Railroad heavy haul car truck with knuckle-type frame incorporating a pair of truck bolster wheels

Abstract

The present application relates to railway heavy load freight vehicle, specifically to a kind of knotted frame combined with a pair of supporting wheel bogie.Aiming at the defects that the longitudinal structure of traditional 3-axle bogie is strong in rigidity, the middle wheelset is easy to produce second guide force, cause the poor curve negotiation performance of bogie, the serious wheel-rail wear and the large damage to track panel, the bogie of the present application adopts knotted frame structure, replaces the rigid integrated side frame structure of traditional 3-axle bogie, and adopts a pair of non-flanged, horizontal tread, and one-wheel one-axle supporting wheel, replaces the middle wheelset in traditional 3-axle bogie.Meanwhile, mechanism with rotary torque function is added in multiple directions and multiple levels in bogie structure, further improves the stability of anti-snaking performance of bogie.Through the above technical scheme, the bogie of the present application is expected to realize heavy load transportation of 100t level and above vehicles on existing special railway line, and realize the passing transportation of 80t level and above vehicles on existing general railway line.

Description

Technical Field

[0001] This invention relates to the structure of a bogie for heavy-duty freight cars, specifically a bogie with a jointed frame combined with a pair of support rollers. Background Technology

[0002] The distribution characteristics of China's resources dictate that rail transport of bulk commodities such as minerals offers economic, environmental, safe, and sustainable advantages. Given existing railways and rail materials, there is still significant room for improvement in vehicle running gear to further enhance freight efficiency.

[0003] Currently, the vast majority of freight cars on existing dedicated and general-purpose railway lines use two-axle bogies with a three-component structure. When the axle load of the two-axle bogie reaches 25t on dedicated lines and 23t on general-purpose lines, the wheel-rail contact area is small, resulting in stress concentration and highlighting wheel-rail damage issues. This is especially true on curved sections, where the daily maintenance workload for the rails and rail foundations increases, leading to higher operating costs.

[0004] People have also tried to reduce the load on each axle by increasing the number of axles and increasing the wheel-rail contact area to distribute and reduce the contact stress between the wheel and rail. For example, theoretically, a 3-axle bogie can be used to run 100-ton vehicles on existing railways with an axle load not exceeding 22t, and its carrying capacity is equal to that of a 2-axle bogie with an axle load of 30t.

[0005] However, despite employing technical measures such as reducing wheelset positioning stiffness and thinning the flange thickness of the middle wheelset, traditional 3-axle bogies ultimately fail to break free from traditional design principles. Specifically, the axle structure and tread profile of the middle wheelset, as well as the rigidly integrated side frame structure, remain rooted in traditional design concepts. This results in a second guiding force generated in curves due to the difference in circumferential rotation between the left and right wheels of the middle wheelset with its tapered tread. When a bogie experiences two inconsistent and rigid guiding forces simultaneously during curve travel, each wheelset is forced to adjust its axial radial angle to match the curve through multiple rounds of non-rolling friction vibration.

[0006] Therefore, while traditional 3-axle bogies offer advantages such as increased carrying capacity, reduced wheel-rail contact stress, and shorter train braking distances, they have consistently failed to overcome traditional technological bottlenecks in their overall structure and the wheel-axle structure of the intermediate wheelsets. Their poor curve clearance performance, high wheel-rail wear rate, significant destructive force on track panel morphology, and even the safety hazard of wheel flange creeping onto the rails are among the technical shortcomings that prevent traditional 3-axle bogies from becoming standard equipment for improving freight car carrying capacity and thus limiting their use to a few specific scenarios as specialized equipment.

[0007] The jointed frame of this invention, combined with a pair of support rollers, aims to improve the structural shortcomings of the intermediate wheelset by modifying the traditional 3-axle bogie architecture, thereby enhancing the various operational functions and technical level of a bogie with a 3-axle load capacity. Summary of the Invention

[0008] Addressing the advantages and technical challenges of 2-axle and 3-axle bogies under existing railway conditions, this invention combines a segmented frame bogie with a pair of support wheels. While maintaining the unchanged axle structure of the front and rear wheels, the design optimizes the geometry, functional settings, and spatial arrangement of other essential bogie components such as the central load-bearing beam, side frames, primary and secondary suspension springs, and intermediate wheelsets. This optimization aims to increase the bogie's carrying capacity, improve its operational performance, reduce axle load, distribute wheel-rail contact stress, and improve wheel-rail friction conditions.

