WO2024110244A1

WO2024110244A1 - Stabilizing assembly for stabilizing a track

Info

Publication number: WO2024110244A1
Application number: PCT/EP2023/081673
Authority: WO
Inventors: Michael SCHINAGL; Wolfgang ANDROSCH
Original assignee: Plasser & Theurer, Export von Bahnbaumaschinen, Gesellschaft m.b.H.
Priority date: 2022-11-22
Filing date: 2023-11-14
Publication date: 2024-05-30
Also published as: AT18205U1

Abstract

The invention relates to a stabilizing assembly (11) for stabilizing a track (2), having a vibration generator (12) and having assembly rollers (15, 16) for transmitting vibrations (14) generated by means of the vibration generator (12) to a track grid (4), which consists of sleepers (5) and rails (6) fastened thereon, of the track (2) that is to be stabilized. In said stabilizing assembly, assembly rollers (15, 16) assigned to a left-hand rail (6) of the track (2) are arranged on a first side frame (19), and assembly rollers (15, 16) assigned to a right-hand rail (6) of the track (2) are arranged on a second side frame (20), wherein the two side frames (19, 20) are connected by a self-supporting central part (18) that comprises the vibration generator (12). A lower center of gravity (21) of the stabilizing assembly (11) as a whole is thus achieved.

Description

Stabilization unit for stabilizing a track

Technical area

[01] The invention relates to a stabilization unit for stabilizing a track, with a vibration generator and with unit rollers for transmitting vibrations generated by the vibration generator to a track grid of the track to be stabilized, consisting of sleepers and rails fastened thereto.

State of the art

[02] A ballasted track is constantly subjected to stress by rail traffic and environmental influences. For example, the position of a track grid in the ballast bed changes. The ballast bed itself becomes dirty over time due to abrasion and foreign matter. Maintenance measures such as tamping or cleaning processes remedy these defects. However, this leads to a temporary loosening of the ballast bed. Even after optimal compaction using a tamping unit, subsequent settlements can occur. A machine for stabilizing the track, which is also called a dynamic track stabilizer, is used to anticipate such settlements.

[03] The machine can be moved on the track and includes a stabilization unit that is clamped to the rails of the track using unit rollers. A vibration generator arranged on the stabilization unit generates vibrations that are transmitted to the track grid. The design and dimensions of the vibration generator determine an impact force that acts on the track with the vibration frequency. To generate a static load, the stabilization unit is supported against a machine frame. The transmitted vibrations cause the grains in the grain structure of the ballast bed to become mobile, to be able to move and to be distributed in a denser Storage. This optimized ballast compaction results in an increase in the load-bearing capacity and the transverse displacement resistance of the track.

[04] AT 16604 U1 discloses an exemplary stabilization unit with variable impact force. The vibration generator comprises several rotating unbalanced masses arranged on parallel shafts. The unbalanced masses are driven with a variably adjustable phase shift relative to one another. Depending on the arrangement of the unbalanced masses, a changed phase shift changes both the direction and the strength of the impact force.

Description of the invention

[05] The invention is based on the object of improving a stabilization unit of the type mentioned at the outset so that the impact force acts on the track in an optimized manner. Furthermore, the arrangement of the vibration generator on the stabilization unit is to be simplified.

[06] According to the invention, these objects are achieved by the features of independent claim 1 . Dependent claims specify advantageous embodiments of the invention.

[07] In this case, aggregate rollers assigned to a left rail of the track as seen in a direction of travel are arranged on a first side frame, aggregate rollers assigned to a right rail of the track are arranged on a second side frame and the two side frames are connected by a self-supporting middle section which includes the vibration generator. This new design has several advantages. The self-supporting middle section with the vibration generator lies between the two side frames and is not placed on a supporting frame as before. This results in a low center of gravity for the entire stabilization unit. The plane of action of the impact force generated by the vibration generator is also a short distance from the top edges of the rails of the track to be stabilized. Both the low center of gravity and the low plane of action of the impact force avoid disruptive tipping moments during a stabilization process. With conventional stabilization units, such tipping moments can, if severe, lead to the sleepers being saddled on a ballast layer in the middle of the track.

