertical and near-vertical directions, the seal is not only achieved by the mutual compression of the first and second sealing surfaces, but also by the oblique pressing force generated by the restriction of the draft direction and the arc shape when the battery outer box 800 is opened.

[0091] Figure 11 This is a schematic diagram of the structure of a waterproof sealing cap according to one embodiment of the present disclosure.

[0092] like Figure 2 and Figure 11As shown, a waterproof sealing cover 1400 is added to the battery socket. The sealing cover 1400 fits the internal structure of the socket on the battery pack and can be interference-fitted with the socket on the battery pack for sealing. The sealing cover 1400 extends to a perforated tail 1410, and the sealing cover 1400 is threadedly connected to the battery housing 840 through the perforated tail 1410. The waterproof sealing cover 1400 is used to provide a waterproof and dustproof seal for the battery socket when active cooling measures are in place or during normal storage.

[0093] This embodiment provides a battery charger 1600.

[0094] Figure 12 This is a perspective view of a battery charger according to one embodiment of the present disclosure. Figure 13 This is a schematic diagram of the structure of a battery charger according to one embodiment of the present disclosure. Figure 14 This is a front view of a battery charger according to one embodiment of the present disclosure. Figure 15 This is a side view of a battery charger according to one embodiment of the present disclosure.

[0095] like Figures 12 to 13 As shown, the battery charger 1600 of this embodiment can charge the battery pack of the above embodiment, and also includes a cooling fan 1601 disposed towards the heat dissipation part 1010. The cooling fan 1601 can be disposed on the charger frame 1610 facing both sides of the battery pack, and is used to actively remove heat from the heat dissipation part 1010 to improve heat dissipation efficiency. For example, the cooling fan 1601 is arranged to adapt to the shape of the heat dissipation part 1010, so that the heat dissipation area of ​​the cooling fan 1601 covers the heat dissipation part 1010 as evenly as possible.

[0096] The cooling fan 1601 can also be installed on the top of the charger frame 1610 body and / or on the air outlet surface of the frame body. Its function is to rectify and guide the airflow, making the heat dissipation measures more efficient.

[0097] When active cooling measures are adopted, taking cooling fan 1601 as an example, the battery pack is placed on the battery charger 1600, and the bottom damping block of the battery is supported on the top of the battery charger frame 1610. Gaps are left between the surface of the battery pack and each surface of the battery charger frame 1610. Cooling fans 1601 facing both sides of the battery pack blow air from the outside towards the heat dissipation part 1010 of the battery pack. Cooling fan 1601 on the top of the charger frame 1610 draws air from the bottom of the battery pack into the inside of the charger frame 1610 from top to bottom, and then the cooling fan 1601 on the exhaust side of the battery charger frame 1610 dissipates heat from the inside of the charger frame 1610 to the outside of the battery charger 1600.

[0098] The cooling medium is first blown from both sides of the battery charger frame 1610 to the heat dissipation section 1010 of the battery pack. After the medium absorbs heat through the heat dissipation section 1010, part of it flows directly to the outside, and part of it is absorbed by the cooling fan 1601 at the top of the charger frame 1610 and flows to the bottom gap of the battery pack. At this time, the heat dissipation fins 1020 inside the heat dissipation section 1010 are arranged in the same direction as the flow of the cooling medium, which plays the role of guiding the flow and increasing the heat dissipation rate of the heat dissipation section 1010. The cooling medium that enters the charger frame 1610 is attracted by the cooling fan 1601 on the air outlet surface of the charger frame 1610 and dissipates heat outward after the flow direction is integrated.

[0099] The aforementioned battery pack can be used to power the motor. During actual operation, the motor generates a significant amount of heat, and its power output is limited by its heat dissipation capacity. Existing motors have structural shortcomings in heat dissipation, typically relying solely on fans, which easily leads to insufficient heat dissipation capacity. This insufficient heat dissipation capacity further restricts the increase of the motor's rated power.

[0100] To address this technical problem, this embodiment provides a liquid-cooled motor.

