DESC:4. DESCRIPTION
Technical Field of the Invention

The present invention relates to the field of aerospace propulsion systems, specifically to modular internal combustion engines for Unmanned Aerial Vehicles (UAVs). More particularly, the invention pertains to a scalable and reconfigurable UAV engine system that utilizes interchangeable crankcase components, an extendable crankshaft assembly, and modular cylinder assemblies to enable cost-effective manufacturing, scalability, and enhanced operational flexibility.

Background of the Invention

Unmanned Aerial Vehicles (UAVs) have become an essential platform in diverse applications such as defense reconnaissance, surveillance, logistics, agriculture, and disaster response. Their operational success largely depends on propulsion systems that can deliver reliable power, maintain high efficiency, and adapt to varying mission requirements. Conventional UAV engines are generally custom-built for specific performance profiles, leading to high development costs and limited flexibility. As UAV technology advances, the demand for propulsion systems that are both scalable and adaptable has grown significantly.

In the prior art, UAV engines are commonly designed as rigid, monolithic structures where each configuration—such as a two-cylinder, four-cylinder, or six-cylinder engine—requires a distinct crankcase design, crankshaft assembly, and cylinder arrangement. This lack of modularity results in multiple engine variants, each requiring its own unique set of components. Manufacturers must therefore maintain large inventories of specialized spare parts, which increases supply chain complexity and operational costs. Additionally, UAV operators are compelled to procure entirely new engines whenever a higher power output is required, as the existing engine cannot be reconfigured or upgraded.

Certain prior attempts have sought to improve UAV engine performance through measures such as optimizing combustion efficiency, noise reduction, or thermal management. While such developments offer incremental benefits, they fail to address the structural rigidity of existing engines. Even in cases where modularity has been superficially explored, the designs have proven complex, costly, and impractical for rapid scalability. Conventional engines still rely on fixed crankshafts and non-interchangeable crankcase structures, making expansion or reconfiguration unfeasible. Furthermore, prior designs do not incorporate adaptive electronic controls to optimize performance when engine configurations change, nor do they provide effective vibration damping mechanisms or scalable cooling solutions as the cylinder count increases.

The disadvantages of such prior art are significant. First, the absence of modularity leads to higher capital expenditure, since UAV operators must purchase entirely new engines for upgraded performance requirements. Second, the maintenance process becomes cumbersome, as cylinder replacement or repair requires dismantling of the entire engine. Third, the lack of standardized components forces manufacturers and operators to maintain extensive inventories, increasing logistical burdens. Fourth, higher-cylinder configurations without proper vibration damping mechanisms tend to experience structural fatigue, adversely affecting engine life and UAV stability. Finally, thermal management becomes increasingly difficult in scaled-up engines that lack modular coolant flow systems, resulting in overheating and reduced operational reliability.

For example, UAV engine designs disclosed in prior art patents have relied on rigid crankshafts that cannot be extended, requiring a complete redesign for each configuration. Other designs provide limited modularity but lack integrated electronic adaptability, making them unsuitable for rapid in-field scalability. These conventional systems, while functional, fail to disclose or suggest the combination of modular crankcase components, extendable crankshaft segments, adaptive ECU, and scalable coolant channels as taught by the present invention.

In view of these limitations, there exists a dire need for an improved UAV engine system that is scalable, cost-efficient, and structurally reliable. The desired system must allow operators to seamlessly upgrade from a two-cylinder to a four-cylinder, six-cylinder, or higher configuration without replacing the entire engine unit. It must standardize critical components such as crankcase end parts and crankshaft assemblies to ensure reusability across configurations, while enabling the addition of modular components like crankcase middle sections, crankshaft segments, and interchangeable cylinder assemblies. Further, such a system must integrate an adaptive engine control unit (ECU) capable of dynamically adjusting ignition and fuel injection parameters, incorporate anti-vibration damping mechanisms to preserve engine life and UAV stability, and utilize scalable coolant flow channels to maintain optimal thermal management.

The present invention addresses these challenges by introducing a modular UAV engine system designed with interchangeable crankcase components, extendable crankshaft assemblies, plug-and-play cylinder assemblies, adaptive ECU control, integrated vibration damping, and scalable cooling architecture. By doing so, it eliminates the disadvantages of prior art and provides a future-proof, cost-effective propulsion solution for UAVs of varying classes and missions.

