Hydraulic damper for railway rolling stock

Abstract

FIELD: machine engineering.SUBSTANCE: hydraulic damper for a railway rolling stock comprises an upper eye, a lower eye with a threaded stud, a housing, a working cylinder closed at the bottom with a bottom including a bypass valve with a petal spring, and also closed at the top with a guide sleeve having protective seals and a nut pressing them, an adjustable throttle opening with a needle, overflow tubes connecting the working cylinder with a recuperative chamber, a rod having a throttle opening, equipped with upper and lower limit washers, a piston elastically connected to the rod, having a plate valve and a threaded sleeve. The elastic connection between the piston and the rod is achieved by means of successively arranged packages of disc springs.EFFECT: capabilities of hydraulic dampers of railway rolling stock are expanded, namely: the implementation of a variable resistance characteristic depending on the amount of movement of the rod with an elastically fixed piston and an increase in the efficiency of vibration damping under low- and high-frequency loading during the movement of a unit of rolling stock of railway transport, as well as the minimization of the influence of temperature changes in the viscosity of the working fluid on the resistance forces developed by the hydraulic damper.1 cl, 1 dwg

Description

[0001] The invention relates to the field of mechanical engineering, namely to devices for damping vibrations, in particular hydraulic dampers for vibrations of spring suspension of railway rolling stock.

[0002] A device for damping shock and vibration loads is known, consisting of a rod and a piston, a hydraulic chamber, which is filled with a viscous liquid, the constituent elements of the device are enclosed in a cylindrical cartridge [1].

[0003] The disadvantage of this device is the equality of resistance to the movement of the piston with the rod during the forward and reverse stroke, which reduces the smoothness of the vehicle's movement.

[0004] A shock absorber with a self-locking function [2] is known from the prior art, comprising a piston with a floating seat.

[0005] The disadvantages of this device, in addition to the structural complexity during manufacture and maintenance, is the inability to relieve stress arising from impacts from the mounting eyes of the sprung and unsprung parts.

[0006] A hydraulic shock absorber with adjustable characteristics [3] is known, in which the valve plates close the bypass openings of the pressure valve under the action of springs. Since the piston surfaces are ridge-free and the plates are pressed against the smooth surface of the piston without preload, the bypass openings of the pressure valve are not closed tightly enough, and the shock absorber does not achieve the required performance.

[0007] A hydraulic damper is known [4], which includes a base, a guide and a shock-absorbing device in its design. The rod is rigidly fixed in the bottom of a cylindrical sleeve, forming a sealed annular cavity. The bottom of the cylindrical sleeve is fixed in a bushing, rigidly connected to the base of the protected object. A spring is located in the annular cavity, whose lower end rests against the bottom, and its upper end against the piston. The piston is designed as a disk and is located with a throttling gap relative to the rod. In the upper part of the rod, a cover movable relative to the rod is located. The cover consists of an annular flange with a seal and a bushing rigidly connected to the flange, enclosing the outer surface of the cylindrical sleeve through a seal. A spring is located coaxially to the rod, the upper end of which rests against the cover, and the lower end against the piston. A support element of the vibration-isolated object is fixed on the cover. Increased efficiency of vibration isolation is achieved.

[0008] This hydraulic damper has a drawback: its design does not allow for shock absorption, as the constant throttle clearance prevents the required volume of working fluid from flowing from one cavity to the other. This disadvantage results in the sprung mass being harshly affected by shock loads.

[0009] There is a first stage hydraulic damper for a spring suspension of a vehicle [5], comprising a housing with a base and a cylinder coaxially located in the housing, in which a piston with a rod is installed with the possibility of movement, wherein the piston is installed with the possibility of movement relative to the rod and is spring-loaded from above and below by springs.

[0010] This hydraulic damper has two drawbacks. One is the difficulty of manufacturing the piston, as creating a circular groove is a rather complex manufacturing operation. Another drawback is that when the damper is subjected to impact loads, the circular groove in the piston and the radial bore in the piston rod may misalign, preventing the hydraulic fluid from flowing and overloading the hydraulic damper.

[0011] There is a hydraulic vibration damper for a single-stage spring suspension [6] containing a housing, a casing, a working cylinder, a reservoir, rubber and metal bushings, a rod with a piston, the piston is made in the form of upper and lower limiting washers with bypass channels and a washer moving between them with throttle holes, limited on both sides by coil springs.

