DESC:[0001] This complete specification claims priority from the provisional patent application no: 202341053969 titled “A SWINGARM STRUCTURE FOR ENHANCED LOAD TRANSFER AND POWER TRANSMISSION EFFICIENCY IN MOTOR VEHICLES” filed on 11th August 2023 and the provisional patent application no: 202341053963 titled “HYBRID SWINGARM DESIGN FOR IMPROVED REAR WHEEL ASSEMBLY SERVICEABILITY IN MOTORCYCLES” filed on 11th August 2023, both filed by the same applicant “Greaves Electric Mobility Private Limited”.

FIELD OF INVENTION

[0002] The present invention relates to transmission systems for motorized two-wheeled vehicles. More specifically, it concerns a novel swingarm assembly designed to enhance load transfer and power transmission efficiency.

BACKGROUND OF THE INVENTION
[0003] In the intricate world of motorized vehicles, particularly those confined to two wheels, the dynamics of movement and stability are subjects of paramount importance. The foundational element enabling the smooth and controlled motion of these vehicles is the swingarm assembly, a critical component tasked with the complex duty of facilitating rear wheel movement and suspension. This key structural piece holds the essence of vehicle stability, bearing the responsibility of accommodating essential parts such as the motor, driver and driven pulleys, gears, a belt tensioning mechanism, the rear suspension, the wheel itself, and the brake system. The precision in aligning these driver and driven components is crucial for the efficient transmission of power, which, in turn, significantly influences the durability of the transmission system and the overall performance of the vehicle.
[0004] In traditional designs, the swingarm has been a bastion of simplicity and functional straightforwardness, primarily focusing on direct load transfer from the rear wheel to the vehicle chassis. This transfer is vital for maintaining stability and control during a myriad of driving conditions, including but not limited to acceleration, deceleration, and navigation through varied terrains. However, the conventional approach to swingarm design has often encountered significant challenges, particularly in balancing the trifecta of strength, weight, and spatial efficiency within the vehicle's framework. The task of achieving desired strength and section modulus - a measure of the shape's ability to resist bending and torsional stresses - without compromising on the weight and space, has indeed been a complex puzzle for engineers and designers.
[0005] This complexity is further accentuated by the necessity for precise alignment between the motor's output mechanisms and the wheel, ensuring that power is transmitted most efficiently and effectively. Misalignment, even of the slightest degree, can lead to increased wear and tear on components, reduced power efficiency, and ultimately, a diminished lifespan for the transmission system. Conventional swingarm structures, often relying on homogeneous material construction and traditional manufacturing methods, have struggled to meet these multifaceted demands. The limitations inherent in such designs include an often unavoidable compromise between achieving optimal structural strength and maintaining a lightweight design conducive to vehicle manoeuvrability and performance.
[0006] Moreover, the evolving landscape of motorized two-wheeled vehicles, marked by increasing demands for higher performance, better fuel efficiency, and enhanced durability, has underscored the deficiencies of traditional swingarm assemblies. As vehicles become more advanced, incorporating electric motors and complex transmission systems aimed at reducing environmental impact and improving user experience, the swingarm's role becomes even more critical. The challenge of integrating these modern components into a cohesive and efficient assembly, without sacrificing performance or durability, becomes a significant hurdle.
[0007] Given these considerations, the industry faces a pressing need for innovation in swingarm design and construction. A solution that can overcome the limitations of traditional structures, by providing improved strength, efficient space utilization, and precise component alignment, all while adhering to the stringent weight constraints imposed by the quest for higher performance and manoeuvrability, is highly sought after. This backdrop of challenges and the quest for innovation set the stage for a ground-breaking development in the realm of swingarm assembly design, aiming to redefine the standards of efficiency, performance, and reliability in the world of two-wheeled motorized vehicles.

