DESC:TECHNICAL FIELD
The present disclosure relates to power steering systems, particularly to hydraulic assisted power steering systems for vehicles, including tractors and off-road vehicles. More particularly, the present disclosure relates to a double sector shaft gear assembly that improves the force distribution in the steering system.
BACKGROUND
Conventional power steering systems utilize three main internal mechanisms to provide power assistance: rack and pinion, rack and sector gear, and worm and roller mechanisms to assist the driver in steering by reducing the effort needed to turn the wheel, particularly in vehicles with heavy steering loads, such as agricultural tractors. In the case of traditional Hydraulic Assisted Power Steering systems, the full design force is transferred directly to the drag link, which leads to increased wear and a reduced lifespan of the part. This situation also requires additional reinforcement of the drag link to withstand the load, leading to higher production and maintenance costs.
Current Hydraulic Assisted Power Steering systems present challenges in ensuring reliability and ease of maintenance. One key improvement needed in the current steering systems is the incorporation of redundant mechanisms that ensure functionality even in the event of a failure. Specifically, if one of the mechanisms fails, the remaining mechanism can still operate, allowing the vehicle to maintain its steering ability without complete loss of control. This redundancy feature can significantly improve safety and ensure operational reliability during critical tasks.
Furthermore, off-road vehicles, such as those used in agriculture and tractor applications, often operate in rugged terrains like dirt, sand, snow, or rocky surfaces. Conventional steering mechanisms may struggle to provide the necessary control in these challenging environments. Advanced systems need to be developed to address this problem, that allows the system to manage the amount of steering force directed to the axle or wheel, thus enabling better traction, stability, and handling on difficult terrains.
In tractor applications, the front axle weight (FAW) presents a significant challenge to the steering system, particularly during turning or when maneuvering heavy loads. There is a need to mitigate this issue by introducing a more efficient power steering mechanism that not only improves the distribution of force but also addresses the limitations of traditional systems. The new approach needs to reduce wear on components, enhance longevity of the steering parts, and allow the system to better handle the demands of both agricultural and off-road vehicle applications.
Moreover, in current tractor steering systems, the design of the linkage includes a tie rod to connect the wheels, is simplified through the use of an independent type front axle. A design that eliminates the need for tie rods will ensure that the vehicle’s steering performance remains consistent, even under heavy loads, while reducing the number of mechanical parts and the associated maintenance requirements.
Therefore, there is a need for a technology that addresses these limitations by more effectively distributing the force, thereby reducing the strain on the drag link, extending its lifespan, and minimizing the requirement for expensive reinforcement.
SUMMARY
In one aspect of the present disclosure, a double sector shaft gear assembly for a hydraulic assisted power steering system is provided.
The double sector shaft gear assembly includes a primary sector shaft gear, a secondary sector shaft gear, and a rack piston. The primary sector shaft gear includes a first gear teeth, that is positioned on a first side of the primary sector shaft gear and a second gear teeth, that is positioned on the corresponding side of the first gear teeth. The secondary sector shaft gear is positioned adjacent to the primary sector shaft gear, with a gear teeth configured to engage the first gear teeth of the primary sector gear and adapted to rotate the secondary sector shaft gear in a clockwise direction when the primary sector shaft gear rotates in counter-clockwise direction and vice versa. The rack piston is positioned adjacent to the second teeth of the primary sector shaft gear with a gear teeth adapted to rotate the primary sector shaft gear, when the rack piston moves in a linear direction. The rack piston transfers hydraulic pressure from the system and generates force to rotate the primary sector shaft gear and the secondary sector shaft gear.
In some aspects of the present disclosure, the primary sector shaft gear is connected to a first drag link and the secondary sector shaft gear is connected to a second drag link such that the rack piston transmits the hydraulic force evenly to the first drag link and to the second drag link.
In some aspects of the present disclosure, the double sector shaft gear assembly is securely enclosed in a gear box housing, that is made of a rigid structure.
In some aspects of the present disclosure, a face sealing side cover provides a tight seal between the side cover and the gear box housing to protect the gear box housing from external elements.
In some aspects of the present disclosure, an adjustment mechanism including an adjustment screw and nut is provided in the gear box housing to adjust the alignment of the primary sector shaft gear and the secondary sector shaft gear.
In some aspects of the present disclosure, a plurality of bearings are provided to support the primary sector shaft gear and the secondary sector shaft gear, ensuring smooth rotational motion within the housing.
In another aspect of the disclosure, a hydraulic assisted power steering system with a double sector shaft assembly is provided.
The hydraulic assisted power steering system includes a double sector shaft gear assembly, a hydraulic assist mechanism, a first pitman arm, a second pitman arm, a first drag link, and a second drag link. The primary sector shaft gear is operatively connected to the first pitman arm and the secondary sector shaft gear is operatively connected to the second pitman arm. The rack piston gear engages with the primary sector shaft gear and the secondary sector shaft gear. The rack piston gear is configured to transmit hydraulic pressure forces to the primary sector shaft gear and the secondary sector shaft gear and the primary sector shaft gear and secondary sector shaft gear are configured to transfer torque evenly to the first pitman arm and to the second pitman arm. The hydraulic assist mechanism is configured to apply hydraulic pressure to assist the movement of the rack piston gear. The first pitman arm is operatively connected to the primary sector shaft gear and to the first drag link. The second pitman arm is operatively connected to the secondary sector shaft gear and to the second drag link. The first drag link is operatively connected to the first pitman arm and to an LH wheel. The second drag link is operatively connected to the second pitman arm and to an RH wheel. The hydraulic assist mechanism facilitates steering assistance by transmitting torque from the hydraulic system to the rack piston gear, ensuring smooth steering operation for both the LH wheel and the RH wheel.
