A flexible frame bogie

Abstract

This invention discloses a flexible bogie frame. It includes a wheel and axle assembly, a frame, an axle box suspension system, a braking system, and side bearings. The bogie has an internal axle box structure, with bearings located inside the wheels. One end of the bolster beam constituting the frame is welded to a side beam on one side to form a single structure; the other end of the bolster beam is hinged to the side beam on the other side using a center plate. Two parallel small crossbeams are also provided between the two side beams, symmetrically arranged along the center of the bogie. One end of each small crossbeam is welded to a side beam on one side to form a single structure, and the other end is elastically connected to the side beam on the other side via an elastic hinge to form a flexible frame structure. This invention significantly reduces the weight of the bogie, effectively reducing unsprung weight, lowering wheel-rail dynamic forces, reducing noise, improving vehicle running quality, and enhancing the bogie's curve handling performance. The torsional stiffness of the bogie is significantly reduced, while the anti-diamond stiffness is high. The strength of the load-bearing structure meets operational requirements, achieving the flexibility requirement of the frame and improving its dynamic performance.

Description

Technical Field

[0001] This invention belongs to the field of railway freight car design technology, and more particularly to the field of railway freight car bogie design and manufacturing technology, specifically relating to a flexible frame bogie with a built-in axle box and spherical hinge. Background Technology

[0002] Currently, railway freight car bogies mainly come in two structural types: the three-piece type and the integral frame type. The three-piece type bogie, characterized by cast bolsters, side frames, wheelset guide frames for positioning, and central suspension, is mainly used, while the integral frame type bogie, characterized by welded frames and axle box primary suspension, is mainly used.

[0003] Comparing the technical characteristics of the two different bogie structures, the three-piece bogie frame has a loose connection, lower anti-diamond stiffness, lower critical speed for hunting instability, and poorer lateral stability. Although it has better adaptability to track torsion, it also has problems such as insufficient flexibility in the selection of braking type, difficulty in using disc brakes, and inability to meet the needs of further increasing the operating speed of railway freight cars. The integral frame bogie frame is a rigid integrated structure with higher anti-diamond stiffness, higher critical speed for hunting instability, and good running stability, but the wheel load reduction rate is relatively large and the adaptability to track torsion is poor.

[0004] To address the above issues, flexible frame technology is adopted. While ensuring high anti-diamond stiffness, it achieves relatively low torsional stiffness between the two beams. This can better balance the adaptability to track torsion and the critical speed of snake instability, and is one of the development trends of future railway freight car bogie technology. Summary of the Invention

[0005] This invention discloses a flexible bogie with a spherically hinged built-in axle box, addressing the shortcomings of existing technologies. The objective of this invention is to design a flexible bogie with low torsional stiffness, which can effectively balance track torsion adaptability and critical speed for hunting instability.

[0006] This invention is achieved through the following technical solution:

[0007] A flexible frame bogie includes a wheel and axle assembly, a frame, an axle box suspension assembly, a braking device, and side bearings; characterized in that: the bogie has an internal axle box structure, and the bearings are located inside the wheels;

[0008] One end of the bolster beam that forms the frame is welded to the side beam on one side to form an integral structure, and the other end of the bolster beam is hinged to the side beam on the other side using a center plate; two parallel small crossbeams are also set between the two side beams, and the two small crossbeams are symmetrically arranged along the center of the bogie. One end of each small crossbeam is welded to the side beam on one side to form an integral structure, and the other end is elastically connected to the side beam on the other side through an elastic hinge to form a flexible frame structure.

[0009] Furthermore, the wheel and axle assembly consists of an axle, a wheel, and a bearing. A brake disc is mounted on the axle, and the wheel and axle assembly has an axisymmetric structure. The bearing is located inside the wheel, between the wheel and the brake disc.

[0010] Furthermore, the wheel and axle assembly consists of two brake discs, two bearings, and two wheels, which are sequentially press-fitted onto the axle through interference fit; the wheels are located at both ends of the axle, and the brake discs are located on both sides of the axis of symmetry of the wheel and axle assembly near the center.

[0011] Preferably, the frame of the present invention includes a first side beam, a second side beam, a pillow beam, a first small crossbeam, a second small crossbeam, and an elastic hinge; the first side beam, the second side beam, and the pillow beam are arranged in an H-shape; the first small crossbeam and the second small crossbeam are symmetrically arranged on both sides of the pillow beam; the elastic hinge is set between the pins at the ends of the two small crossbeams and the mounting holes of the elastic hinge on the side beam; and the two ends of the side beam are provided with transverse small end beams with braking unit mounting seats.