[0012] The disadvantage of the vibration damper is: the use of welded joints to fix the upper limiting washer to the piston rod, which significantly reduces the repairability of the product and makes maintenance difficult, since the piston unit becomes non-disassemblable, as well as the use of several small-diameter springs connected in parallel, the vertical stabilization of which can be disrupted in the event of possible rotation of the piston relative to the axis of the rod.

[0013] A hydraulic damper design is known [7], containing a reservoir with a working cylinder placed in it, in the upper part of the working cylinder there is a rod guide, in the central axial hole of which a rod equipped with a piston is movably fixed, as well as a nut with a cover of a protective cylindrical casing of the reservoir in the upper part of the reservoir and the bottom of the reservoir with a compression valve in the lower part of the reservoir, the feature of which is fixation with the help of grooves of the guide and the wall of the reservoir.

[0014] A disadvantage of this hydraulic damper is its inability to dampen high-frequency vibrations, as the design does not include compensation valves designed for higher rod and piston speeds. Therefore, increased mechanical stress may occur in the eye and rod, which can lead to hydraulic damper failure.

[0015] This hydraulic damper [8] is designed with upper and lower lugs, a coaxially located housing and piston rod, a protective seal for the piston rod, a corrugated casing, the upper part of which is attached to the piston rod and the lower part to the housing, and a protective casing secured to the upper lug. A distinctive feature of this design is the presence of through holes on the surface of the lug base.

[0016] The disadvantage of this design is the rigid connection of the piston and rod, which, when exposed to high-frequency loads, causes increased mechanical damage to the eye and rod, which can lead to both a fracture of the connection between the rod and piston, and a fracture of the rod.

[0017] A design of a two-pipe hydropneumatic shock absorber is known [9], containing outer and inner coaxial cylinders, a lower and upper cover, a nipple for filling with gas and a piston, characterized in that it contains a separator made in the form of a ring.

[0018] The disadvantage of this shock absorber is the dependence of its characteristics on the viscosity of the working fluid, as well as the vulnerability of the piston and rod to high-frequency loads when the vehicle is moving.

[0019] A device is known for ensuring the operability of hydraulic shock absorbers of military tracked and wheeled vehicles in low temperature conditions

[10] , comprising a housing in which a working cylinder is placed, filled with working fluid, between which a compensation chamber, a rod and a piston are placed, the difference of which is the presence of a flexible heating element on the outer surface of the working cylinder, which has an electrical connection with a controller, a temperature sensor and a power input.

[0020] The disadvantages of this device are low reliability, which is caused by the presence of electrical devices, as well as an increased level of mechanical stress in the rod and piston when exposed to high-frequency loads that occur when the vehicle is moving.

[0021] There is a design of a telescopic hydraulic shock absorber for a controlled suspension

[11] , comprising a cylindrical body with a hollow rod located inside, made integral with the piston, a shaped nut screwed coaxially into the piston, with an axial through hole and radial holes, a safety valve, a compensation chamber connected to the piston and rod cavities of the shock absorber, end sealing caps, a support with a check valve connected to the compensation chamber and the rod cavity of the shock absorber, characterized in that the shock absorber is designed with the possibility of changing the static forces of the shock absorber by using the piston cavity as a hydraulic cylinder.

[0022] The disadvantages of this shock absorber are the complexity of its design, as well as the change in the developed resistance force depending on the temperature change in the viscosity of the working fluid.

[0023] A hydraulic damper is known

[12] comprising a housing and a cylinder coaxially placed in the housing with a bottom having a throttle, an inlet and a discharge valve, a rod with a piston having throttles, above-piston and below-piston valves, a compensation cavity between the housing and the cylinder is mounted with the possibility of movement, wherein the above-piston, below-piston and compensation cavities of the cylinder are filled with a working fluid, the cylinder is closed from above by a guide unit, while the rod is passed through the central hole of the guide unit, the entire cylinder-piston group of parts is fixed in the housing with a nut, at the end of the rod, opposite the piston, an upper flange is rigidly fixed, along the perimeter of which, coaxially to the housing, a casing is fixed, on the upper flange and the housing there are lugs in which elastic fastening elements in the form of a rubber bearing are placed.

[0024] The distinctive feature of this design is the presence of plate-spring valves, a piston ring made of composite material, and drain holes are made in the volume of the guide, a pin is installed in the valve seat on the bottom and a drainage gap is made on the seating belt of the guide.

