An electric machine, a housing unit and a method thereof

Abstract

The present invention relates to a housing unit (200), an electric machine, and a method (300) to manufacture the housing unit (200). The housing unit (200) comprises a casing (201) and a plurality of cavities (203). The casing (201) is configured to receive a plurality of components of the electric machine through an opening (202). The casing (201) is made up of a first predefined material. The plurality of cavities (203) is disposed on an inner circumferential surface (201S) of the casing (201). The plurality of cavities (203) is configured to receive a second predefined material. The electric machine comprises a rotor, a stator, and a housing unit (200). The housing unit (200) is configured to enclose the rotor, stator, and a plurality of predefined components of the electric machine.

Description

TITLE OF INVENTION:AN ELECTRIC MACHINE, A HOUSING UNIT AND A METHOD THEREOFTECHNICAL FIELD

[0001] The present disclosure relates to an electric machine, a housing unit for the electric machine and a method to manufacture the housing unit. More particularly, but not exclusively, the present subject matter relates to an electric motor for a vehicle, a housing unit for the electric motor and a method to manufacture the housing unit.BACKGROUND

[0002] In the electrical manufacturing sector, the processes of encapsulation and potting are crucial for improving the reliability, performance, and lifespan of electric machines used in essential applications. These processes are vital for safeguarding sensitive components from environmental influences, mechanical stress, and electrical interference. Potting involves filling a housing or cavity containing motor parts with a protective material, effectively embedding the components within it. Traditionally, potting was used to encapsulate sensors, connectors, and electronic control units, making them resistant to harsh environmental conditions. These applications typically did not require heat dissipation, as they were usually applied to low-voltage components or exposed areas in vehicles. However, in recent years, the rise of electric vehicle (EV) and hybrid technologies has introduced new, high-voltage components that demand not only protection but also efficient heat management. Thermal potting has gained renewed importance in the automobile sector by both protecting and directing heat away from sensitive components of the electric machines such as on-board chargers, inverters, converters, and motors.

[0003] In particular, the traction motor encounters a major issue with excessive heat, primarily caused by insufficient thermal conductivity around its end windings. This heat buildup elevates the motor’s temperature to critical levels defined by the magnet grade. Once these thresholds are surpassed, the motorexperiences derating, which reduces its torque output to avoid additional thermal damage. Continuous exposure to such conditions not only diminishes performance but also increases the risk of customer dissatisfaction, as the motor may fail to meet the required operational demands over prolonged use.

[0004] To overcome this, the space between the motor windings and the casing is filled with a thermally conductive potting material, aiming to improve heat dissipation. However, the current potting methods have notable limitations. Achieving a thorough and even distribution of the potting material is difficult, often leading to defects like uneven material coverage, solidification problems, and porosity (air gaps). These flaws weaken the motor's thermal performance by hindering proper heat transfer and diminish its mechanical reliability.

[0005] For motors with a larger stack length, the existing motor housing presents an additional challenge during the potting process. Conventional housing configurations are not optimized for properly filling the epoxy, resin, or potting material necessary for effective thermal management. The increased stack length complicates achieving a uniform and complete fill due to the greater volume and intricate internal geometry of the motor housing. This limitation not only increases the risk of incomplete fills, porosity, and uneven material distribution but also heightens the likelihood of solidification defects, further compromising the thermal and mechanical performance of the motor. Consequently, larger motor requires a tailored approach to ensure the potting material is applied evenly and effectively without gaps or air bubbles.

[0006] The end windings of the motor are particularly susceptible to overheating because they are exposed to concentrated heat with inadequate thermal dissipation pathways. Without efficient thermal management, such as uniform application of potting material, heat generated during motor operation gets trapped in this region. This trapped heat can elevate the temperature beyond safe operating limits, causing performance degradation. Overheating of the end windings not only diminishes the torque output but also accelerates wear on other critical components, ultimately shortening the motor’s lifespan and reliability.

[0007] Insulation materials in the motor windings are configured to withstand specific temperature limits. However, prolonged exposure to such elevated temperatures leads to the thermal degradation of these insulation materials. This degradation weakens their insulating properties, reducing dielectric strength and increasing the risk of electrical short circuits and winding failure. Loss of insulation integrity can also pose safety hazards, leading to expensive repairs or replacements, thus negatively impacting customer satisfaction and operational efficiency.

[0008] The permanent magnets in traction motors are sensitive to high temperatures, which can cause partial or full demagnetization. When the motor exceeds the critical thermal limit defined by the magnet grade, the magnetic properties of the magnetic material , reducing the motor’s torque and overall efficiency. In severe cases, this demagnetization can be irreversible, resulting in permanent performance loss. This failure is particularly detrimental in electric vehicles, where consistent and reliable torque delivery is essential for maintaining vehicle performance and the driving experience.

[0009] Porosity and voids in the potting material may also occur due to incomplete filling or air bubbles trapped during the potting process. These defects impair the material’s ability to conduct heat effectively, leading to hotspots and uneven thermal distribution within the motor. Additionally, the structural integrity of the potting material is compromised, making it more vulnerable to mechanical stresses and vibrations. Porosity and air bubbles also create pathways for moisture ingress, which accelerate corrosion and can further damage the motor’s internal components. In high-voltage applications, voids and air pockets within the potting material are problematic as they can lead to partial discharge, a phenomenon where localized electrical discharges occur in weak insulation areas. These discharges degrade the insulation over time, increasing the likelihood of electrical failure.

