Railway vehicle actively driven by cylindrical wheels

Abstract

The present invention relates to a railway vehicle actively driven by cylindrical wheels. The present invention provides a single-axle cylindrical truck structure wherein cylindrical wheels having an inclination of 0 are adopted, thereby fundamentally suppressing the meandering that occurs in fixed-shaft conical wheels, and the horizontal vibration load is accordingly eliminated, thereby structurally separating the path of transfer of vertical load and the path of transfer of horizontal load. The single-axle cylindrical truck allows only one vertical degree of freedom by using a square guide-type vertical connection unit, and removes vibration interference during driving by separating the vertical and horizontal load paths. In addition, safety wheels that contact rail inner surfaces in an emergency form a four-point restraint, thereby performing the function of mechanical safety devices that prevent derailment. Furthermore, the number of rotations of the left and right cylindrical wheels is independently controlled, thereby implementing first-stage active driving in which the vehicle steers by itself and second-stage active driving in which a path is selected in a fixed branching section. Accordingly, it is possible to autonomously pass through a fixed branching section without an external mechanical branching machine.

Description

Railway vehicle with active movement using cylindrical wheels

[0001] The present invention relates to a railway vehicle that operates actively using cylindrical wheels. More specifically, it relates to an active driving technology that eliminates hunting motion by precisely controlling the rotational speed of cylindrical wheels that rotate independently left and right, and to a new single-axle cylindrical bogie structure for implementing this.

[0002] The single-axle cylindrical bogie of the present invention has a structure in which a cylindrical wheel that fundamentally eliminates hunting motion and a safety wheel that prevents derailment in emergencies are functionally separated and then recombined. In addition, by applying a load path separation concept that structurally separates the transmission paths of vertical and horizontal loads, it is configured to stably support heavy railway vehicles while enabling precise steering of the driving direction.

[0003] Furthermore, the present invention belongs to the field of railway vehicle system technology that overcomes the conventional manual driving paradigm and simultaneously improves the efficiency and safety of the railway system by implementing a first-stage active driving (autonomous steering) based on the above-mentioned single-axle cylindrical bogie, which allows the vehicle to travel along the rail without derailing and smoothly pass through curved sections, and a second-stage active driving (autonomous path selection) which allows the vehicle to independently determine the driving direction and select a path in fixed branching sections.

[0004] Since railway vehicles emerged about 200 years ago as a new means of land transportation capable of fast and mass transport, they have functioned as a core means of transportation for humanity. However, despite this long history, railway systems have maintained the structure of passively moving fixed-axle conical wheels as a wheel-rail mechanism.

[0005] Fixed-axis conical wheels are a structure in which two conical wheels are fixed to a single axis of rotation and always rotate together. Utilizing the geometric shape of an inclined conical surface, they provide a center-restoring function that automatically prevents derailment from the rail without a separate steering device. Conical wheels, which consist of a conical structure in which the effective diameter decreases as they move away from the center of the wheel, cause the effective diameter of contact with the rail to increase when the wheel center deviates from the center of the rail. This increases the travel distance of the wheel that has moved away, and as a result, the wheel moves back toward the center of the rail, restoring the wheel center to the center of the rail. However, this very center-restoring structure of the conical wheel creates limitations such as hunting motion and manual driving, which fundamentally restricts the development of railway systems.

[0006] First, the structure of the fixed-axis conical wheel described above inevitably leads to hunting motion. Although the conical wheel's center returns to the rail center through a center-restoring mechanism, it inevitably deviates in the opposite direction due to inertia. Consequently, a center-restoring mechanism acts again in the opposite direction; this repeated cycle of center-restoring and deviating causes the vehicle to vibrate while repeatedly moving left and right—this phenomenon is known as hunting motion. Since this hunting motion shakes the vehicle more rapidly as speed increases, the vibration load increases significantly, drastically worsening ride comfort. Furthermore, it causes severe fatigue damage to the wheels and rails, and the severe fluctuations in friction between the wheels and rails reduce driving stability, thereby limiting high-speed operation.

[0007] Furthermore, this very hunting motion imposed another fundamental constraint on conventional bogie designs. To withstand the powerful and unpredictable horizontal vibration loads generated by hunting motion, conventional bogies for heavy railway vehicles were compelled to adopt a rigid structure with all components tightly fixed; consequently, existing bogies could not ensure structural flexibility. In particular, such rigid bogies could not utilize devices that allow the wheels to move freely vertically while simultaneously accurately transmitting large horizontal vibration loads. Horizontal load transmission devices are at a very high risk of damage caused by the powerful horizontal vibrations of hunting motion.

[0008] Due to these structural limitations, it has been difficult to attempt a new concept like the present invention, which separates the transmission paths of vertical and horizontal loads and uses the horizontal load to rotate the wheel of a single axle horizontally for steering. Therefore, the development of railway technology has so far focused on devices and technologies that accommodate the hunting motion of conical wheels to prevent derailment of heavy railway vehicles, and suppress, absorb, or withstand the various problems caused by hunting motion.

[0009] Second, there is the manual driving paradigm, which relies entirely on external facilities to change the driving route of railway vehicles. Since the fixed-axle conical wheels fixed to the bogies to suppress vibrations caused by hunting must rely on the rails to run, independent steering is impossible. Consequently, railway vehicles can only change their route using external mechanical track switches called turnouts. This structure has been the primary cause of severely hindering the flexibility and operational efficiency of railways for the past 200 years.

[0010] The primary objective for the bogies of conventional heavy railway vehicles was to firmly restrain the strong horizontal vibrations generated by the hunting motion of the conical wheels, block these vibrations from being transmitted to the vehicle, and stably transfer vertical loads to the wheels. Therefore, two-axle bogies were designed so that the hunting motion of each axle was offset by rigidly fixing the two axles to a single bogie frame. (Three-axle bogies are sometimes used in cases requiring the support of particularly heavy loads, such as in locomotives.)

[0011] For fixed-axle conical wheels of a two-axle bogie, the most stable and proven design method was to firmly fix the entire axle to the bogie frame to restrict axle steering, allowing the bogie frame to handle steering. This resulted in a significant increase in the weight of the bogie, and as the entire bogie formed an unsprung mass, the cost of configuring and maintaining the suspension system to block vibrations caused by this increased significantly. For this reason, active driving technology has not been developed to prevent derailment by creating a single-axle bogie that supports vertical loads due to hunting motion and using a steering method that precisely rotates the single-axle bogie.

[0012] The following is a summary of the existing background technology to aid in the understanding, investigation, and examination of the present invention.

[0013] (1) Independent rotating wheel

[0014] A structure was used in which the left and right wheels of the vehicle are positioned without mechanical axle coupling, allowing each wheel to rotate independently. It has been applied primarily in low-floor trams to achieve a low-profile design; generally, it utilizes a conical wheel shape with flanges and operates by synchronizing the rotation of the left and right wheels through control.

[0015] (2) Diverter technology

[0016] Technology has been proposed to assist in selecting the driving direction in fixed branching sections by utilizing a device mounted on the vehicle side. The concept involves inducing a change of direction without rail-side moving parts by using auxiliary devices such as magnets or auxiliary wheels.

[0017] The above technologies are for reference to aid in understanding the present invention, and the applicant does not acknowledge them as prior art.

[0018] The present invention was designed to solve the complex and fundamental problems of the prior art as described above.

[0019] The limitations of existing railway technology present a technical dilemma involving the simultaneous resolution of two mutually contradictory phenomena: the elimination of hunting motion and active driving. To fundamentally eliminate hunting motion, it is necessary to simultaneously implement a single-axle bogie featuring a wheel structure that achieves precise travel distances by controlling the rotational speeds of independently rotating left and right wheels, and active driving that flexibly steers the direction using this single-axle bogie. Realizing precise active driving requires a flexible bogie structure that separates the load paths of vertical and horizontal loads and utilizes only the horizontal load generated by rotational force for the steering control of the single-axle bogie; however, a bogie with such a flexible structure struggles to withstand the powerful horizontal vibration loads caused by hunting motion.

