FRICTION CLUTCH WITH ADJUSTMENT OF TRANSMITTED TORQUE, CHANGING THE FORCE ON THE SWITCH DRIVE GATE

Abstract

The utility model relates to mechanical engineering, in particular to electric drives of railway turnouts with disc friction clutches having friction disks with metal-ceramic friction elements (inserts). The objective of the claimed technical solution is to improve the safety of rail transport on sections of railways equipped with turnouts with friction clutches. The technical result achieved in the process of solving the stated problem consists in increasing the stable operability of the turnout electric drive for the entire regulated period of operation, having in its composition friction disc clutches with friction inserts, under conditions of intermittent operation, moderate humidity and a temperature range of -40 + 100 ° C, and dry friction between the disks. The technical result is achieved by a friction clutch with adjustment of the transmitted torque, changing the force on the gate of the turnout drive, containing a hub,made in the form of a flange, on the cylindrical part of which movable and fixed friction steel disks are mounted, and a clamping device consisting of an elastic element, a clamping disk, a clamping nut and a locking screw, when compressing the friction disks, allowing for stepwise adjustment of the torque transmitted by the clutch changing the force on the switch drive gate, with a step of no more than 500 N in the range of 0-8500 N, at a temperature of -40 ° C to + 100 ° C, on the movable friction disks having an oxidation coating, a hardness of 40-45 HRC, there is a number of holes located around the circumference, into which friction inserts in the form of a prism are pressed, 4-6 mm high, with a base area of ​​85-115 mm2, protruding above the plane of the disk by 1.0-3.0 mm on each side and with one of the corners directed toward the center of the disk, while the inserts are obtained by the method sintering of the powder composition, after sintering have an open porosity of 15-30%, a density of 5.0-5.85 g / cm3,oil absorption of 1-4%, impregnated with hydraulic oil, and after deformation within 15-20%, have a Brinell hardness HB of no more than 650 MPa, with a dynamic friction coefficient of at least 0.3 for steel at a relative sliding speed of 1.3-2.7 m / s, in the temperature range from - 40 ° C to + 100 ° C, and a static force on the gate of 5000-6500 N, fixed in the holes of the disk by deformation, until a force is obtained for extruding the insert from the hole of at least 1500 N.

Description

[0001] The utility model relates to mechanical engineering, in particular to electric drives of railway turnouts with disc friction clutches having friction discs with metal-ceramic friction elements (inserts).

[0002] A friction clutch for a switch drive is known, comprising a hub, movable and fixed friction disks, and a pressure plate, wherein the hub consists of a sleeve and a flange made of different materials, a groove is made on the end of the sleeve, flared onto the outer surface of the pressure plate, making the connection of the sleeve and the pressure plate non-detachable, and the clutch non-dismountable. In addition, the outer surface of the pressure plate is made conical, the flange of the hub is made of the same material as the material of the fixed friction disks, the connection of the flange and the sleeve is non-detachable. (Patent RU 161146, application No. 2015112972 dated 08.04.2015, IPC B61L5 / 06).

[0003] The disadvantage of this coupling is the decrease in the stable performance of the switch electric drive with an increase in the operating period during the regulated operating period, under operating temperatures from -40°C to +100°C, instability of the switching forces and pressing of the switches to the frame rails of the switch, which leads to an overload of the electric drive and premature failure of the electric motor.