[0010] Solidification cracking occurs when the potting material cools and hardens unevenly, often due to inconsistencies in material distribution or improper curing conditions. These cracks reduce the mechanical strength andthermal conductivity of the potting material, creating weak points that can propagate under operational stress. Solidification cracks undermine the motor's ability to dissipate heat and increase the risk of insulation failure, further exacerbating overheating and reducing the motor’s reliability. This failure mode is especially problematic in larger motors with extended stack lengths, where achieving consistent potting is already challenging.

[0011] To address the above cited issues, the solution is needed that focuses on adapting the motor housing or developing a compatible process that enables efficient, consistent potting for motors with longer stack lengths. The solution must prioritize high thermal conductivity and mechanical integrity to ensure the motor operates reliably while maintaining performance standards in demanding conditions.SUMMARY OF THE INVENTION

[0012] The present subject matter relates to a housing unit for an electric machine. The housing unit comprises a casing and a plurality of cavities. The casing is configured to receive a plurality of components of the electric machine through an opening. The casing is made up of a first predefined material. The plurality of cavities is disposed on an inner circumferential surface of the casing. The plurality of cavities is configured to receive a second predefined material.

[0013] The present subject matter also relates to an electric machine. The electric machine comprises a rotor, a stator, and a housing unit. The rotor is installed in a rotatory configuration. The stator is installed in a stationary configuration. The housing unit is configured to enclose the rotor, and the stator of the electric machine. The housing unit comprises a casing and a plurality of cavities. The casing is configured to receive the rotor and the stator through an opening. The casing is made up of a first predefined material. The plurality of cavities is disposed on an inner circumferential surface of the casing. The plurality of cavities is configured to receive a second predefined material.

[0014] The present subject matter further relates to a method to manufacture a housing unit for an electric machine. The method comprises a plurality of steps.A first step of the plurality of steps involves employing a casing. The casing is configured to receive a plurality of components of the electric machine through an opening. The casing is made up of a first predefined material. A second step of the plurality of steps involves forming a plurality of cavities on an inner circumferential surface of the casing. A third step of the plurality of steps involves filling the plurality of cavities with a second predefined material.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The details are described with reference to an embodiment of a housing unit, an electric machine and a method to manufacture the housing unit for the electric machine. The same reference numbers are used throughout the drawings to refer to similar features and components.

[0016] Figure 1 illustrates a side perspective of the housing unit, in accordance with an embodiment of the present disclosure.

[0017] Figure 2 illustrates a cross-sectional view of the housing unit along an axis A-A’ shown in Figure 1, in accordance with an embodiment of the present disclosure.

[0018] Figure 3a illustrates a side perspective of the housing unit, in accordance with an embodiment of the present disclosure.

[0019] Figure 3b illustrates a side perspective of the housing unit, in accordance with an embodiment of the present disclosure.

[0020] Figure 4 illustrates a flow chart of the method to manufacture a housing unit for an electric machine, as per another embodiment of the present disclosure.DETAILED DESCRIPTION

[0021] In order to overcome one or more of the above-mentioned challenges, the present disclosure has been described with reference to the following embodiments. It will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the scope of the disclosure.

[0022] The present disclosure entails an electric machine, a housing unit thereof and a method to manufacture the housing unit. The present disclosure addresscritical issues such as incomplete fills, air entrapment, and uneven material distribution, all of which can impair the thermal and mechanical performance of the electric machine.

[0023] As per one embodiment of the disclosure, a housing unit for an electric machine has been disclosed. The housing unit comprises a casing and a plurality of cavities. The casing is configured to receive a plurality of components of the electric machine through an opening. The casing is made up of a first predefined material. The plurality of cavities is disposed on an inner circumferential surface of the casing. The plurality of cavities is configured to receive a second predefined material.

[0024] As per one embodiment of the disclosure, a thermal conductivity of the second predefined material is greater than a thermal conductivity of the first predefined material.

[0025] As per one embodiment of the disclosure, the thermal conductivity of the second predefined material is configured to vary along a predefined gradient.

[0026] As per one embodiment of the disclosure, the second predefined material is a muti-phase material and a self-healing material.

[0027] As per one embodiment of the disclosure, the casing comprises a plurality of raised surfaces. The plurality of raised surfaces is configured to separate the plurality of cavities. A surface area of the inner circumferential surface of the casing is ‘SI’. A combined surface area of the plurality of raised surfaces is ‘S2’. A ratio of ‘ S 1’ to a difference between ‘SI’ and ‘ S2’ ranges between 1.06 to 1.2.

[0028] As per one embodiment of the disclosure, a combined value of a volume of the plurality of cavities is ‘VI’ and a ratio of ‘SI’ to ‘VI’ ranges between 16.5 to 1.4.

[0029] As per one embodiment of the disclosure, the plurality of cavities comprises a plurality of coolant channels. The plurality of coolant channels is configured to circulate a coolant medium across the second predefined material.