[08] Another advantage of the invention is its modular design. In particular, the self-supporting middle section can be designed in different variants to meet different requirements. For example, the stabilization unit can be adapted to different track widths by varying the width of the middle section. The side frames remain identical in construction. Even different vibration generators only affect the middle section and do not lead to any changes to the side frames. In this way, variants with different drives and impact force ranges are easy to implement.

[09] In an advantageous further development, the middle part is designed as the housing of the vibration generator. The vibration generator itself thus forms the supporting middle part that connects the two side frames to one another.

[10] In a cheap variant, the vibration generator includes a hydraulic or pneumatic cylinder. This allows a flywheel to be set in oscillating movements in order to generate vibrations in a desired plane of action.

[11] Another preferred variant of the vibration generator comprises rotatable unbalanced masses. By means of these rotatable unbalanced masses, impact forces can be generated in different planes of action and with adjustable intensity.

[12] The unbalanced masses are sensibly coupled to a rotary drive, in particular an electric one, arranged on the middle part. In this way, no transmission elements such as cardan shafts are required to transmit a rotary movement to the unbalanced masses. In addition, the control is simplified if the rotary drive is designed as an electric motor, in particular as a torque motor. Compared to hydraulic or pneumatic drives, lower noise emissions result. In addition, no Additional units such as pumps or coolers are required. The connection to an existing electrical power supply system is usually made easily via an electrical cable.

[13] Unbalanced masses arranged on several parallel rotating shafts are advantageous, with the rotating shafts and/or unbalanced masses being coupled to one another. The type of coupling determines how the centrifugal forces caused by the unbalanced masses produce the resulting impact forces. For example, the centrifugal forces in one plane of action reinforce one another, whereas the centrifugal forces in another plane of action cancel each other out.

[14] Advantageously, at least two rotary shafts and/or unbalanced masses are coupled to gear elements. In this way, a common rotary drive can be used to drive the rotary shafts or unbalanced masses. In addition, the gear elements can be used to determine the phase shift of the unbalanced masses relative to one another during rotation, which results in the desired resulting impact forces.

[15] In a further improvement, at least one unbalanced mass is rotatably mounted on each rotating shaft. This unbalanced mass can be driven with a variable angular position, rotation speed and direction of rotation relative to an unbalanced mass fixed on the rotating shaft. This allows the direction and magnitude of a resulting centrifugal force to be adjusted. Depending on the direction of rotation, two different resulting centrifugal forces can be created if two unbalanced masses arranged on a rotating shaft assume different angular positions relative to each other depending on the direction of rotation. As a result, the stabilization unit can be operated with different impact forces at the same vibration frequency.

[16] In a particularly advantageous embodiment of the alternative design, the unbalanced masses are arranged on at least two vertically aligned rotation shafts. This allows a particularly low center of gravity of the stabilization unit and a particularly low-lying effective plane of the Impact force can be achieved. In addition, no vertical vibrations occur, which may have to be compensated for with other construction variants.

[17] Preferably, four rotation shafts are arranged symmetrically with respect to a vertical plane of symmetry in the longitudinal direction and a vertical plane of symmetry in the transverse direction. In this way, the central part with the vibration generator can be constructed symmetrically in two axes, thereby avoiding disruptive inertial forces during operation as a result of an uneven mass distribution.

[18] This advantage is reinforced with a symmetrical drive arrangement in which two rotary drives with a respective vertical axis in the vertical plane of symmetry in the longitudinal direction are arranged symmetrically to the vertical plane of symmetry in the transverse direction. Advantageously, two groups of rotary shafts and/or unbalanced masses are each driven by their own rotary drive. The rotary drives are controlled by a common control device to couple the two groups. Various control algorithms are set up in the control device, which cause different drive states. For example, different combinations of the direction of rotation and/or the angular velocity of the respective rotary shaft or unbalanced mass lead to a changed impact force and/or vibration frequency of the stabilization unit.

[19] In an advantageous development, each rotary shaft and/or unbalanced mass is assigned a sensor for detecting a current angle of rotation, wherein the respective sensor is connected to the control device and wherein the control device is set up to control the respective rotary drive depending on the angle of rotation. In this way, the phase positions and the angular speeds of the rotary shafts or the unbalanced masses can be precisely regulated. This allows continuous adjustment of the impact force and the vibration frequency during operation.

[20] In a preferred embodiment, the middle part comprises an oil pan with a predetermined filling level, whereby the unbalance masses are partially below the fill level. This allows the unbalanced masses to be positioned particularly low and also provides splash lubrication for lubricating and cooling the rotating components of the vibration generator.