[0004] A friction clutch is known, comprising a hub made in the form of a flange, on the cylindrical part of which four friction disks with a thickness of 2-3 mm and a pressure disk are mounted, the end part of the cylindrical part of the flange is flared onto the inner end surface of the pressure disk, making the connection of the hub and the pressure disk non-detachable, and the friction disks movable, two friction disks have a number of holes, the centers of which, located along the circumference, have the shape of an equilateral triangle with rounded vertices, and one angle directed to the center of the metal disk, in the said holes friction inserts are fixed by pressing, 3-6 mm high, symmetrically protruding above the planes of the disk on each side by 1.0-3.0 mm, the material of the friction inserts contains copper, silicon oxide, graphite, zinc stearate and iron, with the following ratio of components, wt.%: copper 8.0-13.0, silicon oxide 3-8.0, graphite 2.0-5.0, zinc stearate 0.1-0.5, the rest is iron, has an open porosity of 15-20%, Brinell hardness HB 350-450 MPa, density 5.00-5.25 g / cm. 3 , a relative settlement of at least 12% and oil absorption of 2-5%. In addition, the outer surface of the disc with friction inserts has three rectangular protrusions located symmetrically relative to each other, along the circumference, the force of the press settlement of the friction inserts is (4-8)10 4 N per one insert, the press upsetting is carried out by deforming the inserts in height by 0.75-0.85 mm in a special device with the application of upsetting force simultaneously to all inserts, the friction inserts are impregnated with hydraulic frost-resistant oil (RU patent 204601, application: 2021100688, 14.01.2021 IPC B61L5 / 06).

[0005] This technical solution is adopted as a prototype.

[0006] The disadvantage of this coupling is the decrease in the stable performance of the switch electric drive with an increase in the operating period during the regulated operating period, under operating temperatures from -40°C to +100°C, manifested in the instability of the switching forces and pressing of the switches to the frame rails of the switch, which leads to an overload of the electric drive and premature failure of the electric motor.

[0007] The objective of the claimed technical solution is to improve the safety of rail transport on sections of railways equipped with turnouts with friction clutches.

[0008] The technical result achieved in the process of solving the assigned problem consists in increasing the stable performance of the switch electric drive for the entire regulated period of operation, which has friction disc clutches with friction inserts, under conditions of intermittent operation, moderate humidity and a temperature range of -40 to +100°C, and dry friction between the discs.

[0009] The technical result is achieved by a friction clutch with adjustment of the transmitted torque changing the force on the switch drive gate, containing a hub made in the form of a flange, on the cylindrical part of which movable and fixed friction steel disks are mounted, and a clamping device consisting of an elastic element, a clamping disk, a clamping nut and a locking screw, when compressing the friction disks, allowing for stepwise adjustment of the torque transmitted by the clutch changing the force on the switch drive gate, with a step of no more than 500 N in the range of 0-8500 N, at a temperature of -40 ° C to + 100 ° C, on movable friction disks having an oxidation coating, a hardness of 40-45 HRC, there is a number of holes located around the circumference, into which friction inserts are pressed in the form of a prism, 4-6 mm high, with a base area 85-115 mm 2, protruding above the plane of the disk by 1.0-3.0 mm on each side and with one of the corners directed towards the center of the disk, while the inserts are obtained by sintering a powder composition, after sintering they have an open porosity of 15-30%, a density of 5.0-5.85 g / cm 3 , oil absorption of 1-4%, impregnated with hydraulic oil, and after deformation within 15-20%, have a Brinell hardness HB of no more than 650 MPa, with a dynamic friction coefficient of at least 0.3 for steel at a relative sliding speed of 1.3-2.7 m / s, in the temperature range from - 40 ° C to + 100 ° C, and a static force on the gate of 5000-6500 N, fixed in the holes of the disk by deformation, until a force is obtained for extruding the insert from the hole of at least 1500 N.

[0010] The movable friction disc is made of structural steel with a thickness of 2-4 mm, splines are made along the outer diameter of the disc to transmit torque.

[0011] The inserts contain copper, tin, barite, silicon oxide, graphite and iron with the following component content, wt.%: copper - (10.5-17.5), tin - (0.2-5.2), barite - (2.0-5.2), silicon oxide - (2-5.0), graphite - (2-5), iron - the rest, except for this The inserts are impregnated with hydraulic oil of the AMG-10 or VMGZ brand in a vacuum with an absolute pressure of no more than 1000 Pa.

