Description:FIELD OF INVENTION
[0001] Embodiments of the present disclosure relate to the field of sealing of brushless direct current in-runner motor, and more particularly a cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor.
BACKGROUND
[0002] Brushless direct current (BLDC) motors contribute to a significant advancement in electric vehicles (EVs) due to their efficiency, reliability, and performance. Compared to traditional brushed DC motors, BLDC motors offer higher efficiency, reduced maintenance, and superior power density. They integrate seamlessly with power electronic control systems, allowing precise regulation of speed, torque, and direction. Additionally, BLDC motors support regenerative braking, converting kinetic energy into electrical energy during deceleration, extending driving range and improving efficiency. Further, integration of brushless DC motors into runner motors for electric vehicles (EVs) is a significant advancement in automotive technology, as the motors drive auxiliary systems like cooling fans, power steering, and air conditioning compressors.
[0003] Further, in a brushless direct current in-runner motor, a rotor is positioned within a stator, allowing the rotor to rotate within the stator windings. Typically, a shaft of the brushless direct current in-runner motor is connected to a drivetrain of an electric vehicle or e-rickshaw.
[0004] Sealing in the brushless direct current in-runner motor is a process of enclosing internal components within a protective barrier to prevent contaminants from dust, dirt, moisture, and fluids. Further, the sealing is crucial to maintain an environmental integrity of the brushless direct current in-runner motor, ensuring consistent performance and reliability amidst environmental conditions like temperature fluctuations and humidity.
[0005] However, using poor-quality sealing in the brushless direct current in-runner motor may increase risk of contamination, lubrication loss, short circuits, and environmental sensitivity. Contaminants like dust, dirt, moisture, and fluids may enter the brushless direct current in-runner motor, causing wear and damage due to the poor-quality sealing. Additionally, inadequate quality sealing may also fail to retain lubricants, leading to accelerated wear and potential damage to critical components inside the brushless direct current in-runner motor. Further, using the poor-quality sealing may be less durable in environments with varying temperatures and humidity levels, compromising the motor's performance and reliability over time.
[0006] Moreover, oil-sealing is a crucial component between the brushless direct current in-runner motor and the drivetrain. Oil-sealing is essential to prevent oil leakage from the drivetrain into the brushless direct current in-runner motor. Further, low rotation per minute (RPM) oil-sealing between the brushless direct current in-runner motor and the drive train causes drivetrain’s oil entry into the brushless direct current in-runner motor.
[0007] Additionally, inefficient sealing between the brushless direct current in-runner motor body and side covers, results in water and dust ingress inside the brushless direct current in-runner motor which leads to brushless direct current in-runner motor winding and hall sensor failure. Typically, a hall sensor is used in brushless DC in-runner motor to detect rotor position, but water and dust may damage the hall sensors, leading to malfunction or failure. Further, improper insulation of lead wires leads to short circuits.
[0008] Moreover, fault tolerance relies on redundancy, which is limited due to the presence of only limited hall sensors as it enables controller to compensate for the failure of the hall sensors.
[0009] Hence, there is a need for a cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor which addresses the aforementioned issue(s).
OBJECTIVE OF THE INVENTION
[0010] An objective of the invention is to provide a unibody casing for a motor unit to prevent from dust, water and foreign particles.
[0011] Another objective of the invention is to use a plurality of hall sensors to provide common feedback to a controller unit thereby reducing frequency of failure of the motor unit at the time of a potential failure of one of the plurality of hall sensors.
[0012] Another objective of the invention is to utilize an O-ring sealing between the unibody casing and bottom cover thereby protecting the motor unit from water and dust.
[0013] Yet another objective is to provide an O-ring near the gear box thereby preventing oil spillage to the external atmosphere.
[0014] Yet another objective is to solve critical connection between motor phase/current wires with the external harness wires using a terminal block.
[0015] Yet another objective is to ensure cooling of the motor from the heat generated using a centrifugal fan by arranging radial fins inline or parallel to the air flow.