[0025] The disadvantage of the design of this hydraulic damper is the complexity of manufacturing its parts.

[0026] A hydraulic shock absorber with an adjustable characteristic is known from the prior art

[13] , consisting of a hydraulic single-tube shock absorber, characterized in that it consists of a working cylinder, inside which a piston is installed by means of a nut with a washer, and a compensation chamber, the piston is made of two plates having annular slots for passing shock-absorbing fluid, between which a gasket is installed, the slots in the plates are made in such a way that when they rotate relative to each other, the openings can partially or completely overlap, rebound valves with a spring and a washer and compression valves with a spring and a washer are installed in the piston. The upper plate of the piston is capable of rotation relative to the lower one. This possibility is realized with the help of a heat-sensitive spring.

[0027] The disadvantages of this shock absorber are the high cost and complexity of manufacturing the heat-sensitive spring, as well as the vulnerability of the structure to high-frequency loads during the extension stroke of the shock absorber.

[0028] The closest analogue is a vibration damping device with a variable characteristic

[14] , which includes a working cylinder, a floating piston with a plate valve, a pressure sleeve, a rod equipped with upper and lower limit washers, the feature of which is the elastic connections of the piston with the limit washers by means of cylindrical springs.

[0029] The disadvantages of this device are: insufficient effective operation of the throttle holes in the rod when the upper cylindrical spring is compressed and insufficient elastic properties of the cylindrical springs that can be placed in the limited dimensions of the piston part of the vibration damping device.

[0030] The hydraulic damper of a railway rolling stock is characterized by the fact that the damper design contains a working cylinder, a rod equipped with upper and lower limit washers, and a floating piston with throttle channels, spring-loaded by successively arranged packs of disc springs during the compression and extension strokes.

[0031] The objective of the invention is to expand the capabilities of hydraulic dampers of railway rolling stock, namely: the implementation of a variable resistance characteristic depending on the amount of movement of a rod with an elastically fixed piston and an increase in the efficiency of vibration damping under low- and high-frequency loading during the movement of a unit of rolling stock of railway transport, as well as minimizing the influence of temperature changes in the viscosity of the working fluid on the resistance forces developed by the hydraulic damper.

[0032] The objective of the invention is achieved by using successively arranged packages of disc springs as an elastic connection between the rod and the piston.

[0033] A hydraulic damper for a railway rolling stock comprising an upper eye, a lower eye with a threaded stud, a housing within which a working cylinder is placed, closed at the bottom by a bottom including a bypass valve with a petal spring, and also closed at the top by a guide sleeve having protective seals and a nut pressing them, an adjustable throttle opening with a needle, overflow tubes connecting the working cylinder with a recuperative chamber, a rod having a throttle opening, equipped with upper and lower limit washers, a piston elastically connected to the rod, having a plate valve and a threaded sleeve, characterized in that the elastic connection between the piston and the rod is realized by means of successively arranged packs of disc springs.

[0034] The essence of the invention is explained by the drawing in Fig. 1 - a hydraulic damper for a railway rolling stock;

[0035] The design of the hydraulic damper for railway rolling stock provides for circular circulation of the working fluid. The hydraulic damper is mounted in a spring suspension system using eye 1 and a threaded housing stud 2 with nut 3, which are located on the bottom of housing 4. A protective cover 5 is attached to the eye via a threaded connection and secured with bolts 6 to prevent accidental loosening.

[0036] In the working cylinder 7, a rod 8 is placed, on which the upper 9 and lower 10 limiting washers are placed, between which a piston 11 is located with throttle channels 12, closed by a plate valve 13, limited at the top and bottom by packs of disc springs 14 and 15. The lower limiting washer 10 is fixed with a threaded connection.

[0037] The design of reed valve 13 involves rigidly fixing the inner portion of the valve plate to piston 11 to ensure its deflection under high pressure in the cavity beneath the piston and to create an annular gap along the outer portion of the reed valve. Therefore, to ensure operation of the floating piston design while maintaining the functionality of the reed valve, it is necessary to press the valve stop against the piston, without connecting it to the piston rod.

[0038] The plate valve stop is fixed using sleeve 16, on the outer part of which a thread is applied; the valve is pressed against the piston by means of an expansion located above the threaded part.

[0039] The top of the bushing has a flat, widened surface to provide a stop for the upper pack of disc springs, and also has two grooves to facilitate its removal with a wrench.