[0012] The side beam and the pillow beam are welded together to form a T-shaped structure. One end of the small crossbeam is welded to the side beam to form a cantilever structure. A pin is provided at the far end of the cantilever for connecting the elastic hinge. Elastic hinge mounting holes are provided at the welding point of the small crossbeam on the side beam, symmetrically positioned relative to the center of the pillow beam. Guide frame structures that cooperate with the axle box suspension device are provided at both ends of the side beam. A center plate is provided at the center of the pillow beam. Elastic side bearing mounting holes or seats are provided at both ends of the upper cover plate of the pillow beam. A hinged spherical center plate is provided at the lower cover plate at the other end where the pillow beam connects to the side beam, forming a side frame.

[0013] A rectangular frame structure is set in the center of the second side beam. A hinged spherical lower center plate is set directly below the rectangle. One end of the second small crossbeam is welded to the second side beam as a whole, forming a cantilever structure. A pin is set at the far end of the cantilever for connecting the elastic hinge. Elastic hinge mounting holes are set at the welding point of the second small crossbeam on the second side beam, symmetrically positioned relative to the center of the rectangular frame. Guide frame structures that cooperate with the axle box suspension device are set at both ends of the second side beam to form the other side frame.

[0014] The elastic hinge consists of an outer sleeve, a rubber body, and an inner sleeve, forming a cylindrical structure with a tapered inner hole. The rubber body is filled between the outer sleeve and the inner sleeve, and the elastic hinge is centrally symmetrically mounted on the frame.

[0015] The axle box suspension device of the present invention consists of an axle box, an outer circular spring, an inner circular spring, a spring cap, a top, a lifting ring, and an axle box hanging plate; wherein, the axle box is a split axle box structure, consisting of an upper axle box body, a lower axle box support plate, and connecting fasteners.

[0016] The axle box suspension device of the present invention consists of a two-stage stiffness spring group composed of an outer circular spring and an inner circular spring, and together with a spring cap, a top, and a lifting ring, forms a Linor vibration damper.

[0017] The braking device described in this invention adopts a unit-type axle disc brake, with two cast steel brake discs on each axle and powder metallurgy brake pads. The hand brake unit and conventional brake unit of each bogie are configured in a 1:3 ratio, with the hand brake unit located on the side of the second wheel. The brake unit is connected to the frame by high-strength bolts through a four-point suspension method.

[0018] The side bearing described in this invention is a long-stroke constant-contact steel spring side bearing, which consists of a side bearing seat, a side bearing cover, and a spring; the side bearing seat is connected to the frame by bolts, and the side bearing cover is provided with a nylon wear plate.

[0019] The present invention has the following advantages:

[0020] Existing railway freight car bogies generally employ an external axle box structure, meaning the bearings are located on the outside of the wheels. The bogie described in this invention, however, adopts an internal axle box structure, where the bearings are located on the inside of the wheels. Due to this change in bearing position, the axle length can be significantly shortened, resulting in a substantial reduction in weight. This effectively reduces unsprung weight, lowers wheel-rail dynamic forces, reduces noise, and improves vehicle running quality. Simultaneously, the significantly shortened lateral span between the two bearings in the same wheelset also significantly reduces the wheelset's yaw angle stiffness, effectively improving the bogie's curve-passing performance. Correspondingly, the lateral span of the load-bearing frame structure is also shortened, and the frame mass is reduced, making the bogie lighter than conventional external axle box bogies. Under the same axle load conditions, this allows for further increases in vehicle load capacity.

[0021] Existing railway freight car bogies are all integral rigid frames, with almost no mature applications of flexible frame bogies. Flexible frame technology is mainly used in urban rail vehicles such as subways, but its structure and load-bearing method are completely different from railway freight car bogies. Furthermore, because the frame uses elastic components for connection, it is difficult to adapt to the needs of large axle loads. Traditional rigid frames, due to their statically indeterminate four-point support structure, will generate additional oblique symmetrical loads under the influence of various irregularities on railway lines, resulting in relatively large wheel load reduction rates and poor track adaptability. The bogie described in this invention adopts a flexible frame structure with spherical hinges and elastic connections between the two side beams. This significantly reduces the torsional stiffness of the bogie while maintaining a high anti-diamond stiffness, achieving higher operating speeds and good curve torsion adaptability. Simultaneously, the rigid support structure with spherical hinges can adapt to the large axle loads of railway freight cars, ensuring the structural strength meets operational requirements; it also constrains the translational freedom of the frame while releasing its rotational freedom, fulfilling the flexibility requirements of the frame and solving the design problem of general flexible frames being unable to adapt to large axle load-bearing structures. From the perspective of the overall stress of the frame, decoupling the statically indeterminate structure of the traditional rigid frame into the hinge of two statically determinate structures eliminates the additional oblique symmetric load of the frame, which can effectively reduce the wheel load reduction rate of the bogie and improve its dynamic performance. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the bogie structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the wheel and axle device of the present invention;