[0020] In a contradictory situation where hunting vibrations hinder the flexible bogie structure required to simultaneously solve hunting motion and active driving, it is difficult to resolve this dilemma by simply combining existing prior art. Therefore, a new 1-axle bogie technology must be developed that structurally organizes the causes of hunting motion to eliminate horizontal vibration loads, separates the large vertical load of the railway vehicle from the horizontal load created by the rotational force transmitted by the drive motor, and simultaneously solves hunting motion and active driving through active steering that controls the rotational speed of the running wheels.

[0021] The technical starting point of the present invention lies in a single-axle bogie with wheels that eliminates hunting motion, prevents derailment, and enables active driving control through a new structure.

[0022] The first task is to eliminate hunting motion. Conventional conical wheels not only induce hunting motion but also make it difficult to accurately control travel distance based on rotational speed; consequently, rotating the conical wheels independently significantly increases the risk of derailment. A new wheel is required to replace the conical wheel in order to fundamentally eliminate the powerful and unpredictable horizontal vibration loads generated by hunting motion. The new wheel must be able to overcome the fundamental constraints of existing bogie designs, which previously necessitated heavy and rigid structures to withstand combined loads of strong vertical and horizontal vibration loads.

[0023] The second task is to separate the paths of the transmitted loads. After eliminating horizontal vibration loads by removing hunting motion, the massive vertical and horizontal loads of the railway vehicle are separated. By providing transmission paths and components optimized for each load, the goal is to secure a lightweight and flexible bogie structure capable of implementing active driving using horizontal loads while sufficiently supporting vertical loads.

[0024] The third task is to implement active driving. Based on the aforementioned unique bogie structure, the vehicle controls the rotational speed of the left and right wheels to enable it to drive stably along the rails on its own (Stage 1 autonomous steering), and realizes complete active driving by overcoming manual driving that relied on external mechanical switches to autonomously select a path in fixed branching sections (Stage 2 autonomous path selection).

[0025] The fourth task is to ensure safety by reliably preventing derailment. This involves ensuring reliable safety by including mechanical safety devices that guarantee the stability of the aforementioned active driving system, thereby preventing vehicle derailment in any emergency situation, such as external collisions, natural disasters like earthquakes or typhoons, control unit failures, or emergency braking.

[0026] The fifth task is to improve efficiency. It aims to secure the practicality and economic viability of innovative technology by not only providing an efficient railway system optimized for new railway infrastructure but also maintaining compatibility with existing infrastructure, allowing existing rolling stock to operate on existing tracks simply by replacing the bogies.

[0027] To solve the above technical problem, the present invention provides a new railway vehicle using cylindrical wheels and a single-axle cylindrical bogie structure to simultaneously overcome the fundamental limitations of railway systems, namely hunting motion and manual driving.

[0028] (1) Adoption of cylindrical wheels to eliminate meandering motion

[0029] The starting point of the technical concept conceived to eliminate hunting motion in this invention lies in the geometric characteristics of hunting motion, where the vibration period of hunting motion is determined by the inclination of the conical surface. Based on this geometric principle that the vibration period becomes longer as the inclination becomes smaller, a flat cylindrical wheel with a conical surface inclination of 0 is adopted.

[0030] In a flat cylindrical wheel, the geometric inclination becomes zero, and the period of the serpentine motion becomes infinitely long; therefore, no further serpentine vibrations occur in the flat cylindrical wheel. Using a flat cylindrical wheel in this way is the starting point of the first technical concept of the present invention to fundamentally eliminate the geometric cause of serpentine motion.

[0031] (2) Single-axis cylindrical bogie separating vertical and horizontal loads

[0032] In a single-axle cylindrical bogie composed of cylindrical wheels in which hunting motion is eliminated and horizontal vibration loads are eliminated, the load path separation structure is configured to structurally separate the path supporting the vertical load of the vehicle from the path transmitting the horizontal load and moment required for active driving.

[0033] To this end, a vertical connecting unit is installed to connect the wheel unit constituting the single-axis cylindrical bogie and the wheel bogie, and is composed of a bogie insertion rod with a square cross section, a bogie insertion opening having a corresponding square guide inner wall, and two or more vertical connecting wheels arranged on each side, thereby allowing only one degree of freedom of movement in the vertical direction and restricting horizontal movement in the other two directions and rotation in the roll, pitch, and yaw directions, thereby stably transmitting horizontal loads and moments.

[0034] (3) Unsprung mass structure by suspension unit

[0035] The present invention is configured such that a suspension unit is installed between the wheel unit and the wheel bogie to directly transmit the large vertical load of the railway vehicle to the cylindrical wheel through an elastic member and to absorb vertical vibrations with a damper. As a result, only the wheel unit, rather than the entire bogie, acts as the unsprung mass of the railway vehicle, thereby suppressing vibrations and increasing stability even during high-speed operation.

[0036] (4) Derailment prevention function using safety wheels

[0037] The present invention is equipped with a safety wheel having a conical outer surface capable of contacting the inner surface of the rail to ensure driving stability and prevent derailment in emergency situations. During normal driving, a gap is maintained with the inner surface of the rail to prevent horizontal load transmission, but in emergency situations such as sudden braking, external force, or control abnormality, it immediately contacts the inner surface of the rail to form a four-point restraint in all directions (front, back, left, and right), thereby mechanically restraining lateral movement and horizontal rotation to prevent derailment.

[0038] (5) Composite wheel unit

[0039] The cylindrical wheels for driving and the safety wheels for preventing derailment are functionally separated and integrated to form a single wheel unit. This wheel unit is a set of wheels arranged with a 180-degree left-right reversal, with a total of four safety wheels installed—two on each inner side of the rail—to form a stable four-point restraint structure. The depth of the safety wheels facing the inner side of the rail is always maintained at a constant level below the upper surface of the rail to prevent derailment under any circumstances.

[0040] (6) Active driving control system

[0041] An active driving control system including left and right independent drive motors is provided based on the structure of a single-axle cylindrical bogie. The control unit measures the gap between the safety wheel and the inner surface of the rail in real time and uses that information to adjust the rotational speed of the left and right cylindrical wheels, thereby controlling the vehicle to drive stably along the rail on its own. Accordingly, the vehicle can perform both Level 1 active driving (steering), which drives without derailing in straight and curved sections, and Level 2 active driving (path selection), which selects a path on its own in fixed branching sections.

[0042] (7) Load distribution structure of wheel bogies

[0043] The wheel bogie constituting the single-axle cylindrical bogie consists of a rotational center support, a bogie insertion port support, and a suspension unit support, centered around a rotational center unit connected to the vehicle. The insertion port support is a unit that distributes the load transmitted from the rotational center support; it is configured so that the vertical load is transmitted through the upper suspension unit support, while the horizontal load and moment are transmitted through the bogie insertion ports on both sides. Through this structure, the vertical load, horizontal load, and moment are separated and configured with different transmission paths in the wheel bogie, thereby enabling active driving while transmitting a large vertical load.

[0044] (8) Fixed branch section active driving technology

[0045] By utilizing a fixed branching section configured with long rails extending the existing route and short rails forming a new branching route fixed to sleepers, the railway vehicle is enabled to autonomously select its direction of travel. The control unit differentially controls the rotational speeds of the left and right motors to allow the vehicle to enter the selected route; at this time, the width of the cylindrical wheels is formed to be greater than the sum of the rail width, the width of the passage space, and the reserve for construction and thermal expansion, thereby stably bridging the disconnected area of ​​the branching intersection. As a result, the vehicle is configured to actively determine its direction of travel and pass through the fixed branching section without the need for separate movable parts.