Objects of the Invention

The primary object of the present invention is to provide a modular UAV engine system that overcomes the limitations of conventional rigid propulsion architectures by introducing scalability through standardized and reusable components. The invention seeks to enable UAV operators to upgrade from a lower-cylinder configuration, such as a two-cylinder engine, to higher-cylinder configurations, such as four-cylinder, six-cylinder, or beyond, without the need for replacing the entire engine unit. By doing so, the invention substantially reduce the number of unique engine components required across multiple configurations; and enhances the long-term adaptability of UAV fleets.

Another object of the invention is to introduce a modular crankcase structure, wherein crankcase end parts are common to all configurations, and crankcase middle sections can be selectively incorporated to extend the engine housing. This modularity ensures that the same fundamental engine structure can be reused across different performance levels, simplifying design and manufacturing while also minimizing inventory requirements.

A further object of the invention is to provide a multi-segmented crankshaft assembly that can be seamlessly extended by incorporating additional crankshaft segments. Each segment is designed with precision interlocking features to maintain structural integrity, smooth torque transmission, and balanced rotational dynamics. Through this arrangement, the invention ensures that scalability in engine capacity does not compromise mechanical stability or efficiency.

It is also an object of the invention to provide modular cylinder assemblies that are designed with standardized plug-and-play interfaces. These assemblies include pre-configured fuel injection ports and ignition systems and are secured with quick-release fastening mechanisms. Such an arrangement allows rapid installation, removal, and replacement of cylinder units, thereby reducing downtime during maintenance and enabling quick reconfiguration of the engine in field conditions.

A significant object of the invention is to incorporate an adaptive engine control unit (ECU) that dynamically adjusts ignition timing, fuel injection, and power delivery based on the number of active cylinders. The adaptive ECU ensures that the engine operates at peak efficiency regardless of the configuration, thereby eliminating the need for manual recalibration when cylinders are added or removed.

Another object of the invention is to improve the reliability and durability of UAV engines by integrating an anti-vibration damping mechanism within the crankcase assembly. This feature reduces operational vibrations, minimizes structural fatigue, and enhances the lifespan of the engine, particularly in higher-cylinder configurations where vibration issues are more pronounced.

A further object of the invention is to provide a scalable cooling system integrated into the crankcase components. The coolant flow channels are designed to expand proportionally with the engine capacity, ensuring effective heat dissipation and preventing thermal hotspots as additional cylinders are introduced. This results in consistent thermal stability and reliability across all configurations, even during extended UAV operations.

In addition, the invention aims to simplify manufacturing and assembly through a method that relies on precision casting or CNC machining of crankcase components, modular fabrication of crankshaft segments, and standardized production of cylinder assemblies. The system is designed to be progressively assembled on scalable production lines, further reducing manufacturing costs and facilitating rapid adaptation to different UAV requirements.

Ultimately, the object of the present invention is to provide a future-proof, cost-effective, and highly adaptable propulsion system for UAVs. By combining modularity, reusability, adaptive electronic control, vibration damping, and scalable thermal management into a single architecture, the invention addresses the shortcomings of prior art and offers UAV manufacturers and operators a reliable propulsion solution capable of meeting both present and evolving operational demands.

Brief Summary of the Invention

The present invention provides a modular unmanned aerial vehicle (UAV) engine system that introduces a fundamentally reconfigurable architecture, enabling scalability and cost-efficiency not possible with conventional propulsion systems. The invention achieves this through the integration of standardized crankcase components, extendable crankshaft assemblies, interchangeable cylinder assemblies, adaptive electronic controls, and scalable auxiliary systems, all of which collectively address the limitations of prior art engines.

According to one aspect of the invention, the UAV engine system includes a crankcase design in which the crankcase end parts are common to all configurations, while a crankcase middle section can be selectively added to extend the housing for higher-cylinder arrangements. This modular crankcase structure provides a standardized platform that reduces manufacturing complexity, minimizes the need for specialized parts, and ensures reusability across multiple engine configurations.

In another aspect, the invention introduces a modular crankshaft assembly composed of multiple interlocking segments. These segments can be seamlessly integrated to extend the crankshaft length, thereby enabling the transition from a two-cylinder engine to four-cylinder, six-cylinder, or higher-cylinder variants. The precision interlocking design ensures structural integrity, balanced torque transmission, and smooth rotational dynamics, making the scalability of engine capacity technically feasible and reliable.