[0009] By combining the three wheeled running components of the bogie—the front wheelset, the support rollers, and the rear wheelset—with their associated supporting components into three independent mechanical units, and using the central bearing longitudinal beam as the hub to control the wheelbase of the front and rear wheelsets and the frame assembly section, a frame-type joint mechanism is formed that is relatively independent in the front, middle, and rear, but is non-rigidly connected to each other.

[0010] The bogie of this invention has the same load-bearing capacity as the traditional 3-axle bogie, but the structure of the intermediate support, i.e., the intermediate axle, and the application mechanism of the overall architecture are completely different from those of the traditional 3-axle bogie. Instead, it uses two frames positioned by fixed-distance tie rods, and uses four sets of primary suspension springs, bearing axle box devices, and axle box positioning devices to frame two short axles and flangeless, horizontally shaped support rollers. The intermediate wheelset of the traditional 3-axle bogie is replaced by a support roller frame assembly.

[0011] The bogie of the present invention further reduces the diameter of the support rollers, so that the bogie can achieve non-interference of related components in operation without raising the height of the central center plate, that is, the height of the load-bearing center of gravity, and maintain the height matching with the coupler of adjacent vehicles, while meeting the matching level between vehicles and station facilities.

[0012] The bogie of the present invention has an olive-shaped central load-bearing beam arranged longitudinally along its long axis parallel to the track. A central center plate is provided on the upper plane of the wider and thicker part in the middle of the beam. With the center pin as the axis, it is matched and connected to the upper center plate of the fixed distance node of the car body. While bearing the entire load of the car body, it provides the bogie as a whole structure with the freedom to rotate horizontally around the central center plate relative to the car body.

[0013] On the lower planes of the smaller beams at both ends of the central load-bearing longitudinal beam, symmetrically arranged concave upper load-bearing discs are fitted, respectively, to match the long-axis lower load-bearing discs located in the middle of the two bolster-type transverse beams, forming a rotatable connection. These two load-bearing discs thus become the two load-bearing nodes that divide the load of the central load-bearing longitudinal beam in two. Simultaneously, these discs provide the front and rear wheelset frame assembly sections with degrees of freedom to rotate horizontally around the two ends of the central load-bearing longitudinal beam, allowing for positive and negative rotation.

[0014] The track roller frame assembly section serves as the intermediate support of the entire bogie and is also the intermediate section of the jointed frame. It does not have a direct mechanical connection mechanism with the central load-bearing longitudinal beam. The connection with the overall bogie is achieved through the four crossbeams of the frame-type frame and the U-shaped grooves, which respectively support the transverse rollers set at the inner ends of the folded side frames of the front and rear wheelset frame assembly sections. While bearing one-third of the load of the wheelset frame assembly section, the structural relationship that the width of the transverse U-shaped groove is greater than the diameter of the transverse rollers allows the track roller frame assembly section to have lateral and longitudinal displacement freedom relative to the front and rear wheelset frame assembly sections.

[0015] This invention not only sets up degrees of freedom at multiple connection nodes of the bogie's guide structure and intermediate support structure to facilitate automatic radial matching of each shaft with the track as the track changes in curvature, but also sets up mechanisms with slewing function at multiple parts and multiple levels of the bogie, so that the bending changes of the bogie's longitudinal structure during curve operation are always accompanied by a flexible slewing and correcting torque.

[0016] The joint-frame bogie of this invention, combined with a pair of support rollers, employs two different stiffness and layout structures for its primary suspension springs, depending on the function of the wheelset and the support roller. The primary suspension springs for the wheelset must not only meet the load-bearing function but also enhance the positioning stiffness of the wheelset, thus requiring higher spring stiffness. In contrast, the primary suspension springs for the support rollers are not only more numerous but also less stiff. While meeting the load-bearing function of the support rollers, they must also mitigate some of the bogie's lateral rolling force and balance the wheel weight. Therefore, suspension springs are provided on both the left and right sides of each support roller.