[0012] The inserts have a coarse-grained structure consisting of granular pearlite with inclusions of up to 20%, lamellar pearlite and ferrite, having intergranular and intragranular porosity, inclusions of graphite, silicon oxide, sulfides, copper and cementite in the form of a broken network, along the grain boundaries, copper inclusions are also present inside the grains.

[0013] The total area of ​​the bases of the friction inserts protruding above the plane of the disc on one side is at least 1100 mm 2 with a total disk area of ​​no more than 5600 mm 2, and the geometric centers of the inserts coincide with the circle of the inserts' location on the disk.

[0014] The clamping device uses disc springs or coil springs as the elastic element.

[0015] In addition, on the cylindrical end of the hub, it is possible to make a thread and an additional section for installing additional friction discs, a pressure disc, a pressure housing and a pressure nut, while in the pressure housing a series of stepped holes are made, located along a circle of a diameter equal to the diameter of the circle with pressed friction elements on the friction discs, in the holes of a larger diameter, on the one hand, coil springs are installed, and in the holes of a smaller diameter, on the other hand, a locking screw of the fixing device enters, and in the pressure disc a series of blind holes are made, into which elastic elements enter, located along a circle of a diameter equal to the diameter of the installation circle of the coil springs on the pressure housing.

[0016] On the moving friction discs, on the non-working surfaces that are not involved in frictional contact, a heat indicator paint is applied with the property of irreversible color change when heated to a temperature of a certain value and above.

[0017] The end part of the cylindrical part of the flange is flared onto the outer surface of the pressure plate, making the connection of the hub and the pressure plate inseparable, and the friction discs movable.

[0018] Friction clutch, installed on the shaft of the gearbox of the switch electric drive, designed for intermittent operation in conditions of moderate humidity and a temperature range of -40 + 100 ° C, and dry friction between the disks.

[0019] The coupling contains a hub made in the form of a flange, on the cylindrical part of which movable and fixed friction steel disks are installed, and a clamping device.

[0020] The sliding discs have a series of holes around the circumference for installing friction inserts and splines along the outer diameter of the disc to transmit torque. The discs are made of 2-4 mm thick structural steel with an oxidation coating and a hardness of 40-45 HRC. The fixed discs are mounted on the shaft of the switch gearbox and are made of 2-4 mm thick structural steel. There can be two or three sliding friction discs, and two or three fixed discs, respectively. Additional friction discs can be installed on an additional section of the cylindrical end of the hub.

[0021] Friction inserts in the shape of a prism, 4-6 mm high, with a base area of ​​85-115 mm, are pressed into the holes on the movable disk, located around the circumference. 2, protruding above the disc plane by 1.0-3.0 mm on each side and with one corner directed toward the disc center. The geometric centers of the inserts coincide with the circumference of the inserts on the disc, and the total area of ​​the bases of the friction inserts protruding above the disc plane on one side is at least 1100 mm. 2 , with a total disk area of ​​no more than 5600 mm 2 The relative sliding speed of friction inserts on steel discs can vary from 1.3 to 2.7 m / s, depending on the radius of the friction inserts on the disc.

[0022] Friction inserts are obtained by sintering a powder composition containing copper, tin, barite, silicon oxide, graphite and iron with the following component content, wt.%: copper - (10.5-17.5), tin - (0.2-5.2), barite - (2.0-5.2), silicon oxide - (2-5.0), graphite - (2-5), iron - the rest. The inserts have a coarse-grained structure, consisting of granular pearlite with inclusions of up to 20%, lamellar pearlite and ferrite, having intergranular and intragranular porosity, inclusions of graphite, silicon oxide, sulfides, copper and cementite in the form of a broken network, along the grain boundaries, copper inclusions are also present inside the grains.