[21] The respective unbalanced mass advantageously comprises a scoop-shaped extension in the area below the fill level, by means of which oil can be transported from the oil pan into lateral collecting pans during operation. This design of the unbalanced masses results in particularly efficient circulating lubrication. During operation, oil flows back from the collecting pans into the oil pan, which ensures continuous lubrication and cooling. There is only a small amount of oil in the oil pan itself, so that the unbalanced masses can rotate without a braking effect.

[22] A further improvement to the overall structure concerns the side frames. A front flange roller and a rear flange roller are mounted in each side frame, with a clamp mechanism for pressing a pressure roller onto the respective rail arranged between the two flange rollers. This compact structure ensures optimal transmission of the vibrations generated to the track grid.

[23] An advantageous further development is characterized in that the flanged rollers are mounted in at least one side frame so that they can be adjusted in the direction of a rotation axis and can be pressed against the associated rail by means of actuators supported on the same side frame. These device elements are arranged exclusively on the same side frame and do not require any coupling via the middle part. There is therefore no need for a spreading axis known from the prior art to press the stabilization unit against the inside of the rails.

Short description of the drawings

[24] The invention is explained below by way of example with reference to the accompanying figures. They show in schematic representation:

Fig. 1 Rail vehicle with stabilization unit

Fig. 2 Track cross-section with stabilization unit Fig. 3 Front view of a stabilization unit with vertically aligned rotation shafts

Fig. 4 Top view of the stabilization unit according to Fig. 3 Fig. 5 Side view of the stabilization unit according to Fig. 3 Fig. 6 Side frame with flanged roller in retracted state Fig. 7 Side frame with flanged roller in extended state Fig. 8 Middle section with four vertically aligned rotation shafts and two rotation drives

Fig. 9 Middle part according to Fig. 8 with opened housing Fig. 10 Middle part according to Fig. 8 in a top view Fig. 11 Middle part according to Fig. 8 with coupling of the rotary shafts Fig. 12 Rotary shaft with unbalance mass

Description of the embodiments

[25] A rail vehicle 1 shown in Fig. 1 is a so-called dynamic track stabilizer for stabilizing a ballasted track 2 following a tamping process. The track 2 comprises a ballast bed 3 in which a track grid 4, consisting of sleepers 5 and rails 6 fastened to them, is mounted. During a continuous forward travel of the rail vehicle 1 in a working direction 7, the track grid 4 is set in vibration and pressed into the ballast bed 3. This targeted settlement of the track grid 4 is recorded by means of a tendon measuring system 8 or by means of optical measuring devices. The exemplary rail vehicle 1 comprises a machine frame 9, which can be moved on the track 2 to be stabilized, supported on rail bogies 10. Two stabilization units 11 are movably connected to the machine frame 9. In other machines, only a single stabilization unit 11 is arranged.

[26] Fig. 2 shows a cross-section of the track 2 with the stabilization unit 11 during a stabilization process. The stabilization unit 11 comprises a vibration generator 12 as its main component. Load cylinders 13 support the stabilization unit 11 against the machine frame 9. Preferably, the vibration generator 12 generates horizontal vibrations 14 in the transverse direction of the track. Aggregate rollers 15, 16 transfer the vibrations 14 to the track grid 13, whereby flange rollers 15 are guided along the inner edges of the rails and pressure rollers 16 are pressed against the rails 6 from the outside. A continuously adjustable load 17 is applied by means of the load cylinders 13. The vertical load 17 ensures the transmission of the vibrations 14 into the ballast bed and is important for the compaction effect and for the track lowering.

[27] According to the invention, the stabilization unit 11 comprises a self-supporting central part 18 with the vibration generator 12. Viewed in the longitudinal direction of the track, a first side frame 19 is connected to the central part 18 on the left side and a second side frame 20 on the right side (Fig. 2). The connection of the central part 18 to the respective side frames 19, 20 is made, for example, by means of screw connections on a circumferential flange. The respective side frames 19, 20 serve as a carrier of the unit rollers 15, 16 for the respective associated rail 6. The flange rollers 15 and the pressure roller 16 for the left rail 6 of the track 2 are arranged on the first side frame 19 and the flange rollers 15 and the pressure roller 16 for the right rail 6 are arranged on the second side frame 20. The bearings of the respective unit rollers 15, 16 are mounted exclusively on the associated side frames 19, 20. There is no common continuous axis for the left and right flange rollers 15. The lack of a continuous axis creates space for the low arrangement of the middle section. The result is a low center of gravity 21 of the entire stabilization unit 11 and a low effective plane 22 of the vibration generator 12. The center of gravity 21 is preferably located in the effective plane 22.