[0030] As per one embodiment of the disclosure, the second predefined material comprises a damping material.

[0031] As per one embodiment of the disclosure, the casing comprises a plurality of dampening members. The plurality of dampening members is disposed within the plurality of cavities.

[0032] As per one embodiment of the disclosure, the casing comprises one or more sensing units. The one or more sensing units are disposed within the plurality of cavities.

[0033] As per one embodiment of the disclosure, the casing comprises a plurality of reinforcement members. The plurality of reinforcement members is disposed within the plurality of cavities.

[0034] As per another embodiment of the disclosure, an electric machine is disclosed herein. The electric machine comprises a rotor, a stator, and a housing unit. The rotor is installed in a rotatory configuration. The stator is installed in a stationary configuration. The housing unit is configured to enclose the rotor, and the stator of the electric machine. The housing unit comprises a casing and a plurality of cavities. The casing is configured to receive the rotor and the stator through an opening. The casing is made up of a first predefined material. The plurality of cavities is disposed on an inner circumferential surface of the casing. The plurality of cavities is configured to receive a second predefined material.

[0035] As per another embodiment of the disclosure, the housing unit comprises a circumferential notch.

[0036] As per another embodiment of the disclosure, the stator comprises a plurality of pockets. The plurality of pockets is configured to receive the second predefined material.

[0037] As per another embodiment of the disclosure, a total number of the plurality of cavities is a predetermined value ‘N’. The predetermined value ‘N’ is dependent on a total volume of the casing, a total volume of the second predefined material used, a volume of one of the plurality of cavities, a thermal profile of the electric machine, a shape of the plurality of cavities, mechanical strength of the first predefined material and a rate of flow of the second predefined material.

[0038] As per yet another embodiment of the disclosure, a method to manufacture a housing unit for an electric machine is disclosed herein. The method comprises a plurality of steps. A first step of the plurality of steps involves employing a casing. The casing is configured to receive a plurality of components of the electric machine through an opening. The casing is made up of a first predefined material. A second step of the plurality of steps involves forming a plurality of cavities on an inner circumferential surface of the casing. A third step of the plurality of steps involves filling the plurality of cavities with a second predefined material.

[0039] The embodiments of the present disclosure will now be described in detail with reference to an embodiment of a housing unit (200) and a method (300) to manufacture a housing unit (200) for an electric machine along with the accompanying drawings. However, the disclosed invention is not limited to the present embodiments. The embodiments shown in Figure 1 and Figure 2 are taken together for discussion. Figure 1 illustrates a side perspective of the housing unit (200) for an electric machine. Figure 2 illustrates a cross-sectional view of the housing unit (200) along an axis A-A’ shown in Figure 1,

[0040] In one embodiment of the present disclosure, the electric machine is an electric motor. The housing unit (200) encloses the rotor and the stator. The rotor is installed in a rotatory configuration. In electric motors, the rotor is the rotating part that interacts with the magnetic field to produce mechanical motion. The rotor works in conjunction with the stator, which is installed in a stationary configuration and is responsible for generating a magnetic field, which interacts with the rotor to produce mechanical motion. In Alternating Current motors, the stator contains windings (coils of wire) through which alternating current passes. This current creates a rotating magnetic field that interacts with the rotor, causing it to spin. In Direct Current motors, the stator typically contains permanent magnets or electromagnets that create a static magnetic field. The interaction between this magnetic field and the current in the windings of the rotor produces the mechanical motion.

[0041] The housing unit (200) comprises a casing (201) and a plurality of cavities (203). The casing (201) is configured to receive the rotor and the stator through an opening (202). The casing (201) is made up of a first predefined material. The first predefined material is selected on the basis of key considerations like corrosion resistance, heat dissipation, weight, strength and durability. The first predefined material includes but not limited to cast aluminium, steel (carbon or stainless), die-cast zinc, plastics such as polycarbonate or nylon and cast iron and composite materials like glass fibre reinforced polymers (GFRP), carbon fibre reinforced polymers (CFRP), and aramid fibre composites (AFRP).

[0042] The plurality of cavities (203) is disposed on an inner circumferential surface (201 S) of the casing (201). The plurality of cavities (203) receives a second predefined material. A thermal conductivity of the second predefined material is greater than a thermal conductivity of the first predefined material.

[0043] The second predefined material is a thermally conductive potting materials which provides both electrical insulation and efficient heat dissipation for a plurality of components of the electric machine. The thermally conductive potting material base resin and thermally conductive fillers as key components. The base resin is the matrix material such as epoxy, silicone, or urethane, which forms the primary structure of the potting compound. The thermally conductive fillers increase the ability of the second predefined material to conduct heat. Commonly used thermally conductive fillers are Aluminium Oxide (AI2O3), Boron Nitride (BN), Silicon Carbide (SiC), Graphite, Aluminum Nitride (AIN) and Copper Powders.

[0044] The thermal conductivity of the second predefined material varies along a predefined gradient. In high-performance electric machines, certain regions may experience more significant heat buildup than others. To optimize heat dissipation, the plurality of cavities (203) could be filled with the second predefined material having varied material composition such that the thermal conductivity of the second predefined material gradually shifts to accommodate higher thermal demands in specific regions. For example, the region of the plurality of cavities (203) experiencing higher temperature from the windings ofthe rotor or stator could be filled with the second predefined material having high thermal conductivity. This dynamic configuration would allow the electric machines to effectively manage varying heat levels, reducing the risk of overheating, insulation degradation, and ensuring efficient performance.