[0024] Figure 3 This is a schematic diagram of the invention's structure;

[0025] Figure 4 This is an exploded view of the structure of this invention;

[0026] Figure 5 This is a schematic diagram of the axle box suspension device of the present invention;

[0027] Figure 6 This is a schematic diagram of the conventional braking unit of the present invention;

[0028] Figure 7 This is a schematic diagram of the handbrake unit of the present invention;

[0029] Figure 8 This is a schematic diagram of the side support of the present invention.

[0030] In the diagram, 1 is the wheel and axle assembly, 2 is the frame, 3 is the axle box suspension system, 4 is the braking system, 5 is the side bearing, 11 is the wheel, 12 is the axle, 13 is the bearing, 21 is the center plate, 22 is the bolster beam, 23 is side beam one, 24 is side beam two, 25 is small crossbeam one, 26 is small crossbeam two, 261 is the pin, 27 is the elastic hinge, 271 is the elastic hinge mounting hole, 28 is the small end beam, and 29 is the guide frame. 301 is the lower center plate of the hinged spherical surface, 302 is the upper center plate of the hinged spherical surface, 31 is the outer circular spring, 32 is the inner circular spring, 33 is the spring cap, 34 is the lifting ring, 35 is the axle box support plate, 36 is the top plate, 37 is the axle box body, 38 is the axle box hanging plate, 41 is the brake disc, 42 is the high-strength bolt, 43 is the brake pad, 44 is the hand brake lever, 51 is the side bearing cover, 52 is the side bearing seat, and 53 is the side bearing spring. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments. These specific embodiments are further explanations of the principles of the present invention and are not intended to limit the present invention in any way. Any technology that is the same as or similar to the present invention does not exceed the scope of protection of the present invention.

[0032] Refer to the attached diagram.

[0033] like Figure 1 As shown, the spherically hinged built-in axle box flexible frame bogie of this embodiment includes a wheel and axle assembly 1, a frame 2, an axle box suspension device 3, a braking device 4, and a side bearing 5.

[0034] like Figure 2As shown, the wheel and axle assembly 1 consists of an axle 12, wheels 11, and bearings 13. A brake disc 41 is mounted on the axle 12, and the assembly has an overall axisymmetric structure. Two brake discs 41, two bearings 13, and two wheels 11 are sequentially press-fitted onto the axle 12 via interference fits. The wheels 11 are located at both ends of the axle 12; the brake discs 41 are located on both sides of the axis of symmetry of the wheel and axle assembly 1 near the center; and the bearings 13 are positioned between the wheels 11 and the brake discs 41.

[0035] like Figure 3 As shown, the frame 2 includes side beam 23, side beam 24, bolster beam 22, small crossbeam 25, small crossbeam 26, and elastic hinge 27. Side beam 23, side beam 24, and bolster beam 22 are generally H-shaped. Two small crossbeams are symmetrically arranged on both sides of bolster beam 22. The two small crossbeams are small crossbeam 25 and small crossbeam 26. The elastic hinge 27 is located between the end pins 261 of the two small crossbeams and the elastic hinge mounting holes 271 of the side beams. Transverse small end beams 28 with braking unit mounting seats are provided at both ends of the side beams.

[0036] like Figure 4 As shown, the side beam 23 and the pillow beam 22 are welded together to form a T-shaped structure. One end of the small crossbeam 25 is welded to the side beam 23 to form a cantilever structure. A pin 271 for connecting the elastic hinge 27 is provided at the far end of the cantilever. An elastic hinge mounting hole 271 is provided at the welding point of the small crossbeam 25 on the side beam 23, symmetrically positioned relative to the center of the pillow beam 22. Guide frames 29 structures that cooperate with the axle box suspension device 3 are provided at both ends of the side beam 23. A center plate 21 is provided at the center of the pillow beam 22. The center plate 21 can be a spherical or planar center plate structure. Elastic side bearing mounting holes or seats are provided at both ends of the upper cover plate of the pillow beam 22. The other end of the pillow beam 22 that connects to the side beam 23, i.e., the far end of the T-shaped cantilever structure, is provided with a hinged spherical center plate 302 at the lower cover plate of the pillow beam 22, thus forming a side frame.