[0040] The lower disc spring pack rests against the lower portion of the piston and bushing. At the bottom, the lower disc spring pack rests against the lower limit washer 10, secured with a threaded connection at the end of the piston rod.

[0041] The end of the piston rod has a throttle hole 17, closed by a ball 18, which is pressed by a spring 19. A bushing 20 with a through hole is screwed into the throttle hole. The working cylinder 7 is closed at the bottom by a bottom 21 with a check valve 22. The valve is spring-loaded by a petal spring 23. A mesh filter 24 is provided for filtering the working fluid.

[0042] The working cylinder is closed from above by a rod guide sleeve 25, in which the rod seals 26 and the nut 27 that presses them are located. In the guide there is a throttle hole 28, adjusted by a throttle needle 29, screwed along the thread into the guide and having rubber rings 30 on the tailpiece.

[0043] The guide is connected by overflow pipes 31 to the recuperative chamber 32. The cylinder-piston group assembly is fixed in the housing 33.

[0044] The following can be used as supports for the proposed design of the hydraulic damper: lugs with rubber and rubber-metal bushings of cylindrical shape and in the form of two-cavity hyperboloids, as well as lugs with swivel bearings; threaded studs; combinations of lugs of various shapes and a threaded stud.

[0045] The hydraulic damper of railway rolling stock can operate in throttle, valve and vibration isolation modes.

[0046] The operation of the proposed hydraulic damper in throttle and valve mode during the extension (rebound) stroke and the extension stroke is similar to the operation of similar devices currently used.

[0047] In throttle mode, oil flows from the cavity below the piston to the cavity above it through the throttle bore sleeve, the open throttle bore ball valve, the valve cavity, and the throttle passages. As the fluid flows through the throttle bores, it creates the necessary viscous friction, ensuring optimal damping of vertical vibrations.

[0048] The introduction of an elastic spring connection, realized using disc spring packs, between the piston and the rod of the hydraulic damper reduces the hard impact effect on the rod and the upper eye, reducing the mechanical stress in them.

[0049] When the piston speed increases as a result of impact loads, the oil pressure under the piston increases to the extent of the plate valve deformation, it bends and begins to pass oil through the annular gap, which reduces the resistance force to piston movement.

[0050] In vibration isolation mode, low- and high-frequency vibrations are damped. This process is achieved by compressing and stretching the disc spring packs located above and below the piston.

[0051] The difference lies in the use of an elastically connected piston, spring-loaded by disc spring packs at the top and bottom, resulting in an elastic connection between the piston and the device piston rod. This technical feature reduces the impact of shock loads on the device structure and ensures smooth operation, as well as reduces the influence of temperature-related changes in the viscosity of the working fluid on the resistance force developed by the hydraulic damper. Smooth operation is ensured by converting the mechanical energy of vertical low- and high-frequency vibrations into elastic deformation energy of the springs. This energy is generated as a result of viscous friction when the working fluid passes through the throttle and valve openings, and is dissipated into the external environment. The influence of temperature-related changes in the viscosity of the working fluid is also reduced thanks to the elastic force of the disc spring packs.

[0052] At this point in time, a prototype of a hydraulic damper of the proposed design has been manufactured and tested.

[0053] Sources of information

[0054] 1. Device for damping shock and vibration loads (US Patent No. 3875612, 1975 E05F 03 / 22).

[0055] 2. Shock absorber with self-locking function (Patent CN212616056, F16F 9 / 16, 2021).

[0056] 3. Patent No. 2316685 C1 Russian Federation, IPC F16F 9 / 342, F16F 5 / 00. Hydraulic shock absorber with adjustable characteristics: No. 2006123299 / 11: declared 06 / 29 / 2006: published 02 / 10 / 2008 / S.S. Kadnikov, S.P. Rykov; applicant State Educational Institution of Higher Professional Education "Bratsk State University". Vibration damping device with variable characteristics (Patent for Utility Model No. 221859 U1 Russian Federation, IPC F16F 5 / 00, F16F 9 / 16)

[0057] 4. Patent No. 2435999 C1 Russian Federation, IPC F16F 5 / 00, F16F 9 / 16. Hydraulic damper: No. 2010134723 / 11: declared 20.08.2010: published 10.12.2011 / O.S. Kochetov, M.O. Stareeva.