In some aspects of the present disclosure, the hydraulic assisted power steering system with a double sector shaft assembly further includes a first-half independent front axle operatively connected to the LH wheel, a second-half independent front axle operatively connected to the RH wheel and a pivot pin, upon which the first-half independent front axle and the second-half independent front axle are mounted. The first-half independent front axle and the second-half independent front axle are configured to rotate with respect to the pivot pin during left-hand and right-hand steering movements.
In some aspects of the present disclosure, the hydraulic assisted power steering system with a double sector shaft assembly further includes an LH steering arm, that is operatively connected to the first drag link and to the end of the first-half independent front axle adjacent to the LH wheel and an RH steering arm, that is operatively connected to the second drag link and to the end of the second-half independent front axle adjacent to the RH wheel. The LH steering arm and the RH steering arm are configured to facilitate the movement of the first-half independent front axle and the second-half independent front axle during left-hand and right-hand steering.
In some aspects of the present disclosure, the hydraulic assisted power steering system is configured to provide efficient steering with reduced mechanical complexity by minimizing the number of ball joints and eliminating the need for tie rods in the steering linkage.
In yet another aspect of the present disclosure, a method for operating a hydraulic assisted power steering system with a double sector shaft assembly is provided.
The method for operating a hydraulic assisted power steering system with a double sector shaft assembly includes the steps of providing a double sector shaft gear assembly including a primary sector shaft gear operatively connected to a first pitman arm, a secondary sector shaft gear operatively connected to a second pitman arm, and a rack piston gear engaging with the primary sector shaft gear and the secondary sector shaft gear, transmitting hydraulic pressure forces to the rack piston gear via a hydraulic assist mechanism to assist the movement of the rack piston gear, applying the hydraulic pressure forces to rotate the primary sector shaft gear and secondary sector shaft gear and transfer torque evenly to the first pitman arm and second pitman arm, operatively connecting the first drag link to the first pitman arm and the LH wheel, and the second drag link to the second pitman arm and the RH wheel, and enabling smooth steering operation for both the LH wheel and the RH wheels by transferring the applied torque through the primary sector shaft gear and the secondary sector shaft gears via the first drag link and the secondary drag link.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawing,
Figure 1 illustrates a double sector shaft hydraulic assist power steering assembly, in accordance with an aspect of the present disclosure;
Figure 2 illustrates the cross-sectional view of double sector shaft hydraulic assist Power steering assembly, in accordance with an aspect of the present disclosure;
Figure 3 illustrates the cross-sectional view of double sector shaft hydraulic assist Power steering assembly, in accordance with an aspect of the present disclosure; and
Figure 4 illustrates the double sector shaft tractor steering linkage to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, known details are not described in order to avoid obscuring the description.
References to one or an embodiment in the present disclosure can be references to the same embodiment or any embodiment; and, such references mean at least one of the embodiments.
Reference to "one embodiment", "an embodiment", “one aspect”, “some aspects”, “an aspect” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others.
The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided.
A recital of one or more synonyms does not exclude the use of other synonyms.
The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various embodiments given in this specification. Without intent to limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims, or can be learned by the practice of the principles set forth herein.
The term “user” is referred as a person who is operating the hydraulic assisted power steering system.
The term “X-axis” and “X direction” are used interchangeably across the context. The term “Y-axis” and “Y direction” are used interchangeably across the context.
As mentioned before, there is a need for a technology that addresses these limitations by more effectively distributing the force, thereby reducing the strain on the drag link, extending its lifespan, and minimizing the requirement for expensive reinforcement.
In one aspect of the present disclosure, a double sector shaft gear assembly (100) is provided.
Figure 1 illustrates a double sector shaft hydraulic assist power steering assembly (100), in accordance with an aspect of the present disclosure.
The double sector shaft gear assembly (100) may include a primary sector shaft gear (2) and a secondary sector shaft gear (4) that work in unison.
The primary sector shaft gear (2) features two segments of tooth profiles, designed to engage both the rack piston gear teeth [14] and the secondary sector shaft gear teeth [12] simultaneously.
Figure 2 illustrates the cross-sectional view of double sector shaft hydraulic assist Power steering assembly (100), in accordance with an aspect of the present disclosure.
This dual engagement ensures that the primary sector shaft gear (2) is capable of transferring torque and motion efficiently to both the rack piston (14) and the secondary gear (4). By connecting to both the rack piston (14) and the secondary gear (4) at the same time, the assembly (100) enhances the overall torque distribution, resulting in smoother and more reliable operation of the steering mechanism.
In some aspects of the present disclosure, the primary sector shaft gear (2) is designed with multiple teeth along its circumference. These teeth engage with the rack assembly (14), which is part of the steering mechanism that controls the movement of the steering wheels. The primary sector shaft gear (2) also meshes with the secondary sector shaft gear (4), transmitting rotational movement to the secondary sector shaft gear (4), which further transfers the motion to pitman arms (3,5). This interaction allows for the efficient distribution of rotational motion throughout the system, ensuring that the steering mechanism operates smoothly.
The secondary sector shaft gear (4) features multiple teeth (12) that, in contrast to the primary sector gear, engage exclusively with the primary sector shaft gear (2). The secondary sector gear (4) doesn’t directly engage with the rack assembly. Instead, it solely transfers the rotational motion from the primary sector shaft gear (2) to the pitman arm (5). The multiple teeth on both gears ensure that the motion transfer is smooth, stable, and efficient, reducing wear on the components and enabling the assembly (100) to function reliably.