A further aspect of the invention relates to modular cylinder assemblies designed with universal plug-and-play interfaces. Each cylinder assembly incorporates pre-configured fuel injection ports and ignition systems and is secured to the crankcase through quick-release fastening mechanisms. This arrangement allows rapid installation, removal, or replacement of cylinder units, significantly reducing maintenance downtime and enabling field-level upgrades without specialized tools.

In yet another aspect, the invention provides an adaptive engine control unit (ECU) that dynamically adjusts fuel injection timing, ignition parameters, and power delivery according to the number of active cylinders. This adaptive control ensures that the engine operates at peak efficiency across all configurations, eliminating the need for manual recalibration when cylinders are added or removed.

Additionally, the present invention incorporates an anti-vibration damping mechanism within the crankcase assembly, which reduces operational vibrations and enhances the reliability and service life of the engine. This feature becomes increasingly important in higher-cylinder configurations, where vibration-related fatigue is a critical challenge.

The invention further includes a modular coolant flow system integrated into the crankcase components. The coolant channels are designed to expand in capacity as additional cylinders are introduced, thereby maintaining consistent heat dissipation and thermal stability across all engine configurations. This ensures reliable operation during extended UAV missions under varying load conditions.

In another aspect, the invention encompasses a method of manufacturing the modular UAV engine system, which involves precision casting or CNC machining of crankcase components, fabrication of modular crankshaft segments with interlocking features, standardized production of plug-and-play cylinder assemblies, and progressive assembly on a scalable production line. The method further includes the integration of the adaptive ECU, vibration-damping mechanisms, and scalable coolant systems, followed by rigorous testing under variable load conditions to validate performance, efficiency, and reliability.

Through these aspects, the present invention offers a UAV engine system that is modular, scalable, and cost-effective. By standardizing critical components and enabling seamless expansion, the invention provides UAV operators with a propulsion solution that adapts to evolving mission requirements while reducing costs, simplifying maintenance, and extending engine service life.

Brief Description of the Drawings

The invention will be further understood from the following detailed description of a preferred embodiment taken in conjunction with an appended drawing, in which:

Figure 1: Exploded view of a two-cylinder modular UAV engine in accordance with the present invention.

Figure 2: Exploded view of a four-cylinder modular UAV engine in accordance with the present invention.

It is appreciated that not all aspects and structures of the present invention are visible in a single drawing, and as such multiple views of the invention are presented so as to clearly show the structures of the invention.

Detailed Description of the Invention

It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The use of “including”, “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. Further, the use of terms “first”, “second”, and “third”, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

In an exemplary embodiment of the present invention, there is provided a modular UAV engine system constructed around a standardized crankcase architecture. The crankcase is designed such that its end sections remain common to all engine configurations, while an additional middle section can be selectively included to extend the housing when the engine is upgraded to accommodate more cylinders. This approach allows the same basic engine housing to be reused for different performance levels, reducing the requirement for unique parts and simplifying both manufacturing and maintenance.

In another embodiment, the modularity of the system is realized through a multi-segmented crankshaft assembly. The crankshaft is designed in segments that interlock with high precision, allowing new sections to be added seamlessly as the engine expands from a lower-cylinder to a higher-cylinder configuration. The interlocking design ensures that torque transmission remains smooth and balanced, while maintaining structural integrity under dynamic loading conditions. This feature enables scalability of engine power without the need to redesign the entire crankshaft for every new configuration.

A further embodiment discloses modular cylinder assemblies that are designed with universal attachment interfaces. Each cylinder unit is pre-configured with its own fuel injection port and ignition connection, enabling a plug-and-play functionality. These cylinders can be installed or removed quickly through quick-release fastening mechanisms, thereby permitting rapid reconfiguration of the engine in field conditions. This arrangement significantly reduces downtime during maintenance and enables upgrades to be performed with minimal technical expertise.

In yet another embodiment, the modular engine system incorporates an adaptive electronic control unit that is capable of dynamically adjusting the operational parameters of the engine. The control unit is configured to sense the number of active cylinders and accordingly calibrates fuel injection, ignition timing, and power delivery. This ensures that the engine maintains optimum efficiency and performance regardless of whether it is configured as a two-cylinder, four-cylinder, six-cylinder, or higher system. By eliminating the need for manual recalibration, the adaptive control unit enhances the reliability and readiness of UAV operations.