[0101] Figure 16 This is a schematic diagram of the internal structure of a liquid-cooled motor according to one embodiment of the present disclosure. Figure 17 This is a schematic diagram of the structure of a flow guiding component according to one embodiment of the present disclosure.

[0102] like Figure 16 and Figure 17 As shown, the liquid-cooled motor provided in this embodiment includes a motor housing 100 and a rotor 200. The heat dissipation structure of the liquid-cooled motor will be described below.

[0103] The motor housing 100 has an internal cavity 110 that houses the stator coils 111, rotor 200, and coolant 300. A vent 120 is provided on the motor housing 100, connecting the internal cavity 110 to the atmosphere. The rotor 200 is rotatably mounted within the motor housing 100 via an output shaft 230. A flow guide component is provided on the rotor 200 and is also located within the internal cavity 110.

[0104] In the initial state, part of the guide component is immersed in the cooling liquid 300. When the rotor 200 rotates at high speed, the guide component rotates accordingly and adheres to the cooling liquid 300, lifting the part immersed in the cooling liquid 300 to the non-immersion area inside the inner cavity 110. Under the action of gravity and centrifugal force, the adhered and lifted cooling liquid 300 splashes onto the stator coil 111 and the inner wall of the inner cavity 110, thereby transferring the heat of the stator coil 111 to the motor housing 100, thus forming an efficient heat dissipation path.

[0105] In some embodiments, the coolant 300 is a low-viscosity, high-specific-heat, and high-dielectric-strength cooling oil with a flash point temperature higher than the motor's rated maximum operating temperature, such as 1.3 times, to meet safety requirements. The filling volume of the coolant 300 is controlled to be 1 / 6 to 1 / 4 of the height of the inner cavity 110, such as 1 / 4 to 1 / 5, that is, the liquid level is 1 / 4 of the height of the motor's inner cavity. This liquid level submerges the bottom magnet 221 and partially submerges the stator coil 111, but is lower than the minimum height of the rotational seal between the output shaft 230 and the motor housing 100, ensuring minimal rotational resistance and no risk of shaft seal oil leakage. For example, filling the motor with cooling oil can cause a large pressure difference if too much oil is used, and if the pressure is not released in time, it will affect the rotation of the output shaft and there is also a risk of leakage. The filling amount of cooling oil is limited to 1 / 4 to 1 / 5 of the oil level in the inner cavity 110 of the motor, which is about the height range of the bottom of the entire coil, and submerges the front end of the rotor magnet 221 and the rotor guide vane 211 (corner connection), and is lower than the minimum height of the rotation seal between the output shaft and the motor housing.

[0106] like Figure 16 and Figure 17 As shown, the flow guiding component includes an end cap 210 disposed on the rotor 200, and a plurality of flow guiding blades 211 disposed on the end cap 210. For example, the end cap 210 of the rotor 200 is fixed to the output shaft 230, and the plurality of flow guiding blades 211 are integrally formed at the corners of the end cap 210, spaced apart from the air vents on the rotor 200. Some of the flow guiding blades 211 are partially immersed in the cooling liquid 300. When the rotor 200 rotates at high speed, the flow guiding blades 211 rotate accordingly and adhere to the cooling liquid 300, lifting the portion immersed in the cooling liquid 300 to the non-immersed area within the inner cavity 110, causing the lifted cooling liquid 300 to splash onto the inner wall of the inner cavity 110 under centrifugal force. The shape of the flow guiding blades 211 can be designed as a paddle to improve liquid carrying efficiency.

[0107] like Figure 16 As shown, the flow guiding component also includes a magnetic yoke 220 and magnets 221 on the rotor 200, with a portion of the rotation trajectory of the magnets 221 partially immersed in the cooling liquid 300. When the rotor 200 rotates at high speed, the magnetic yoke 220 is alternately immersed in the cooling liquid 300 according to the rotation trajectory of the magnetic yoke 220 and magnets 221. The magnets 221 rotate with the magnetic yoke and adhere to the cooling liquid 300, lifting the portion submerged in the cooling liquid 300 to the non-submerged area within the inner cavity 110. This lifted cooling liquid 300 then drips and splashes onto the stator coils 111 and the inner wall of the inner cavity 110 under the action of gravity and centrifugal force.