The primary sector shaft gear (2) is typically mounted within the housing (1) in such a way that its teeth are aligned to engage with the rack piston gear (14) and the secondary sector shaft gear (4). The orientation of the primary sector shaft gear (2) is typically horizontal or slightly angled, ensuring that the teeth can engage with the rack piston gear (14) and secondary sector shaft gear (4) as intended. This orientation allows for the conversion of angular motion into linear motion that moves the rack piston (14), which in turn controls the steering of the vehicle.
The secondary sector shaft gear (4) is typically mounted adjacent to or below the primary sector shaft gear (2). Its gear teeth (12) mesh with the gear teeth (11) of the primary sector shaft gear (2) to transfer the angular motion from the primary sector shaft gear (2) to the pitman arm (5), which connects to the drag links (16) for steering control.
In some aspects of the present disclosure, the secondary sector shaft gear (4) may be oriented vertically or at a slight angled position in relation to the primary sector shaft gear (2), ensuring proper meshing and torque transfer between the gears.
In some aspects of the present disclosure, the secondary sector shaft gear (4) is also supported by bearings that are housed within the base, ensuring stability and smooth rotational motion.
In some aspects of the present disclosure, the primary sector shaft gear (2) and secondary sector shaft gear (4) are mounted within the housing (1) at specific angles that allow proper engagement with the rack piston gear (14) and each other. This orientation ensures that angular motion from the primary gear (2) is efficiently transferred to the secondary gear (4), which in turn drives the pitman arms (3,5) to control the steering.
In some aspects of the present disclosure, the center distance between the primary sector shaft gear (2) and secondary sector shaft gear (4) is a crucial parameter in determining the overall packaging of the gear system. Proper selection of the center distance ensures smooth gear meshing, efficient torque transmission, and allows the steering system to fit within the space constraints of the vehicle. It also ensures optimal performance and durability while minimizing the size and weight of the system.
In some aspects of the present disclosure, in the double sector shaft gear assembly (100), the primary sector shaft gear (2) and the secondary sector shaft gear (4) are used to connect the pitman arms (3) and (5) to the left-hand (LH) and right-hand (RH) sides of the steering mechanism. These pitman arms (3,5) are essential components for transmitting the steering force to the drag links, which ultimately control the movement of the tractor wheels.
The primary sector shaft gear (2) is directly connected to the rack piston (14) and experiences the hydraulic pressure force generated within the cylinder. This hydraulic pressure aids in steering by assisting in the movement of the rack piston.
The secondary sector shaft gear (4) is connected to the primary sector shaft gear (2) and takes torque from it. The secondary gear (4) then transfers this torque to the pitman arm (5), which is responsible for steering the vehicle's wheels. This design also ensures that the secondary gear (4) reverses the direction of rotation compared to the primary gear (2).
In some aspects of the present disclosure, the primary sector gear (2) rotates in a clockwise direction, while the secondary sector shaft gear (4) rotates counterclockwise. This double sector shaft gear assembly (100) effectively transmits torque and angular motion with a 1:1 gear ratio, allowing for smooth and synchronized movement between the gears.
The double sector shaft gear assembly (100) features dual pitman arms (3,5) that equally share the transmission force to the drag links, improving the system’s balance and efficiency. This configuration is unique to the tractor's OEM requirements, offering a more robust and efficient design compared to traditional systems.
In some aspects of the present disclosure, the double sector shaft gear assembly (100) obviates the necessity for a tie rod to connect the wheels, facilitated by the independent front axle design and the optimized geometry of the steering linkage. This offers greater stability and reduces complexity in the vehicle's steering mechanism, resulting in more efficient steering performance and reduced wear on components.
The rack piston (14) bears the entire load of both the primary gear (2) and the secondary gear (4). This load is managed by the hydraulic pressure generated inside the cylinder bore, which assists in operating the vehicle's steering linkage. The hydraulic pressure helps reduce the amount of effort required by the operator to turn the steering wheel.
As the rack piston teeth (14) moves up and down, the primary gear (2) rotates, transferring its motion to the secondary gear teeth (12). This motion is then transmitted to the pitman arms (3,5), which are responsible for steering the vehicle.
The rack piston (14) not only carries the load of the primary gear (2) and secondary gear (4) but also provides controlled movement for both gears. The secondary gear (4) acts as a follower gear, mirroring the movement of the primary gear (2) during the steering operation, but in opposite direction.
In some aspects of the present disclosure, the synchronized motion in the double sector shaft gear assembly (100) ensures that both gears move in tandem, maintaining the proper alignment and torque transfer from the primary gear (2) to the secondary gear (4). As the rack piston (14) moves up and down in response to steering input, it controls the motion of both gears. The secondary gear (4), as a follower, simply follows the motion of the primary gear (2) in opposite direction, ensuring smooth and consistent operation of the steering system. This assembly allows for precise and reliable steering performance with minimal effort from the operator.
In some aspects of the present disclosure, the primary gear (2) and secondary gear (4) are designed so that their teeth center planes are aligned with the straight line of the rack piston (14) gear tooth plane. This alignment ensures that the gears mesh correctly with the rack piston (14), maintaining precise and efficient transfer of torque during the steering operation. By aligning the tooth center planes, the gears operate smoothly, reducing friction and wear. The design helps ensure that the motion of the rack piston (14) is efficiently transmitted to both the primary gear (2) and secondary gear (4), ensuring optimal steering performance. This alignment also contributes to the overall stability and durability of the steering system, as it minimizes misalignment and the associated mechanical stress during operation.
In yet another aspect of the present disclosure, a steering system (200) including a double sector shaft gear assembly (100) is provided.
Figure 3 illustrates the cross-sectional view of double sector shaft hydraulic assist Power steering assembly (100), in accordance with an aspect of the present disclosure.
