Suspension system in a vehicle

Abstract

A suspension system (100) in a vehicle comprising a wheel (120); a motor (130) attached to the rim (140) of the wheel (120); wherein the motor (130) is bolted to at-least one rim (140) of the wheel (120); at least a swing arm (150) comprising two forks (110) attached to the motor (130) of the vehicle; wherein at least one fork (110) has plurality of beams 5 (170) attached one with another.

Description

SUSPENSION SYSTEM IN A VEHICLEFIELD OF INVENTON

[0001] The invention relates to a suspension assembly in a vehicle & method and more particularly, it relates to integration of the motor and suspension system to ensure that the system improves ride quality, streamline the process of detaching wheels, enhancing safety and reducing the effort and time required for maintenance.CROSS REFERENCE TO RELATED INVENTION

[0002] This invention takes priority from an earlier filed provisional patent application no. 202421099523 filed on December 16, 2024; which is incorporated herein as reference.BACKGROUND OF THE INVENTION

[0003] Conventionally, the design of two wheeled vehicles, whether powered by internal combustion engines or electric drivetrains, has relied on a rear frame architecture almost similar in structure having a fixed swing arm that connects the wheel assembly to the vehicle chassis through a suspension system. The swingarm, which connects the rear wheel to the main chassis, has been a central component in ensuring the stability and handling of the motorcycle. In conventional two wheelers, the swingarm is typically pivoted at the rear of the frame, allowing the rear wheel to move vertically in response to terrain changes and rider input. The swingarm facilitates the structural support for the suspension system, brake system and contributes to the overall structural integrity of the vehicle.

[0004] Electric vehicles (EVs) and hybrids employ a variety of motors to meet performance and efficiency requirements. Electric and hybrid vehicles have seen remarkable advancements, primarily driven by improvements in motor technologies such as Induction Motors (IMs), Brushless DC Motors (BLDCs), and Switched Reluctance Motors (SRMs). These motors have propelled the industry by offering high efficiency, robustness, and cost-effectiveness. However, their centralized design often requires complex suspension systems, leading to challenges such as increased weight,mechanical losses, and intricate drivetrain architectures. These limitations have paved the way for the widespread adoption of hub motors, which directly address these inefficiencies.

[0005] Unlike traditional motors that require a drivetrain to transmit power to the wheels, hub motors integrate the motor directly into the wheel assembly. This design eliminates the need for components like gearboxes, drive shafts, and differentials, significantly reducing weight and mechanical losses. By decentralizing power delivery, hub motors improve efficiency, simplify the vehicle's mechanical layout, and free up space for other critical components like batteries or cargo.

[0006] Hub motors are particularly advantageous in vehicles where space and weight are critical, such as e-bikes, scooters, and light EVs. They also enable advanced features like independent wheel control, which enhances vehicle stability, handling, and traction in dynamic driving conditions. This makes hub motors an ideal choice for vehicles targeting urban mobility, where compactness, simplicity, and efficiency are paramount. Additionally, by removing the need for a centralized motor, hub motors reduce maintenance requirements, contributing to lower overall ownership costs. Positioning hub motors directly on the wheels, while simplifying the drivetrain and reducing mechanical complexity, can lead to some efficiency challenges. A key concern is the increased unsprung weight. Since the motor is mounted within the wheel assembly, it adds significant weight to the wheels. This increased unsprung weight affects the suspension system’s ability to respond to road irregularities, reducing ride quality and handling performance. It also increases rolling resistance, which can slightly decrease the vehicle's overall efficiency. Hence, reduction of weight of hub motor is required.

[0007] Hub motor vehicles introduce several challenges for tire replacement due to the integration of the motor within the wheel hub. Traditionally to replace a tire, wheel assembly integrated with hub motor completely needs to be removed from vehicle and then tire can then be removed from wheel rim. While removing tire, load is applied on rim / spoke region and then tire is removed from wheel rim. So while removing tire, load gets applied on this hub motor and there is a possibility of durability issues / damages in hub motor. This can result in huge expenditure to customer since the hub motor isexpensive. In the existing hub motor designs, if there is a failure in wheel rim, customer needs to replace entire wheel assembly including hub motor and this will not only incur significant charges, but also increase in service time.