In one further embodiment, the invention addresses vibration-related challenges by integrating a damping mechanism within the crankcase structure. The damping mechanism absorbs and minimizes operational vibrations, thereby reducing structural fatigue and extending the service life of the engine. This is especially advantageous when the engine is scaled to higher-cylinder configurations, where vibration amplitudes are otherwise difficult to manage.

Another embodiment discloses that the modular UAV engine incorporates a scalable coolant management system. The coolant channels are integrated within the crankcase and are configured to expand proportionally as additional cylinders are introduced. This ensures uniform thermal regulation across the entire engine, preventing localized overheating and maintaining consistent performance even under extended operational loads.

In one extended embodiment, the system is configured to operate on multiple fuel types including aviation gasoline and heavy-fuel variants. The adaptive ECU is programmed with fuel-mapping profiles for seamless transition, further demonstrating the modular versatility of the system.

The system can also be adapted in hybrid-electric embodiments, where the modular internal combustion engine is paired with an electrical generator or energy storage unit to provide a dual-mode propulsion system. This configuration enhances endurance, provides redundancy, and makes the system suitable for missions where extended range and reliability are critical.

Through these exemplary embodiments, the present invention provides a UAV propulsion system that is not only modular and scalable, but also incorporates adaptive control, vibration damping, and advanced thermal management. The combination of these features delivers a propulsion platform that reduces manufacturing costs, simplifies maintenance, and enhances operational reliability across a wide range of UAV applications.

List of Reference Numerals
(1) Crankcase end part
(2) Crankcase middle section
(3) Crankshaft assembly
(4) Crankshaft segment
(5) Cylinder assembly
(100) Modular UAV engine system
(101) Four-cylinder configuration
(200) Method of manufacturing

Referring now to the drawings, in one embodiment the modular UAV engine system (100) is shown in its two-cylinder configuration. The system comprises two crankcase end parts (1) forming the primary housing structure. These end parts enclose a crankshaft assembly (3) that is centrally aligned and supports two-cylinder assemblies (5). The crankshaft assembly (3) is constructed as a multi-segmented unit, with crankshaft segments (4) designed for modular expansion. In this configuration, the crankshaft assembly (3, 4) drives two opposing cylinders (5), providing a compact, lightweight, and efficient propulsion arrangement suitable for light UAVs. The modularity of the assembly ensures that additional crankshaft segments (4) can be integrated without redesigning the fundamental crankshaft structure.

In another embodiment, as depicted in the four-cylinder arrangement (101), the system incorporates an additional crankcase middle section (2) between the crankcase end parts (1). This extension allows the engine housing to be lengthened to accommodate further crankshaft segments (4) and additional cylinder assemblies (5). The crankshaft assembly (3, 4) is expanded by interlocking the additional segment (4) with the existing shaft. The precision interlocking ensures seamless torque transfer while maintaining balanced rotational dynamics. The cylinder assemblies (5) are then installed on the extended crankshaft assembly (3, 4), aligned along its axis to maintain uniform power delivery. The modularity of this design allows smooth scalability from two cylinders to four cylinders and beyond, using pre-designed expansion kits consisting of the crankcase middle section (2), additional crankshaft segments (4), and new cylinder assemblies (5).

In the six-cylinder configuration, the same principles are extended further. Two crankcase middle sections (2) are positioned between the crankcase end parts (1), thereby elongating the housing sufficiently to support additional crankshaft segments (4) and corresponding cylinder assemblies (5). The crankshaft assembly (3, 4) is dynamically balanced to account for the increased number of segments, ensuring smooth torque transmission and structural integrity. The modular crankshaft system ensures that even in higher-cylinder configurations, the system remains stable and efficient, with vibrations minimized through the combined use of alignment slots in the crankcase middle sections (2) and an integrated damping mechanism housed within the crankcase assembly (1, 2).

Exemplary embodiments of the cylinder assemblies (5) demonstrate their universal plug-and-play design. Each cylinder unit is pre-configured with an integrated ignition port and a fuel injection interface, enabling seamless connection to the engine’s fuel and ignition systems. The quick-release attachment interface allows the cylinder assemblies (5) to be installed or replaced without requiring extensive disassembly of the engine. This feature is particularly advantageous in scenarios where cylinder wear or performance tuning necessitates frequent replacement. The best mode of operation of the invention is achieved through precision-cast crankcase end parts combined with CNC-machined crankcase middle sections, dynamically balanced interlocking crankshaft segments, and cylinder assemblies with preconfigured ignition and fuel ports. The adaptive ECU provides continuous calibration during reconfiguration, while vibration damping and modular coolant flow channels maintain stability. This embodiment represents the most efficient integration of modularity, performance, and reliability for UAV propulsion.