BRIEF DESCRIPTION
[0016] In accordance with an embodiment of the present disclosure, an assembly for a cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor is provided. The assembly includes a Unibody Casing is an Aluminum Die cast unit encompassing the motor unit from external environment. The Unibody casing is casted along with outer casing and top cover making it as a single entity. wherein the unibody casing is adapted to provide dimensional accuracy of the unibody casing upon machining inner diameter and bearing housing of the unibody casing are concurrently processed machined for housing a stator and guiding feature for a rotor. Further, the unibody casing provides a machined surface for conduit interface for harness sealing. Further, the assembly also includes a single entity casted body including both the unibody casing and the top cover. Furthermore, the unibody casing includes the O-ring sealing between the bottom cover and the unibody casing. Moreover, the unibody casing provide sealing characteristics upon utilizing multi-lip oil seal between the motor unit and the gearbox assembly to withstand the multi-lip oil seal at high temperature, high revolutions per minute wherein the multi-lip oil seal is made of multi-lip fluoroelastomers -70A material. Further, the unibody casing includes a winding housing cap mechanically coupled to the unibody casing wherein the winding housing cap is adapted to route plurality of lead wires and plurality of windings of the motor unit for insulation thereby avoiding short circuits. Further, the unibody casing also includes a terminal block mechanically coupled to the unibody casing wherein the terminal block is assembled on a flat surface of the unibody casing with the O-ring sealing to ensure sealing characteristics of the unibody casing. Furthermore, the terminal block is adapted to provide electrically conductive inserts for motor harness connection wherein the terminal block comprises electrically conductive terminals or copper contacts to connect with the motor unit harness wherein the terminal block is a leak-proof injection molded plastic part. Additionally, the unibody casing includes a centrifugal fan mechanically coupled to the unibody casing wherein the centrifugal fan is adapted to provide heat dissipation and maintain temperature of the motor wherein the centrifugal fan is positioned behind the motor propelled by shaft of the motor thereby maintaining optimal temperature of the motor unit form overheating.
[0017] To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:
[0019] FIG. 1 is a block diagram representation of a cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor. in accordance with an embodiment of the present disclosure;
[0020] FIG. 2 is a schematic representation of unibody casing for the motor unit with O-ring sealing between the bottom cover and the unibody casing of FIG. 1 in accordance with an embodiment of the present disclosure;
[0021] FIG. 3 is a schematic representation of an O-ring positioned between the unibody casing and bottom cover of FIG. 2 in accordance with an embodiment of the present disclosure;
[0022] FIG. 4 is a schematic representation of plurality of hall sensors in a motor unit of FIG. 2 in accordance with an embodiment of the present disclosure;
[0023] FIG. 5 is a schematic representation of multi-lip oil seal between the motor unit and the gearbox assembly of FIG. 2 in accordance with an embodiment of the present disclosure;
[0024] FIG. 6 is a schematic representation of O-ring seal between the motor unit and the gearbox assembly of FIG. 2 in accordance with an embodiment of the present disclosure;
[0025] FIG. 7 is a schematic representation of the winding housing cap in accordance with an embodiment of the present disclosure;
[0026] FIG.8 is a schematic representation of the terminal block in accordance with an embodiment of the present disclosure; and
[0027] FIG. 9 is a schematic representation of the plurality radial fins and the centrifugal fan in accordance with an embodiment of the present disclosure.
[0028] Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.
DETAILED DESCRIPTION
[0029] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.
[0030] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or subsystems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.
[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.