[0058] 5. Patent for utility model No. 131106 U1 Russian Federation, IPC F16F 9 / 16, F16F 9 / 512. Hydraulic damper of the first stage of spring suspension of a vehicle: No. 2013108272 / 11: declared 25.02.2013: published 10.08.2013 / Yu.P. Boronenko, G.M. Levit, S.V. Mamontov; applicant Federal State Budgetary Educational Institution of Higher Professional Education "St. Petersburg State Transport University".

[0059] 6. Patent No. 2098688 C1 Russian Federation, IPC F16F 5 / 00. Hydraulic vibration damper for single-stage spring suspension: No. 96109287 / 28: declared 05.05.1996: published 10.12.1997 / A.G. Kupriyanov, V.M. Ruban, A.M. Matva.

[0060] 7. Utility model patent No. 236508 U1 Russian Federation, IPC F16F 9 / 16. hydraulic damper: declared 08.07.2025: published 11.08.2025 / A.A. Starikov; applicant Pervouralsk Automobile Unit Plant Limited Liability Company.

[0061] 8. Patent for Utility Model No. 233912 U1 Russian Federation, IPC F16F 9 / 16. Hydraulic vibration damper: declared 18.12.2024: published 13.05.2025 / S.V. Treskin, E.Yu. Dulsky, V.A. Kruchek [et al.]; applicant Federal State Budgetary Educational Institution of Higher Education Irkutsk State Transport University.

[0062] 9. Utility Model Patent No. 208694 U1 Russian Federation, IPC F16F 9 / 06. Twin-pipe hydropneumatic shock absorber: No. 2021122869: declared 07 / 29 / 2021: published 12 / 30 / 2021 / S.A. Metlyakova, S.V. Repin, A.A. Vorobyov, I.K. Samarkina; applicant Federal State Budgetary Educational Institution of Higher Education "Emperor Alexander I St. Petersburg State Transport University".

[0063] 10. Patent for utility model No. 200121 U1 Russian Federation, IPC F16F 9 / 46. Device for ensuring the operability of hydraulic shock absorbers of military tracked and wheeled vehicles in low temperature conditions: No. 2020119248: declared 03.06.2020: published 07.10.2020 / D.V. Shabalin, P.S. Kazorin, N.E. Rakimzhanov [et al.].

[0064] 11. Patent for Utility Model No. 233595 U1 Russian Federation, IPC B62D 55 / 00, F16F 5 / 00, F16F 9 / 00. Telescopic hydraulic shock absorber for controlled suspension: declared 13.12.2024: published 28.04.2025 / A.A. Alekseev, A.I. Kovalchuk, S.A. Lemesh [et al.]; applicant Joint Stock Company "Omsk Transport Engineering Plant".

[0065] 12. Patent for utility model No. 237006 U1 Russian Federation, IPC F16F 9 / 16. Hydraulic damper: declared 31.05.2025: published 03.09.2025 / I.I. Bondarev; applicant TransTrain LLC.

[0066] 13. Patent No. 2547106 C2 Russian Federation, IPC F16F 5 / 00, F16F 9 / 16. Hydraulic shock absorber with adjustable characteristics: No. 2013127861 / 11: declared 18.06.2013: published 10.04.2015 / S.P. Rykov, M.V. Berezhnoy; applicant Federal State Budgetary Educational Institution of Higher Professional Education "Bratsk State University".

[0067] 14. Patent for Utility Model No. 221859 U1 Russian Federation, IPC F16F 5 / 00, F16F 9 / 16. Variable-characteristic oscillation damping device: No. 2023119091: declared 18.07.2023: published 28.11.2023 / P.Yu. Ivanov, E.Yu. Dulsky, E.A. Milovanova [et al.]; applicant Federal State Budgetary Educational Institution of Higher Education Irkutsk State Transport University.

Claims

A hydraulic damper for a railway rolling stock comprising an upper eye, a lower eye with a threaded stud, a housing within which a working cylinder is placed, closed at the bottom by a bottom including a bypass valve with a petal spring, and also closed at the top by a guide sleeve having protective seals and a nut pressing them, an adjustable throttle opening with a needle, overflow tubes connecting the working cylinder with a recuperative chamber, a rod having a throttle opening, equipped with upper and lower limit washers, a piston elastically connected to the rod, having a plate valve and a threaded sleeve, characterized in that the elastic connection between the piston and the rod is realized by means of successively arranged packs of disc springs.

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