[0045] In an embodiment of the present disclosure, the second predefined material is a muti-phase material and a self-healing material. The muti-phase material consists of two or more phases. One is typically the matrix phase, and the other(s) are reinforcing phases. Different regions of the plurality of cavities (203) are filled with the second predefined material having distinct phases based on their specific functional requirements. For example, highly thermally conductive materials could be used in the regions of the plurality of cavities (203) near the end windings of the rotor or stator and the regions that experience higher thermal stress. Mechanically robust or flexible materials could be used in the regions of the plurality of cavities (203) configured to hold the stator or rotor in place. This multi-phase approach further enhances the ability of the electric machine to manage both thermal and mechanical stresses, reducing failure modes such as overheating, solidification cracking of the second predefined material, and slipping of the rotor. The use of these varying materials in combination with the optimized plurality of cavities (203) would allow for a more targeted and efficient solution to challenges during the assembly of the electric machine.

[0046] The second predefined material is a self-healing material which is thermally responsive and allow the housing unit (200) to recover from minor thermal damage, such as small cracks or voids that may form over time due to thermal cycling or mechanical stress. The self-healing material would seal any defects that occur, maintaining the structural integrity and thermal performance of the housing unit (200). This innovation would significantly extend the lifespan and improve the reliability of the electric machine under demanding operational conditions.

[0047] In an embodiment of the present disclosure, the plurality of cavities (203) comprises a plurality of coolant channels, the plurality of coolant channels being configured to circulate a coolant medium across the second predefined material.The plurality of coolant channels are connected to an external cooling system, allowing for active thermal management in high-temperature zones. The coolant medium (e.g., water or refrigerants) are circulate through these plurality of cavities (203), efficiently absorbing heat from the plurality of components of the electric machine and dissipating it away from the sensitive areas. This configuration provides superior heat management and prevent overheating, particularly in regions of the electric machine that experience constant high-temperature, such as the end windings.

[0048] The second predefined material comprises a damping material. The casing (201) is subjected to significant mechanical stresses, including vibrations and shocks. To counteract this, the second predefined material can integrate damping materials such as elastomers or foams that absorb vibrations. Alternatively, the casing (201) is provided with a plurality of dampening members. The plurality of dampening members is disposed within the plurality of cavities (203). The dampening members reduce the mechanical strain on the casing (201) and stator, preventing rotor slipping, stator misalignment, or failure caused by continuous mechanical loading. These damping features could be particularly beneficial in applications with high mechanical stress, like electric vehicles or industrial motors.

[0049] The casing (201) comprises one or more sensing units. The one or more sensing units is disposed within the plurality of cavities (203). The one or more sensing units are integrated thermal and mechanical sensors that monitor temperature, pressure, and stress levels within the casing (201). The one or more sensing units provide real-time data on the operating condition of the electric machine and enable proactive thermal management or mechanical adjustments through a control system. For instance, if temperatures rise beyond a safe threshold in a specific region, the control system triggers external cooling system or alter the operation of the electric machine to prevent thermal overload. This provides better control over the performance of the electric machine, ensuring long-term reliability and preventing failure modes such as overheating or insulation degradation.

[0050] The casing (201) comprises a plurality of reinforcement members. The plurality of reinforcement members is disposed within the plurality of cavities (203). The reinforcement members within the plurality of cavities (203) further enhances the mechanical integrity of the electric machine. By integrating reinforcement members like reinforced ribs or supports within the plurality of cavities (203), the casing (201) could achieve improved structural strength without compromising the effectiveness of heat dissipation. The reinforcement members ensures that the electric machine is able to withstand high mechanical loads and vibrations, reducing the risk of rotor displacement, stator misalignment, or other mechanical failures during operation. This would be especially beneficial in high-performance applications where reliability of the electric machine is critical.

[0051] The housing unit (200) comprises a circumferential notch (205). The circumferential notch (205) guides and secures a placement for the stator. The circumferential notch (205) is a machine-cut section, precisely created within the casing (201) to provide a stable resting place for the stator. The circumferential notch (205) ensures the stator is securely seated and positioned for optimal functionality. Adjacent to the circumferential notch (205), a space is configured to accommodate the winding of the poles associated with the magnet, allowing for an efficient and compact placement of the winding components. The lower portion underneath the circumferential notch (205) is cut to facilitate the distribution of the second predefined material, which is introduced from the top. This directs the flow of the second predefined material outward to a surface extension, forcing it into the circumferential notch (205) to provide uniform coverage and secure encapsulation. Further, a temporary wall is incorporated into the circumferential notch (205), acting as a barrier to prevent the second predefined material from spilling or escaping during the curing process. This ensures that the second predefined material remains confined to the desired sections, enhancing structural integrity, electrical insulation, and environmental protection for the stator and its components.