In the steering system (200), the primary sector shaft gear (2) is a crucial component designed to convert rotational motion into linear motion. The primary sector shaft gear (2) is designed with two segments of tooth profiles that are geometrically designed to simultaneously engage with the rack piston gear teeth (14) and the secondary sector shaft gear teeth (12). The first segment of the tooth profile (13) of the primary sector shaft gear (2) is engaged with the rack piston gear teeth (14), which is responsible for converting the rotational motion from the primary sector shaft gear (2) into linear motion. The second segment of the tooth profile (11) of the primary sector shaft gear (2) is engaged with the secondary sector shaft gear teeth (12). The secondary sector shaft gear (4) transmits rotational force and helps in the smooth operation of the steering system (200) by synchronizing with the movement of the rack piston (14) and distributing the forces evenly.
In the double sector shaft gear assembly (100), the primary gear (2) has two segments of tooth profiles, which engage simultaneously with both the rack piston gear teeth (14) and the secondary gear teeth (12). As the rack piston teeth (14) moves linearly, it causes the primary gear (2) to rotate, transmitting torque to the pitman arm (3). This rotation of the primary gear (2) is then transferred to the secondary gear teeth (12), which transmits torque to the pitman arm (5), driving the steering mechanism (200).
The rack piston (14) carries the entire load of both the primary gear (13) and the secondary gear (12). This load is overcome by the hydraulic pressure generated inside the cylinder bore, allowing the vehicle linkage to operate with reduced effort on the steering wheel by the operator. The rack piston (14) controls the movement of both the primary and secondary gears. The secondary gear (4) acts as a follower, mirroring the movement of the primary gear during the steering operation. This results in smooth and controlled steering, reducing the overall effort required for steering and improving the system’s efficiency.
The LH pitman arm (3) and the RH pitman arm (5) connect the LH drag link (22) and RH drag link (16) to the double sector shaft gear assembly (100), allowing the driver to control the movement of the wheels via the steering mechanism (200).
A hydraulic assist mechanism (30) configured to apply hydraulic pressure to assist the movement of the rack piston gear (14), that facilitates steering assistance by transmitting torque from the hydraulic system to the rack piston gear (14), facilitating smooth steering operation for both the LH wheel (23) and the RH wheel (15).
Figure 4 illustrates the double sector shaft tractor steering linkage to the present invention.
The LH drag link (22) may be connected to the LH pitman arm (3) and the LH steering arm (21). The RH drag link (16) is connected to the RH pitman arm (5) and the RH steering arm (17). Both pitman arms are secured with nuts (10), tightened to the OEM recommended torque.
In some aspects of the present disclosure, the unique design of the primary sector shaft gear (2) allows it to simultaneously engage with both the rack piston gear (14) and the secondary sector shaft gear teeth (12). This simultaneous engagement ensures that the forces are efficiently distributed across the steering system (200).
In some aspects of the present disclosure, the use of a double sector shaft gear assembly (100) in a tractor's power steering system (200) may reduce the forces transmitted through the drag link, which helps increase the lifecycle of the component. The double sector shaft gear assembly (100) ensures that the forces are distributed more evenly across both sides of the steering system (200). Unlike a single-sector gear system where force is applied only from one side, the double-sector shaft gear assembly (100) shares the load between the two sector gears, effectively reducing the strain on any one component.
In some aspects of the present disclosure, the double sector shaft gear assembly (100) ensures balanced force distribution, reducing wear and tear on parts like the drag link by evenly splitting the load between the left and right sides. This minimizes stress and friction, extending the drag link's lifespan. Designed to handle higher torque with reduced energy loss, the assembly (100) lessens the load on the steering linkage and related components, resulting in smoother operation and lower stress on the drag link. This reduces the likelihood of fatigue, improving durability and increasing the part's lifecycle.
In some aspects of the present disclosure, the double sector shaft gear assembly (100) distributes the steering load more efficiently between the two sector gears (primary and secondary) as opposed to using a single sector gear. This distribution of forces reduces the overall stress placed on any one individual component, including the draglink. By splitting the load between the two gears, the torque required to steer the tractor is shared more evenly, leading to reduced strain on the draglink during operation.
In some aspects of the present disclosure, in the steering system (200), tie rod is eliminated and an additional drag link is added, which creates a perfectly balanced mechanical linkage for the steering system (200). Adding an additional drag link along with the double sector shaft gear assembly (100) improves the force distribution, ensuring that both sides of the steering mechanism (200) are equally loaded. The two drag links are responsible for sharing the load of steering, leading to reduced stress on any single link. This not only improves the overall performance and responsiveness of the steering system (200) but also ensures more uniform wear on the parts. Also, by replacing tie rod with a second drag link, the steering system (200) achieves a more symmetrical and evenly distributed force application. This results in smoother steering and lower risk of component failure due to the balanced forces across the system (200). Since the load is now shared more evenly, parts such as the drag links, pitman arms, and the double sector shaft gear assembly experience less strain during operation. This balanced configuration results in a longer lifespan for the mechanical parts, as well as a more reliable steering system. The risk of parts wearing out unevenly, or the system becoming misaligned, is significantly reduced.
By eliminating tie rod and adding another drag link, the steering system (200) achieves a perfectly balanced mechanical linkage, which enhances both performance and durability. The forces are now evenly distributed, reducing wear on the components, improving steering accuracy, and ensuring longer-lasting functionality. This change optimizes the steering system (200) for greater reliability, especially in demanding environments or heavy-duty applications like tractors and off-road vehicles.