[0008] Hub motors are mounted to the wheel rim using various techniques. One common method is direct integration, where the motor is built into the wheel rim during manufacturing. This technique eliminates the need for additional hardware, simplifying the assembly process and enhancing durability by reducing mechanical joints. However, a significant drawback is that if the motor fails, the entire wheel assembly may need replacement, leading to higher repair costs. Additionally, this approach offers limited flexibility for customization or independent replacement of the motor or rim, which can be a challenge in certain applications.

[0009] Welding a hub motor to the rim, while offering a strong and permanent connection, presents several significant drawbacks that can limit its practicality in many applications. One of the primary issues is the lack of serviceability. Once the motor is welded to the rim, it becomes a permanent assembly, making it difficult to repair or replace the motor without cutting the weld. This process can be both time-consuming and expensive, particularly for consumer vehicles where ease of maintenance is a priority.

[0010] Another concern is the risk of heat damage during the welding process. Also, motors contain sensitive components such as magnets, insulation, and windings, which can be compromised by the high temperatures generated during welding. Damage to these components can degrade motor performance or cause premature failure, necessitating careful heat management, which adds complexity to the manufacturing process.

[0011] When the wheel rim and motor assembly are welded together, routine maintenance tasks like tire replacement or brake servicing become significantly more challenging. Unlike conventional setups where the wheel can be removed independently, the welded configuration necessitates removing the entire motor assembly from the vehicle. This process is cumbersome, as the motor is typically mounted on the axle and securely fixed to the vehicle’s frame. Additionally, the risk of accidental damage to themotor or its electrical connections during removal is heightened, potentially leading to costly repairs.

[0012] Moreover, this design reduces the practicality of such vehicles for consumers or fleet operators who prioritize ease of servicing. Routine tasks like brake pad replacement, which are straightforward in conventional systems, become labor-intensive and less economical with a welded motor-rim assembly.

[0013] Hence, there is a need to provide a suspension assembly which can effectively address the challenges posed by motor integrated in the wheel rim, particularly in terms of maintenance and efficiency. By decoupling the wheel from the motor integrated with a suspension system, the wheel can be independently removed for tire replacement or brake servicing, simplifying routine maintenance and reducing costs.OBJECT OF THE INVENTION

[0014] An object of the invention is to provide a suspension system that enables ease of serviceability for service personnel during tire removal or any maintenance operation.

[0015] Yet another object of the invention is to prevent damage to the motor during maintenance activities, thereby increasing the lifespan, offering economic advantages and mitigating any frequent maintenance requirements.

[0016] Yet another object of the invention is to reduce the customer expenditure for repair and maintenance.

[0017] Yet another object of the invention is to reduce the cost and assembly time for an electric vehicle.

[0018] Yet another object of the present invention is to provide an enhanced suspension system that improves ride comfort, stability, and vehicle handling characteristics. Yet another object of the invention is to provide a cost effective & user-friendly quick disassembly of tire and rim including wheel for automotive vehicles.

[0019] Another object of the invention is to reduce overall weight of a hub-motor- based suspension system.

[0020] Still another object of the invention is to overcome lacunas of existing systems explained in background section.SUMMARY OF THE INVENTION

[0021] With the above objectives in view, the present invention provides a suspension system in a vehicle comprising: a frame structure of the vehicle; a wheel comprising a rim attached to the frame structure; a motor mounted to the rim of the wheel; at-least one swing arm comprising at least one fork mounted at a rear end on an axle of the motor and connected at a front end to the frame structure of the vehicle; wherein at least one fork is formed of plurality of beams interconnected with one another.

[0022] The plurality of beams attached together using at least one bolt , the bolt enabling removal of at least one beam to facilitate removal of the wheel. The bolt connecting the two beams is positioned at a distance between 170 mm and 210 mm from a hub of the wheel to provide structural strength to the swing arm.

[0023] The suspension system comprises a motor casing encapsulating the motor, which is attached to the rim of the wheel.

[0024] The swing arm comprises a second fork on other side of the wheel, wherein the second fork is formed from a single beam. The distance between the first fork and the second fork ranges from 150 mm to 300 mm for accommodating the motor mounted to the wheel rim .

[0025] The forks of the swing arm are attached to an axle of the motor through a brake panel using a combination of bolts, spacers, and bushings to allow secure attachment while enabling smooth operation of the wheel.

[0026] The brake panel houses a braking mechanism comprising a drum brake system or disc brake system.

[0027] The swing arm is connected to at least one shocker wherein the shocker is pivoted at one end to the frame of the vehicle and another end pivoted at the swing arm by means of a shocker bracket.