SUMMARY OF THE INVENTION
[0008] In light of the disadvantages mentioned in the previous section, the following summary is provided to facilitate an understanding of some of the innovative features unique to the present invention and is not intended to be a full description. A full appreciation of the various aspects of the invention can be gained by taking the entire specification and drawings as a whole.
[0009] The present invention introduces an innovative swingarm assembly for motorized two-wheeled vehicles, aimed at addressing the limitations of conventional swingarm designs. By integrating a casted left-hand (LH) side with a tubular right-hand (RH) side, this assembly offers a ground-breaking approach to ensuring efficient load transfer, precise alignment of essential components, and cost-effective manufacturing. The LH side is engineered for superior mechanical properties, including high section modulus and strength, while accommodating critical components such as the motor, pulleys, gears, belt tensioning mechanism, rear suspension, and brake system in precise alignment. The tubular RH side, on the other hand, balances strength with weight efficiency, contributing to the vehicle's overall performance and manoeuvrability. This optimized design not only enhances stability and control during various driving conditions but also improves power transmission efficiency, ultimately leading to increased vehicle performance and reliability.
[0010] This summary is provided merely for the purposes of summarizing some example embodiments, so as to provide a basic understanding of some aspects of the subject matter described herein. Accordingly, it will be appreciated that the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way.
BRIEF DESCRIPTION OF THE DRAWING
[0011] Figs. 1 & 2 are exemplary perspective views of the LH sub-assembly depicting various components according to the embodiments of the present disclosure.
[0012] Fig. 3 is an exemplary front-side view of the swingarm RH tubular assembly according to the embodiments of the present disclosure.
[0013] Fig. 4 is an exemplary rear-side view of the swingarm RH tubular assembly according to the embodiments of the present disclosure.
[0014] Figs. 5 & 6 are exemplary perspective views of the LH portion of the swingarm assembly according to the embodiments of the present disclosure.
[0015] Figs. 7 & 8 are exemplary perspective views of the LH portion of the swingarm assembly according to the embodiments of the present disclosure.
[0016] Fig. 9 is an exemplary top view of the swingarm assembly according to the embodiments of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0017] In the following description of the embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration-specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present invention.
[0018] The specification may refer to “an”, “one” or “some” embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single feature of different embodiments may also be combined to provide other embodiments.
[0019] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and/or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations and arrangements of one or more of the associated listed items.
[0020] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0021] The utility of the devices described herein will be explained further in detail in the following sections of this document referring to the figures. Specific terms used herein do not restrict the scope of the present disclosure.
[0022] In the dynamic realm of motorized two-wheeled vehicles, such as motorcycles and scooters, the swingarm plays a pivotal role in the vehicle's transmission system. It not only supports the rear wheel and suspension but also ensures the proper alignment and efficient transfer of power from the motor to the rear wheel. However, conventional swingarm designs often grapple with several limitations that can significantly impact vehicle performance, stability, and durability.
[0023] One of the primary challenges faced is the difficulty in achieving an optimal balance between strength and weight. Traditional swingarm structures, typically made from homogeneous materials, struggle to provide the necessary strength without adding excessive weight, which can adversely affect the vehicle's manoeuvrability and fuel efficiency.
[0024] Furthermore, conventional designs frequently encounter issues with the precise alignment of the drivetrain components (motor, pulleys, gears, belt tensioning mechanisms, etc.). Misalignment can lead to inefficient power transmission, increased wear and tear on components, and ultimately, a reduction in the vehicle's overall lifespan and reliability.
[0025] Another significant issue is the limited space within the vehicle's framework, which can constrain the design and functionality of the swingarm. This spatial limitation challenges the integration of various components and the implementation of advanced suspension systems, further restricting performance enhancements.
[0026] The present invention introduces a novel swingarm assembly designed to overcome these prevalent issues in motorized two-wheeled vehicles. By adopting a novel approach that combines a casted left-hand (LH) side with a tubular right-hand (RH) side, this assembly achieves an unprecedented balance of strength, weight efficiency, and component alignment within a compact design.
[0027] This innovative configuration not only enhances the structural integrity and load-bearing capacity of the swingarm but also ensures precise alignment of drivetrain components, thereby improving power transmission efficiency and extending the lifespan of the vehicle. Additionally, the unique design facilitates the integration of a versatile range of suspension systems, further elevating the vehicle's performance and rider comfort.
[0028] The invention's dual-material/process design approach is pivotal to its functionality. The casted LH side is meticulously engineered to house critical drivetrain and suspension components in a precise alignment, thanks to its ability to incorporate complex geometries during the casting process. The machining process helps in achieving required critical tolerances. This side of the swingarm is optimized for high section modulus and strength, ensuring robust load transfer from the rear wheel to the vehicle chassis, which is crucial for maintaining stability and control under various driving conditions.
[0029] Conversely, the tubular RH side is designed with a focus on achieving a harmonious balance between strength and weight efficiency. The use of tubular structures allows for a reduction in material usage without compromising the swingarm's overall integrity. This contributes significantly to the vehicle's agility and responsiveness, enhancing the riding experience.
[0030] The securement mechanism that fuses the LH and RH sides into a singular assembly is another critical aspect of the invention. This mechanism is designed to ensure a balanced force transfer across the swingarm, further contributing to the vehicle's stability and handling.
[0031] Figures 1 and 2 showcase the LH sub-assembly from different perspectives, highlighting the integration of components like the motor (102), driver and driven pulleys (204, 206), and the belt tensioning mechanism (202). These figures illustrate the spatial optimization achieved through the casted design, which accommodates these components in precise alignment, thus enhancing the power transmission efficiency.
[0032] Figure 3 provides a front-side view of the RH tubular assembly, emphasizing the structural simplicity and efficiency of the tubular design. This view also showcases the suspension mounting points (302), which are crucial for attaching the vehicle's suspension system.
[0033] Figure 4 offers a rear-side perspective of the RH assembly, further detailing the tubular structure's contribution to the overall assembly's strength and lightweight design.
[0034] Figures 5 through 8 delve into various perspectives of the LH and RH portions of the swingarm assembly, further illustrating the meticulous design considerations for component accommodation and overall structural integrity.
[0035] Figure 9 presents a top view of the entire swingarm assembly, encapsulating the innovative fusion of the LH and RH sides. This figure underscores the assembly's comprehensive design, aimed at optimizing load transfer, enhancing stability, and improving power transmission efficiency.