[0032] In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[0033] Embodiments of the present disclosure relate to a cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor. A motor unit assembled on a drivetrain of an electric vehicle wherein the motor unit is mechanically coupled to a gearbox assembly through a housing unit. a plurality of sensors mechanically coupled to the motor unit wherein the plurality of sensors is positioned inside the motor unit for rotor sensing. The unibody casing includes a unibody casing encompassing the motor unit wherein the unibody casing is a covering shield adapted to protect the motor unit from an external environment wherein the unibody casing comprises a top cover and a bottom cover wherein the unibody casing is adapted to provide dimensional accuracy of the unibody casing upon machining inner diameter and bearing housing of the unibody casing are concurrently processed between a stator and a rotor. Further, the unibody casing provides a machined surface for conduit interface for harness sealing. Further, the unibody casing also includes an O-ring sealing between the top cover and the unibody casing thereby protecting the motor unit from at least one of dust, water, and foreign particles. Furthermore, the unibody casing includes the O-ring sealing between the bottom cover and the unibody casing. Moreover, the unibody casing provide sealing characteristics upon utilizing multi-lip oil seal between the motor unit and the gearbox assembly to withstand the multi-lip oil seal at high temperature, high revolutions per minute wherein the multi-lip oil seal is made of multi-lip fluoroelastomers -70A or FKM or Viton or any similar suitable high temperature sealing material. Further, the unibody casing includes a winding housing cap mechanically coupled to the unibody casing wherein the winding housing cap is adapted to route plurality of lead wires and plurality of windings of the motor unit for insulation thereby avoiding short circuits. Further, the unibody casing also includes a terminal block mechanically coupled to the unibody casing wherein the terminal block is assembled on a flat surface of the unibody casing with the O-ring sealing to ensure sealing characteristics of the unibody casing. Furthermore, the terminal block is adapted to provide electrically conductive inserts for motor harness connection wherein the terminal block comprises electrically conductive terminals or copper contacts to connect with the motor unit harness wherein the terminal block is a leak-proof injection molded plastic part. Additionally, the unibody casing includes a centrifugal fan mechanically coupled to the unibody casing wherein the centrifugal fan is adapted to provide heat dissipation and maintain temperature of the motor wherein the centrifugal fan is positioned behind the motor propelled by shaft of the motor thereby maintaining optimal temperature of the motor unit form overheating.
[0034] FIG. 1 is a block diagram representation of an assembly (100) a cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor in accordance with an embodiment of the present disclosure. Typically, a motor unit (not shown in FIG. 1) is assembled on a drivetrain of an electric vehicle (105). In a specific embodiment, the electric vehicle (105) is an E-Rickshaw. As used herein, the motor unit is a brushless direct current (DC) motor. Further, the drivetrain (not shown in FIG. 1) in the electric vehicle transmits power from the motor unit to wheels of the electric vehicle. The drivetrain includes various components. Examples of the components in the drivetrain includes, but is not limited to, gearbox, driveshaft, and axles. Further, the motor unit is mechanically coupled to a gearbox assembly through a housing unit. Typically, the gearbox assembly is a component that optimizes vehicle performance and efficiency by providing variable gear ratios. The gearbox assembly also allows the motor unit to operate at its optimal speed and delivers the right torque to the wheels. Further, the gearbox assembly includes, but is not limited to gears, shafts, and bearings. Further, the housing unit is a protective enclosure that houses the motor unit and gearbox assembly, providing structural integrity and protection from external elements. Furthermore, a plurality of sensors is mechanically coupled to the motor unit. The plurality of sensors is positioned inside the motor unit for rotor sensing. Typically, the plurality of sensors are placed in specific locations relative to the rotor, covering different angles and positions as the rotor rotates. Further, the plurality of sensors detects magnetic field generated by the rotor's permanent magnets, determining precise position of the rotor at any given moment. Upon detection, information regarding the position of the rotor is fed back to controller unit that uses feedback to control timing and sequence of electrical pulses sent to the windings of the motor.
[0035] The assembly (100) includes a unibody casing (110) encompassing the motor unit. The unibody casing (110) is a covering shield adapted to protect the motor unit from an external environment. The unibody casing (110) and a top cover (145) are manufactured as a single entity. The bottom cover (135) can be split from the single entity. Typically, the bottom cover (135) is integrated with the single entity to eliminate potential leakage points between the motor unit and the assembly (100). The unibody casing (110) is adapted to provide dimensional accuracy of the unibody casing (110) upon machining inner diameter and bearing housing of the unibody casing (110) are concurrently processed between a stator and a rotor of the motor unit.