The center distance between the pitman arm (3,5) and double sector shaft gear assembly (100) plays a critical role in reducing draglink force. By optimizing this distance, the steering system (200) may efficiently distribute forces, reduce mechanical stress, and decrease the effort required by the operator. This results in improved performance, durability, and comfort, making the steering system (200) more efficient and responsive, particularly in demanding or off-road environments.
By including a primary sector shaft gear (2) and a secondary sector shaft gear (4) and two drag links, the steering system (200) becomes fail-safe. If the primary sector gear (2) or drag link fails, the secondary system automatically compensates for the failure, ensuring the driver retains control of the vehicle. The fail-safe mechanism would ensure that the steering could still be operated at least partially, giving the operator enough time to safely maneuver the vehicle to a stop and have the system repaired or inspected. Thus, by incorporating redundant components and force distribution mechanisms, fail-safe linkages provide a more resilient system, reducing the risk of complete failure and maintaining operational control.
In some aspects of the present disclosure, no tie rod is used in the tractor application. Instead, the first-half independent front axle (20) and second-half independent front axle (24) rotate with respect to a pivot pin (19) during left-hand (LH) and right-hand (RH) steering turns.
The first-half independent front axle (20) and second-half independent front axle (24) are mounted on the pivot pin (19), allowing the axle to rotate independently during turns. This design is key to improving maneuverability and steering efficiency. The rotation of the independent axle during turning allows for a more flexible and responsive steering experience, which is particularly beneficial in applications like tractors where precise control is needed.
The independent front axle’s rotation during turns enhances the tractor’s ability to make tight turns and maneuver in confined spaces. The steering geometry becomes more efficient, reducing the effort required by the operator. The double sector shaft gears (2) and (4) and drag links (16) and (22) connection are designed to be more mechanically connected during left-hand (LH) and right-hand (RH) turning.
The double sector shaft gear linkages are designed to be fully balanced, ensuring that there is no linkage loss. This is achieved by reducing the number of ball joints (18) in the system (200). By reducing the number of ball joints, the potential for frictional losses and energy dissipation is minimized. This results in a more efficient power transmission throughout the steering system (200), leading to less wear and tear on components and improved overall system performance.
In some aspects of the present disclosure, with a more balanced design and fewer joints, the steering system (200) operates more smoothly, offering better driving experience. This is particularly noticeable in critical turning conditions, where smoother and more responsive steering is required.
In some aspects of the present disclosure, a gearbox housing (1) provided in the Hydraulic Assisted Power Steering system (200) is a rigid structure that encloses and protects critical internal components, including the shaft, hydraulic power double sector shaft gear, and the clutch housing. Its role is to maintain the integrity, safety, and functionality of the system while providing stability and protection to the mechanical components inside.
In some aspects of the present disclosure, the housing (1) in the HAPS system (200) serves dual purpose: it both protects internal components and acts as a guide member for the speed shift lever, ensuring smooth, accurate, and durable operation for shifting gears in the tractor.
The primary sector shaft gear (2) and secondary sector shaft gear (4) are supported by bearings that are mounted in the housing (1). The bearings provide stability and smooth rotation to the gears, ensuring efficient operation of the steering system. The housing (1) serves as the structural base that holds these components in place, enabling proper gear function.
In some aspects of the present disclosure, a side cover (6) is provided in the steering system (200), which is a protective, rigid casing for the steering components like bearings, O-rings, and backup washers to ensure smooth operation and prevent fluid leakage. This side cover (6) is manufactured with precision machining to ensure a secure fit and durability. The cover (6) uses a face sealing concept to provide an effective barrier against water and mud. The face seal creates a tight seal between the side cover (6) and the housing (1), preventing contaminants from entering the system. This feature is particularly important in harsh operating environments where water, mud, or other debris may otherwise compromise the performance and longevity of the steering components.
In some aspects of the present disclosure, to adjust backlash and tooth wear in the system (200), an adjustment screw (8) and nut (9) are incorporated into the design. These components are used to fine-tune the alignment of the primary sector shaft gear (2) and secondary sector shaft gear (4) during service conditions. The adjustment screw (8) allows for precise movement of the gears, ensuring that any wear or misalignment is corrected, and backlash is minimized. This adjustment mechanism enables technicians to make necessary modifications to maintain optimal gear meshing and smooth operation. The ability to adjust the gears during service ensures that the power steering system (200) can continue to function efficiently even as the gears experience wear over time. By compensating for this wear, the system reduces the risk of performance degradation and extends the lifespan of the steering mechanism, contributing to the overall durability and reliability of the system (200).
During the assembly process, the primary gear (2) is first inserted into the housing. Following this, the secondary gear (4) is assembled along with the side cover (6), which is then installed into the housing (1). Once these components are properly positioned, the side cover screws (7) are used to secure the side cover (6) to the housing (1), ensuring that all components are tightly and securely fitted. This assembly process ensures the proper alignment and functioning of the gears, allowing the steering system (200) to operate smoothly and efficiently. The entire assembly is designed to withstand operational stresses, and the components are sealed to prevent contamination from external elements like water and dirt.
In some aspects of the present disclosure, about 50 percent of the total design force is transferred to each side of the drag links from the double sector shaft gear assembly (100).
In some aspects of the present disclosure, the introduction of an additional drag link and the elimination of tie rod in the steering system (200) results in less effort operation for the user. The balanced mechanical linkage created by the extra drag link allows the load to be more evenly distributed across the system, thus reducing the mechanical load on any single part, especially the steering components like the gears and the pitman arm.