[0017] The bogie of this invention employs a secondary suspension consisting of four sets of 20 cylindrical springs, each mounted on a support platform in the central opening of one of the four folded side frames. These springs support two bolster-type transverse beams, including four sets of wedge-type friction damping devices. This creates equidistant elastic platforms in the front, rear, left, and right directions of the bogie, mitigating and balancing various loads from the vehicle from above and reaction forces and vibrations from the track from below.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1) The joint frame of the present invention, combined with a bogie with a pair of support rollers, not only breaks through the technical bottleneck of the traditional 3-axle bogie in terms of bogie structural design, but also provides favorable conditions for lengthening freight cars and increasing the volume of cargo box.

[0020] 2) Comparing the load-bearing modes of a 2-axle bogie, this invention adds a pair of support rollers with a different structure from the wheelset, forming a bogie with a 3-bearing load equivalent. In heavy-load transportation, this reduces the contact stress between each wheel and the rail, thus unlocking the load-bearing potential inherent in the existing railway. This allows for raising the upper limit of the existing railway's maximum load-bearing capacity with minimal track and bridge modification costs. The aim is to achieve heavy-load transportation of 100-ton and above vehicles using bogies with an axle load not exceeding 23 tons and a load per meter of 10 tons on dedicated railway lines with a rail weight of 75 kg per meter; and to achieve the transportation of 80-ton and above vehicles using bogies with an axle load not exceeding 20 tons and a load per meter of 8 tons on general-purpose railway lines with a rail weight of 60 kg per meter, maximizing transportation efficiency and operational benefits under existing railway conditions.

[0021] 3) By rationally incorporating a pair of flangeless, independently rotating support rollers into the bogie, the design can break away from the traditional 3-axle bogie load-bearing mode. This allows for the replacement of the rigid, integrated side frame structure with a segmented frame structure, enabling the 3-axle load-bearing bogie to possess full radial functionality. This reduces the angle-of-attack vibration of the guide wheelset with the rail in curves and eliminates non-rolling friction between the wheel and rail during operation, excluding guide creep. This achieves the dual goals of improving vehicle carrying capacity and enhancing wheel-rail dynamics.

[0022] 4) The support rollers in the bogie of this invention have nominally horizontal treads, yet they also possess independent rotation capabilities. This avoids the structural drawback of the intermediate wheelset of a multi-axle bogie actively participating in the guiding process and generating a second guiding force within the bogie. Simultaneously, utilizing the "Ackermann" effect generated by the support rollers' support at the center of the bogie, the axial direction of the rear wheelset automatically achieves a "figure-eight" angle with the axial direction of the front wheelset in the curve, allowing each axle in the bogie to pass through the curve with the least resistance radial orientation.

[0023] 5) Because the tread of the support roller is nominally horizontal, the interface that rubs against the rail is not on the same working zone as the interface that rubs against the wheel pair with its tapered tread. Therefore, under the same load, the wear on the effective working surface of the rail by the bogie of this invention is not only less than that of a 2-axle bogie, but also less than that of a 3-axle bogie with the same axle load. Thus, the jointed frame combined with a pair of support rollers in the bogie can maximize the service life of the rail.

[0024] 6) By having the support roller frame assembly section bear a portion of the load, the load on each stress-bearing node and stress-exerting node in the bogie is reduced. Due to track irregularities, lateral pulsating wind, and other operating conditions, the peak value of the additional load instantaneously generated on the bogie will be reduced accordingly, thereby extending the service life of components such as journals and bearings in the wheel axle structure of the bogie, and reducing the safety risks of axle burnout and axle shedding in heavy-duty vehicles.

[0025] 7) By having the support roller frame assembly section bear part of the load, the structural layout of the suspension and vibration damping devices of the heavy-duty freight car bogie can be arranged more rationally. At the same time, the addition of rubber vibration damping devices between the axle box and the load-bearing saddle creates conditions for further reducing the unsprung mass of the bogie.

[0026] 8) The joint frame of the present invention combines a bogie with a pair of support rollers. By utilizing the structural relationship that the support roller frame assembly can make lateral displacement relative to the front and rear wheel pair frame assembly in curves, a portion of the lateral force is relieved, thus solving the long-standing problem of multi-axle bogies damaging the track panel geometry due to excessive lateral force in curves.