[0023] After sintering, the inserts have an open porosity of 15-30%, a density of 5.0-5.85 g / cm 3, oil absorption of 1-4%, impregnated with hydraulic oil, and after deformation within 15-20%, have a Brinell hardness HB of no more than 650 MPa, with a dynamic friction coefficient of at least 0.3 for steel at a relative sliding speed of 1.3-2.7 m / s, in the temperature range from - 40 ° C to + 100 ° C, and a static force on the gate of 5000-6500 N, fixed in the holes of the disk by deformation, until a force is obtained for extruding the insert from the hole of at least 1500 N.

[0024] The force of extruding the insert from the hole of at least 1500 N is determined after the inserts obtained by the powder metallurgy method are placed in the holes of the disk in a special device and deformed there within 15-20% of the height of the inserts, i.e. the fastening of the inserts is carried out by deformation.

[0025] The inserts are impregnated with AMG-10 or VMGZ hydraulic oil, which maintains its properties over a wide temperature range (from -60°C to +100°C) in a vacuum with an absolute pressure of no more than 1000 Pa. Experiments have shown that impregnating the inserts with oil reduces the friction coefficient only during the initial break-in period of the discs. Subsequently, sliding of the inserts on steel discs should be considered dry friction.

[0026] The clamping device, used to compress the friction discs, consists of an elastic element, a pressure disc, a pressure nut and a locking screw. It allows for stepwise adjustment of the torque transmitted by the clutch, changing the force on the switch drive gate, by tightening or loosening the pressure nut and then fixing the locking screw, in increments of no more than 500 N in the range of 0-8500 N, at a temperature of -40 ° C to + 100 ° C. Compression of the friction discs to transmit torque occurs through the action of the elastic element on the pressure disc, which in turn acts on the friction discs. Fixing the locking screw by tightening it prevents the pressure nut from loosening, thereby maintaining a constant set compression force designed for a specific torque, which the clutch transmits without slipping the friction discs relative to each other. Disc springs are used as elastic elements.

[0027] Additionally, if the cylindrical end of the hub has a thread and an additional section for mounting additional friction discs, a pressure plate, a pressure housing, and a pressure nut, it is possible to use coil springs as the elastic element. For this purpose, a series of stepped holes are made in the pressure housing, arranged in a circle with a diameter equal to the diameter of the circle with pressed friction elements on the friction discs. The larger diameter holes, on one side, accommodate the coil springs, while the smaller diameter holes, on the other side, accommodate the locking screw of the locking device. A series of blind holes are made in the pressure disk, which receive elastic elements arranged in a circle with a diameter equal to the diameter of the installation circle of the coil springs on the pressure housing.

[0028] The design feature, namely the end part of the cylindrical part of the flange is flared onto the outer surface of the pressure disk, making the connection of the hub and the pressure disk inseparable, and the friction disks movable, makes it possible to significantly simplify the maintenance of the switch drive, namely the installation of the coupling in the gearbox.

[0029] The use of heat-indicating paint with the property of irreversible color change when heated to a temperature of a certain value and above, applied to non-working surfaces of friction discs that are not involved in frictional contact, makes it possible to significantly simplify defect detection during servicing of the switch drive clutch.