[0036] Further, the unibody casing (110) provides a machined surface for conduit interface for harness sealing. Typically, the harness consists of electrical wires or cables, and further sealing prevents moisture, dust, or contaminants from entering the unibody casing (110) through the conduit interface, ensuring internal component integrity and protection from environmental hazards. Further, the conduit is a protective tube or channel that holds the electrical wires or cables.
[0037] Furthermore, the assembly (100) includes an O-ring sealing between the bottom cover (135) and the unibody casing (110) thereby protecting the motor unit from at least one of dust, water, and foreign particles. As used herein, the O-ring is a method used to create a tight seal between the bottom cover (135) and the unibody casing (110).
[0038] Moreover, the unibody casing (110) provide sealing characteristics upon utilizing multi-lip oil seal between the motor unit and the gearbox assembly to withstand the multi-lip oil seal at high temperature, high revolutions per minute. Typically, the sealing characteristics are properties and capabilities of a sealing mechanism that prevents leakage of fluids between surfaces. Further, multi-lip oil seal is a radial shaft seal designed to prevent fluid leakage from a rotating shaft or housing, with two or more sealing lips arranged in series, unlike single-lip seals with a single lip. Further, the multi-lip oil seal is made of multi-lip fluoroelastomers -70A material or FKM or Viton or any similar suitable high temperature sealing. Typically, fluoroelastomers are synthetic rubber materials known for resistance to heat, chemicals, oils, and fuels. Fluroelastomers are commonly referred as FKM (fluoroelastomer). The "-70A" designation indicates the material durometer hardness, that measures resistance to indentation or deformation.
[0039] Additionally, the unibody casing (110) includes a winding housing cap (120) mechanically coupled to the unibody casing (110). The winding housing cap (120) is adapted to route plurality of lead wires and plurality of windings wire that are soldered or welded or connected by any other means with the harness phase wires of the motor unit for insulation thereby avoiding short circuits between individual phases or with the motor body or any other parts in the motor. Typically, the winding housing cap (120) is designed to facilitate organized routing of the plurality of lead wires and the plurality of windings, ensuring clean arrangement and separation, thereby reducing the risk of tangling or contact, which could lead to short circuits, by preventing tangling.
[0040] Further, the unibody casing (110) includes a terminal block (130) mechanically coupled to the unibody casing (110). The terminal block (130) is assembled on a flat surface of the unibody casing (110) with the O-ring sealing to ensure sealing characteristics of the unibody casing. The terminal block (130) is adapted to provide electrically conductive inserts for motor harness connection. Typically, the conductive inserts provide contact points where the lead wires from the motor harness may be securely attached or terminated. The terminal block (130) includes electrically conductive terminals or copper contacts to connect with the motor winding wires with a unit harness. The motor unit harness include a plurality of wires that transmit electrical signal, power or control to and from the motor unit, which are secured through screws. Further, the terminal block (130) is a leak-proof injection molded plastic part. Typically, injection moulding is a manufacturing process where molten plastic material is injected into a mold cavity at high pressure, solidifying and shaping the mold cavity into a finished plastic part. To ensure leak-proofing, design incorporate features like tight seals, precise tolerances, and appropriate material selection, along with sealing elements like gaskets and O-rings to prevent fluid or gas leakage. Further, the terminal block (130) support phase wire connection and connection for the plurality of sensors.