[0108] The end cap 210 and magnetic yoke 220, as inherent components of the rotor, together with the cooling liquid 300, can simultaneously act on the hot air flow and coolant circulation inside the liquid-cooled motor, maintaining the compact size of the motor, improving space utilization, increasing heat dissipation paths, improving heat dissipation efficiency, and effectively enhancing the heat dissipation effect.

[0109] The heat dissipation path of the cooling liquid 300 in the above technical solution includes: (1) the bottom stator coil 111 is directly immersed in the cooling liquid 300, and the heat is transferred to the motor housing 100 through heat conduction; (2) the magnetic yoke 220 and the magnet 221 are first immersed in the cooling liquid 300 to dissipate heat during rotation, and then rotate to carry the cooling liquid 300 out; when rotating to the top, the liquid drips onto the top stator coil 111 under the action of gravity and centrifugal force, dissipating heat for the top stator coil 111; (3) the guide vanes 211 are in high-speed rotation process After absorbing heat, the cooling liquid 300 is driven from the bottom of the inner cavity 110 and splashed onto the inner wall of the inner cavity 110 that is not submerged, transferring heat to the motor housing 100 and the heat dissipation fins 130; (4) Under the action of gravity and centrifugal force, the cooling liquid 300 is splashed onto the inner wall of the inner cavity 110 and the heat is transferred to the motor housing 100. After being cooled again, it drips onto the magnetic yoke 220, the magnet 221, the stator coil 111 and the output shaft 230, and after carrying away the heat for the second time, it returns to the cooling liquid 300 at the bottom of the inner cavity 110.

[0110] Figure 18 This is a schematic diagram of the external structure of a liquid-cooled motor according to one embodiment of the present disclosure.

[0111] like Figure 16 and Figure 18 As shown, the output shaft 230 on the rotor 200 includes a rotating part 231 and an output part 232. The liquid-cooled motor also includes a fan 400 and an outer cover 401 located on the front side of the motor housing 100 and mounted on the rotating part 231. The rotating part 231 passes through the motor housing 100, and the fan 400 and the outer cover 401 are mounted on the front side of the motor housing 100.

[0112] Based on the existing heat dissipation path of the motor: an air inlet is located at the center of the outer casing 401, and air outlets are distributed circumferentially around the outer casing 401 and the motor housing 100. When the rotor 200 rotates, it first drives the output shaft 230, which in turn drives the fan 400 to rotate. The blades on the fan 400 are arranged in a rotating manner, causing external air to enter from the air inlet and exit from the air outlet, flowing rapidly along the motor housing 100 to cool and dissipate heat.

[0113] The motor housing 100 has several heat dissipation fins 130 arranged on its outer circumference, following the direction of heat dissipation airflow. The heat dissipation fins 130 increase the contact area between the motor housing 100 and the external air. After absorbing the heat dissipated by the coolant 300, the surface temperature of the motor housing 100 further increases during operation. The heat dissipation fins help improve heat dissipation efficiency. Moreover, the heat from the stator coil 111 is conducted to the coolant 300 through multiple internal paths, and then from the coolant 300 to the motor housing 100. The motor housing 100 is also a major component of the original air-cooled heat dissipation path. Thus, the two paths intersect to form a composite heat dissipation system combining liquid cooling and air cooling, which also helps improve heat dissipation efficiency.

[0114] like Figure 16 and Figure 18 As shown, the motor housing 100 includes a motor cover 101. A vent 120 is preferably located on the top of the motor cover 101, on one side of the output section 232. The axial direction of the vent 120 forms a 100° angle (within the range of 90°-180°) with the direction in which the motor rotor 200 rotates and splashes cooling liquid. This angle has been experimentally verified as optimal, ensuring both exhaust efficiency and minimizing the amount of cooling liquid entering the vent.