[0028] The motor is a hub motor including a permanent magnet synchronous machine and having a power rating ranging from 200 W to 300W.

[0029] The motor diameter is between and including 125-200 mm and having a width of 30-40 mm.

[0030] The wheel is having a diameter ranging from including 10 to 20 inches.

[0031] The wheel is a rear wheel of a two wheeled or a three wheeled vehicle.BRIEF DESCRIPTION OF DRAWINGS:

[0032] The above and other objects, features, and advantages of the present disclosure will be more apparent from the detailed description taken in conjunction with the accompanying drawings. One or more embodiments of the present invention are now described, by way of example only with reference to the accompanied drawings wherein like reference numerals represent like elements.

[0033] Fig. 1 illustrates a suspension system in a vehicle according to an embodiment of the invention.

[0034] Fig. 2 illustrates a detachable swing arm assembly according to an embodiment of the invention.

[0035] Fig.3 illustrates the two portions of the swing arm assembly in disassembled form.

[0036] Fig. 4 illustrates a bolted hub motor according to an embodiment of the invention.DETAILED DESCRIPTION:

[0037] The invention along with preferred embodiments will now be described in detail with reference to the accompanying drawings. The preferred embodiment does not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.

[0038] It will be readily understood that components of the present invention, as generally described and illustrated in figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed descriptionof the embodiments of the invention as represented in the figures is not intended to limit the scope of the invention but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.

[0039] According to an embodiment of the invention, Fig. 1 illustrates a suspension system (100) in a vehicle. A vehicle wheel preferably the rear wheel (120) of the vehicle has at-least one rim. The rim (140) is the outer circular edge of the wheel, designed to hold the tire in place and provide a secure fit. Typically made of materials like steel, aluminum alloy, or magnesium alloy, the rim (140) combines strength with lightweight properties to enhance performance and fuel efficiency. A wheel hub forms the central part of the wheel (120) and connects to the vehicle's axle, allowing rotational movement. According to an embodiment, the rim's design often includes a bead seat, where the tire's bead (reinforced edge) rests, ensuring a tight seal to prevent air leakage in tubeless tires. In the present embodiment, a motor (130) is mounted on the hub of the wheel assembly. The motor's rotor, which rotates to generate motion, is attached to the wheel rim (140) ensuring that the motor's output directly propels the wheel (120). A stator that is a stationary part of the motor (130), is fixed to the axle (190) or a non-rotating part of the wheel hub, providing a stable base for the motor's operation. The design typically includes bearings between the rotor and stator to allow smooth and frictionless rotation. Power and control cables run from the motor (130) to an external controller or battery system, which supplies the necessary electricity and regulates the motor's (130) performance. According to an embodiment of the invention, the swing arm (150) comprises two forks (110), which is attached to the motor (130) of the vehicle mounted on the hub (140) of the wheel (120) at a mounting aperture point (230). The swing arm (150) is a pivotal component in many two-wheeled and some three-wheeled vehicles, connecting chassis to the rear wheel (120). It is typically attached to the axle (190) of the wheel (120) through a brake panel (200), which serves as both a structural and functional interface. The brake panel (200) houses a braking mechanism, such as a drum brake system or disc brake system according to another embodiment of the invention.This provides a mounting point for the swing arm (150) to connect to the wheel's axle (190). This setup ensures that the brake panel (200) remains stationary relative to the swing arm (150) while the wheel (120) rotates. The swing arm's (150) connection to the brake panel (200) is usually facilitated by a combination of bolts, spacers, and bushings to allow secure attachment while enabling smooth operation of the wheel. The design ensures that the braking forces are transmitted effectively to the swing arm (150) and, subsequently, to the vehicle frame, maintaining stability during deceleration.

[0040] To enhance ride quality and absorb shocks from the road or terrain, the swing arm (150) is equipped with at least one shock absorber (shocker) (210). The shock absorber (210) is attached at one end to the swing arm (150) with the help of atleast one shocker bracket (220), typically near the wheel axle (190), and at the other end, is pivoted to the frame of the vehicle. This configuration allows the shock absorber to effectively dampen the forces generated by bumps, uneven surfaces, or impacts, reducing the strain on the vehicle and providing a smoother ride.