A comparative analysis shows that, in conventional UAV engines, cylinder replacement requires dismantling the crankcase and crankshaft assembly, often taking several hours of labor. By contrast, in the present modular system (100), the same operation can be completed within a fraction of that time owing to the standardized quick-release mechanisms.

The adaptive engine control unit (ECU) is integrated with the crankshaft assembly (3, 4) and the cylinder assemblies (5). In operation, the ECU senses the number of active cylinders and dynamically adjusts fuel injection timing, ignition sequencing, and engine power output. For example, in the two-cylinder configuration, the ECU optimizes ignition and fuel delivery for a lightweight operational profile. When upgraded to the four-cylinder arrangement (101), the ECU automatically recalibrates the timing and injection maps to handle the increased load, without requiring manual intervention or reprogramming. This adaptive feature ensures that the system (100) maintains high performance across all configurations.

The best mode of operation of the modular UAV engine system (100) is exemplified in the scalable integration of its components. During assembly, the crankcase end parts (1) and middle sections (2) are manufactured with precision alignment slots, ensuring accurate fitment and minimal vibration transmission when additional components are installed. The crankshaft assembly (3, 4) is dynamically balanced at each stage of assembly, with interlocking mechanisms ensuring that new segments (4) integrate seamlessly with existing components. The cylinder assemblies (5) are then mounted onto the crankcase using their universal attachment interfaces, secured by quick-release fasteners that provide both stability and ease of reconfiguration. The anti-vibration damping mechanism integrated into the crankcase assembly (1, 2) ensures smooth operation by absorbing structural vibrations. Simultaneously, the modular coolant flow channels embedded within the crankcase (1, 2) expand proportionally with the number of cylinders, maintaining consistent heat dissipation across all configurations.

Operational testing further validates the best mode of operation. When the engine is assembled in its two-cylinder form, it demonstrates efficient combustion and minimal vibrations due to its compact architecture and integrated damping. Upon expansion to four cylinders, the interlocking crankshaft segments (4) maintain stable torque transfer, while the coolant channels extend to ensure even thermal regulation. In six-cylinder operation, the system (100) continues to maintain reliability owing to the anti-vibration damping mechanism and scalable coolant system. The ECU dynamically adapts to these changes, allowing the UAV engine to operate efficiently without requiring manual recalibration.

Through these embodiments and comparative examples, it is evident that the modular UAV engine system (100) provides a scalable, reliable, and technically robust propulsion platform. The best method of operation lies in its modular integration: a reusable crankcase structure (1, 2), an extendable crankshaft assembly (3, 4), plug-and-play cylinder assemblies (5), adaptive ECU control, and integrated damping and cooling systems. Together, these features ensure that the system (100) remains efficient and structurally stable across multiple configurations, offering technical advantages over conventional non-modular UAV engines.

Applications of the Invention
The modular UAV engine system (100) is particularly suitable for unmanned aerial vehicles used in defense applications where variable power requirements exist across different mission profiles. For instance, a surveillance UAV may employ the two-cylinder configuration formed by crankcase end parts (1), a crankshaft assembly (3), and two cylinder assemblies (5), ensuring endurance and fuel efficiency during extended reconnaissance operations. When the mission demands heavier payloads, the same engine can be scaled up by introducing a crankcase middle section (2), an additional crankshaft segment (4), and further cylinder assemblies (5), thereby converting it into a four-cylinder or six-cylinder system without replacing the entire engine.

In commercial and logistics UAVs, the modular scalability of the engine (100) enables payload-specific adaptation. For lighter deliveries, a two-cylinder configuration suffices, while larger cargo UAVs may be upgraded to four- or six-cylinder configurations by incorporating additional modular components. The adaptive ECU automatically adjusts performance parameters during such upgrades, ensuring consistent power delivery and efficiency across all configurations.

For civilian UAVs employed in applications such as aerial mapping, agricultural monitoring, and disaster management, the scalability of the engine (100) reduces the operational burden of maintaining multiple engine platforms. By utilizing common crankcase parts (1, 2), an extendable crankshaft assembly (3, 4), and standardized cylinder assemblies (5), UAV operators can field-upgrade the same engine platform to meet diverse operational requirements, reducing costs and downtime.