[0115] In some embodiments, the output shaft 230 outputs power vertically downwards. The liquid-cooled motor also includes an outer casing 401 and a fan 400, which are mounted on the top of the liquid-cooled motor. During operation, the fan 400 blows air downwards onto the motor housing 100 for heat dissipation. The level of the cooling liquid 300 is 1 / 3 to 1 / 2 of the height of the inner cavity 110. A vent 120 is located in the main body of the motor housing 100, and its horizontal position is slightly higher than that of the guide vanes 211. The axial angle of the vent 120 is as described above.

[0116] like Figure 18 As shown, a liquid maintenance hole 140 is provided at the bottom of the motor housing 100. The liquid maintenance hole 140 is configured as a channel for the injection and / or drainage of coolant 300. The position of the liquid maintenance hole 140 is offset from the motor mounting holes to avoid accidental blockage by tools or parts during assembly. That is, the oil inlet and drain holes on the liquid-cooled motor can be set as one liquid maintenance hole 140 at the bottom, or as two separate liquid maintenance holes 140. The setting principle is to avoid the mounting holes. For example, the drain hole is located near the bottom of the motor cavity, and the oil inlet is located in the upper right part of the middle. The purpose of this setting is to facilitate oil injection and ensure thorough oil drainage.

[0117] The liquid maintenance hole 140 is equipped with a sealing bolt 141 and a sealing ring to seal the liquid maintenance hole 140 and prevent leakage during movement or operation. The sealing bolt 141 can preferably be replaced with an oil sight glass (transparent observation window), through which the internal liquid level and liquid condition can be visually observed for timely maintenance.

[0118] like Figure 16 and Figure 18 As shown, the liquid-cooled motor includes an output shaft 230 connected to the rotor 200, which extends out of the rear of the liquid-cooled motor through the motor cover 101. When the motor is mounted on a drive unit, no other components are installed on the exterior of the motor on the output portion 232 side of the output shaft 230. The liquid maintenance hole 140 is preferably located on the motor cover 101 on the output portion 232 side, allowing for direct replacement during motor maintenance and fluid changes without prior disassembly of other drive unit components.

[0119] When the liquid-cooled motor of the above technical solution is working, the rotation of the rotor 200 drives the guiding components (the guiding vanes 211 on the end cover 210 or the magnetic yoke 220 and magnet 221) to lift the cooling liquid 300 from the immersion area to the non-immersion area inside the inner cavity 110. Under the action of centrifugal force and gravity, the cooling liquid 300 splashes onto the inner wall of the inner cavity 110 and the stator coil 111, absorbs heat and flows back to the bottom, forming a circulating cooling system; at the same time, the heat dissipation fins 130 and the fan 400 on the motor housing 100 accelerate the heat dissipation of the motor housing 100, forming a composite cooling system.

[0120] The principle of heat dissipation of the liquid-cooled motor in the above technical solution is as follows: During the operation of the liquid-cooled motor, the heat source mainly comes from the stator coil 111 and the magnet 221, and part of it comes from the friction between the oil seal and the output shaft 230. Cooling liquid 300 is filled into the motor, and the heat on the stator coil 111 and the magnet 221 is transferred to the motor housing 100 for heat dissipation through the cooling liquid 300. At the same time, the heat accumulated by the rotation friction of the output shaft 230 can also be transferred to the motor housing 100 for heat dissipation. Specifically, the bottom stator coil 111 is immersed in the cooling liquid 300, which transfers heat from the coil to the motor housing 100 for heat dissipation. The magnets 221 on the rotor are first immersed in the cooling liquid 300 for heat dissipation during rotation, and then the rotation carries the cooling liquid 300 out. When the magnets 221 reach the top, the oil drips onto the stator coil 111 under the influence of gravity and centrifugal force, dissipating heat from the top stator coil 111. The guide vanes 211 on the rotor end cover 210 are paddle-shaped against the cooling liquid surface, and during high-speed rotation, they carry the heat-absorbing cooling liquid 300, splashing it onto the motor housing 100. The cooling liquid 300, under the influence of gravity and centrifugal force, is splashed onto the surface of the inner cavity 110, transferring heat to the motor housing 100, and then re-cooled and drips onto the magnets 221, stator coil 111, and output shaft 230, carrying away heat a second time. After the motor housing 100 absorbs the heat emitted by the cooling liquid 300, it evenly conducts the surface temperature of the inner cavity 110 to the heat dissipation fins 130 of the motor housing 100. At the same time, the fan 400, which is located on the front side of the motor housing, rotates together with the output shaft 230 and cools the motor housing 100 and the heat dissipation fins 130 under the guidance of the motor cover 401.