[0052] The stator comprises a plurality of pockets. The plurality of pockets receives the second predefined material. The plurality of pockets facilitate the flow of second predefined material around the stator windings, ensuring that high-temperature regions within the stator are adequately covered. This configuration further enhances the thermal management capabilities of the electric machine by promoting efficient heat dissipation from both the stator and housing, effectively addressing overheating and insulation degradation issues.

[0053] The embodiments shown in Figure 3a and 3b are taken together for discussion. Figure 3a illustrates a side perspective of the housing unit (200), in accordance with an embodiment of the present disclosure. Figure 3b illustrates a side perspective of the housing unit (200), in accordance with an embodiment of the present disclosure.

[0054] A shape of the plurality of cavities (203) includes but not limited to cylindrical shape, spherical shape, and prismatic shape. The shape of the plurality of cavities (203) allows for flexibility in adapting to different configuration and architecture of the housing unit (200) and the electric machine. This customization ensures the solution is scalable and applicable to electric machine with varying sizes and requirements. In an embodiment of the present disclosure, the plurality of cavities (203) is spherical in shape ensuring that the second predefined material flows evenly around all sides of the casing (201). The spherical shape reduces the chances of stagnation of the second predefined material or uneven distribution, as it encourages the even flow of the second predefined material around the plurality of components of the electric machine. This is particularly beneficial in large electric machines where traditional, straight shapes may not fully optimize the filling process. The plurality of cavities (203) with hollow configuration also reduce the weight of the motor housing, offering a more lightweight and efficient configuration while still providing effective thermal management.

[0055] In another embodiment, the volume of the plurality of cavities (203) is strategically increased in regions where the winding temperature is higher. This adaptive configuration ensures that more second predefined material is directedto regions with greater thermal stress, thereby enhancing localized heat dissipation. By targeting high-temperature zones, this approach prevents thermal hotspots, mitigates the risk of thermal degradation of insulation, and ensures that the electric machine operates within safe temperature limits. The variation in the volume of the plurality of cavities (203) also optimizes material usage, reducing waste and improving manufacturing efficiency. For an example, the volume of the plurality of cavities (203) shown in Figure 3a is higher than the volume of the plurality of cavities (203) shown in Figure 3b. This makes plurality of cavities (203) shown in Figure 3a suitable for high-performance applications while making the plurality of cavities (203) shown in Figure 3b suitable when high mechanical strength and durability is needed.

[0056] The shape and dimensions of the plurality of cavities (203) are also varied across different regions of the electric machine. This flexibility allows the plurality of cavities (203) to adapt to the specific thermal and mechanical requirements of each area. For example, larger and deeper plurality of cavities (203) can be used in high-temperature zones to maximize heat transfer, while smaller plurality of cavities (203) may be employed in regions requiring additional structural strength. By tailoring the dimensions of the plurality of cavities (203) to the functional needs of the plurality of cavities (203). This strikes a balance between thermal performance and mechanical integrity, addressing failure modes such as rotor slipping, solidification cracking, and stress-induced weaknesses.

[0057] The casing (201) comprises a plurality of raised surfaces (204). The plurality of raised surfaces (204) separates the plurality of cavities (203). A surface area of the inner circumferential surface (201 S) of the casing (201) is ‘SI’. A combined surface area of the plurality of raised surfaces (204) is ‘S2’. A ratio of ‘SI’ to ‘S2’ is preferably within a range of 1.06 tol.2. This ratio ensures that the potential defects such as solidification cracking or stress concentrations that arise from uneven curing are eliminated. Consequently, the housing unit (200) benefits from improved mechanical stability and durability, even under demanding operational conditions. Further, this ratio simplifies the fillingprocess for the second predefined material by reducing filling time and ensuring complete encapsulation without leaving gaps or air bubbles. This not only enhances the thermal performance of the electric machine but also supports the long-term reliability and customer satisfaction. By addressing multiple failure modes including overheating, insulation degradation, and porosity, this ratio significantly improves the operational lifespan and performance of the electric motors, particularly those with larger stack lengths.

[0058] A combined value of a volume of the plurality of cavities (203) is ‘VI’. A ratio of ‘SI’ to ‘VI’ is preferably kept within a range of 16.5 to 1.4. This ratio ensures that the second predefined material is sufficiently and evenly applied without adding any unnecessary weight to the housing unit (200) thereby achieving lightweight and efficient configuration.

[0059] The implementation of the plurality of cavities (203) in the housing unit (200) are guided by critical factors to ensure optimal performance, durability, and efficiency of the electric machine. Two primary considerations are filling time and the fitment of the stacking stator fix within the casing (201). These factors directly influence the effectiveness of the process of filling the plurality of cavities (203) with a second predefined material, the structural stability of the housing unit (200), and the ability to perform reliably under operational stresses.

[0060] Fill time is a key determinant in the configuration of the plurality of cavities (203). Efficient potting processes require a balance between rapid filling and complete encapsulation. The plurality of cavities (203) are positioned and sized to facilitate smooth and uniform flow of the second predefined material into the casing (201), reducing the time required for filling while ensuring that no voids or air pockets are left behind. Faster and more thorough filling enhances the thermal conductivity of the second predefined material, prevents overheating, and mitigates defects such as porosity or uneven curing.