[0037] like Figure 4 As shown, a rectangular frame structure is set in the center of the second side beam 24, and a hinged spherical lower center plate 301 is set directly below the rectangular frame. One end of the second small crossbeam 26 is welded to the second side beam 24 as a whole, forming a cantilever structure. A pin 261 for connecting the elastic hinge 27 is set at the far end of the cantilever. An elastic hinge mounting hole 271 is set at the welding point of the second small crossbeam 26 on the second side beam 24, symmetrically positioned relative to the center of the rectangular frame. Guide frame 29 structures that cooperate with the axle box suspension device 3 are set at both ends of the second side beam 24, thus forming the other side frame.

[0038] like Figure 3 , 4As shown, the elastic hinge 27 mainly consists of an outer sleeve, a rubber body, and an inner sleeve, forming a cylindrical structure with a tapered inner hole. The rubber body fills the space between the outer sleeve and the inner sleeve. The elastic hinge 27 is centrally symmetrically installed on the frame 2. The elastic hinge 27 has large axial and radial stiffness, while having small deflection and torsional stiffness. After the frame 2 is assembled, the rotational freedom between the first side beam 23 and the second side beam 24 is released and the translational freedom between them is constrained through the cooperation between the centrally symmetrically arranged elastic hinges 27 with the above-mentioned stiffness characteristics, so that the frame 2 as a whole has large anti-diamond stiffness and small torsional stiffness.

[0039] like Figure 5 As shown, the axle box suspension device 3 mainly consists of an axle box, an outer circular spring 31, an inner circular spring 32, a spring cap 33, a top plate 36, a lifting ring 34, and an axle box lifting plate 38. Based on the structural characteristics of the built-in axle box bogie, a split axle box is adopted for ease of installation and maintenance; a two-stage stiffness spring assembly consisting of an outer circular spring 31 and an inner circular spring 32, and a Linor shock absorber consisting of a spring cap 33, a top plate 36, and a lifting ring 34 are used. The axle box consists of an axle box body 37, an axle box support plate 35, and related fasteners; the axle box body 37 is disconnected from the bottom and can be directly placed on the outer ring of the bearing 13 from top to bottom, then combined with the axle box support plate 35 and connected with fasteners. An axle box lifting plate 38 is installed on one side of the top of the axle box for lifting the bogie as a whole.

[0040] like Figure 6 , Figure 7 As shown, the braking device 4 adopts a unit-type axle disc brake, with two cast steel brake discs 41 on each axle, and powder metallurgy brake pads 43 are used in conjunction. The hand brake unit and conventional brake unit of each bogie are configured in a 1:3 ratio. The hand brake unit is located on the side of the second wheel 11. The brake unit is connected to the frame 2 by a four-point suspension method through high-strength bolts 42.

[0041] like Figure 8 As shown, the side bearing 5 is a long-stroke constant-contact steel spring side bearing, mainly composed of a side bearing seat 52, a side bearing cover 51, and a side bearing spring 53. The side bearing seat 52 is connected to the frame 2 by bolts, and the side bearing cover 51 is provided with a nylon wear plate.

[0042] The assembly process of the spherically hinged built-in axle box flexible frame bogie of the present invention includes the following steps:

[0043] S1: The brake disc 41, bearing 13, and wheel 11 are sequentially press-fitted onto the axle 12 with an interference fit to form the wheel and axle assembly 1.

[0044] S2: Place the axle box body 37 onto the outer ring of the bearing 13 of the first and second position wheel axle devices 1, then tighten the axle box support plate 35, and install the inner round spring 32, outer round spring 31, spring cap 33, etc. to form the axle box suspension device 3.

[0045] S3: Connect one side frame to the other side frame through the hinged spherical center plate 302 and the receiving spherical lower center plate 301, then install the elastic hinge 27 into the elastic hinge mounting hole 271 and fasten it with relevant fasteners to form the frame 2.

[0046] S4: The frame 2 is placed onto the 1st and 2nd position wheel axle devices 1 of the axle box suspension device 3, and the frame guide frame 29 and the spring cap 33 of the axle box suspension device 3 are connected by a lifting ring to form a Linor shock absorber.

[0047] S5: The braking unit is suspended at the end of the frame 2 by high-strength bolts 42 and cooperates with the brake disc 41.

[0048] S6: The side bearing 5 is installed at both ends of the frame pillow beam 22 by bolt connection.