[0041] Further, the unibody casing (110) includes a centrifugal fan (155) mechanically coupled to the unibody casing (110). The centrifugal fan (155) is adapted to provide heat dissipation and maintain temperature of the motor. Typically, the centrifugal fans are essential in maintaining temperature of the motor unit by promoting heat dissipation and regulating airflow over the components in the motor unit. The centrifugal fans draw ambient air and force through the motor unit, creating airflow that helps carry away heat generated during operation. The centrifugal fan (155) along with the fan cap directs airflow over the unibody casing (110) containing the fins wherein the heat from the windings is conducted by stator to the unibody casing (110). In the motor unit with a rotating rotor, centrifugal fans help cool the rotor by directing airflow over surface, transferring heat away and reducing overall temperature. Further, the centrifugal fan (155) is positioned behind the motor unit propelled by shaft of the motor unit thereby maintaining optimal temperature of the motor unit form overheating. Typically, the shaft in the motor unit is a rotating component that transmits mechanical power from the motor unit to the driven load. Further, the unibody casing (110) includes a plurality of radial cooling fins for natural cooling during movement. The plurality of radial cooling fins is parallel to natural air flow. The plurality of radial cooling fins along with the centrifugal cooling fan is adapted for heat dissipation from the motor unit.
[0042] FIG. 2 are schematic representations of an assembly (100) for the motor unit with O-ring seal between the bottom cover and the unibody casing of FIG. 1 in accordance with an embodiment of the present disclosure. The top cover (145) is integrated with the unibody casing (110) to form a single entity. Further, this single entity is coupled to a bottom cover (135) via an O-ring, wherein the said bottom cover (135) is separable from the single entity. This type of arrangement is called as ‘Uni-Body’ or ‘Casted Uni-Body’. Typically, the O-ring seal (150) between the bottom cover (135) and the unibody casing (110), and sealing the conduit (165), is crucial for the integrity of the motor unit. These seals create barriers against contaminants, protecting internal components from damage or corrosion. They also maintain the efficacy of the motor unit internal lubrication system, ensuring optimal performance and longevity. The inclusion of the O-ring seal (150) enhances the motor unit reliability and durability, minimizing risk of malfunctions or breakdowns due to external factors. Further, the conduit (165) is a protective tube or channel used to enclose and protect electrical wires or cables.
[0043] FIG. 3 is a schematic representation of an O-ring positioned between the unibody casing and bottom cover of FIG. 2 in accordance with an embodiment of the present disclosure. The bottom cover (135) is integrated with the unibody casing (110) through the aid of the O-ring (150). This eliminates potential leakage points between the bottom cover (135) and the unibody casing (110).
[0044] FIG. 4 is a schematic representation of plurality of sensors in a motor unit in accordance with an embodiment of the present disclosure. The plurality of sensors (170a, 170b) are positioned at a redundant position equipped as Printed Circuit Board (PCB). As a result, if one set of the plurality of sensors (170a) fails, then the other set of the plurality of sensors (170b) is adapted to detect a potential failure of the motor unit and provide feedback to a controller. Further, the plurality of sensors (170a, 170b) may be a hall sensor. Furthermore, the hall sensors are commonly used in brushless DC motors to measure position of rotor, enabling precise commutation of phases of the motor unit for optimal torque production and smooth operation.
[0045] FIG. 5 is a schematic representation of multi-lip oil seal between the motor unit and the gearbox assembly in accordance with an embodiment of the present disclosure. Typically, the multi-lip oil seal (175) between the motor unit (not shown in FIG. 4) and the gearbox assembly (180) is crucial for maintaining proper lubrication and preventing oil leakage into the motor. The multi-lip oil seal protects against environmental factors like dust and water, aids in temperature regulation, and reduces friction between moving parts. The multi-lip oil seal (175) also minimizes wear and tear, dampens vibrations, and enhances stability and efficiency of the motor unit and the gearbox assembly (180). Additionally, the multi-lip oil seal (175) has superior sealing characteristics even at high temperatures and at high Revolutions Per Minute (RPMs). In one embodiment, the multi-lip oil seal (175) is Multi-lip FKM-70A or Viton or any suitable similar high-temperature seal material oil seal.