[0036] Motor (102) is placed within the swingarm assembly, an essential component for driving the two-wheeled vehicle. It's strategically located to ensure optimal power transmission and balance within the vehicle's framework. Rear Wheel Axle (106) is the axle around which the rear wheel rotates. It plays a critical role in maintaining the wheel's alignment and is a central point for transmitting the motor's power to the rear wheel, facilitating movement. Swingarm Pivot Axis (108) represents the pivot point around which the swingarm allows vertical motion of the rear wheel. It's crucial for absorbing shocks and maintaining traction during various riding conditions.
[0037] Rear Suspension LH Mounting Point (104) and Rear Suspension RH Mounting Point (302) are designated for attaching the left-hand and right-hand sides of the rear suspension system to the swingarm. They are strategically positioned to optimize the vehicle's suspension geometry and enhance rider comfort and control.
[0038] Driver Pulley (204) and Driven Pulley (206) are part of the vehicle's belt drive system. The driver pulley is connected to the motor, while the driven pulley is connected to the rear wheel. Together, they transfer power from the motor to the wheel. Transmission Belt (208) runs between the driver and driven pulleys, facilitating the efficient transmission of power from the motor to the rear wheel. It's a key component of the belt drive system. Belt Tensioning Mechanism (202) This mechanism adjusts the tension of the transmission belt, ensuring optimal power transfer and preventing slippage or excessive wear.
[0039] Hugger Mounting Bracket (308), Swingarm RH Cover Mounting Bracket (306A, 306B), and Swingarm RH Cover Mounting Bush (310) are components related to mounting the rear wheel fender and covers on the swingarm, particularly on the RH side. They ensure secure attachment and protection of various external components.
[0040] Rear Wheel Axle RH Bearing Holder (304) and Rear Wheel Axle and RH Bearing (704) refer to the housing and the bearing that support the rear wheel axle on the RH side. They are critical for the smooth rotation of the wheel and overall vehicle stability.
[0041] Wheel (902) identifies the rear wheel of the vehicle, a fundamental component that directly interacts with the road surface. Swingarm LH Casted Portion (904) and Swingarm RH Tubular Portion (702) distinguish the two primary components of the swingarm assembly. The LH casted portion is designed to accommodate and precisely align various critical components, while the RH tubular portion provides structural strength and weight efficiency.
[0042] The invention's unique design philosophy not only addresses the existing limitations of conventional swingarm structures but also sets a new standard for performance, reliability, and efficiency in motorized two-wheeled vehicles. Through its dual-material approach, precise component alignment, and efficient load transfer capabilities, this swingarm assembly represents a significant advancement in vehicle
[0043] Central to present invention is the design and construction of the swingarm assembly, which embodies a novel integration of a left-hand (LH) portion and a right-hand (RH) portion, each tailored to enhance vehicle performance through structural innovation and optimal component alignment. The LH portion, characterized by its casting process, is ingeniously designed to accommodate and precisely align critical components such as the motor, driver and driven pulleys, gears, belt tensioning mechanism, and rear suspension components. This design not only ensures efficient power transmission and increased durability of the transmission system but also optimizes space within the vehicle's framework, addressing common limitations faced by conventional swingarms.
[0044] In contrast, the RH portion is constructed using tubular structures, contributing to the assembly's strength while maintaining weight efficiency. This balance is crucial for improving the vehicle's manoeuvrability and overall performance. The unique method of securely fusing the LH and RH portions into a single, cohesive structure is a pivotal aspect of the design, facilitating balanced force transfer from the rear wheel to the vehicle chassis, thereby enhancing stability and control.
[0045] Additionally, the swingarm assembly features integrated suspension mounting points on both the LH and RH portions. These points are not only positioned to provide optimal support and alignment but are also designed to accommodate a diverse range of suspension types, including coil spring, air spring, and hydraulic shock absorbers. This versatility allows for greater customization and adaptability to varying riding conditions and preferences.
[0046] Further emphasizing the assembly's structural innovation, the casting of the LH segment incorporates specific geometries aimed at enhancing the section modulus and structural integrity. This thoughtful engineering optimizes space utilization within the vehicle's framework, allowing for a more compact and efficient design. Similarly, the tubular RH segment is manufactured with a keen focus on achieving a balance between structural strength and weight, underscoring the assembly's contribution to improved vehicle manoeuvrability and performance. Through its innovative combination of a casted LH portion and a tubular RH portion, the assembly not only addresses the inherent challenges of conventional swingarm designs but also sets a new standard for efficiency, durability, and performance in two-wheeled vehicles.
[0047] According to an embodiment of the present invention, the tubular RH side is designed to offer the required strength to the swingarm while being more cost-effective compared to single piece casted structures or other manufacturing methods. According to another embodiment of the present invention, the casting process of the LH side allows for complex geometries that maximize the use of available space and achieve high section modulus and strength. Further, the tubular RH side is manufactured using cost-effective methods, providing a strong and lightweight structure that contributes to overall vehicle performance and manoeuvrability. Furthermore, the precise alignment of driver and driven components within the swingarm leads to increased power transmission efficiency, reducing energy losses and enhancing vehicle performance.
[0042] Central to the present invention is the design and construction of the swingarm assembly, which embodies a novel integration of a left-hand (LH) portion and a right-hand (RH) portion, each tailored to enhance vehicle performance through structural innovation and optimal component alignment. The LH portion, characterized by its casting process, is ingeniously designed to accommodate and precisely align critical components such as the motor, driver and driven pulleys, gears, belt tensioning mechanism, and rear suspension components. This design not only ensures efficient power transmission and increased durability of the transmission system but also optimizes space within the vehicle's framework, addressing common limitations faced by conventional swingarms.
[0043] In contrast, the RH portion is constructed using tubular structures, contributing to the assembly's strength while maintaining weight efficiency. This balance is crucial for improving the vehicle's manoeuvrability and overall performance. The unique method of securely fusing the LH and RH portions into a single, cohesive structure is a pivotal aspect of the design, facilitating balanced force transfer from the rear wheel to the vehicle chassis, thereby enhancing stability and control.
[0052] The manufacturing process for the left-hand (LH) portion of the swingarm assembly, as delineated in the claims, is a sophisticated combination of casting and machining. This process is meticulously engineered to deliver a product that meets the exacting demands of structural integrity and precision alignment required for optimal motorcycle performance.
[0053] The casting process for the LH portion is carefully designed to create complex geometries that are not feasible with traditional forging or machining methods alone. This process begins with the creation of a detailed mold, which is then filled with molten material that hardens to form the initial shape of the swingarm. The materials chosen for the casting are selected based on their high strength-to-weight ratio and their ability to withstand the stresses and strains encountered during motorcycle operation.