In some aspects of the present disclosure, the steering system (200) is designed to integrate seamlessly with the tractor’s existing steering geometry, requiring minimal modifications. The power assist complements the original steering system, maintaining the tractor's steering performance, response, and precision. This design reduces steering effort for the operator while preserving the integrity of the original linkage structure, ensuring efficient operation without significant changes to the existing setup.
In some aspects of the present disclosure, the integrated power steering system (200) with the double sector shaft assembly (100) is designed to address the challenge of the front axle weight (FAW) of the tractor. The double sector shaft gear mechanism enhances the distribution of steering forces, allowing the system (200) to better handle the weight of the front axle. By incorporating the primary sector shat gear (2) and the secondary sector shaft gear (4), the load is more evenly distributed, leading to improved balance and reduced stress on individual components. This system (200) is especially useful for overcoming the front axle weight (FAW) and maintaining steering performance.
In some aspects of the present disclosure, the position of the primary gear (2) and secondary gear (4) are determined based on the specific requirements of the vehicle's steering linkage. These positions are adjusted to ensure proper connection and alignment with the pitman arms (3) and (5), which are responsible for transmitting the steering motion to the vehicle's wheels.
In some aspects of the present disclosure, the turning angles of the inner wheel and outer wheel, specifically for the LH wheel (23) and the RH wheel (15), are designed and controlled by adjusting the number of teeth on the internal primary sector shaft gear (2), the primary sector shaft gear (2), and the secondary sector shaft gear (4).
In some aspects of the present disclosure, the design of the double sector shaft gear assembly (100) may lead to a reduction in the weight of the pitman arms (5) and (3) by 50%. By reducing the weight of the pitman arms, there is less stress and strain on the entire steering system (200) during operation. This reduction in load leads to less wear and tear on the components, which in turn improves their operational lifespan and also contributes to reduced manufacturing and maintenance costs.
In some aspects of the present disclosure, the steering system (200) provides a compact hydraulic assisted power system (HAPS) designed for tractor applications, which incorporates several key features for ease of assembly and adaptability.
In some aspects of the present disclosure, the steering system (200) includes a steering gear that is coupled with a column assembly, forming the core component responsible for steering the tractor. This design integrates the steering mechanism with the hydraulic power system to provide enhanced steering assistance.
In some aspects of the present disclosure, the compact design of the HAPS system (200) makes it easier to assemble and adaptable to different tractor applications. This ease of assembly is a crucial benefit in manufacturing, reducing the time and complexity involved in setting up the steering system (200) for various models of tractors.
In yet another aspect of the invention, a method (300) for operating a hydraulic assisted power steering system (200) with a double sector shaft assembly (100) is provided. The method (300) includes the steps of: providing a double sector shaft gear assembly (100) including a primary sector shaft gear (2) operatively connected to a first pitman arm (3), a secondary sector shaft gear (4) operatively connected to a second pitman arm (5), and a rack piston gear (14) engaging with the primary sector shaft gear (2) and the secondary sector shaft gear (4), transmitting hydraulic pressure forces to the rack piston gear (14) via a hydraulic assist mechanism (30) to assist the movement of the rack piston gear (14), applying the hydraulic pressure forces to rotate the primary sector shaft gear (2) and secondary sector shaft gear (4) and transfer torque evenly to the first pitman arm (3) and second pitman arm (5), operatively connecting the first drag link (22) to the first pitman arm (3) and the LH wheel (23), and the second drag link (16) to the second pitman arm (5) and the RH wheel (15), and enabling smooth steering operation for both the LH wheel (23) and the RH wheels (15) by transferring the applied torque through the primary sector shaft gear (2) and the secondary sector shaft gears (4) via the first drag link (22) and the secondary drag link (16).
In an exemplary scenario, the steering operation (300) may be performed with a minimal steering wheel effort of approximately 3 to 5 Nm for tractor applications.
Advantages:
• The present disclosure ensures that torque is equally shared between the primary and secondary sector shaft gears, reducing the load on the linkage and minimizing the wear on components like the pitman arms.
• The present disclosure ensures increased pitman arm lifecycle by distributing the torque between two gears, leading to an extended service life and improved durability of these components.
• The present disclosure enables smooth and balanced operation during both left-hand (LH) and right-hand (RH) turns, providing consistent steering performance.
• The present disclosure is designed to be compact, saving space within the vehicle's steering system while maintaining effective torque transmission.
• The dual gear mechanism of the present disclosure provides better handling characteristics, as both pitman arms are operated simultaneously with balanced force distribution, resulting in more precise control during steering.
• The present disclosure ensures reduced linkage wear and tear by reducing the number of ball joints and ensuring even torque distribution. The system helps minimize friction and wear, thus increasing the longevity of the steering system's components.
• The present disclosure reduces the need for multiple components and additional hardware, contributing to lower manufacturing and maintenance costs.
• The system in the present disclosure is designed to be adaptable, with easy assembly and integration into existing tractor and vehicle steering geometries, making it highly versatile for different applications.
• The present disclosure ensures improved safety and minimal maintenance by the redundancy built into the design. By using dual sector gears and separate pitman arms, operational safety is ensured even in the case of failure of one component.
The implementation set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementation described can be directed to various combinations and sub combinations of the disclosed features and/or combinations and sub combinations of the several further features disclosed above. In addition, the logic flows depicted in the accompany figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims. ,CLAIMS:We claim:
1. A double sector shaft gear assembly (100) for a hydraulic assisted power steering system, comprises:

a primary sector shaft gear (2) comprising:
a first gear teeth (11), that is positioned on a first side of the primary sector shaft gear (2); and
a second gear teeth (13), that is positioned on corresponding side of the first gear teeth (11);
a secondary sector shaft gear (4), that is positioned adjacent to the primary sector shaft gear (2), with a gear teeth (12), that is configured to engage the first gear teeth (11) of the primary sector gear (2) and adapted to rotate the secondary sector shaft gear (4) in a clockwise direction when the primary sector shaft gear (2) rotates in counter clockwise direction and vice versa; and
a rack piston (14), that is positioned adjacent to the second teeth (13) of the primary sector shaft gear (2) with a gear teeth (41) adapted to rotate the primary sector shaft gear (2), when the rack piston (14) moves in a linear direction;
wherein, the rack piston (14) transfers hydraulic pressure from the system and generates force to rotate the primary sector shaft gear (2) and the secondary sector shaft gear (4).
2. The double sector shaft gear assembly (100) for a hydraulic assisted power steering system as claimed in claim 1, wherein the primary sector shaft gear (2) is connected to a first drag link (22) via a first pitman arm (3) and the secondary sector shaft gear (4) is connected to a second drag link (16) via a second pitman arm (5), such that the rack piston (14) transmits the hydraulic force evenly to the first drag link (22) and to the second drag link (16).
3. The double sector shaft gear assembly (100) for a hydraulic assisted power steering system as claimed in claim 1, wherein the double sector shaft gear assembly (100) is securely enclosed in a gear box housing (1), that is made in a rigid structure.