[0030] Increasing the stable performance of the switch electric drive, which includes a friction clutch with disks with friction metal-ceramic elements (inserts), is achieved by a dynamic friction coefficient of at least 0.3 for steel in the temperature range of (-40 + 100) ° C, with a Brinell hardness HB of no more than 650 MPa, in the presence of dry friction between the disks, at a relative sliding speed of 1.3-2.7 m / s, in the temperature range from - 40 ° C to + 100 ° C, and a static force on the gate of 5000-6500 N. In addition, the strength of the inserts, capable of resisting destruction or the occurrence of plastic deformations under the action of loads applied to it, is an important factor determining the stable performance of the switch electric drive. Strength is achieved with a Brinell hardness of HB no more than 650 MPa and a density of 5.0-5.85 g / cm 3The presence of 15-30% open porosity and the possibility of relative insert settlement by 15-20% allows for impregnation of the insert with hydraulic oil, thereby reducing the friction coefficient at the initial stage of operation. This change in the friction coefficient allows, during insert running-in under production conditions, to refine the mechanism for changing forces and to determine the relationship between the compression force of the clamping device on the contacting surfaces, which determines changes in the friction coefficient. This is necessary when assigning the compression force of the friction discs, as seasonal temperatures change. Compression of the friction discs allows for stepwise adjustment of the torque transmitted by the clutch, changing the force on the switch mechanism gate, in increments of no more than 500 N in the range of 0-8500 N, thereby maintaining a constant force pressing the switch point to the stock rail. Stable operation of the electric switch drive is also achieved by securely fastening the insert to the friction disc.It has been experimentally determined that when manufacturing a friction clutch, the friction insert must be pressed out of the disk hole with a force of at least 1500 N.

[0031] The performance of a point drive incorporating a clutch with friction discs and friction inserts is determined by the entire set of technical parameters of the clutch as a whole, and not just the technical parameters of its individual components. To ensure stable operation (the standard service life of the point drive is 15 years), the clutches' technical parameters specified above in the utility model formula must enhance the performance of the other parameters. These parameters, taken together, will ensure the operation of the electric drive "under conditions of intermittent operation, moderate humidity, and a temperature range of -40°C to +100°C, and dry friction between the discs" for the specified period.

[0032] So the features, for example, “movable disks have a number of holes located around the circumference for installing friction inserts and splines along the outer diameter of the disk to transmit torque, the disks are made of structural steel 2-4 mm thick, have an oxidation coating, hardness 40-45 HRC, fixed disks are installed on the shaft of the switch gear reducer, made of structural steel 2-4 mm thick”, “friction inserts in the form of a prism, 4-6 mm high, with a base area of ​​85-115 mm are pressed into the holes on the moving disk, located around the circumference 2, protruding above the plane of the disk by 1.0-3.0 mm”, “the relative sliding speed of the friction inserts on the steel disks, changing depending on the radius of the inserts, from 1.3 to 2.7 m / s”, “a clamping device used to compress the friction disks, consisting of an elastic element, a clamping disk, a clamping nut and a locking screw, allows for stepwise adjustment of the torque transmitted by the clutch, changing the force on the gate of the switch drive, with a step of no more than 500 N in the range of 0-8500 N, at a temperature of -40 ° C to + 100 ° C”, allow these parameters to be maintained throughout the entire period of operation of the switch drive, provided that other parameters; "the inserts after deformation within 15-20% have a Brinell hardness HB of no more than 650 MPa, a dynamic friction coefficient of at least 0.3 for steel, at a relative sliding speed of 1.3-2.7 m / s, in the temperature range from - 40°C to +100°C, and a static force on the gate of 5000-6500 N", "the total area of ​​the bases of the friction inserts protruding above the plane of the disk on one side is at least 1100 mm. 2 with a total disk area of ​​no more than 5600 mm 2", "friction inserts of moving disks are obtained by powder metallurgy, have a porosity after sintering of 15-30%, the hardness of the inserts according to Brinell is not less than 650 MPa", selected and manufactured in such a way that such a design ensures the standardized period of operation of the friction clutch and stable operability of the turnout.

[0033] The kinematic diagram of the switch electric drive is designed so that a friction clutch transmits torque from the electric motor to the first stage of the gearbox. This torque is transmitted through the friction force of the friction discs and is determined by the friction coefficient. Changes in temperature alter the friction coefficient, resulting in a change in the force exerted by the gate on the switch operating rod. By adjusting the clamping device, the compression force of the friction discs is varied, thereby maintaining a constant force exerted by the gate on the switch operating rod. The friction clutch limits the torque on the electric motor shaft to prevent the stock rail from being forced out by the rail tip if a foreign object gets caught between them, thereby overloading the motor.The third important function of the friction clutch is to compensate for the inertia of the gearbox elements connected to the electric motor at the end of the switch movement. All three of these factors, ultimately related to the friction coefficient—the "determining torque," "pressing force," and "inertia compensation"—determine the long-term stability of the switch drive.