[0046] (9) Wear dispersion device

[0047] To evenly distribute the concentration of wear occurring on the rail contact surface of the cylindrical wheel, the vehicle may further include a wear distribution device. This device is configured to continuously change the relative position of the two centers within a certain range as the vehicle travels, thereby dispersing the contact surface where the cylindrical wheel contacts the rail.

[0048] In one embodiment, it may consist of two horizontal connecting rods that simultaneously move four safety wheels supporting the inner surfaces of the left and right rails, a horizontal rotation unit that simultaneously drives them, and a worm gear connecting the two elements. When the horizontal rotation unit is rotated, the two horizontal connecting rods rotate simultaneously, causing the four safety wheels to move simultaneously, thereby dispersing the wear on the cylindrical wheels and increasing durability and driving stability.

[0049] The single-axle cylindrical bogie of the present invention exhibits a technical integration effect that is difficult to achieve with only a simple combination of individual technologies, thereby eliminating hunting motion, a long-standing challenge in railway technology, and enabling active driving.

[0050] The first effect is the elimination of hunting motion. By introducing cylindrical wheels, hunting motion is eliminated, providing a technical foundation to resolve the contradictory technical dilemma between the heavy and strong bogies required for hunting motion suppression and the light and flexible bogies required for active driving, thereby generating a complex synergistic effect of subsequent technologies. Hunting motion was eliminated by separating flanged conical wheels into inclination-free cylindrical wheels and safety wheels that prevent derailment. This elimination of hunting motion provides the mechanical and control basis for a single-axle cylindrical bogie to implement active driving.

[0051] The second effect is the implementation of Level 1 active driving. By eliminating hunting motion, the strong horizontal vibrations and resulting horizontal loads caused by hunting motion disappear, allowing the single-axle cylindrical bogie to be configured with flexible bogie devices and components that separate the vertical load transmitted from the railway vehicle from the horizontal load generated by the wheel rotation force. In this single-axle cylindrical bogie with the vertical and horizontal loads separated, the vertical connection unit, which transmits only the horizontal load and moment separated from the vertical load, is linked to the bogie's center of rotation and precisely steers the direction by utilizing the difference in rotational speed between the left and right cylindrical wheels. Since this steering capability accurately controls the rotational speed of the cylindrical wheels to drive along the rail, the single-axle cylindrical bogie implements Level 1 active driving, allowing it to smoothly pass through sharp curves with a radius of 20m without derailment or noise.

[0052] The third effect is the implementation of Level 2 active driving. The single-axle cylindrical bogie, which performs Level 1 active driving, implements Level 2 active driving by combining with a fixed-rail section consisting of fixed rails instead of the externally operated switch, which is a symbol of manual driving, thereby determining its own direction and driving. Level 2 active driving is a method in which railway vehicles move away from manual driving, which relied on external signals, and select a path on their own to drive. As a result, complex and expensive mechanical track switches and the associated signaling systems are eliminated from the railway, thereby improving the operational efficiency and economic viability of the entire railway system.

[0053] The fourth effect is the realization of high-speed operation. The single-axle cylindrical bogie separates the load path, so that only the wheel units in direct contact with the rails become the bogie's unsprung mass, significantly reducing vibration. This minimizes the sources of vibration that the suspension system must control, providing enhanced driving stability and ride comfort without shaking during operation, even on high-speed trains.

[0054] The fifth benefit is ensuring safety at all times. Safety wheels, separated from the driving function, strongly support the inner side of the rail in emergencies, preventing derailment under any circumstances and thereby ensuring enhanced safety compared to conventional railway vehicles. By eliminating the possibility of derailment of cylindrical wheels, this provides the effect of an emergency safety device that offers psychological reassurance within the new paradigm of active driving.

[0055] The sixth benefit is compatibility with existing railway infrastructure. Since the new single-axle cylindrical bogie is compatible with existing railway infrastructure, it can be operated immediately using existing rails and switches. In addition, if only the existing bogies in existing railway vehicles are replaced with single-axle cylindrical bogies, the hunting motion of the existing vehicles is eliminated and they can pass through sharp curves without friction, thereby reducing inconvenience for subway passengers and providing an economic benefit of reducing vehicle purchase costs.

[0056] FIG. 1 is an enlarged perspective view of a left wheel unit according to the present invention.

[0057] FIG. 2 is an enlarged perspective view of a right wheel unit according to the present invention.

[0058] FIG. 3 is a perspective view of a wheel set according to the present invention.

[0059] FIG. 4 is a front view of a wheel set according to the present invention.

[0060] FIG. 5 is a plan view of a wheel set according to the present invention.

[0061] FIG. 6 is a perspective view of a wheeled bogie according to the present invention.

[0062] FIG. 7 is a perspective view of a single-axis cylindrical bogie according to the present invention.

[0063] FIG. 8 is a plan view of a single-axis cylindrical bogie according to the present invention.

[0064] FIG. 9 is a side view of a single-axis cylindrical bogie according to the present invention.

[0065] FIG. 10 is a detailed structural perspective view of a vertical connection unit according to the present invention.

[0066] FIG. 11 is a perspective view illustrating a two-axle bogie according to the present invention.

[0067] FIG. 12 is a side view of a safety wheel unit according to the present invention.

[0068] FIG. 13 illustrates a block diagram of a cylindrical wheel independent rotation control system according to the present invention.

[0069] FIG. 14 illustrates a plan view of a fixed branch section according to the present invention.

[0070] FIG. 15 is a perspective view illustrating the structure of a conventional fixed-axis conical wheel.

[0071] For a detailed description, refer to 'Forms for carrying out the invention'.

[0072] The present invention relates to a railway vehicle that operates actively using cylindrical wheels, designed to overcome the fundamental limitations of existing railway technology that has maintained the same conical wheel structure for over 200 years. Herein, a new device designed to fundamentally solve the problems of hunting motion and manual driving structurally caused by existing fixed-axle conical wheels is described in detail using drawings.

[0073] Embodiments of the present invention are described with reference to the attached FIGS. 1 through 15. These drawings illustrate the overall structure of the present invention and the operating principle of each embodiment step-by-step, and embodiments for each component are described in detail below in the order of the drawings.

[0074] FIG. 15 is a perspective view showing the structure of a conventional fixed-axis conical wheel (400). It is a structure in which two conical wheels (410) are fixed to a single conical wheel rotation axis (440) and rotate together, and each conical wheel (410) includes a conical driving surface (430) and a flange (420) and runs on a rail (500). Although this fixed-axis conical wheel (400) prevents derailment through a center-restoring function, it has structural limitations of manual driving, such as repeated center deviation in the opposite direction during the center-restoring process causing drifting motion, and being unable to change direction on its own and relying absolutely on the rail.

[0075] The configuration of the new device is designed to first geometrically eliminate the cause of hunting motion by adopting flat cylindrical wheels with a gradient of 0, second autonomously steer direction even on curves using a single-axle cylindrical bogie with a left and right independent drive structure, third prevent derailment under any external force or braking situation using safety wheels, and fourth realize active driving technology in which the vehicle selects its own driving path even in fixed branching sections.

[0076] With this configuration, five key effects are achieved: (1) elimination of hunting motion, (2) Level 1 active driving autonomous steering, (3) Level 2 active driving autonomous path selection, (4) ensuring emergency safety, and (5) maintaining compatibility with existing infrastructure.

[0077] In the following, preferred embodiments of a single-axis cylindrical bogie implementing this technology and its components will be described in detail with reference to the attached drawings. It should be noted in advance that the present invention is not limited to the described embodiments and that various modifications are possible within the scope of the claims without departing from the essence of the invention.