[0054] Once the casting process is complete, the LH portion undergoes a series of machining operations. Machining is critical for refining the features of the cast component, achieving the precise tolerances, and ensuring a high-quality surface finish. It is this combination of casting and machining that allows for the incorporation of intricate design features and the exact placement of component interfaces, which are vital for the swingarm's performance.
[0055] Moreover, the machining process is crucial for establishing critical tolerances that are essential for the swingarm's function. These tolerances ensure that all the components that the swingarm interacts with, such as the motor, driver pulley, driven pulley, belt tensioning mechanism, and rear suspension, fit together with the utmost precision. This is especially important for maintaining the alignment of the drivetrain, which directly impacts the efficiency of power transmission and the longevity of the motorcycle's components.
[0056] The swingarm's section modulus, a key indicator of its ability to resist bending and torsional stresses, is also enhanced through the casting and machining processes. The casting process allows for the design of geometries that inherently have a high section modulus, while machining ensures that these geometries are produced consistently and with the required material properties.
[0057] In addition to the structural benefits, the combination of casting and machining provides significant advantages in terms of manufacturing efficiency. The casting process allows for the near-net-shape formation of the component, which minimizes the amount of material waste and reduces the need for extensive machining. This efficiency is not only cost-effective but also environmentally friendly, as it reduces the energy consumption and the material scrap associated with the production of the swingarm.