[0041] Fig. 2 illustrates a detachable swing arm (150) assembly according to an embodiment of the invention. The swing arm (150) comprising atleast two forks (110) attached to the motor (130) of the vehicle. The forks (110) are joined together with the help of a member (175). The respective fork (110) comprises two beams (170) attached together with at least one bolt (180) enabling the beams (170) to be detached for removing the wheel (120) including the rim (140). According to an embodiment, the two beams (170) of the fork (110) are joined together using a combination of fasteners, and bearings (180). Preferably, two fasteners (180) are used for joining the two beams (170).

[0042] Fig. 3 illustrates two portions of the swing arm (150) assembly in disassembled form. The technical advancement of the present invention lies in the fact that the hub motor (130) is mounted directly onto the vehicle's axle (190), with the motor (130) shaft aligned with the vehicle's axle (190). This attachment is secured using bolts (240), nuts, or a clamping mechanism to ensure a solid connection. Bearings are typically used around the motor’s axle (190) shaft to reduce friction and allow smooth rotation. These bearings are housed either within the motor (130) casing or the axle (190) assembly, ensuring the motor (130) remains in proper alignment and operates efficiently. The axle(190) housing or mount is designed to keep the motor (130) stable while allowing the wheel (120) to rotate freely. The axle (190) is a fixed component that is securely connected to the vehicle’s frame. Tire Replacement and Brake Maintenance for Hub Motor Vehicles require specific considerations due to the integrated design of the hub motor within the wheel. Hence, for removing the tire from the wheel, the hub motor (130) needs to be also dislodged from the axle (190), which in turn is fixed to the frame. This is cumbersome and needs more time & efforts for the personnel to do services. According to an embodiment, the swing arm fork (110) comprising two beams (170) detached in order to enable the tire of the swing arm (150) removed laterally or sideways for maintenance or replacement. Further, the shocker (210) is rotated in order to enable space for tire removal. This leads to non-removal of the hub motor (130) and it saves efforts and time for the service personnel.

[0043] According to Fig. 4, a bolted hub motor (130) is illustrated according to an embodiment of the invention. The motor (130) is a hub motor preferably a permanent magnet synchronous machine, although brushless direct current motor may be used in another embodiment. The motor (130) is having a power rating preferably between and including 200 W to 300W. The motor (130) diameter may be between and including 125-200 mm and having a width of 30-40 mm. The hub motor (130) diameter has been reduced and width increased to cater to weight reduction in motor. The bolting (180) for the two beams (170) are present at a distance ranging from including 170 to 210 mm from the hub of the wheel. The spacing between the two forks ranging from including 150 mm to 300 mm at the rear for accommodating a motor (130) bolted with the wheel rim (140). The wheel (120) is having a diameter ranging between and including 10 to 20 inches. The motor (130) is bolted to the rim (140) of the vehicle. The rim (140) of the wheel (120) comprises of a flange further comprises of plurality of protrusions for accommodating bolts (240) to house the motor (130). The suspension system (100) is connected to a motor casing encapsulating the motor (130), which is attached to the rim (140) of the wheel (120). Bolting a hub motor (130) directly to the rim (140) provides significant advantages, particularly in terms of structural stability and operational efficiency. By securing the motor (130) to the rim (140) with bolts (240), the connectionbecomes strong and stable, ensuring that the motor’s (130) torque is evenly distributed to the wheel (120). This reduces the risk of misalignment or wobbling, even during highspeed operation or under heavy loads.

[0044] The bolted connection also minimizes wear and tear on individual components, enhancing the overall durability of the system. One of the key benefits of bolting is the ease of assembly and maintenance. The bolted design allows for straightforward installation and removal of the motor, which simplifies the manufacturing process and reduces assembly time. During maintenance or repair, the motor (130) or rim (140) can be quickly detached from one another and replaced without requiring specialized tools. This feature is particularly useful in scenarios where the motor (130) or rim (140) needs servicing, as it minimizes vehicle downtime. Another advantage is the efficiency of power transfer. Bolting (240) the hub motor (130) to the rim (140), eliminates the need for intermediary components, such as couplings or additional hubs, which can introduce energy losses. This direct connection ensures that the motor’s torque is applied directly to the rim (140), resulting in efficient power delivery to the wheel (120). The reduction in energy loss enhances the overall performance of the vehicle, particularly in electric propulsion systems. Further, the motor (130) remains protected from external abrasions during tire removal, which is predominant if the motor (130) is welded to the wheel rim (140). The stator contains permanent magnets, which is expensive & if damaged during such tire replacement leads to unnecessary replacement of motor too.