[0046] FIG. 6 is a schematic representation of the O-ring seal (185) between the motor unit and the gearbox assembly in accordance with an embodiment of the present disclosure. Typically, the O-ring seal (185) is a protective barrier between the motor unit and the gearbox assembly (not shown in FIG. 5), preventing oil leakage and contaminants ingress. Further, it must be noted that the O-ring seal (185) automatically secures with the gearbox when it is assembled on a drivetrain (not shown in FIG.5).
[0047] FIG. 7 is a schematic representation of the winding housing cap (120) in accordance with an embodiment of the present disclosure. Typically, the winding housing cap (120) is used to route plurality of lead wires and plurality of windings wire that are soldered or welded or connected by any other means with the harness phase wires of the motor unit for insulation thereby avoiding short circuits between individual phases or with the motor body or any other parts in the motor. Additionally, the winding housing cap (120) is a high temperature plastic housing cap that is adapted to optimize wire routing and keeps it secure.
[0048] FIG. 8 is a schematic representation of the terminal block (130) in accordance with an embodiment of the present disclosure. Typically, the terminal block (130) is a structured method for connecting electrical wires (Motor harness wires) or cables in a motor harness assembly with the winding wires and sensor wires. It consists of a rigid base with metal terminals or conductive inserts, ensuring secure fastening of wires and efficient transmission of electrical signals or power. The terminal block (130) is assembled on the motor unit to connect the harness with the motor unit via an O-ring for sealing purpose. Specifically, the terminal block (130) is made of plastic material. It must be noted that the terminal block (130) is a leak-proof injection moulded plastic terminal block with the electric conductive inserts to connect the harness with the motor unit.
[0049] FIG. 9 is a schematic representation of the plurality radial fins and the centrifugal fan (155) in accordance with an embodiment of the present disclosure. The radial fins (140) are arranged to provide better surface area for the heat transfer. Typically, the motor generates heat due to electrical resistance and mechanical friction, which can lead to decreased efficiency, premature wear, and motor failure if not properly dissipated. The centrifugal fan (155) helps by circulating air around the motor unit, ensuring it remains within its safe operating temperature range. Further, the plurality of radial fins (140) along with the centrifugal fan (155) is adapted for heat dissipation from the motor unit and is a vital feature of the disclosure.
[0050] Various embodiments of an assembly (100) for cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor as described above provides several benefits. The integration of the bottom cover (135) with the motor casing (Casted Uni-Body) 110 removes the presence of gaps and hence prevents leakage points between the bottom cover (135) and motor casing. Additionally, this type of integration eliminates the need for a sealing and assembly process. Further, the inclusion of the O-ring seal between the bottom cover (135) and unibody casing (110) improves motor sealing of the motor unit and ingress protection from water, dust, and foreign particles. The accurate dimensions of the motor casing results in better concentricity between the stator and rotor. Further, by using two sets of the plurality of sensors at redundant position reduces potential failure of the motor caused by the failure of the plurality of sensors. Further, using high-temperature, high-RPM, multi-lip oil seal provides heat resistance, high-speed performance, enhanced sealing effectiveness, chemical resistance, longevity, reliability, and versatility. Furthermore, utilizing O-ring seal between the motor unit and the gearbox assembly prevents the leakage of lubricants like oil or grease from the gearbox into the motor unit and onto the roads. Moreover, the terminal block (130) enables easy termination and installation of multiple wires or cables, making it suitable for various wiring configurations without the need for soldering or specialized tools. Additionally, the combination of the plurality of radial cooling fins along with the centrifugal fan (155) increases heat dissipation and maintain the temperature of the motor unit.
[0051] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
[0052] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
[0053] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, the order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.