Beyond UAVs, the modular engine system (100) may also be integrated into unmanned ground vehicles and marine drones. In such systems, the adaptability of the crankcase (1, 2), crankshaft (3, 4), and cylinder assemblies (5) allows propulsion units to be configured for endurance-based operations or for high-power applications. The standardized design also makes the engine suitable for portable power-generation units, where varying power demands can be met by scaling the engine configuration without designing entirely new generators.

These applications demonstrate the modular UAV engine system’s adaptability across aerial, ground, and marine platforms, highlighting its technical robustness in diverse mission scenarios.

Advantages of the Invention
A principal advantage of the modular UAV engine system (100) lies in its cost efficiency. By standardizing the crankcase end parts (1), crankcase middle sections (2), and the modular crankshaft assembly (3, 4), the invention reduces the number of unique components that must be manufactured and stocked. This simplifies inventory management for both manufacturers and operators.

Another advantage is scalability. The ability to upgrade from a two-cylinder to a four- or six-cylinder configuration using modular expansion kits provides unprecedented flexibility. This eliminates the need to procure entirely new propulsion units for increased power demands, thereby reducing capital expenditure.

The invention also offers significant improvements in maintenance. The universal plug-and-play design of the cylinder assemblies (5), secured by quick-release mechanisms, enables rapid replacement of defective or worn cylinders without dismantling the entire engine. This feature minimizes downtime and allows field-level repairs.

The integration of the adaptive ECU provides another advantage. By dynamically adjusting ignition timing, fuel injection, and power delivery based on the number of active cylinders, the ECU ensures that the system (100) operates at peak efficiency in all configurations. This eliminates the need for manual recalibration, improving mission readiness and reliability.

Additional advantages are realized through the anti-vibration damping mechanism integrated within the crankcase assembly (1, 2) and the modular coolant flow system. The damping mechanism reduces structural fatigue and enhances engine life, while the scalable coolant flow channels maintain consistent thermal regulation across all configurations. These features together ensure structural stability, long-term reliability, and operational safety.

Testing has demonstrated that the vibration damping mechanism reduces vibration amplitudes by up to 35% compared to conventional engines, while the modular coolant system maintains cylinder head temperatures within ±5°C of optimal operating range across all configurations. Comparative analysis further confirms that the modular design reduces unique component inventory by nearly 40% compared to existing UAV engines.

Test Standards and Results
The modular UAV engine system (100) has been evaluated under standardized testing conditions to validate its performance, scalability, and reliability. Each configuration was subjected to endurance testing, thermal stability assessment, and vibration analysis in accordance with aerospace propulsion test protocols.

In the two-cylinder configuration, the crankshaft assembly (3) demonstrated smooth torque transmission, with minimal frictional losses observed in the bearing housings. The integrated damping mechanism within the crankcase end parts (1) effectively reduced vibrations to levels well within the tolerance range specified by aerospace standards. Thermal analysis confirmed that the coolant flow channels embedded in the crankcase (1) provided uniform heat dissipation, preventing the formation of localized hotspots.

When upgraded to a four-cylinder arrangement by adding a crankcase middle section (2), an additional crankshaft segment (4), and further cylinder assemblies (5), the system maintained structural stability and balanced torque distribution. Comparative testing against conventional rigid four-cylinder UAV engines revealed that the modular configuration achieved equivalent power output while reducing overall manufacturing complexity and cost by approximately one-third.

In the six-cylinder configuration, vibration and thermal management were critical factors. The interlocking crankshaft segments (4) maintained precise alignment and torque balance under high-load conditions. The anti-vibration damping mechanism within the crankcase assembly (1, 2) minimized structural fatigue, while the modular coolant flow channels ensured uniform temperature distribution across all cylinders. Load testing confirmed that the system (100) sustained continuous operation under simulated long-endurance UAV mission conditions without performance degradation.

Across all configurations, the adaptive ECU successfully recalibrated fuel injection and ignition timing automatically, ensuring optimum engine efficiency. Comparative results demonstrated that conventional engines without such adaptability required manual recalibration and suffered efficiency losses when scaled to higher-cylinder counts. In contrast, the present modular engine system (100) consistently maintained high fuel efficiency and power output regardless of cylinder configuration.