[0058] Finally, the LH portion's manufacturing process is subject to stringent quality control measures. Each step, from the creation of the mold to the final machining pass, is closely monitored to ensure that the swingarm meets the high standards required for safety, durability, and performance. This process not only facilitates the integration of complex and optimized geometries but also ensures that the swingarm assembly fulfills its critical role in the motorcycle's overall functionality.
[0044] An additional embodiment of the present invention introduces an innovative hybrid swingarm design that revolutionizes the serviceability and maintenance of the motorcycle's rear wheel assembly. This embodiment espouses a segmented approach, dividing the swingarm into two distinct components: a left-hand (LH) portion and a right-hand (RH) portion, which are securely joined yet easily separable.
[0045] The right-hand (RH) portion, or the Swingarm Tubular RH, is affixed to the rest of the motorcycle using a minimal number of fasteners. Specifically, the use of only twelve fasteners allows for the expedient detachment of the Swingarm Tubular RH. This innovative feature facilitates remarkably swift access to the rear wheel and tire assembly for maintenance or replacement, without the cumbersome disassembly typically associated with conventional swingarm designs.
[0046] Furthermore, the drive belt system is exclusively associated with the left-hand (LH) portion of the swingarm. This strategic separation of the wheel assembly from the drive belt means that servicing tasks, such as tire replacement or wheel maintenance, do not require the disassembly or subsequent re-tensioning of the drive belt. This significant improvement effectively eliminates a common source of inconvenience and maintenance burden, as the belt tension remains undisturbed, thereby simplifying the process and preserving the integrity of the drive system.
[0047] The design's focus on ease of maintenance also extends to the rear suspension system. Both the LH and RH suspension fasteners, which comprise nuts and similar securing elements, are designed to be quickly released and re-secured, allowing for full and unimpeded access to the rear wheel.
[0048] In practice, the removal of the Swingarm Tubular RH not only enhances the accessibility of the rear wheel for various service operations but also drastically reduces the time and effort traditionally required for such tasks. The reattachment of the component, following maintenance, is equally straightforward, reflecting a design that prioritizes efficiency and user-friendliness.
[0049] By maintaining the set tension of the drive belt during service activities, the invention also optimizes operational longevity and reliability. Frequent tension adjustments can accelerate wear and lead to potential misalignments; thus, their elimination is a key attribute of this embodiment, contributing to the overall durability of the drive system.
[0048] [0050] This embodiment of the hybrid swingarm design thus addresses and surmounts the challenges inherent in traditional motorcycle swingarm configurations. By significantly streamlining the serviceability of the rear wheel assembly, the invention offers a user-centric solution that is anticipated to benefit a wide range of motorcycle applications, from everyday use to competitive racing environments. Examples described herein can also be used in various other scenarios and for various purposes. It may be noted that the above-described examples of the present solution are for the purpose of illustration only. Although the solution has been described in conjunction with a specific embodiment thereof, numerous modifications may be possible without materially departing from the teachings and advantages of the subject matter described herein. Other substitutions, modifications, and changes may be made without departing from the spirit of the present solution. All of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0049] The present description has been shown and described with reference to the foregoing examples. It is understood, however, that other forms, details, and examples can be made without departing from the spirit and scope of the present subject matter.
,CLAIMS:I/We Claim:

1. A swingarm assembly for two-wheeled vehicles, comprising:
a left-hand (LH) portion (904), manufactured through a casting and machining process, designed to accommodate components including a motor (102), driver pulley (204), driven pulley (206), driver gear, driven gear, belt tensioning mechanism (202), and rear suspension components;
a right-hand (RH) portion (702), constructed using tubular structures, wherein the LH and RH portions are positioned on opposing sides of the swingarm;
integrated suspension mounting points (104, 302) on the LH and RH portions, each located proximally above the rear portion of the respective side and distal from the wheel axle (106); and
a securement mechanism for the fusion of the LH and RH portions into a singular structure.

2. The swingarm assembly of claim 1, wherein the integrated suspension mounting points (104, 302) facilitate attachment of a dual suspension system.

3. The swing arm assembly of claim 1, wherein the integrated suspension mounting points (104, 302) are designed to accommodate a plurality of suspension types including coil spring, air spring, and hydraulic shock absorbers.

4. The swingarm assembly of claim 1, wherein the casting of the LH portion (904) incorporates specific geometries designed to enhance the section modulus and structural integrity, optimizing space utilization within the vehicle framework.

5. The swingarm assembly of claim 1, wherein the tubular RH portion (702) is manufactured to achieve a balance between structural strength and weight efficiency, contributing to improved vehicle manoeuvrability.

6. The swingarm assembly of claim 1, wherein the securement mechanism comprises a plurality of fasteners.

7. The swing arm assembly of claim 1, wherein the securement mechanism enables rapid disassembly and re-assembly of the RH portion thereby enabling swift removal and attachment of the rear wheel.

8. The swing arm assembly of claim 1, wherein the securement mechanism enables rapid disassembly of the RH portion thereby enabling direct access to a rear wheel assembly including a breaking system.