, Claims:1. An assembly (100) for a cast unibody casing for sealing and redundant rotor position sensing in brushless direct-current motor comprising:
a unibody casing (110) casted with a top cover (145) to:
provide dimensional accuracy of the unibody casing (110) upon machining inner diameter and bearing housing of the unibody casing (110) are concurrently machined for housing a stator and a guiding feature for a rotor;
provide a machined surface for conduit (165) interface for harness sealing;
an O-ring (150) sealing positioned between the unibody casing (110) and a bottom cover (135) thereby protecting a motor unit from at least one of dust, water and foreign particles;
wherein the unibody casing (110) and the top cover (145) is a casted single entity and wherein the bottom cover (135) is separable from the casted single entity;
wherein the motor unit and the gearbox assembly is provided with a multi-lip oil seal (175) to withstand the multi-lip oil seal at high temperature, high revolutions per minute wherein the multi-lip oil seal (175) is made of multi-lip fluoro elastomers -70A material;
wherein the motor unit comprises a redundant sensor PCB assembly to ensure consistent running of the motor unit even at an occurrence of at least one PCB failure,
wherein the unibody casing (110) houses an Oring (185) near the gear box assembly thereby avoiding the oil from the gear box to leak to an external environment;
a winding housing cap (120) mechanically coupled to the unibody casing (110) wherein the winding housing cap (120) is adapted to route a plurality of lead wires and plurality of windings wire that are soldered or welded or connected by any other means with the harness phase wires of the motor unit for insulation thereby avoiding short circuits between individual phases or with the motor body or any other parts in the motor;
a terminal block (130) mechanically coupled to the unibody casing (110) wherein the terminal block (130) is assembled on a flat surface of the unibody casing (110) with the O-ring sealing to ensure sealing characteristics of the unibody casing (110),
wherein the terminal block (130) is adapted to provide electrically conductive inserts for motor harness connection;
wherein the terminal block (130) comprises electrically conductive terminals or copper contacts to connect with the motor winding wires with a unit harness;
wherein the terminal block (130) is a leak-proof injection molded plastic part;
a plurality of radial fins (140) provided on the unibody casing (110) to facilitate cooling of the motor unit during operation; and
a centrifugal fan (155) mechanically coupled to the unibody casing (110) wherein the centrifugal fan (155) is adapted to provide heat dissipation and maintain temperature of the motor wherein the centrifugal fan (155) is positioned behind the motor unit propelled by shaft of the motor unit thereby maintaining optimal temperature of the motor unit form overheating.
2. The assembly (100) as claimed in claim 1, wherein the bottom cover (135) is separable from the unibody casing (110) to eliminate potential leakage points between the motor unit and the unibody casing.
3. The assembly (100) as claimed in claim 1, wherein the plurality of sensors (170a, 170b) are adapted to detect failure of the motor unit wherein the plurality of sensors (170a, 170b) are hall sensors.
4. The assembly (100) as claimed in claim 3, wherein the plurality of sensors (170a, 170b) are integrated on a printed circuit board of a stator.
5. The assembly (100) as claimed in claim 4, wherein the plurality of sensors (170a, 170b) are interconnected to provide a feedback to a controller unit thereby minimizing frequency of failure of the motor unit caused by the failure of the plurality of sensors (170a, 170b).
6. The assembly (100) as claimed in claim 1, wherein the plurality of radial fins (140) are inline or parallel to the air flow.
7. The assembly (100) as claimed in claim 1, wherein the plurality of radial cooling fins along with the centrifugal fan (155) is adapted for heat dissipation from the motor unit.
8. The assembly (100) as claimed in claim 1, wherein the top cover (145) of the unibody casing (100) is fixed and the bottom cover (135) beneath the unibody casing is removable thereby facilitating a plurality of units in the motor unit to be serviced when required wherein the plurality of units comprises at least one of the rotor, stator, shaft, bearings, and the plurality of sensors (170a, 170b).
9. The assembly (100) as claimed in claim 1, wherein the terminal block (130) supports phase wire connection and connection for the plurality of sensors (170a, 170b).

Dated this 25th day of April 2024

Signature

Jinsu Abraham
Patent Agent (IN/PA-3267)
Agent for the Applicant