[0061] The fitment of the stacking stator fix within the casing (201) is another crucial consideration. The plurality of cavities (203) integrates seamlessly with the existing geometry of the electric machine, ensuring that the stator is securely held in place without compromising the integrity of the encapsulation. Theinteraction between the plurality of cavities (203) and the stator avoids any weak points that could impact the mechanical stability or alignment of the electric machine.

[0062] Additionally, the number of the plurality of cavities (203) must be carefully optimized. A total number of the plurality of cavities (203) is a predetermined value ‘N’. The predetermined value ‘N’ is dependent on a total volume of the casing (201), a total volume of the second predefined material used, a volume of one of the plurality of cavities (203), a thermal profile of the electric machine, a shape of the plurality of cavities (203), mechanical strength of the first predefined material and a rate of flow of the second predefined material. While increasing the number of plurality of cavities (203) can improve uniformity and heat dissipation, it can also weaken the structural integrity of the housing unit (200). Too many plurality of cavities (203) may reduce the ability of the housing unit (200) to firmly hold the rotor and stator in place, increasing the risk of the rotor slipping during the operation. This mechanical failure mode is particularly critical in high-performance applications where the electric machine is subject to significant vibrations and dynamic loads. Thus, the number and placement of the plurality of cavities (203) are determined based on the required strength to securely hold the windings and maintain the alignment of the rotor and stator during operation.

[0063] The total volume of the second predefined material required is typically determined by the size of the electric machine and the portion of the electric machine to be encapsulated. The dimensions of the stator (e.g., length, radius, and windings) are determined. The regions of the electric machine that experience the most thermal stress (typically the end windings) is also determined. The dimensions of the portion of the casing (201) where the plurality of cavities (203) are formed is analysed.

[0064] The size and volume of each the plurality of cavities (203) is optimized to allow for efficient flow and fill of the second predefined material. Typically, this depends on the geometry of the housing unit (200) and the required fill rate. The number of plurality of cavities (203) is balanced to provide structuralsupport. Too few plurality of cavities (203) may lead to improper filling or poor mechanical stability, while too many could affect the strength of the housing unit (200) and increase the risk of rotor displacement. The plurality of cavities (203) are strategically placed in areas with the highest thermal stress (e.g., regions where the windings are secured).

[0065] To determine the location and number of plurality of cavities (203), the thermal profile of the electric machine is considered. The plurality of cavities (203) are distributed more heavily in regions of higher thermal stress. The required number of the plurality of cavities (203) in thermal hotspots is determined by a thermal map of the electric machine, which identifies areas where heat dissipation needs to be maximized. The regions of the electric machine that are expected to reach higher temperatures, such as the windings, particularly the end windings are mapped out. These areas require more attention while considering the distribution of the plurality of cavities (203). The thermal conductivity of the second predefined material, and its variation within the plurality of cavities (203) are also taken into consideration.

[0066] The number of the plurality of cavities (203) are balanced with the need for mechanical strength to hold the windings in place without causing rotor displacement. Increasing the number of the plurality of cavities (203) can reduce the holding strength of the casing (201) if not distributed properly. A safe estimate is derived based on the strength of the first predefined material and the space constraints. The shape (e.g., circular, rectangular) and size of the plurality of cavities (203) impacts the amount of the second predefined material that can be contained in each of the plurality of cavities (203). For regions with high thermal loads, the size or the number of the plurality of cavities (203) can be increased for better thermal dissipation. The volume of the plurality of cavities (203) is increased in areas where the temperature is expected to be higher, allowing more second predefined material to be used in those specific regions. This can be achieved through varying the size or number of plurality of cavities (203) in high-stress zones. The number of plurality of cavities (203) is ensured not to interfere with the mechanical support of the casing (201). Too manyplurality of cavities (203) can weaken the housing unit (200) and increase the risk of rotor slipping or instability.

[0067] The number of the plurality of cavities (203) is chosen such that the fill time is minimized, but not so high that it leads to air entrapment or uneven filling. For a given second predefined material, the time required to fill each of the plurality of cavities (203) is dependent on the viscosity of the second predefined material, the geometry of the plurality of cavities (203), and the rate of the filling of the second predefined material.

[0068] The embodiments shown in Figure 4 are taken for discussion. Figure 4 illustrates a flow chart of the method (300) to manufacture a housing unit (200) for an electric machine. The method (300) comprises a steps of employing (301) a casing (201). The casing (201) receives a plurality of components of the electric machine through an opening (202). The casing (201) is made up of a first predefined material. The method (300) also comprises a steps of forming (302) a plurality of cavities (203) on an inner circumferential surface (201 S) of the casing (201). The method (300) further comprises a steps of filling (303) the plurality of cavities (203) with a second predefined material.

[0069] The disclosure and its embodiments have numerous advantages that significantly enhance the performance, reliability, and manufacturability of the electric machine, particularly in applications requiring high thermal and mechanical performance. The primary advantage of the present disclosure lies in the optimized potting process, which improves the uniform distribution of potting materials throughout the housing unit (200). By strategically incorporating plurality of cavities (203) within the casing (201), the potting material fills the space more efficiently, reducing the occurrence of air pockets, voids, and porosity. This leads to a more consistent and high-quality potting process, enhancing the thermal conductivity and mechanical stability of the electric machine, and thereby improving its overall performance and lifespan.