[0078] 1. Overview of the invention and basic constituent unit - Wheel unit (200)

[0079] The wheel unit (200) separates the functions of a railway vehicle wheel into driving functions and safety functions, allowing each function to be performed by an independent wheel, and then integrates them into a single mechanical unit. That is, the existing conical wheel with a flange attached is separated into a cylindrical wheel (110) responsible for driving and a safety wheel (210) that prevents derailment, and then integrated into the wheel unit (200). By separating them according to function and then integrating them into one, the structural limitations that occurred in the conventional technology, where a single conical wheel was responsible for both driving and derailment prevention simultaneously, are eliminated.

[0080] (1) Elimination of erratic behavior and unification of control variables

[0081] The first solution of the present invention is to eliminate the large horizontal vibration load continuously generated by the serpentine motion by adopting a flat cylindrical wheel (110) with a slope of 0 to eliminate the geometric cause of the serpentine motion. When the vibration load is eliminated in this way, the transmission paths of the vertical load and the horizontal load in the wheel bogie (310) can be separated, and the horizontal load transmitted to the wheel unit (200) is related only to the transmission of rotational force of the cylindrical wheel (110), making rotational speed control easy and enabling active driving.

[0082] Using a cylindrical wheel (110) improves the stability of the driving control. The cylindrical wheel (110) can simplify the variables of the control system to a single rotational number. Since the diameter of the cylindrical wheel (110) is always constant regardless of where it contacts the rail, the variable of effective diameter change, which made prediction impossible in the prior art, is fundamentally eliminated.

[0083] Since the travel distance of a cylindrical wheel is proportional to the product of the rotational speed, the diameter, and pi, if the diameter is constant, the travel distance is proportional to the rotational speed; thus, controlling the rotational speed controls the travel distance as well. The control system creates a difference in travel distance based on the difference in rotational speed, and the difference in travel distance between the two wheels enables the stable prediction of the turning angle required for steering. Cylindrical wheels, where this control variable is unified into rotational speed, provide the physical foundation necessary for active steering.

[0084] (2) Structure and operation of the wheel unit (200)

[0085] FIGS. 1 and FIGS. 2 are enlarged perspective views of the left and right wheel units (200), respectively. The wheel unit (200) includes one cylindrical wheel (110) and two safety wheels (210) positioned at the front and rear thereof. The cylindrical wheel (110) has a flat cylindrical running surface (111) without protrusions such as slopes or flanges on its outer surface, and runs by transmitting the vertical load of the railway vehicle to the upper surface of the rail (500). The cylindrical wheel (110) is coupled to a cylindrical wheel axle (120), and the cylindrical wheel axle (120) is rotatably supported by a journal box (135) fixed to the wheel frame (130). The wheel frame (130) has two horizontal support units (140) at the front and rear, and a safety wheel unit (250) that supports the safety wheels (210) is positioned inside. An elastic member (150) that transmits the vertical load of the railway vehicle and dampens vibrations, and a damper (155) that absorbs vibration energy are installed on the upper part of the wheel frame (130). The above components are combined with the wheel bogie (310) described later through a bogie insertion rod (160) installed on the upper part of the horizontal support unit (140).

[0086] Additionally, a rotary gear box (180) is connected to the cylindrical wheel axle (120), and rotational force is transmitted from independent driving motors (195) through the driving motor connection part (190). The rotational force transmitted to the cylindrical wheel in this way is supported as a horizontal load by the wheel bogie (310), and this horizontal load transmission structure controls the rotational speed of the left and right cylindrical wheels to create the steering capability necessary for active driving.

[0087] (3) Separation of driving function and safety function

[0088] The cylindrical wheel (110) performs only the driving function, and the safety wheel (210) maintains a certain gap with the inner surface of the rail and contacts it only in an emergency to mechanically restrain lateral movement and horizontal rotation, thereby performing a safety function to prevent derailment. At this time, the outer surface of the safety wheel (210) installed at an angle is formed as a conical outer surface (211), and the outer surface has a wide opening shape like a trumpet in the direction of travel. The conical outer surface of this angled safety wheel operates to smoothly push out the nose rail at the intersection of the turnout so that no collision or entry error occurs.

[0089] The wheel unit (200) is an assembly in which a cylindrical wheel (110) and a safety wheel (210) each contact the upper surface of the rail (500), and fundamentally solves the problems caused by the existing conical wheel (410) with a flange (420) attached. Since the driving wheel contacting the upper surface and the safety wheel contacting the inner surface are separated from each other and rotate independently, the safety wheel rotates without friction even when it contacts the inner surface of the rail, so no noise or wear occurs. When the flange (420) of the conical wheel (410) contacts the inner surface of the rail, the rail and the conical wheel come into contact at two places: the upper surface and the inner surface of the rail (500). If the diameters of the two contact points are different, the travel distances differ, so friction inevitably occurs, causing inconvenient noise and wear.

[0090] By completely separating the driving function and the safety function in this way, the geometric characteristics of the cylindrical wheel and the derailment prevention function of the safety wheel do not interfere with each other, thereby delivering optimal performance.

[0091] 2. Composition of the wheel set (100)

[0092] (1) Left and right independent rotation structure

[0093] FIG. 3 is a perspective view of a wheel set (100) according to the present invention, FIG. 4 is a front view, and FIG. 5 is a plan view. The wheel set (100) is composed of two wheel units (200) of the same structure described above combined in a direction in which they are inverted 180 degrees relative to each other. At this time, the safety wheels (210) of both wheel units are arranged so that the outer surface of the cone (211) faces the inner surface of the rail (500).

[0094] The left and right cylindrical wheels (110) constituting the wheel set (100) are not connected to each other, and each cylindrical wheel axle (120) rotates independently. Therefore, when driving on a curved section, the difference in driving distance between the inner wheel and the outer wheel is compensated by controlling their respective rotational speeds. That is, based on the structural premise of eliminating hunting motion using cylindrical wheels, the wheel set (100) of the present invention controls the rotational speed through the independent driving of each wheel unit (200), thereby driving smoothly on curved sections without slip, wear, or noise.

[0095] (2) 4-point restraint structure by 4 safety wheels (210)

[0096] The wheel set (100) is composed of two wheel units (200) on the left and right, and two safety wheels (210) included in each unit are arranged in a rectangular shape along the inner surface of each rail. Thus, a four-point restraint structure formed by four safety wheels (210) in total is created. The wheel set (100) is a driving unit module that is structurally simple, functionally supports vertical loads independently on the left and right, and forms a four-point restraint structure in terms of safety.

[0097] During normal operation, each safety wheel maintains a constant gap with the inner surface of the rail, preventing friction or noise. However, in emergency situations such as sudden braking, external force, or control failure, it immediately contacts the inner surface to restrain the vehicle in all directions (front, back, left, and right), thereby preventing derailment. This four-point restraint structure simultaneously achieves the functional effect of preventing derailment in emergency situations, such as external impact or sudden braking, and ensuring safety during high-speed operation.

[0098] (3) Commonization structure and economic effects

[0099] Two wheel units (200) are manufactured with the same structure, and a single wheel set (100) is formed by simply combining them in a 180-degree inversion. This symmetrical combination structure has the following common effects. Compatibility of parts is ensured, which reduces production costs, and maintenance is improved because quick replacement is possible in module units during maintenance, and uniformity of quality is maintained during production, which minimizes variations in driving performance.

[0100] (4) Optional configuration – Wear dispersion device

[0101] To minimize wear on the cylindrical wheel (110) in the wheel set (100), a wear dispersion device composed of a horizontal connecting rod (260) and a horizontal rotating unit (270) may be optionally included. This device adjusts the contact position of the cylindrical wheel (110) left and right to prevent wear from concentrating at a specific point, thereby extending the lifespan of the wheel and improving driving stability. This configuration is an optional component, and its operating principle will be explained in detail later in the section on safety devices and wear dispersion devices.