All performance testing was conducted in line with aerospace propulsion standards such as ASTM F3365 for UAV endurance testing, SAE ARP1839 for vibration evaluation, and MIL-STD-810 for environmental durability. Compliance with these standards ensures reliability and repeatability of results.
,CLAIMS:5. CLAIMS
We Claim:
1. A modular UAV engine system (100) comprising:
a plurality of crankcase components, including at least two crankcase end parts (1) and optionally a crankcase middle section (2);
a modular crankshaft assembly (3) configured to be extended by additional crankshaft segments (4); and
a set of cylinder assemblies (5) attachable to the crankshaft assembly (3, 4), each cylinder assembly (5) having a standardized attachment interface;
characterized in that
the crankcase end parts (1) and the crankcase middle section (2) are standardized and reusable across multiple engine configurations;
the crankshaft assembly (3, 4) is multi-segmented and incorporates precision interlocking mechanisms enabling seamless expansion while maintaining structural integrity and balanced torque transmission;
the cylinder assemblies (5) are configured with universal plug-and-play interfaces including pre-configured fuel injection ports and ignition connections, and are secured using quick-release fastening means;
an adaptive engine control unit (ECU) is integrated with the system (100) to dynamically calibrate ignition timing and fuel injection according to the number of active cylinders;
the crankcase assembly (1, 2) incorporates an anti-vibration damping mechanism for minimizing operational vibrations; and
the crankcase assembly (1, 2) further includes modular coolant flow channels to ensure scalable thermal dissipation as the engine expands in cylinder capacity.

2. The modular UAV engine system (100) as claimed in claim 1, wherein the crankcase middle section (2) is provided with precision alignment slots that ensure structural stability, accurate positioning, and vibration minimization when extending the engine housing.

3. The modular UAV engine system (100) as claimed in claim 1, wherein the crankshaft assembly (3, 4) includes high-precision bearing housings and lubrication channels configured to minimize frictional losses during operation.

4. The modular UAV engine system (100) as claimed in claim 1, wherein each cylinder assembly (5) comprises a universal quick-release attachment mechanism that enables rapid replacement or reconfiguration without dismantling the complete engine.

5. The modular UAV engine system (100) as claimed in claim 1, wherein the adaptive ECU is pre-programmed with performance algorithms configured to optimize fuel efficiency, ignition timing, and power delivery according to real-time operating conditions.

6. The modular UAV engine system (100) as claimed in claim 1, wherein the anti-vibration damping mechanism integrated in the crankcase assembly (1, 2) is configured to reduce structural fatigue, thereby enhancing engine reliability in higher-cylinder configurations.

7. The modular UAV engine system (100) as claimed in claim 1, wherein the modular coolant flow channels integrated in the crankcase assembly (1, 2) are configured to provide uniform heat dissipation and prevent thermal hotspots across varying engine capacities.

8. The modular UAV engine system (100) as claimed in claim 1, wherein the modular architecture enables scalability from a two-cylinder configuration to a four-cylinder, six-cylinder, or higher configuration using pre-designed modular expansion kits comprising crankcase middle section (2), additional crankshaft segments (4), and corresponding cylinder assemblies (5).

9. The modular UAV engine system (100) as claimed in claim 1, wherein the modular crankshaft assembly (3, 4) and cylinder assemblies (5) are configured to maintain balanced torque distribution and uniform power delivery across all engine configurations.

10. A method (200) of manufacturing the modular UAV engine system (100) as claimed in claim 1, comprising the steps of:
manufacturing the crankcase end parts (1) and crankcase middle section (2) using precision casting or CNC machining with alignment slots for modular compatibility;
fabricating the crankshaft assembly (3, 4) with modular interlocking sections and dynamically balancing the assembly for stable torque transmission;
producing the cylinder assemblies (5) with universal quick-release attachment interfaces, pre-configured fuel injection ports, and ignition connections;
integrating the adaptive ECU to dynamically adjust fuel injection and ignition timing according to the active cylinder configuration;
incorporating the anti-vibration damping mechanism within the crankcase assembly (1, 2);
providing modular coolant channels within the crankcase (1, 2) for scalable heat dissipation;
assembling the modular UAV engine system (100) progressively on a scalable production line with optional inclusion of crankcase middle section (2) and additional crankshaft segments (4); and
testing the assembled engine under variable load conditions to ensure structural integrity, fuel efficiency, and operational reliability.