[0027] 9) This invention utilizes the structural relationship that the support roller frame assembly section is only connected to the front and rear wheelset frame assembly section. When track irregularities cause load imbalance, the bogie can mitigate some of the lateral rolling force and maintain the stability of the bogie by using the structural relationship that allows relative torsional motion between the front and rear wheelsets and the support rollers in the longitudinal direction, thereby eliminating the safety risks caused by wheel weight imbalance.

[0028] 10) Operational stability and curve clearance performance are a pair of contradictions that require compromise and accommodation in bogie design. This invention incorporates mechanisms at the nodes connecting the bogie's intermediate support mechanism and the guiding mechanism at the front and rear positions. These mechanisms facilitate the automatic radial matching of each wheel axle with the track as the track curves, giving the bogie full radial functionality. Simultaneously, mechanisms with flexible rotational torque functions are added at multiple locations and levels of the bogie. This allows the bogie's longitudinal structure to obtain timely and appropriate rotational torque when bending horizontally with track curvature. This overcomes the structural drawback of traditional 3-axle bogies, which must sacrifice some curve clearance performance to achieve vehicle stability. In this bogie with a jointed frame and a pair of support wheels, both aspects of the contradiction between curve clearance and operational stability are well balanced.

[0029] 11) This invention improves the overall performance of multi-axle bogies by adopting a jointed frame combined with a pair of support rollers, and also provides a new research path for further optimizing the structure of rail vehicle bogies. Attached Figure Description

[0030] Figure 1 This is a side half-sectional view of a bogie with a jointed frame and a pair of support rollers, according to an embodiment of the present invention.

[0031] Figure 2 for Figure 1 Top view.

[0032] Figure 3 for Figure 1 A frontal half-section diagram.

[0033] Figure 4 for Figure 1 Partial half-section diagram

[0034] Figure 5 for Figure 1 , Figure 2 The partial views of the support roller structure are shown in the side, top, and front half-section views.

[0035] In the diagram: 1. Wheelset; 2. Basic braking device; 3. Upper force distribution plate; 4. Lower force distribution plate; 5. Pillow-type transverse beam; 6. Central load-bearing longitudinal beam; 7. Flange; 8. Support roller suspension spring; 9. Balance tension spring; 10. Central lower plate; 11. Support roller bearing axle box assembly; 12. Center pin; 13. Constant contact elastic side bearing; 14. Support roller; 15. Axle box positioning device; 16. Frame-type longitudinal beam; 17. Frame-type transverse beam and U-shaped groove; 18. Transverse roller; 19. Fixed-distance tie rod; 20. Folded side frame; 21. Pillow-type transverse beam end; 22. Secondary suspension spring; 23. Hole; 24. Spring positioning disc seat; 25. Wheelset bearing axle box assembly; 26. Wheelset suspension spring; 27. Support roller axle; 28. Wedge-type friction damping device. Detailed Implementation

[0036] The present invention will be illustrated by way of example with reference to the accompanying drawings, which describe the bogie of the railway heavy-duty freight car with a pair of support wheels, wherein the same components are described with the same reference numerals.

[0037] Reference Figure 1 , Figure 2 As shown, the joint frame of the present invention, combined with a pair of support rollers, consists of four mechanical units: a central bearing longitudinal beam 6 arranged in an olive shape, a front wheel pair frame assembly section, a support roller frame assembly section, a rear wheel pair frame assembly section, and a basic braking device 2.

[0038] Reference Figure 1 , Figure 2 As shown, the front wheelset frame assembly and the rear wheelset frame assembly are two mechanical frame assemblies with the same structure, symmetrically arranged at the front and rear of the bogie, respectively. Components in each assembly, such as wheelset 1, wheelset bearing axle box assembly 25, wheelset suspension spring 26, folded side frame 20, lateral roller 18, hole 23, secondary suspension spring 22, bolster-type lateral beam 5, and wedge-type friction damping device 28, move synchronously and with the same amplitude in the horizontal rotation relative to both ends of the central load-bearing longitudinal beam 6 and in the longitudinal and lateral displacement relative to the support wheel frame assembly.