[0121] Due to the size limitations and working environment constraints of small construction machinery, the motors used in these machines are generally small in size. Furthermore, the harsh working environment, filled with dust, sand, cement, and other hard particles, necessitates the use of sealed motors. During operation, if the motor remains sealed, the internal pressure cannot be balanced, increasing rotational resistance and affecting normal operation. If vents are added to the motor, the issue of preventing oil leakage must be considered. In addition, if vents are provided, dust and water protection must be addressed to ensure the motor's stability and reliability under various working conditions. The following section describes how liquid-cooled motors, while incorporating vents, offer advantages in preventing coolant leakage and how they achieve waterproofing and dustproofing.

[0122] Figure 19 This is a schematic diagram of the structure of a liquid-cooled motor with an air pipe and an air filter assembly according to one embodiment of the present disclosure.

[0123] like Figure 18 and Figure 19As shown, in this embodiment of the liquid-cooled motor, to address the problem of drastic pressure changes inside the motor, a convoluted air pipe 500 is connected to the vent 120, allowing the interior of the liquid-cooled motor to communicate with the atmosphere, thereby achieving dynamic pressure balance within the motor. When the internal pressure of the motor increases, hot air is discharged through the convoluted path of the air pipe 500; when the pressure decreases, external air enters through the air pipe 500. Simultaneously, the air pipe 500 is connected to an air filter assembly 600. The convoluted path of the air pipe 500 and the air filter assembly 600 work together to ensure smooth gas exchange while preventing liquid leakage.

[0124] like Figure 18 and Figure 19 As shown, the air pipe 500 is connected to the vent 120 and the atmospheric environment at both ends. The air pipe 500 has a tortuous pipe structure. The top of the tortuous pipe structure must be higher than the top of the inner wall of the inner cavity 110, and its bottom must be lower than the bottom of the inner wall of the inner cavity 110. For example, the maximum height difference of the tortuous pipe structure is greater than the outer contour dimension of the motor. Specifically, one end of the air pipe 500 is connected downward from the vent 120. The pipe goes upward to the top lower plane of the support frame 700 and then bends in a U-shape. It goes downward to the bottom of the inner cavity 110 of the motor and below the same level as the bottom surface of the coolant 300. Then it bends in a U-shape again and goes almost vertically upward until it is at the same level as the top outer dimension of the motor housing 100. The air pipe 500 is then fixed with its opening facing upward.

[0125] like Figure 19 As shown, the tortuous pipe structure of the trachea 500 includes two opposing first U-shaped bends 510 and second U-shaped bends 520. The first U-shaped bend 510 connects to the vent 120, and its middle section forms the highest point of the trachea 500. The second U-shaped bend 520 communicates with the atmospheric environment, and its middle section forms the lowest point of the trachea 500. The vertical distance between the highest and lowest points is greater than the maximum outer height of the motor housing 100, and also greater than the height difference between the top and bottom of the inner cavity 110.