[0102] 3. Structure of a single-axle cylindrical bogie (300) and a wheel bogie (310)

[0103] (1) Technical position and role of the wheel bogie

[0104] FIG. 6 is a perspective view of a wheel bogie (310) according to the present invention. The wheel bogie (310) is coupled to the body of a railway vehicle and simultaneously performs the rotation center function and the load transfer function of a single-axle cylindrical bogie (300). The rotation center unit (350) is a unit connected to the body that allows free horizontal rotation while transferring the load from the body, and the rotation center support (340) stably supports the rotation center unit (350).

[0105] The wheel bogie is a structure that forms a single-axle cylindrical bogie (300) by combining with the wheel set (100) described above, and separates the load of the upper railway vehicle into vertical load, horizontal load, and moment and transmits them to each wheel unit (200). At both ends of the insertion support (320) which is connected to the rotation center support and arranged in the left and right directions, bogie insertion openings (330) are installed to accommodate the horizontal load and moment transmitted to the wheel unit (200), and a suspension unit support (360) is formed on the upper surface to transmit the vertical load through the elastic member (150).

[0106] The insertion support (320) of the wheel bogie (310) is a core component of the 1-axle cylindrical bogie that separates the vehicle's composite load into a vertical load transfer path and a horizontal load and moment transfer path, and transfers each load to the wheel unit through the optimal path.

[0107] (2) Structure and Function of a Single-Axle Cylindrical Bogie

[0108] FIG. 7 is a perspective view of a single-axle cylindrical bogie (300) according to the present invention, and FIG. 8 and FIG. 9 are a plan view and a side view, respectively. The single-axle cylindrical bogie is a structure in which a wheel bogie (310) and a wheel set (100) are combined and is connected to a railway vehicle by a rotation center unit (350). Detailed information regarding the single-axle cylindrical bogie (300) is described in the following Chapter 4.

[0109] (3) Combined structure of vertical connection units

[0110] FIG. 10 shows the detailed structure of a vertical connecting unit connecting a wheel bogie (310) and a wheel unit (200). The vertical connecting unit consists of a bogie insertion rod (160) of the wheel unit, a bogie insertion opening (330) of the wheel bogie, and a vertical connecting wheel (170) positioned between them. The feature of this structure is that the wheel unit moves freely only in the vertical direction relative to the wheel bogie, and completely restricts movement in the forward, backward, left, right, and rotational directions to transmit the load.

[0111] At least eight vertical connecting wheels (170) are arranged, with at least two on each of the four sides of the square cross-section of the bogie insertion rod (160), allowing only vertical movement while rotating along the inner surface of the bogie insertion opening (330). With this arrangement structure of the vertical connecting wheels, horizontal loads in two directions and moments in three directions, excluding vertical loads, are transmitted as reaction forces on each side. Thus, the wheel bogie (310) and the wheel unit (200) can move in a vertical direction relative to each other, so that vertical loads are transmitted through the elastic member (150) and horizontal loads and moments are transmitted through the vertical connecting unit, thereby forming a structure in which vertical loads and horizontal loads are separated and transmitted without interfering with each other.

[0112] (4) Driving stability in the cant perceived section of a 2-axle bogie

[0113] FIG. 11 is a perspective view of a two-axle bogie according to the present invention. This embodiment is a two-axle bogie configured to connect two single-axle cylindrical bogies (300) to a vehicle bogie frame (370) and to be coupled to a railway vehicle through a vehicle bogie rotation center (380), wherein each wheel unit (200) constituting the bogie moves vertically independently to actively respond to changes in the track cant.

[0114] In conventional rigid frame type conical wheel 2-axle bogies, when traveling on a transition curve—that is, a section with reduced cant—the front and rear axles are placed on rails with different inclinations, causing a wheel lift phenomenon where the diagonal wheels lift off the rails, which results in a high risk of derailment.

[0115] The two-axle bogie of the present invention eliminates this problem by having the wheel unit of each single-axle cylindrical bogie perform independent vertical movement according to the inclination of the rail. The wheel unit moves in a vertical direction at any inclination to maintain connection with the wheel bogie, transmits horizontal loads and moments through a vertical connecting unit, and transmits vertical loads through an elastic member to maintain constant contact with the rail. As a result, no torsional stress occurs in the vehicle bogie frame (370) connecting the two bogies, and all wheels are always in stable contact with the rail, thereby eliminating the risk of derailment in the cant reduction section.

[0116] 4. Stable operation of single-axle cylindrical bogie

[0117] (1) Overall configuration and distribution of 6-degree-of-freedom loads

[0118] The 1-axle cylindrical bogie (300) is formed by combining a wheel set (100) and a wheel bogie (310). The 1-axle cylindrical bogie is configured to clearly separate and transmit a 6-degree-of-freedom load consisting of three axial loads and three rotational loads transmitted from the railway vehicle. The 1-axle cylindrical bogie (300) enables optimal design of all parts and efficient maintenance by applying the principle of load separation, which is configured so that each load is separated and does not interfere with each other during the entire process in which the load of the railway vehicle is transmitted to the rail (500) via the rotation center unit (350), the wheel bogie (310), and the wheel unit (200).

[0119] The structure and function of the components are explained by describing this load transfer process in more detail. The rotation center unit (350) of the single-axle cylindrical bogie (300) allows vertical axis rotation relative to the vehicle body so that the single-axle cylindrical bogie can steer freely. Therefore, no vertical axis moment is transmitted between the railway vehicle and the single-axle cylindrical bogie, and this free rotation becomes the rotation angle of the single-axle cylindrical bogie (300) and is used for active driving, and the remaining five loads (vertical load, two horizontal loads, two horizontal axis moments) are transmitted to the single-axle cylindrical bogie (300).

[0120] These five loads pass through the center of rotation support (340) that supports the center of rotation unit (350) in a combined load state and are separated into two paths at the insertion support (320). The insertion support transmits the vertical load from this combined load to the suspension unit support (360), and transmits the remaining horizontal load and moment to the bogie insertion ports (330) at both ends. Thus, the insertion support plays an important role as a load distributor that efficiently separates the loads of the railway vehicle, and is configured so that each load can be transmitted along the shortest and most efficient path.

[0121] (2) Vertical load transfer path: Suspension unit

[0122] The vertical load separated from the insertion port support (320) is transmitted to the elastic member (150) via the suspension unit support (360). The elastic member (150) is connected to the upper part of the wheel frame (130) of the wheel unit (200), and the vertical load is transmitted to the rotating cylindrical wheel axle (120) via the bearing through the journal box (135) installed on the wheel frame (130), and to the rail (500) supporting the moving cylindrical wheel (110). In this process, the elastic member (150) absorbs all shocks generated while transmitting the vertical load as elastic energy, and the damper (155) converts this elastic energy into thermal energy and quickly removes it. The suspension unit composed of this elastic member and damper quickly absorbs shocks and vibrations transmitted from the rail through the wheel unit to the vehicle.

[0123] The suspension unit structure of the 1-axis cylindrical bogie (300) is configured so that the wheel unit (200) in direct contact with the rail becomes the unspringed mass. As a result, the unspringed mass, which is the source of vertical vibration to be absorbed by the suspension system, is greatly reduced, thereby improving shock absorption and vibration reduction effects.

[0124] (3) Horizontal load and moment transfer path: Vertical connection unit

[0125] Five loads, including four loads (two horizontal loads and two horizontal axis moments) separated from the insertion support (320) and a vertical axis moment formed internally, are transmitted through a vertical connection unit comprising a bogie insertion opening (330) installed at both ends. The vertical connection unit consists of a bogie insertion rod (160) made of four sides, two or more vertical connection wheels (170) installed on each side, and a bogie insertion opening (330) fixed to a wheel bogie (310). This structure allows the wheel set (100) to perform linear motion only in the vertical direction relative to the wheel bogie (310), and restricts forward, backward, left, and right movement and rotational motion (roll, pitch, yaw) to transmit the corresponding loads between the wheel unit and the wheel bogie.