[0070] Another significant advantage is the enhanced thermal management achieved by the plurality of cavities (203). By directing the potting material to areas of higher thermal stress, such as the end windings, and optimizing the flowof heat throughout the casing (201), the housing unit (200) is better able to manage temperature fluctuations. This results in reduced overheating and prevents thermal degradation of insulation and other critical components. By ensuring that heat is more efficiently transferred from the windings to the housing unit (200), the electric machine operates within safe temperature limits, preventing performance degradation due to excessive heat, which would otherwise lead to thermal derating or demagnetization of magnets. This improved heat dissipation directly contributes to better overall efficiency and reliability of the electric machine.

[0071] The improved encapsulation facilitated by the plurality of cavities (203) also contributes to superior thermal conductivity. The uniform distribution of the potting material ensures that it is in direct and consistent contact with the casing (201). This promotes efficient heat transfer from the electric machine to the casing (201), which acts as a thermal sink. By preventing hotspots and maintaining optimal operating temperatures, the problem of overheating in critical areas like the end windings is addressed. This ensures that the electric machine operates within safe thermal limits, avoiding derating and maintaining consistent performance over prolonged periods.

[0072] Additionally, better heat dissipation reduces internal stresses within the electric machine caused by thermal gradients. These stresses, if unchecked, can lead to material fatigue, cracking, and long-term mechanical degradation. By facilitating even thermal distribution, the inclusion of the plurality of cavities (203) in the casing (201) results in a more robust and mechanically stable housing unit (200). This improvement not only enhances the overall performance of the electric machine but also extends its operational lifespan.

[0073] The inclusion of plurality of cavities (203) also improves the mechanical integrity of the electric machine. By strategically placing the plurality of cavities (203), the structural stability of the electric machine is enhanced without compromising its thermal performance. The plurality of cavities (203) helps to hold the windings securely in place, reducing the risk of rotor slipping or stator misalignment, which are critical failure modes in high-performance electricmachine. Additionally, the plurality of cavities (203) contribute to the prevention of solidification cracking and stress concentrations, as the uniform filling of potting material reduces internal stresses within the electric machine, leading to improved mechanical robustness and vibration resistance.

[0074] Moreover, the adaptability of the layout is another key advantage. The ability to vary the shapes, sizes, and volumes of the plurality of cavities (203) allows the electric machine to be tailored to specific performance requirements, such as increased thermal capacity in certain regions or enhanced mechanical support in others. This flexibility makes the layout highly customizable and adaptable to a variety of applications, from electric vehicles to industrial machinery, where varying operational conditions demand different thermal and structural characteristics. For example, by adjusting the dimensions of the plurality of cavities (203) in high-temperature areas or incorporating channels for cooling, the electric machine can be optimized for both high-performance and energy-efficient applications.

[0075] The plurality of cavities (203) offers advantages in terms of manufacturing efficiency. By streamlining the potting process and ensuring even and uniform distribution of the potting material, the risk of defects such as incomplete filling, solidification problems, material wastage, and the need for extensive post-production refinements is reduced. This leads to cost savings in both material and labour, while also accelerating the manufacturing cycle, making it easier to scale up production for high-volume applications. Furthermore, the configuration allows for the use of advanced manufacturing techniques such as 3 -dimensional printing, which can create plurality of cavities (203) with highly intricate and customized geometries that traditional methods would struggle to achieve. This capability enhances the scalability and flexibility of the manufacturing process. By ensuring better encapsulation with minimal voids or air pockets, weak points are effectively eliminated, significantly reducing the risk of partial discharge and enhancing the electrical reliability ofthe electric machine. Further, plurality of cavities (203) enable the housing unit (200) to enclose the electric machine with larger stack length without compromising with the uniformity in distribution of the second predefined material.

[0076] The present disclosure introduces several innovative approaches aimed at addressing the failure modes and challenges associated with potting in electric machine. A key advancement is the increase in the fill factor by up to 50%, which significantly enhances the uniformity and quality of potting material encapsulation. The improved fill factor ensures a more thorough and complete filling of the housing unit (200), reducing the presence of voids and air pockets. This leads to better thermal conductivity, improved mechanical stability, and a significant reduction in failure modes such as overheating, partial discharge, and porosity-related weaknesses.

[0077] Finally, the improved reliability and durability offered by the plurality of cavities (203) results in longer lifespans of the electric machine and reduced maintenance needs. By addressing potential failure modes such as overheating, mechanical displacement, and insulation degradation, the electric machine is able to perform at a consistently high level over extended periods, reducing the likelihood of unexpected failures and enhancing customer satisfaction. The ability to maintain peak performance despite fluctuating operational conditions makes the electric machine particularly suitable for demanding applications, where reliability is paramount. The present disclosure ensures that any heat buildup does not elevate the temperature of the electric machine to critical levels defined by the magnet grade. Thus, preventing the partial or full demagnetization of the magnetic components. This ensures consistent and reliable torque delivery, which is essential for maintaining vehicle performance, driving experience and customer satisfaction. The present disclosure maintains the dielectric strength and insulating properties of the insulating material used in the windings thereby reducing the risk of electrical short circuits and winding failure. This further prevents expensive repairs and replacements.