4. The double sector shaft gear assembly (100) for a hydraulic assisted power steering system as claimed in claim 1, wherein a face sealing side cover (6) facilitates a tight seal between the side cover (6) and the gear box housing (1) to protect the gear box housing (1) from external elements.

5. The double sector shaft gear assembly (100) for a hydraulic assisted power steering system as claimed in claim 1, wherein an adjustment mechanism (32) comprising an adjustment screw (8) and nut (9) is configured in the gear box housing (1) to adjust the alignment of the primary sector shaft gear (2) and the secondary sector shaft gear (13).

6. The double sector shaft gear assembly (100) for a hydraulic assisted power steering system as claimed in claim 1, wherein a plurality of bearings are provided to support the primary sector shaft gear (2) and the secondary sector shaft gear (4) within the housing (1).

7. A hydraulic assisted power steering system (200) with a double sector shaft assembly (100) comprises:

a double sector shaft gear assembly (100) comprises:

a primary sector shaft gear (2), operatively connected to a first pitman arm (3) and a secondary sector shaft gear (4), operatively connected to a second pitman arm (5); and
a rack piston gear (14) that engages with the primary sector shaft gear (2) and the secondary sector shaft gear (4), wherein the rack piston gear (14) is configured to transmit hydraulic pressure forces to the primary sector shaft gear (2) and the secondary sector shaft gear (4) and the primary sector shaft gear (2) and secondary sector shaft gear (4) are configured to transfer torque evenly to the first pitman arm (3) and to the second pitman arm (5);
a hydraulic assist mechanism (30) configured to apply hydraulic pressure to assist the movement of the rack piston gear (14);
a first pitman arm (3), that is operatively connected to the primary sector shaft gear (2) and to a first drag link (22);
a second pitman arm (5), that is operatively connected to the secondary sector shaft gear (4) and to a second drag link (16);
a first drag link (22), that is operatively connected to the first pitman arm (3) and to an LH wheel (23); and
a second drag link (16), that is operatively connected to the second pitman arm (5) and to an RH wheel (15);
wherein, the hydraulic assist mechanism (30) facilitates steering assistance by transmitting torque from the hydraulic system to the rack piston gear (14), facilitating smooth steering operation for both the LH wheel (23) and the RH wheel (15).

8. The hydraulic assisted power steering system (200) with a double sector shaft assembly (100) as claimed in claim 7, further comprises:
a first-half independent front axle (20) operatively connected to the LH wheel (23);
a second-half independent front axle (24) operatively connected to the RH wheel (15); and
a pivot pin (19), upon which the first-half independent front axle (20) and the second-half independent front axle (24) are mounted;
wherein the first-half independent axle (20) and the second-half independent front axle (24) are configured to rotate with respect to the pivot pin (19) during left-hand and right-hand steering movements.

9. The hydraulic assisted power steering system (200) with a double sector shaft assembly (100) as claimed in claim 7, further comprises:
an LH steering arm (21), that is operatively connected to the first drag link (22) and to the end of the first-half independent front axle (20) adjacent to the LH wheel (23); and
an RH steering arm (17), that is operatively connected to the second drag link (16) and to the end of the second-half independent front axle (24) adjacent to the RH wheel (15);
wherein the LH steering arm (21) and the RH steering arm (17) are configured to facilitate the movement of the first-half independent front axle (20) and the second-half independent front axle (24) during left-hand and right-hand steering.

10. The hydraulic assisted power steering system (200) with a double sector shaft assembly (100) as claimed in claim 7, wherein the hydraulic assisted power steering system (200) is configured to provide efficient steering with reduced mechanical complexity by minimizing the number of ball joints and eliminating the need for tie rods in the steering linkage.

11. A method (300) for operating a hydraulic assisted power steering system (200) with a double sector shaft assembly (100), comprising the steps of:

providing a double sector shaft gear assembly (100) comprising:

a primary sector shaft gear (2) operatively connected to a first pitman arm (3);
a secondary sector shaft gear (4) operatively connected to a second pitman arm (5);
a rack piston gear (14) engaging with the primary sector shaft gear (2) and the secondary sector shaft gear (4);

transmitting hydraulic pressure forces to the rack piston gear (14) via a hydraulic assist mechanism (30) to assist the movement of the rack piston gear (14);

applying the hydraulic pressure forces to rotate the primary sector shaft gear (2) and secondary sector shaft gear (4) and transfer torque evenly to the first pitman arm (3) and second pitman arm (5);

operatively connecting the first drag link (22) to the first pitman arm (3) and the LH wheel (23), and the second drag link (16) to the second pitman arm (5) and the RH wheel (15); and

enabling smooth steering operation for both the LH wheel (23) and the RH wheels (15) by transferring the applied torque through the primary sector shaft gear (2) and the secondary sector shaft gears (4) via the first drag link (22) and the secondary drag link (16).