[0126] The pressure balance principle of the liquid-cooled motor in this embodiment is as follows: When the motor heats up during operation, its internal components expand due to heat, and the hot air is discharged through the tortuous pipe structure. Because the length of the air pipe 500 is more than twice the height of the motor's external dimensions, and its diameter is relatively wide, the pressure during exhaust is low, and the flow rate is slow. The coolant 300 adheres to the inner wall of the air pipe 500, while the gas passes through the top channel. In some cases, when the motor stops working and cools down, the tortuous pipe structure forms a gravity trap, and the coolant 300 adhering to the inner wall of the air pipe 500 deposits at the bottom of the U-bend. At this time, a negative pressure is formed inside the motor, and the deposited oil is drawn back into the motor cavity 110 by the pressure.

[0127] Specifically, the vent 120 on the motor housing 100 is connected to the atmospheric environment, which can regulate the internal pressure fluctuations during the operation of the liquid-cooled motor. When the motor heats up during operation, the internal components of the motor expand due to heat, and hot air needs to be expelled. At this time, the hot air needs to be discharged through the air pipe 500, which is more than twice the height of the motor's external dimensions. The pipe diameter is also relatively large, so the hot air experiences low pressure and slow flow rate within the air pipe 500 during exhaust.

[0128] When hot gas is discharged from the inner cavity 110, because the cooling liquid 300 (taking oil as an example) and gas inside the motor are not separated in advance, the present invention is to take measures in the setting direction of the air pipe 500 and the vent hole 120 to minimize the amount of oil carried out of the motor. First, the vent hole 120 is set in the opposite direction to the direction of oil splashing, so the oil cannot directly enter the air pipe 500 during splashing. Second, the pipeline path of the air pipe 500 is two perpendicular U-shapes, and the height difference between the two U-shaped bends is greater than the external dimensions of the motor. When the internal air pressure of the liquid-cooled motor fluctuates slightly, a small amount of oil splashed near the vent hole 120 will be squeezed into the air pipe 500 by the hot gas and adhere to the inner wall of the pipeline. Meanwhile, an air filter assembly 600 with a volume chamber 610 is installed at the end of the pipeline. The total volume of the volume chamber 610 is larger than the total volume of the air pipe, approximately 5%-10% of the total volume of cooling oil. If oil occasionally blocks the pipeline, affecting the normal discharge of hot air, the volume chamber 610 is much larger than the volume of the blocked oil. The hot air will accumulate pressure until the blocked oil is pushed from the air pipe 500 to the air filter assembly 600, and then smoothly discharged through the second vent 630 of the air filter assembly 600. When the motor stops working and is cooling, the tortuous pipeline forms a gravity trap. The oil inside the volume chamber 610 and on the inner wall of the air pipe 500 deposits at the bottom of the U-bend. At this time, a negative pressure is formed inside the motor, and the blocked oil will be drawn back into the motor through the pipeline with the pressure. A very small portion will continue to adhere to the inner wall of the air pipe 500.

[0129] Considering extreme cases, the oil adhering to the inner wall of the pipe may, after cooling or stabilizing, deposit under gravity in the lower U-shaped bend, still causing pipe congestion. However, because the volume of the storage chamber is much larger than the volume of the empty space inside the U-shaped bend where the deposited oil is deposited, this will not cause oil leakage from the air filter assembly 600 when the motor operates again. Similarly, because the air pipe 500 is designed with two opposing U-shaped bends, a short-term accidental tilt of the motor in either direction will not cause cooling oil leakage.

[0130] Figure 20 This is a schematic diagram of an air filter assembly according to one embodiment of the present disclosure.

[0131] See Figure 20As shown, an air filter assembly 600 is provided at the end of the air pipe 500. The air filter assembly 600 includes a volume chamber 610 and a first vent 620 and a second vent 630 communicating with the volume chamber 610. The first vent 620 is connected to the vent 120 through the air pipe 500, and the second vent 630 is connected to the atmospheric environment. Preferably, the air filter assembly 600 is installed in the following direction: Figure 19 As shown.