[0126] In this way, the horizontal load and moment transmitted along the bogie insertion rod (160) are transferred to the wheel frame (130) via the horizontal support unit (140) of the wheel unit (200), and are transmitted to the cylindrical wheel (110) through the journal box (135) and the cylindrical wheel axle (120), and then to the rail (500). The representative loads of the horizontal load and moment transmitted to the rail in this manner are the rotational force of the motor and the braking force of the brake. At the same time, the safety wheel unit (250) connected to the horizontal support unit (140) transmits the horizontal load of the safety wheel (210) in case of emergency to prevent derailment.

[0127] 5. Level 1 Active Driving

[0128] (1) Key principles of active driving

[0129] Active driving is a technology in which a railway vehicle controls the rotational speed of the left and right separated cylindrical wheels to drive along the rail in the desired direction without derailing. In the present invention, this active driving is divided into a first-stage active driving that drives along the rail and a second-stage active driving that actively determines the driving direction. The first-stage active driving (autonomous steering) is a technology in which a railway vehicle drives smoothly along the rail even in curved sections without derailing from the rail, and this technology is implemented through the mechanical structure of the 1-axle cylindrical bogie (300) described above and the drive and control system coupled thereto.

[0130] The core principle of the first stage active driving is rotational speed control, which creates a difference in the driving distance of the cylindrical wheels. FIG. 13 is a block diagram showing the control flow according to the present invention. The control flow is centered around a control unit (600) that performs the role of a central control device for a railway vehicle, and the rotational speed of each driving motor (195) is controlled by left and right motor control units (610) to transmit rotational force with an accurate rotational speed to the cylindrical wheels (110) that drive on the rail (500). Here, information necessary for driving obtained by a device that recognizes the driving environment in real time, such as an image unit (233), is processed by an analysis unit (620) and transmitted to the control unit (600).

[0131] The control unit (600) analyzes the relative position between the rail (500) and the safety wheel (210) in real time through the image unit (233) and the analysis unit (620), and calculates the deviation between the vehicle's current position and the target driving path. When a path deviation is detected, the control unit calculates the rotation angle required to horizontally rotate the 1-axis cylindrical bogie (300) around the rotation center unit (350) of FIG. 8 to maintain the path, and determines a new target rotation speed for each, reflecting the difference in the rotation speed of the left and right cylindrical wheels (110). The motor control unit (610) controls each driving motor (195) with the target rotation speed determined by the control unit so that the rotation speed of the left and right wheels is accurately maintained.

[0132] The control unit (600) estimates the current vehicle's direction, speed, and track curvature in real time using error information regarding the track centerline and vehicle position transmitted from the analysis unit (620). Based on this, it calculates the required rotational speed and rotational force for the left and right cylindrical wheels (110) and sends control signals to each motor control unit (610). The motor control unit accurately implements the rotation of the driving motor (195) it is responsible for at the calculated target rotational speed. This control continuously corrects errors through real-time video information, similar to an autonomous vehicle. Since the control technology used in the control unit is implemented in a wide variety of ways, including artificial intelligence, and is developing rapidly, it is sufficient to adopt an appropriate control technology suitable for the actual situation.

[0133] (2) Configuration of independent drive systems

[0134] As illustrated in FIGS. 1 and 2, a rotary gearbox (180) is coupled to each cylindrical wheel axle (120), and this gearbox is connected to a driving motor (195) through a driving motor connection part (190). Each driving motor has its rotational speed controlled individually according to a control signal, thereby allowing the left and right cylindrical wheels to rotate independently. The key feature of this structure is that one driving motor corresponds to one cylindrical wheel. That is, since the rotational speeds of the left and right wheels are controlled completely separately from each other, the vehicle actively adjusts the difference in rotational speeds between the left and right wheels while driving, thereby eliminating hunting motion, preventing derailment from the rail, and forming an independent drive system capable of active driving that determines its own driving direction while driving along the rail.

[0135] In an active-driving single-axle cylindrical bogie, when the rotational speed of the left wheel becomes greater than that of the right wheel, the left wheel moves relatively further forward, creating a rotational angle in the bogie, causing the bogie to rotate to the right relative to the rotation center unit. In other words, the control unit identifies the position of the bogie via image and steers it to travel along the center of the rail by actively controlling the rotational speeds of the left and right wheels. This is the core principle of the first stage of active driving.

[0136] (3) Sensor configuration

[0137] An image unit (233) can be installed on the wheel unit (200) as a sensor to acquire control information required for the control unit implementing the first stage active driving (autonomous steering). As shown in FIG. 12, the image unit (233) can be mounted on the lower part of the inclined member (232) of the safety wheel support (230) or on the side of the horizontal support unit (140), and captures the gap between the rail (500) and the safety wheel (210) in real time and transmits the image information to the analysis unit (620). The captured image is transmitted to the analysis unit, undergoes a digital image processing process, and then the current vehicle position, track centerline, rail deviation, etc., are calculated. The analysis unit (620) transmits this data to the control unit (600), and the control unit calculates the error between the current position and the target path based on this. In addition to this image information, the gap between the rail and the safety wheel can be measured using various devices used in autonomous vehicles or conventional railway vehicles.

[0138] (4) Effects of Level 1 Active Driving

[0139] Stage 1 active driving is effective in eliminating hunting motion and reducing vibration. Hunting motion, which inevitably occurs in the geometric structure of a fixed-axis conical wheel, is eliminated by active driving. This is because the wheel does not drive passively based on its geometric shape, but rather the vehicle itself recognizes the center of the rail and actively follows the center of the rail, maintaining a driving path without shaking.

[0140] When lateral vibrations causing hunting motion are eliminated, the rigid structure and heavy-duty design of the two-axle bogie, which were necessary to suppress them, become unnecessary. The present invention implements a lightweight and flexible single-axle cylindrical bogie (300) by replacing it with a single-axle bogie structure and separating the transmission paths of vertical and horizontal loads. This characteristic leads to vehicle weight reduction, energy saving, vibration reduction, and improved ride comfort.

[0141] In addition, Level 1 active driving provides curve driving and friction reduction effects. Level 1 active driving recognizes rail curvature in real time even in curved sections and adjusts the rotation speed of the left and right cylindrical wheels, thereby enabling smooth curve passage without friction or noise. In particular, slip does not occur even in sharp curves with a radius of 20m or less because the difference in rotation speed between the inner and outer wheels is precisely controlled.

[0142] As an example of curved driving, in a curve with a radius of 20 m, the difference in rotational speed between the inner wheel and the outer wheel is such that, in the case of a standard track with a rail center gap of 1.5 m, the outer track radius is 20.75 m and the inner track radius is 19.25 m, and the rotational speed is determined by this ratio, and the value is such that the rotational speed of the outer wheel is approximately 1.078 times greater than that of the inner wheel. By controlling the rotational speed in this way, wear between the wheel and the rail in the curved section is significantly reduced, and rail dust and high-frequency noise are eliminated, creating a quiet driving environment.

[0143] 6. Level 2 Active Driving

[0144] (1) Level 2 active driving that selects its own driving direction

[0145] Level 2 active driving is a technology in which a vehicle independently selects a driving path in a branching section. Unlike conventional railway systems that rely on externally operated switches or signaling devices, this is a new driving technology that allows the railway vehicle to actively drive in the desired direction by controlling the rotational speed of the vehicle's cylindrical wheels using a fixed branching section where all driving directions are open, thereby selecting the direction itself. Level 2 active driving, which combines Level 1 active driving technology with a fixed rail branching section, enables the railway vehicle to independently determine, select, and drive in a specific direction.