[28] In a preferred embodiment, the vibration generator 12 comprises unbalanced masses 23 which are arranged on rotary shafts 24. Such a vibration generator 12 with reduced height is explained with reference to Figures 3-7. Here, four vertically aligned rotary shafts 24 arranged symmetrically with respect to a longitudinal vertical plane of symmetry 25 and a transverse vertical plane of symmetry 26.

[29] Viewed in the working direction 7, the front two rotation shafts 24 form a first group, with the left rotation shaft 24 being directly connected to a rotation drive 27 arranged above it. The right rotation shaft 24 is coupled to the left rotation shaft 24 via gears. The rear two rotation shafts 24, which are also coupled via gears, form a second group. The right rotation shaft 24 is connected to its own rotation drive 27.

[30] The largely symmetrical structure of the central part 18 thus achieved causes a uniform vibration of the entire stabilization unit 11 . The individual unbalanced masses 23 each generate a dynamic excitation force F. In total, these excitation forces F result in the resulting dynamic impact force Fs. With the mass m and the eccentricity e of the respective unbalance 23 as well as the vibration frequency f or the angular velocity ou in the center of rotation, the individual excitation force is obtained according to the following formula:

[31] The resulting dynamic impact force Fs determines the compaction energy introduced and significantly influences the lowering of the track 2. The rotation drives 27 of the two groups are connected to a common control device 28. Various drive modes are set up in this control device 28. This means that the two groups can be driven at different speeds and directions of rotation, which result in different resulting dynamic impact forces Fs.

[32] On both side frames 19, 20, between the front and rear flange rollers 15, a clamp mechanism 29 for adjusting the respective pressure roller 16 is arranged. In the example shown, the respective clamp mechanism 29 comprises a double rocker and two hydraulic cylinders 30, which are arranged symmetrically to the transverse vertical axis of symmetry 26. Extending the piston rods causes the pressure rollers 18 to be pressed against the outer sides of the rails 6. [33] In order for the stabilization unit 11 to be clamped onto the track grid 4 without play, the flanged rollers 15 must also be pressed against the rails 6 from the inside. Advantageously, no conventional spreading axle is used for this, because elements of such a spreading axle would also have to be arranged or mounted on the middle part 18. Instead, only one of the side frames 20 is provided with flanged rollers 15 that can be adjusted in the axial direction 31.

[34] For example, the two flanged rollers 15 of the second side frame 20 are each mounted on a shaft 32 so that they can rotate and move, as shown in Figures 6 and 7. One end of the respective shaft 32 is mounted directly on the side frame 20 and the other end is supported on a bracket 33 of the side frame 20. The load is transferred to the associated rail 6 via this robust bearing.

[35] For adjustment in the axial direction 31, a pivot lever 34 is arranged, which is connected on the one hand to the side frame 20 and on the other hand to an actuator 35 (e.g. pneumatic or hydraulic cylinder). The actuator 35 is tiltably mounted on the same side frame 20. Between the two joints 36, the pivot lever 34 has a positive coupling with a bushing 37 guided on the shaft 32. When the actuator 35 is extended, the pivot lever 34 pushes the bushing 37 and the flanged roller 15 mounted on it outwards. In this way, the flanged rollers 15 are pressed against the inside of the rails 6 without play.

[36] Figures 8 to 12 show a further embodiment of the middle part 18. A housing 38 comprises opposing connection surfaces 39 for connecting to the side frames 19, 20. As before, four vertically aligned rotary shafts 24 are mounted in a base 40 and in a cover 41 of the housing 38. In addition, an oil pan 42 is arranged in the housing. When the rotary shafts 24 are stationary, the oil pan 42 is filled with oil up to a filling level. The unbalanced masses 23 are partially arranged below this filling level so that they are immersed in the oil bath. [37] During operation, the unbalanced masses 23 transport oil from the oil pan 42 upwards and outwards into adjacent collecting pans 43. In order to achieve this conveying effect, a scoop-shaped extension 44 with inclined surfaces is arranged in the lower area of the respective unbalanced mass 23. A corresponding scoop-shaped extension 44 is shown in Fig. 12. Oil flows back into the oil pan 42 via passages in the bottom 40 of the housing 38, so that circulating lubrication is formed during operation.