[0132] A partition shaft 640 is provided within the volume chamber 610. The partition shaft is divided into upper and lower halves by a shoulder in the middle where filter material 650 is installed. Filter material 650 is installed on the outer side of the lower half of the partition shaft 640. The upper half of the partition shaft 640 has a first channel 641. One end of the first channel 641 is connected to a first vent 620, and the other end is connected to the interior of the volume chamber outside the lower half of the partition shaft 640, and is surrounded and isolated by filter material 650. The lower half of the partition shaft 640 has a second channel 642. One end of the second channel 642 is connected to a second vent 630, and the other end is connected to the interior of the volume chamber outside the partition shaft 640.

[0133] The outer wall 611 of the volume chamber 610 is made of transparent material. Combined with the air passage structure described above, if dust enters, it will be deposited at the bottom of the volume chamber outside the filter material 650 due to gravity. The degree of dust deposition can be easily observed from the outside through the transparent outer wall 611, which is convenient for maintenance and judgment. In contrast, conventional air filters can also achieve basic ventilation, but if dust particles are deposited inside the filter material 650, they cannot be observed from the outside, making it inconvenient to judge the condition for maintenance.

[0134] The second vent 630 is surrounded by a filter sponge 660 for filtering the air flowing through it.

[0135] like Figure 16 , Figure 18 and Figure 20 As shown, the air filter assembly 600 is disposed inside the support frame 700 of the motor housing 100, and the air inlet and outlet directions of the assembly are perpendicular to the horizontal plane. The support frame 700 is provided with a shielding structure 710, which is used to partially shield the air filter assembly 600. For example, the air filter assembly 600 is vertically installed at the left front of the liquid-cooled motor, at the inner corner of the support frame 700, and the horizontal plane of the bottom surface of the volume chamber 610 is higher than the horizontal plane of the cooling liquid 300 in the inner cavity 110, preferably twice the height of the horizontal plane of the cooling liquid 300.

[0136] The air filter assembly 600 is vertically mounted at the inner corner of the support frame 700, on the left front of the motor. Components adjacent to the support frame 700 are located on the top, front, and left sides, while the motor is mounted on the right rear. Additionally, an outer casing 720 is installed on the outside of the support frame 700. When the entire drive unit requires washing, the air filter assembly 600 is isolated on all four sides at the corners, preventing water or cleaning agents from contacting the air vents.

[0137] Considering extreme cases, humid air needs to pass through the air filter assembly 600 and the air pipe 500 for a long time before entering the motor, so the impact of a single instance is negligible.

[0138] The principle of dust prevention in the liquid-cooled motor of this embodiment is as follows: First, after adding a pressure balancing pipeline to the liquid-cooled motor, an air filter assembly 600 is installed at the end of the air pipe 500. The air filter assembly 600 contains a filter material 650 (such as a high-density filter screen), and a filter sponge 660 is installed at the end of the second air vent 630 of the air filter assembly 600, thereby forming at least two layers of filtration structure in different planes and dimensions. At the same time, the air filter assembly 600 isolates most of the dust and particulate matter from adhering at the installation position of the support frame 700. Equally important, the tortuous pipeline structure of the air pipe 500 can further prevent dust and particulate matter from entering the liquid-cooled motor.

[0139] The principle behind the waterproofing of the liquid-cooled motor in this embodiment is as follows: During operation, the inner cavity 110 of the liquid-cooled motor is connected to the atmosphere only through the vent 120 via a pressure balance pipe. Therefore, during normal operation, due to atmospheric pressure, water vapor cannot actively flow from the air filter assembly 600 at the end of the pipe to the motor. Furthermore, considering the installation location of the air filter assembly 600—it is installed inside the inner corner of the support frame 700, adjacent to the top, front, and left sides of the support frame 700, with the motor installed at the rear right—and an outer casing 720 is installed outside the overall support frame 700. When the entire drive unit needs washing, this corner is isolated on all four sides, preventing the vent of the air filter assembly 600 from contacting water or cleaning agents.