[0039] Reference Figure 1 , Figure 2 , Figure 4 , Figure 5As shown, the track roller frame assembly consists of a pair of track rollers 14 symmetrically arranged on the left and right, track roller axles 27, track roller bearing axle box assembly 11, track roller suspension springs 8, axle box positioning device 15, frame-type longitudinal beams 16, frame-type transverse beams and U-shaped grooves 17, spacer rods 19, flanges 7, including constantly contacting elastic side bearings 13, and is located between the front and rear wheelsets 1. The track rollers 14 do not have flanges on their rims, and their treads are nominally horizontal. As a relatively independent mechanical assembly, the track roller frame assembly has no direct connection with the central load-bearing longitudinal beam 6 in the bogie. It is only connected to the four transverse rollers 18 set at the inner end of the folded side frame 20 in the front and rear wheelset frame assembly through the four transverse beams and U-shaped grooves 17 in its frame-type frame.

[0040] according to Figure 1 , Figure 2 , Figure 3 As shown, the bogie in this example uses the longitudinally arranged central load-bearing longitudinal beam 6 as its hub. The vertical, lateral, and roll loads from the vehicle are distributed from top to bottom through two force-shaping discs 3, equally distributed to the lower force-shaping disc 4 between the front and rear bolster-type transverse beams 5. Then, through the two ends 21 of the bolster-type transverse beams, and via the secondary suspension springs 22 (including wedge-type friction damping devices 28) mounted on the perforated bearing platform 23, the load is evenly distributed to the two longitudinally arranged folded side frames 20, one on the left and one on the right, where it is further distributed. Two-thirds of the load is then transmitted to the wheelset 1 via the wheel suspension springs 26 through the lever arms at its outer ends. The remaining one-third of the load is transmitted to the support roller frame beam and U-shaped groove 17 in an open mounting manner through the transverse roller 18 set in the inner end lever arm of the bent side frame 20, and then released by the support roller suspension spring 8, and finally transmitted to the support roller 14 through the support roller bearing axle box device 11.

[0041] Conversely, the reaction force from the rails and the foundation, as well as the additional vibration load caused by track irregularities, are first partially absorbed and mitigated by the primary suspension springs 26 of wheelset 1 and the primary suspension springs 8 of support roller 14. The remaining vibration load from bottom to top is ultimately distributed and mitigated and released within the working range of the secondary suspension springs 22 and the wedge-type friction damping devices 28 located in the front, rear, left, and right directions of the bogie.

[0042] Reference Figure 1 Figure 2As shown, the bogie in this example uses a technical solution where both the front and rear wheelset frame assembly sections can rotate horizontally in both positive and negative directions around the force-shaping disks 3 at both ends of the central bearing longitudinal beam 6. Furthermore, through the technical solution where four transverse rollers 18 in the front and rear wheelset frame assembly sections are respectively mounted on the four crossbeams of the support wheel frame structure and the U-shaped groove 17, and the groove diameter of the U-shaped groove 17 is larger than the wheel diameter of the transverse rollers 18, the bogie of this invention has six nodes with positive and negative rotational degrees of freedom in two dimensions in the longitudinal structure. With a jointed structure, the bogie with a 3-bearing load equivalent can achieve full radial function in operation.

[0043] The automatic alignment between the double-conical tread surface of wheelset 1 and the rail, and the frictional relationship between the side bearings and the car body underframe, are two basic mechanisms by which a typical self-guided bogie copes with hunting instability and maintains operational stability. This invention uses a segmented frame instead of a rigid, integrated side frame. Because the three mechanical assembly sections formed by the front and rear wheelsets 1 and the support rollers 14 are non-rigid connections, the rotational resistance torque generated by the two basic mechanisms mentioned above is clearly insufficient to suppress hunting instability caused by the bogie's self-excited vibration. To ensure the bogie's stability during operation, the bogie of this invention incorporates the following mechanisms in its structural design to further enhance its operational stability:

[0044] 1) Utilize the intermediate support function of the support roller 14 on the bogie and the inherent rotational resistance torque of its horizontal tread relative to the front wheel pair 1.

[0045] 2) The rotational resistance torque generated by the shape relationship between the transverse roller 18 set in the inner end lever arm of the bent side frame 20 and the crossbeam and U-shaped groove of the support roller frame structure 17 is utilized.

[0046] 3) The rotational resistance torque is generated by four balancing tension springs 9 set at 45° angles between the central bearing longitudinal beam 6 and the front and rear bolster-type transverse beams 5.