[0146] (2) Structure of the fixed branching section

[0147] FIG. 14 is a plan view of a fixed branch section according to the present invention. In this specification, a fixed branch section refers to a facility that branches a rail in two directions, wherein a right-direction long rail (530) and a left-direction long rail (550) extending the main line rail, a right-direction short rail (540) and a left-direction short rail (560) forming a new branch path are all fixed to sleepers, and the rail configuration includes a branch section (510) composed of these and an intersection section (520) formed by the intersection of the short rails (540, 560).

[0148] Unlike conventional turnouts that open the rails in only one direction, the fixed turnout section is a completely fixed structure that is open in both directions without any movable parts, and all rails are permanently fixed to the sleepers so that they do not move. The turnout section (510) consists of two long rails and two short rails, and a passage space is formed between the long rails and the short rails through which a safety wheel (210) can pass. The intersection section (520) is the part where the short rails (540, 560) intersect to form a nose rail (570), and an additional interrupted passage space for the rails is created in this intersection section. The entire fixed turnout section is fixed to the turnout sleepers so that this passage space is maintained. This passage space is the same as that formed to allow the flange to pass through in conventional turnouts.

[0149] (3) Operating principle of autonomous path selection

[0150] A vehicle traveling in a fixed section determines its own direction of travel based on the judgment of the control unit (600). The control unit recognizes the current position and curve direction of the vehicle and determines the target direction using rail shape information received from the image unit (233) and the analysis unit (620).

[0151] For example, if the vehicle needs to select a right path, the control unit applies the control principle of Level 1 active driving to set the rotational speed of the left cylindrical wheel higher than that of the right. Due to this difference in rotational speed, the 1-axle cylindrical bogie (300) rotates to the right relative to the rotation center unit (350) and naturally enters the path formed by the right-direction long rail (530) and the right-direction short rail (540). The same principle applies in the opposite case. In this way, the railway vehicle selects a branching path and drives by making its own judgment without external signal control or mechanical operation.

[0152] (4) Width of the cylinder wheel

[0153] In the fixed section, a passage space is required where the rails are severed at the point where the rails meet or intersect so that the safety wheel can pass through. To ensure that the cylindrical wheel can pass through this passage space stably, the width of the cylindrical wheel (110) is secured to be wide enough to support two adjacent rails simultaneously. Since the outer diameter of the cylindrical wheel is constant across its entire width, it can support adjacent rails simultaneously; thus, even if one rail is severed, if the other adjacent rail is not severed, it supports the unsevered rail, allowing it to pass through without impact.

[0154] The cylindrical wheel of the present invention is set with a sufficiently wide wheel width so that it can simultaneously support the upper surface of an adjacent rail while the rail of the fixed branch section passes through a disconnected passage space. This wheel width is set to be greater than the value obtained by adding the width of the rail head, the width of the branch section passage space, and adding a margin thereto.

[0155] For example, in the case of a standard 60kg rail, when the rail head width is approximately 65mm and the passage space width is approximately 45mm, the width of the cylindrical wheel must be at least approximately 110mm, so 150mm can be used with an additional margin. Cylindrical wheels with such sufficient width can simultaneously support the upper surfaces of adjacent rails on the left and right in the passage space of a turnout or intersection, so that shock and vibration caused by rail discontinuity do not occur. In other words, the wide width of the cylindrical wheel supports the adjacent rails and acts as a physical bridge, so that shock, noise, and vibration are eliminated when the vehicle passes through the turnout section.

[0156] 7. Derailment prevention and wear dispersion device

[0157] (1) Final derailment prevention device - safety wheel unit (250)

[0158] The present invention includes a safety wheel unit (250), which is a physical safety device that prevents derailment even in emergency situations such as when an abnormality occurs in the active driving function or an external collision. The safety wheel unit (250) is inserted inside the horizontal support unit (140) to form the wheel unit (200). FIG. 12 is a side view showing the detailed structure of the safety wheel unit (250). As illustrated, the safety wheel (210) is composed of a conical rotating body having a conical outer surface (211), rotates around an inclined safety wheel axle (220), and is supported by a support inclined member (232) which is part of the safety wheel support (230). Two or more horizontal connecting wheels (240) are installed on both sides and the upper surface of the support horizontal member (231) to support the moment caused by the horizontal load that occurs when the safety wheel (210) comes into contact with the inner surface of the rail in an emergency situation.

[0159] In a normal active driving state, the safety wheel (210) maintains an intended gap with the inner surface of the rail (500), so no additional friction or wear occurs. However, if the active driving control system fails to operate normally due to sudden situations such as sudden braking, external impact, or failure of the driving motor, the safety wheel (210) immediately contacts the inner surface of the rail to physically restrain the vehicle from lateral deviation. In this way, the safety wheel (210) maintains a non-contact state with the inner surface of the rail during normal times and immediately switches to a contact state during emergencies, acting as a final mechanical safety device to prevent derailment in any emergency situation.

[0160] The safety wheel (210) maintains a gap with the inner surface during normal active driving to prevent friction, wear, and horizontal load transmission, and in emergency situations, immediately contacts the inner surface to restrain the vehicle at four points (front, back, left, and right), thereby mechanically blocking lateral movement and yaw rotation. This gap can be set with a minimum gap and a maximum gap by including rail gap error, manufacturing error, thermal expansion, and clearance value. The minimum gap is a value that accommodates the reduction of the normal rail gap due to rail deformation, and the maximum gap is determined by considering the rigidity of the safety wheel (210) and the width of the passing space of the branch section, which is 45 mm. Therefore, the actual gap can be set by comprehensively considering manufacturing error, thermal expansion, track tolerance, and operating conditions.

[0161] (2) Wear dispersion device for improving maintenance efficiency

[0162] The present invention additionally includes a wear dispersion device to extend the lifespan of the cylindrical wheel (110) and improve maintenance efficiency. If the cylindrical wheel (110) having a flat outer surface repeatedly comes into contact with the rail (500) only at the same location, wear may be concentrated in a specific area. To prevent the concentration of wear on the cylindrical wheel, as shown in FIGS. 3, 4, and 5, the horizontal rotation unit (270) and the horizontal connecting rod (260) are operated in conjunction with the safety wheel unit (250).

[0163] When the horizontal rotation unit (270) is rotated, the four safety wheels (210) move horizontally in the left and right directions simultaneously. At this time, when the position of the safety wheels (210) changes, the position of the cylindrical wheel (110) in contact with the rail (500) also moves together, so that wear is evenly distributed across the entire outer surface of the cylindrical wheel (110).

[0164] Although embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to these embodiments, and various modifications are possible within the same technical scope. Such modified embodiments are also included within the technical scope of the present invention.

[0165] The railway vehicle according to the present invention utilizes cylindrical wheels and an independent drive control system to eliminate hunting motion and enables active steering and driving without derailment even in curved sections, and is applicable to the entire railway industry.

[0166] The present invention can be commonly applied to various railway systems such as high-speed railways, urban railways, light rail, trams, and autonomous freight railways, and can be operated efficiently by utilizing existing railway infrastructure as is or by combining it with new fixed branch sections.

[0167] Therefore, by improving the driving stability, energy efficiency, maintainability, and safety of railway vehicles, the present invention has industrial applicability that allows it to be usefully utilized in a wide range of industrial fields, including not only the railway industry but also logistics, transportation, and environmental infrastructure.

Claims

1. In a railway vehicle that solves the problems of meandering motion and manual driving caused by a fixed-axle conical wheel on a rail, A pair of flat cylindrical wheels that fundamentally eliminate the cause of meandering motion through geometric structure, and A driving motor that drives the above-mentioned cylindrical wheel independently on the left and right sides, and A structure made possible by the elimination of horizontal vibration loads due to the aforementioned elimination of hunting motion, comprising a wheel bogie that structurally separates the path supporting the vehicle's vertical load from the path transmitting the horizontal loads and moments required for active driving, and A railway vehicle that performs active driving using a cylindrical wheel, characterized by including a control unit that controls the driving motor to determine the driving direction of the railway vehicle based on the rotational speed of the cylindrical wheel.