[0140] Considering extreme cases, such as after rain or cleaning of machinery, the surrounding air is humid and contains water vapor. If a negative pressure forms in the pipeline during motor cooling, air enters the motor through the air pipe 500 to balance the pressure. In this case, the humid air needs to pass through two layers of filters in the air filter assembly 600 and then through two U-shaped bends in the air pipe 500 before entering the motor cavity 110. The impact of a single instance of humid air entering the motor is negligible. However, if we consider the long-term accumulation of water droplets under these conditions, the effect of a large amount of dust condensing into water would also be needed to potentially cause a short circuit inside the motor. But the cumulative time of this process exceeds the normal operating life of the liquid-cooled motor.

[0141] It should be noted that the heat dissipation, waterproofing and dustproofing structures of the liquid-cooled motor in the above embodiments can be used in the same liquid-cooled motor to achieve the advantages of significant heat dissipation and cooling effect, simple structure, small space occupation, convenient disassembly and assembly, few failures, light weight and low cost.

[0142] This embodiment provides an electric drive system, including: a liquid-cooled motor and a battery pack as described in the above embodiment; wherein the battery pack powers the liquid-cooled motor.

[0143] It is understood that in the electric drive system provided in this embodiment, the liquid-cooled motor can be replaced with other motors that require battery pack power, and the battery pack can be used to power the motor.

[0144] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0145] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A battery pack, comprising a battery module, the battery module including a battery and a battery bracket, characterized in that, include The battery casing has an opening. A heat dissipation component is provided with a heat dissipation section, the heat dissipation section including annular heat dissipation fins, the annular heat dissipation fins being clearance-fitted with the opening; and An annular seal is fitted onto the annular heat dissipation fins and has a groove structure that engages with the end of the annular heat dissipation fins, a first sealing protrusion located inside the groove structure, and a second sealing protrusion located on the outer periphery of the annular seal. The first sealing protrusion is interference-fitted with the sidewall of the annular heat dissipation fin, and the second sealing protrusion is interference-fitted with the opening.

2. The battery pack according to claim 1, characterized in that, The annular seal is provided with a sealing body, and a first sealing surface and a second sealing surface are respectively provided on both sides of the sealing body. The first sealing protrusion is provided on the first sealing surface, and the second sealing protrusion is provided on the second sealing surface.

3. The battery pack according to claim 2, characterized in that, The opening is provided with sealing ribs that extend in the opposite direction to the second sealing protrusion; The sealing rib is integrally press-fitted with the annular seal to enhance the sealing effect of the second sealing surface.

4. The battery pack according to claim 2, characterized in that, The annular seal has a recess on its outer side, which is located on the outer side of the sealing body.

5. The battery pack according to claim 1, characterized in that, The annular seal is provided with a limiting protrusion, which is located inside the outer casing of the battery.

6. The battery pack according to claim 1, characterized in that, The battery casing includes an assemblable battery housing and a battery housing cover; The heat dissipation section extends through the connection between the battery box body and the battery box cover; The battery box, battery box cover, and heat dissipation part are provided with a through connection structure, so that the battery box, battery box cover, and heat dissipation part are fixed at the same connection point by the same fastener.

7. The battery pack according to claim 6, characterized in that, The through-connection structure includes: a bottom connecting post disposed on the battery box body, a through hole disposed on the heat dissipation part, and a top connecting hole disposed on the battery box cover; The through hole is coaxially arranged with the connecting post and the connecting hole.

8. The battery pack according to claim 1, characterized in that, It also includes a power socket and a waterproof sealing cap, the waterproof sealing cap sealing the power socket.

9. The battery pack according to claim 1, characterized in that, The battery outer casing is provided with a cavity, and the battery module is provided inside the cavity; the battery pack also includes a thermally conductive insulating layer, which is made of a flexible insulating material and has a thermal conductivity greater than that of air, and the thermally conductive insulating layer is attached to the outside of the battery connecting piece; The heat dissipation component is disposed on the outside of the thermally conductive insulating layer. The heat dissipation part penetrates through the battery casing and is provided with a heat dissipation structure extending to the outside of the battery casing.

10. An electric drive system, characterized in that, It includes a motor and a battery pack according to any one of claims 1-9; wherein the battery pack powers the motor.

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