[38] To increase the symmetry, two rotary drives 27 are arranged, the vertical axes 45 of which lie in the longitudinal plane of symmetry 25 and are arranged symmetrically to the transverse plane of symmetry 26. A drive shaft 46 of the respective rotary drive 27 is coupled to the two nearest rotary shafts 24 via gears. In addition, all rotary shafts 24 are coupled to one another via gears, so that a clear position or phase position of the unbalanced masses 23 relative to one another is achieved via these gear elements 47. This eliminates the need for synchronous control of the two rotary drives 27.

Claims

Patent claims

1. Stabilization unit (11) for stabilizing a track (2), with a vibration generator (12) and with unit rollers (15, 16) for transmitting vibrations (14) generated by means of the vibration generator (12) to a track grid (4) of the track to be stabilized (2), consisting of sleepers (5) and rails (6) fastened thereto, characterized in that unit rollers (15, 16) assigned to a left rail (6) of the track (2) are arranged on a first side frame (19), that unit rollers (15, 16) assigned to a right rail (6) of the track (2) are arranged on a second side frame (20), and that the two side frames (19, 20) are connected by a self-supporting central part (18) which comprises the vibration generator (12).

2. Stabilization unit (11) according to claim 1, characterized in that the central part (18) is designed as a housing (38) of the vibration generator (12).

3. Stabilization unit (11) according to claim 1 or 2, characterized in that the vibration generator (12) comprises a hydraulic or pneumatic cylinder.

4. Stabilization unit (11) according to claim 1 or 2, characterized in that the vibration generator (12) comprises rotatable unbalance masses (23).

5. Stabilization unit (11) according to claim 4, characterized in that the unbalanced masses (23) are coupled to a rotary drive (27), in particular an electric one, arranged on the central part (18).

6. Stabilization unit (11) according to claim 5, characterized in that the unbalance masses (23) are arranged on several parallel rotating shafts (24) are arranged and that the rotation shafts (24) and/or unbalanced masses (23) are coupled to one another.

7. Stabilization unit (11) according to claim 6, characterized in that at least two rotation shafts (24) and/or unbalanced masses (23) are coupled to gear elements (47).

8. Stabilization unit (11) according to claim 6 or 7, characterized in that at least one unbalanced mass (23) is rotatably mounted on each rotary shaft (24).

9. Stabilization unit (11) according to one of claims 6 to 8, characterized in that the unbalanced masses (23) are arranged on at least two vertically aligned rotary shafts (24).

10. Stabilization unit (11) according to claim 9, characterized in that four rotation shafts (24) are arranged symmetrically with respect to a longitudinal vertical plane of symmetry (25) and a transverse vertical plane of symmetry (26).

11. Stabilization unit (11) according to claim 10, characterized in that two rotary drives (27) with a respective vertical axis (45) are arranged in the longitudinal vertical plane of symmetry (25) symmetrically to the transverse vertical plane of symmetry (26).

12. Stabilization unit (11) according to one of claims 4 to 11, characterized in that the central part (18) comprises an oil pan (42) with a predetermined filling level and that the unbalanced masses (23) partially extend below the filling level.

13. Stabilization unit (11) according to claim 12, characterized in that the respective unbalance mass (19) in the area below the filling level a scoop-shaped extension (44) by means of which oil can be conveyed from the oil pan (42) into lateral collecting pans (43) during operation.

14. Stabilization unit (11) according to one of claims 1 to 13, characterized in that a front flange roller (15) and a rear flange roller (15) are mounted in each side frame (19, 20) and that a clamp mechanism (29) for pressing a pressure roller (16) onto the respective rail (6) is arranged between the two flange rollers (15).

15. Stabilization unit (11) according to claim 14, characterized in that in at least one side frame (20) the flanged rollers (15) are adjustably mounted in the axial direction (31) and can be pressed onto the associated rail (6) by means of actuators (35) supported on the side frame (20).