[0078] The present disclosure relates to an electric machine, a housing unit (200) and a method (300) to manufacture the housing unit (200) for the same. Embodiments illustrated in the present disclosure can be worked with any type of electric machine that requires potting or encapsulation. Further, the disclosed invention is not limited to the aforementioned embodiments. For example, as used in this specification and the appended claims, the singular forms “a,” “an” and “they” can include plural referents unless the context clearly indicates otherwise. Further, when introducing elements / components / etc. of the assembly / system / method described and / or illustrated herein, the articles “a”, “an”, “the”, and “said” are intended to mean that there is one or more of the element (s) / component(s) / etc. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional element(s) / component(s) / etc. other than the listed element(s) / component(s) / etc.

[0079] This written description uses examples to provide details on the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems. The scope of the disclosure is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

[0080] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in light of the above disclosure.LIST OF REFERENCE NUMERALS Housing unit CasingInner circumferential surface Opening Plurality of cavities Plurality of raised surfaces Circumferential notch Method Employing FormingFilling

Claims

We Claim:

1. A housing unit (200) for an electric machine, the housing unit (200) comprising:a casing (201), the casing (201) being configured to receive a plurality of components of the electric machine through an opening (202), the casing (201) being made up of a first predefined material; anda plurality of cavities (203), the plurality of cavities (203) being disposed on an inner circumferential surface (201 S) of the casing (201), the plurality of cavities (203) being configured to receive a second predefined material.

2. The housing unit (200) for the electric machine as claimed in claim 1, wherein a thermal conductivity of the second predefined material being greater than a thermal conductivity of the first predefined material.

3. The housing unit (200) for the electric machine as claimed in claim 2, wherein the thermal conductivity of the second predefined material being configured to vary along a predefined gradient.

4. The housing unit (200) for the electric machine as claimed in claim 1, wherein the second predefined material being a muti-phase material and a self-healing material.

5. The housing unit (200) for the electric machine as claimed in claim 1, wherein the casing (201) comprises a plurality of raised surfaces (204), the plurality of raised surfaces (204) being configured to separate the plurality of cavities (203);a surface area of the inner circumferential surface (201 S) of the casing (201) being ‘SI’, and a combined surface area of the plurality of raised surfaces (204) being ‘S2’; anda ratio of ‘SI’ to ‘S2’ being within a range of 1.06-1.2.

6. The housing unit (200) for the electric machine as claimed in claim 5, wherein a combined value of a volume of the plurality of cavities (203) being ‘VI’ and a ratio of ‘SI’ to ‘VI’ being within a range of 16.5-1.4.

7. The housing unit (200) for the electric machine as claimed in claim 1, wherein the plurality of cavities (203) comprises a plurality of coolant channels, the plurality of coolant channels being configured to circulate a coolant medium across the second predefined material.

8. The housing unit (200) for the electric machine as claimed in claim 1, wherein the second predefined material comprising a damping material.

9. The housing unit (200) for the electric machine as claimed in claim 1, wherein the casing (201) comprises a plurality of dampening members, the plurality of dampening members being disposed within the plurality of cavities (203).

10. The housing unit (200) for the electric machine as claimed in claim 1, wherein the casing (201) comprises one or more sensing units, the one or more sensing units being disposed within the plurality of cavities (203).

11. The housing unit (200) for the electric machine as claimed in claim 1, wherein the casing (201) comprises a plurality of reinforcement members, the plurality of reinforcement members being disposed within the plurality of cavities (203).

12. An electric machine, the electric machine comprising:a rotor, the rotor being installed in a rotatory configuration;a stator, the stator being installed in a stationary configuration; and a housing unit (200), the housing unit (200) being configured to enclose the rotor, and the stator of the electric machine, the housing unit (200) comprising:a casing (201), the casing (201) being configured to receive the rotor and the stator through an opening (202), the casing (201) being made up of a first predefined material; anda plurality of cavities (203), the plurality of cavities (203) being disposed on an inner circumferential surface (201 S) of the casing (201), the plurality of cavities (203) being configured to receive a second predefined material.

13. The electric machine as claimed in claim 12, wherein the housing unit (200) comprises a circumferential notch (205).

14. The electric machine as claimed in claim 12, wherein the stator comprises a plurality of pockets, the plurality of pockets being configured to receive the second predefined material.

15. The electric machine as claimed in claim 12, wherein a total number of the plurality of cavities (203) being a predetermined value (N); the predetermined value (N) being dependent on a total volume of the casing (201), the amount of secondpredefined material used, a volume of one of the plurality of cavities (203), a thermal profile of the electric machine, a shape of the plurality of cavities (203), a mechanical strength of the first predefined material and a rate of flow of the second predefined material.

16. A method (300) to manufacture a housing unit (200) for an electric machine, the method (300) comprising a plurality of steps ofemploying (301) a casing (201), the casing (201) being configured to receive a plurality of components of the electric machine through an opening (202), the casing (201) being made up of a first predefined material;forming (302) a plurality of cavities (203) on an inner circumferential surface (201 S) of the casing (201); andfilling (303) the plurality of cavities (203) with a second predefined material.

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