Claims

1. A flexible frame bogie comprising an axle arrangement, a frame, an axle box suspension arrangement, a brake arrangement and a side bearing; characterized in that: The bogie has an internal axle box structure, and the bearings are located inside the wheels. One end of the bolster beam that forms the frame is welded to the side beam on one side to form an integral structure, and the other end of the bolster beam is hinged to the side beam on the other side using a center plate; two parallel small crossbeams are also set between the two side beams. The two small crossbeams are symmetrically arranged along the center of the bogie. One end of each small crossbeam is welded to the side beam on one side to form an integral structure, and the other end is elastically connected to the side beam on the other side through an elastic hinge to form a flexible frame structure. The frame includes a first side beam, a second side beam, a pillow beam, a first small crossbeam, a second small crossbeam, and an elastic hinge; the first side beam, the second side beam, and the pillow beam are arranged in an H-shape; the first small crossbeam and the second small crossbeam are symmetrically arranged on both sides of the pillow beam; the elastic hinge is set between the pins at the ends of the two small crossbeams and the mounting holes of the elastic hinge on the side beam; and the two ends of the side beam are provided with transverse small end beams with braking unit mounting seats. The side beam and the pillow beam are welded together to form a T-shaped structure. One end of the small crossbeam is welded to the side beam to form a cantilever structure. A pin is provided at the far end of the cantilever for connecting the elastic hinge. Elastic hinge mounting holes are provided at the welding point of the small crossbeam on the side beam, symmetrically positioned relative to the center of the pillow beam. Guide frame structures that cooperate with the axle box suspension device are provided at both ends of the side beam. A center plate is provided at the center of the pillow beam. Elastic side bearing mounting holes or seats are provided at both ends of the upper cover plate of the pillow beam. A hinged spherical center plate is provided at the lower cover plate at the other end where the pillow beam connects to the side beam, forming a side frame. A rectangular frame structure is set in the center of the second side beam. A hinged spherical lower center plate is set directly below the rectangle. One end of the second small crossbeam is welded to the second side beam as a whole, forming a cantilever structure. A pin is set at the far end of the cantilever for connecting the elastic hinge. Elastic hinge mounting holes are set at the welding point of the second small crossbeam on the second side beam, symmetrically positioned relative to the center of the rectangular frame. Guide frame structures that cooperate with the axle box suspension device are set at both ends of the second side beam to form the other side frame.

2. The flexible frame bogie of claim 1, wherein: The wheel and axle assembly consists of an axle, a wheel, and a bearing. A brake disc is mounted on the axle, and the wheel and axle assembly has an axisymmetric structure. The bearing is located inside the wheel, between the wheel and the brake disc.

3. The flexible frame bogie according to claim 2, characterized in that: The wheel and axle assembly consists of two brake discs, two bearings, and two wheels, which are sequentially press-fitted onto the axle through interference fit. The wheels are located at both ends of the axle, and the brake discs are located on both sides of the axis of symmetry of the wheel and axle assembly, close to the center.

4. The flexible frame bogie according to any one of claims 1 to 3, characterized in that: The elastic hinge consists of an outer sleeve, a rubber body, and an inner sleeve, forming a cylindrical structure with a tapered inner hole. The rubber body is filled between the outer sleeve and the inner sleeve, and the elastic hinge is centrally symmetrically mounted on the frame.

5. The flexible frame bogie according to any one of claims 1 to 3, characterized in that: The axle box suspension device consists of an axle box, an outer circular spring, an inner circular spring, a spring cap, a top, a lifting ring, and an axle box hanging plate; wherein, the axle box is a split axle box structure, consisting of an upper axle box body, a lower axle box support plate, and connecting fasteners.

6. The flexible frame bogie according to claim 5, characterized in that: The axle box suspension device consists of a two-stage stiffness spring group composed of an outer circular spring and an inner circular spring, and together with the spring cap, top, and hanging ring, it forms a Linor vibration damper.

7. The flexible frame bogie according to claim 5, characterized in that: The braking device adopts a unit-type axle disc brake, with two cast steel brake discs on each axle and powder metallurgy brake pads. The hand brake unit and conventional brake unit of each bogie are configured in a 1:3 ratio, with the hand brake unit located on the side of the second wheel. The brake unit is connected to the frame by high-strength bolts through a four-point suspension method.

8. The flexible frame bogie according to claim 5, characterized in that: The side bearing is a long-stroke constant-contact steel spring side bearing, which consists of a side bearing seat, a side bearing cover and a spring; the side bearing seat is connected to the frame by bolts, and the side bearing cover is provided with a nylon wear plate.

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