[0047] 4) Because the front and rear wheelsets 1, together with the primary suspension springs 26 and related components, form a whole frame assembly that moves radially around the two ends of the central bearing longitudinal beam 6 synchronously and with the same amplitude in the curve section, the bogie design of this invention does not need to consider the influence of the stiffness and flexibility of the wheelset suspension springs 26 on the curve passing performance. Instead, the stiffness required to improve the bogie's running stability and improve the critical speed of the serpentine movement is directly used to position and control the wheelsets 1.

[0048] 5) The wedge-type friction damping device 28 set by the hole 23 of the bent side frame 20 clamps the end 21 of the bolster-type transverse beam, so as to control the bent side frame 20 as the longitudinal skeleton and the bolster-type transverse beam 5 as the transverse skeleton to always maintain a 90° angle intersection geometry during the operation of the bogie, and further promote the longitudinal axis of the central bearing longitudinal beam 6 to maintain a relatively parallel and stable longitudinal posture with the center pin as the axis in the bogie.

[0049] The above five mechanisms, which have the functions of rotational torque and stabilizing torque, together with the centering torque of the original double-cone tread of the wheelset 1 and the frictional torque generated between the constantly contacting elastic side bearing 13 and the car body underframe, these seven mechanisms with stabilizing force functions provide alternating assistance from multiple levels and angles during the operation of the bogie of this invention. The resulting superimposed effect can completely make up for the shortcomings of the joint frame that affect the structural stability of the bogie due to the non-rigid connection between the sections.

[0050] In the bogie of the present invention, apart from the centering torque generated by the double conical tread of wheelset 1 which has rigidity, the rotational torque generated by the other mechanisms with stability functions is flexible. Therefore, while implementing the above measures to enhance the stability of the bogie, it will not constitute a rigid obstacle to the radial adjustment process of the guiding wheelset 1 and its frame assembly section on the curve.

[0051] Reference Figure 3 , Figure 5 As shown, the primary suspension springs 8 of the support roller frame assembly in this example differ from the primary suspension springs 26 of wheelset 1 in layout and stiffness setting due to the special structure and function of the support roller 14. Through the short axle 27 and bearing axle box device 11 of each support roller 14, relatively weak cylindrical suspension springs 8 are installed on both the left and right sides of the support roller 14, making each support roller an independent suspension structure. This suspension mechanism, in addition to meeting the vertical load of the support roller 14, can also utilize its layout advantages to maximize the mitigation of lateral and rolling forces generated by the bogie on curves. Furthermore, by utilizing the supporting role of the support roller 14 in the bogie, the longitudinal structure of the entire bogie is divided into three interconnected, elastically connected joints. This maintains the relative torsional function of the support roller frame assembly relative to the front and rear wheelset frame assemblies in the longitudinal direction, eliminating safety risks caused by uneven wheel weight distribution during operation.

[0052] Reference Figure 1 , Figure 3 , Figure 4As shown, the bogie of the present invention is fitted with the four ends 21 of the front and rear bolster-type crossbeams 5 at a 90° angle through the holes 23 provided in the four bent side frames 20. Furthermore, through the cooperation of the wedge-type friction damping device 28 and the secondary suspension spring 22, four equidistant damping platforms are formed in the front, rear, left and right of the bogie. With this structural form, the vibration load from all directions is absorbed to the greatest extent, and the vibration energy is converted into heat energy and released through the friction between the wedge and the wear plate.

[0053] Reference Figure 1 As shown, the basic braking device 2 used in the bogie of this example consists of components such as brake levers, brake shoes, brake frames, pull rods, and fixed pull rod fulcrums. Its characteristic is that wheelset 1 is a one-way brake, using brake shoes that match the standard 840mm diameter of a freight car wheel. The support roller 14, however, is a two-way brake, and its brake shoes are determined by the diameter of the support roller, matching brake shoes for non-standard diameter wheels.