[0045] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in respects as illustrative and not restrictive.

[0046] Within this patent specification, it is crucial to acknowledge the versatility and potential variations of the invention. Other embodiments may incorporate a variety of component units, logical units, and switching units to achieve similar or modified functionalities. These embodiments may involve different arrangements, configurations, or combinations of these units, depending on specific application requirements or design preferences. The scope of the invention encompasses such alternative embodiments, wherein the essential features and principles remain applicable, albeit with potentialmodifications to suit particular contexts or objectives. Thus, while the embodiments described herein serve as examples, it is understood that numerous other configurations and arrangements are feasible and fall within the scope of the invention as defined by the claims.Reference Numerals: -100 - Suspension system110 - Forks120 - Wheel130 - Motor140 - Rim150 - Swing Arm170 - Beam175- Member180 - Bolts190 - Axle200 - Brake panel210 - Shocker220 - Shocker Brackets230 - Mounting Aperture point240 - Motor Casing bolt

Claims

We Claim:

1. A suspension system (100) in a vehicle comprising: a frame structure of the vehicle; a wheel (120) comprising a rim attached to the frame structure; a motor (130) mounted to the rim of the wheel (120); at-least one swing arm (150) comprising at least one fork (110) mounted at a rear end on an axle of the motor (130) and connected at a front end to the frame structure of the vehicle; wherein at least one fork (110) is formed of plurality of beams (170) interconnected one another.

2. The suspension system (100) in a vehicle as claimed in claim 1, wherein the plurality of beams (170) attached together using at least one bolt (180), the bolt (180) enabling removal of at least one beam (170) to facilitate removal of the wheel (120).

3. The suspension system (100) in a vehicle as claimed in claim 2, wherein the bolt (180) connecting the two beams (170) is positioned at a distance between 170 mm and 210 mm from a hub of the wheel (120) to provide structural strength to the swing arm (150).

4. The suspension system (100) in a vehicle as claimed in claim 1, wherein the rim (140) of the wheel (120) comprises a flange having plurality of protrusions for accommodating motor casing bolts (240) to secure a motor casing.

5. The suspension system (100) in a vehicle as claimed in claim 4, wherein the motor (130) is encapsulated inside the motor casing.

6. The suspension system (100) in a vehicle as claimed in claim 1, wherein the swing arm (150) comprises a second fork (110) on other side of the wheel, wherein the second fork (110) is formed from a single beam.

7. The suspension system (100) in a vehicle as claimed in claim 6, wherein the distance between the first fork (110) and the second fork (110) ranges from 150 mm to 300 mm for accommodating the motor (130) mounted to the wheel rim (140).

8. The suspension system (100) in a vehicle as claimed in claim 1 , wherein the forks (110) of the swing arm (150) are attached to an axle (190) of the motor (130) through a brake panel (200) using a combination of bolts, spacers, and bushings to allow secure attachment while enabling smooth operation of the wheel (120).

9. The suspension system (100) in a vehicle as claimed in claim 8, wherein the brake panel (200) houses a braking mechanism comprising a drum brake system or disc brake system.

10. The suspension system (100) in a vehicle as claimed in claim 1 , wherein the forks (110) of the swing arm (150) are joined together with the help of a member (175).

11. The suspension system (100) in a vehicle as claimed in claim 1, wherein the swing arm (150) is connected to at least one shocker (210) wherein the shocker (210) is pivoted at one end to the frame of the vehicle and another end pivoted at the swing arm (150) by means of a shocker bracket (220).

12. The suspension system (100) in a vehicle as claimed in claim 1, wherein the motor (130) is a hub motor including a permanent magnet synchronous machine.

13. The suspension system (100) in a vehicle as claimed in claim 1, wherein the motor (130) is having a power rating ranging from 200 W to 300W.

14. The suspension system (100) in a vehicle as claimed in claim 1, wherein the motor (130) diameter is between and including 125-200 mm and having a width of 30- 40 mm.

15. The suspension system (100) in a vehicle as claimed in claim 1, wherein the wheel (120) is having a diameter ranging from including 10 to 20 inches.

16. The suspension system (100) in a vehicle as claimed in claim 1, wherein the wheel (120) is a rear wheel of a two wheeled or a three wheeled vehicle.

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