2. In Paragraph 1, The above railway vehicle is, It further includes a safety wheel having a conical outer surface capable of contacting the inner surface of the rail, and During normal driving, a gap is maintained with the aforementioned inner surface to prevent horizontal load from being transmitted, and A railway vehicle that operates actively with cylindrical wheels, characterized by preventing derailment by mechanically restraining the left-right movement and horizontal rotation of the railway vehicle by immediately contacting the inner surface of the safety wheel in an emergency situation to form a four-point restraint in the front-rear, left-right, and right directions.

3. In Paragraph 2, The above railway vehicle is, It includes a wheel unit that integrates the cylindrical wheel responsible for driving and the safety wheel preventing derailment, by functionally separating them respectively. The above wheel unit integrates the above cylindrical wheel and the above safety wheel to function as a single wheel, and A railway vehicle that operates actively with cylindrical wheels, characterized in that the safety wheel is configured to maintain a contact surface of a certain depth below the upper surface of the rail between the rails.

4. In Paragraph 3, The above wheel unit is, A cylindrical wheel axle supporting the above cylindrical wheel, and A wheel frame supporting the above-mentioned cylindrical wheel axle, and A horizontal support unit connecting the front and rear of the wheel frame, and A railway vehicle that actively moves with a cylindrical wheel, characterized by including the safety wheel positioned at the bottom of the horizontal support unit.

5. In Paragraph 4, The above railway vehicle is, A pair of the above-mentioned wheel units on the left and right are combined by being reversed 180 degrees relative to each other, A railway vehicle that operates actively with cylindrical wheels, characterized by having a total of four safety wheels arranged two on each inner side of the left and right rails to form a four-point restraint structure.

6. In Paragraph 3, The above railway vehicle is, It includes a vertical connecting unit connecting the wheel unit and the wheel bogie, The above vertical connection unit is, A bogie insertion rod with a square cross section, and A bogie insertion opening having a square guide inner wall corresponding to this, and It includes two or more vertical connecting wheels arranged on each side, A railway vehicle that operates actively with cylindrical wheels, characterized in that the vertical connection unit allows only vertical linear movement of the wheel unit and restrains horizontal movement and three-axis rotation (roll, pitch, yaw) to transmit horizontal loads and moments through the bogie insertion port.

7. In Paragraph 6, The above railway vehicle is, It further includes a suspension unit connecting the wheel unit and the wheel bogie to each other, The above suspension unit is, An elastic member that transmits the vertical load of the above railway vehicle to the above cylindrical wheel, and Including a damper that absorbs the above-mentioned vertical vibration, A railway vehicle that actively moves with a cylindrical wheel, characterized in that the above wheel unit is configured as the unspringed mass of the railway vehicle.

8. In Paragraph 7, The above suspension unit forms a vertical load transfer path of the above railway vehicle, and The above vertical connection unit forms a horizontal load and moment transfer path, A railway vehicle that operates actively with cylindrical wheels, characterized in that the transmission paths of vertical load, horizontal load, and moment are separated from each other.

9. In Paragraph 2, The above control unit is, Measure the gap between the safety wheel and the inner surface of the rail, and A railway vehicle that actively drives with cylindrical wheels, characterized by adjusting the rotational speed of the left and right cylindrical wheels in real time using measured gap information.

10. In Paragraph 1, The above active driving is, A first stage active driving that travels along the rail without derailing on straight and curved rails by independently controlling the rotational speeds of the left and right cylindrical wheels, and A railway vehicle that operates actively with cylindrical wheels, characterized by being classified into two stages of active driving in which the railway vehicle itself selects the driving direction in a fixed section.

11. In railway rolling stock, A single-axle cylindrical bogie supporting the axle load of the above-mentioned railway vehicle is, A wheel set consisting of left and right independently rotating cylindrical wheels, and A wheel bogie connected to the upper part of the above wheel set, and A vertical connecting unit that transmits horizontal loads and moments by allowing only one vertical degree of freedom between the wheel bogie and the wheel set, and A suspension unit that transmits a vertical load between the above-mentioned wheel bogie and the above-mentioned wheel set, and Including a rotation center unit connecting the above wheel bogie to the body of the above railway vehicle, A railway vehicle that operates actively with cylindrical wheels, characterized in that the vertical load transfer path and the horizontal load and moment transfer path are structurally separated in the above-mentioned wheel bogie.

12. In Paragraph 11, The above wheel bogie is, A rotation center support that supports the above-mentioned rotation center unit, and An insertion support having bogie insertion openings formed at both ends, which are part of the above-mentioned vertical connection unit, and A railway vehicle that operates actively with cylindrical wheels, characterized by including a suspension unit support connected to the upper surface of the insertion port support and supporting the suspension unit.

13. In Paragraph 12, The above insertion port support is, By distributing the load transmitted from the above-mentioned center of rotation support, The vertical load is transmitted through the above suspension unit support, and A railway vehicle that operates actively with cylindrical wheels, characterized in that horizontal loads and moments are configured to be transmitted through the bogie insertion port.

14. A railway vehicle passing through a fixed branch section in which two long rails extending an existing path on the rail and two short rails forming a new branch path are fixed to sleepers, The above railway vehicle is, A pair of cylindrical wheels separated left and right, rotating independently, with an outer surface being a cylindrical running surface, and A driving motor that independently drives the above-mentioned cylindrical wheel, and It includes a control unit that controls the rotational speed of the above-mentioned driving motor, and The above control unit differentially controls the rotational speeds of the left and right driving motors, A railway vehicle that actively travels on cylindrical wheels, characterized by enabling the above railway vehicle to travel along a selected path in the above fixed branch section.

15. In Paragraph 14, The above railway vehicle is, It further includes a safety wheel installed to support the inner surface of the rail so as not to derail the above cylindrical wheel, and The above fixed branch section is, A spaced passage between the long rail and the short rail to allow the safety wheel to pass, and A railway vehicle that actively runs on cylindrical wheels, characterized by including an intersection where the short rails cross and the rails are severed.

16. In Paragraph 15, The above cylindrical wheel is, In order to simultaneously support the upper surface of an adjacent rail at the intersection of the above fixed branch section, A railway vehicle that actively runs on a cylindrical wheel, characterized in that the width of the cylindrical wheel is set such that it is greater than or equal to the value obtained by adding the width of the passage space through which the safety wheel passes to the width of the rail head.

17. In Paragraph 15, The above railway vehicle is, The above-mentioned cylindrical wheel further includes a wear dispersion device for evenly distributing wear occurring at the contact surface with the rail, and The above-mentioned wear dispersion device is, While maintaining the distance between the center of the rail and the center of the cylindrical wheel within a certain range, A railway vehicle that actively runs on a cylindrical wheel, characterized by being configured to change the relative position of the center of the cylindrical wheel from the center of the rail according to the movement of the cylindrical wheel to disperse the wear of the contact surface.

18. In Paragraph 17, The above-mentioned wear dispersion device is, A horizontal connecting rod that simultaneously moves the safety wheel, installed to support the inner surface of the left and right rails, and It includes a horizontal rotation unit that rotates the two horizontal connecting rods simultaneously, By rotating the two horizontal connecting rods simultaneously with the horizontal rotation unit, A railway vehicle that operates actively with cylindrical wheels, characterized in that the four safety wheels are configured to move simultaneously.

19. In a railway vehicle running on rails, A pair of cylindrical wheels having a cylindrical running surface and A pair of driving motors that independently drive the above-mentioned cylindrical wheel and Including a wheel bogie configured such that the transmission path of vertical loads and the transmission paths of horizontal loads and moments are separated, A railway vehicle that operates actively with a cylindrical wheel, characterized by driving along the rail without derailing by utilizing the rotational speed of the cylindrical wheel.

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