Claims

1. A bogie for heavy-duty railway freight cars with a segmented frame and a pair of support rollers, comprising a central load-bearing longitudinal beam, a front wheel pair frame assembly section, a support roller frame assembly section, and a rear wheel pair frame assembly section, characterized in that, These four relatively independent mechanical assembly sections are connected using two different structural mechanisms. The two ends of the central load-bearing longitudinal beam are connected by two symmetrically arranged upper force-shaping discs, which are matched with the lower force-shaping discs in the middle of the bolster-type transverse beams in the front and rear wheel set frame assembly sections, respectively, forming a connection mechanism that allows for positive and negative rotation in the horizontal direction. The support wheel frame assembly section, located in the middle of the bogie, is not directly connected to the central load-bearing longitudinal beam. Instead, it is connected by four transverse beams and U-shaped grooves on the front, rear, left, and right sides of its frame frame, which in an open manner support four transverse rollers set on the inner end lever arms of the folded side frames, so that the longitudinal structure of the bogie forms a jointed connection mechanism. The support roller frame assembly is composed of a frame frame, spaced tie rods, constant contact elastic side bearings, support roller suspension springs, support roller bearing axle box assembly, axle box positioning device, support rollers, and support roller axles. The frame frame consists of two rectangular frames welded together from four box-shaped longitudinal beams, four transverse beams, and U-shaped grooves. These frames are horizontally parallel to each other on the left and right sides of the central load-bearing longitudinal beam and are connected laterally by two spaced tie rods through flanges located below the frames. The frame structure, as the middle section of the jointed frame, is equipped with transverse rollers set at the inner end of the folded side frame in the frame assembly section through its front and rear crossbeams and U-shaped grooves, forming a jointed frame structure in which the folded side frame can be longitudinally displaced relative to the frame structure. Each support roller is formed by an interference fit between its hub and a short axle, creating a structure where each axle and roller can rotate independently; the working surface of the support roller's rim is not flanged, and the tread is nominally horizontal; its diameter is smaller than the diameter of the front and rear wheelsets.

2. The bogie with a jointed frame and a pair of support rollers according to claim 1, characterized in that, The support roller axle is equipped with bearing axle box devices and axle box positioning devices at both the left and right ends of the journal, and is elastically positioned and connected to the frame structure through a matching series of suspension springs.

3. The bogie with a jointed frame and a pair of support rollers according to claim 1, characterized in that, The aforementioned front and rear wheel set frame assembly sections are two identical and independent mechanical assembly sections, respectively located at the front and rear of the bogie. Each front and rear wheel set frame assembly section consists of wheelsets, bearing axle box assemblies, axle box positioning devices, primary suspension springs, folded side frames, secondary suspension springs, bolster-type transverse beams, a force-shaping lower center plate located in the middle of the bolster-type transverse beams, and wedge-type vibration damping devices located at both ends of the bolster-type transverse beams. These components constituting the front and rear wheel set frame assembly sections, as a mechanical assembly, undergo synchronous and equal-amplitude positive and negative rotational displacements in the horizontal direction relative to other structures of the bogie, with the force-shaping lower center plate as the axis, on curved sections.

4. The bogie with a jointed frame combined with a pair of support wheels according to claim 3, comprising a bent side frame in the front and rear wheel pair frame assembly section, characterized in that, The folded side frame is symmetrical on both sides and arranged longitudinally. The inner end arm, which is closer to the central plate, and the outer end arm, which is farther from the central plate, are designed in a folded shape along the horizontal direction because the nodes where the forces are applied and the nodes where the forces are applied in the longitudinal structure are not on the same baseline.

5. The bogie with a jointed frame combined with a pair of support rollers according to claim 4, comprising holes in the folded side frames of the front and rear wheel-pair frame assembly sections, characterized in that, The opening in the folded side frame serves as a bearing platform for the 90° angle laterally assembled bolster-type transverse beam end. The opening is located below the folded portion of the folded side frame, acting as a balancing and complementary load-bearing structure. The opening consists of two approximately right-angled triangular sidewalls facing opposite directions and a rectangular horizontal support platform. The inner sides of the sidewalls are fitted with wear plates that cooperate with wedge-type vibration damping devices. The horizontal support platform serves as the bearing base of the opening, with a circular navel on the platform for positioning the secondary suspension spring and the vibration damping device spring. The load center of the opening is not located in the middle between the wheelset and the support roller, but rather closer to the bearing housing of the wheelset and farther from the load-bearing device of the support roller, namely the frame-type transverse beam and the U-shaped groove.

Images