[0034] The stability of the friction elements' performance in friction discs is assessed by testing on a dedicated rig during friction disc break-in, measuring the stability of friction force. To assess their suitability for their intended use, forces transmitted to the gate were generated in the range of 1000 to 6500 N, within a temperature range of (-40 to +100)°C.

[0035] The proposed technical solution is characterized by the stability of the friction clutch characteristics, in particular the friction coefficient, during its production and, as a consequence, the stability of the pressing force of the switch point to the stock rail.

[0036] This technical solution can be used in various types of pointer electric drives.

[0037] The claimed friction clutch, with adjustable transmitted torque that changes the force on the gate of the switch drive, is installed in switch drives of the SP-6, SP-6M, SP-6K, SP-5K, SP-12N, SP-12K types, which differ from each other in the type of electric motor, operating voltage, and assembly option.

Claims

1. A friction clutch with adjustable transmitted torque changing the force on the switch drive gate, comprising a hub made in the form of a flange, on the cylindrical part of which movable and fixed friction steel disks are mounted, and a clamping device, wherein the clamping device consists of an elastic element, a clamping disk, a clamping nut and a locking screw, when the friction disks are compressed, it allows for stepwise adjustment of the torque transmitted by the clutch changing the force on the switch drive gate, with a step of no more than 500 N in the range of 0-8500 N, at a temperature of -40 ° C to + 100 ° C, and on the movable friction disks, which have an oxidation coating, a hardness of 40-45 HRC, there is a number of holes located around the circumference, into which friction inserts in the form of a prism, 4-6 mm high, with a base area are pressed 85-115 mm 2, protruding above the plane of the disk by 1.0-3.0 mm on each side and with one of the corners directed towards the center of the disk, while the inserts are obtained by sintering a powder composition, after sintering they have an open porosity of 15-30%, a density of 5.0-5.85 g / cm 3 , oil absorption of 1-4%, impregnated with hydraulic oil, and after deformation within 15-20%, have a Brinell hardness HB of no more than 650 MPa, with a dynamic friction coefficient of at least 0.3 for steel at a relative sliding speed of 1.3-2.7 m / s, in the temperature range from - 40 ° C to + 100 ° C, and a static force on the gate of 5000-6500 N, are fixed in the holes of the disk by deformation until a force of extrusion of the insert from the hole of at least 1500 N is obtained.

2. A friction clutch according to paragraph 1, characterized in that The movable friction disk is made of structural steel with a thickness of 2-4 mm, with splines along the outer diameter of the disk for transmitting torque.

3. A friction clutch according to claim 1, characterized in that the inserts contain copper, tin, barite, silicon oxide, graphite and iron with the following component content, wt.%: copper - 10.5-17.5, tin - 0.2-5.2, barite - 2.0-5.2, silicon oxide - 2-5.0, graphite - 2-5, iron - the rest.

4. A friction clutch according to item 1, characterized in that The inserts are impregnated with hydraulic oil of the AMG-10 or VMGZ brand in a vacuum with an absolute pressure of no more than 1000 Pa.

5. A friction clutch according to claim 1, characterized in that the inserts have a coarse-grained structure consisting of granular pearlite with inclusions of up to 20%, lamellar pearlite and ferrite, having intergranular and intragranular porosity, inclusions of graphite, silicon oxide, sulfides, copper and cementite in the form of a broken network, along the grain boundaries, copper inclusions are also present inside the grains.

6. A friction clutch according to item 1, characterized in that the total area of ​​the bases of the friction inserts protruding above the plane of the disk on one side is at least 1100 mm 2 with a total disk area of ​​no more than 5600 mm 2 .

7. A friction clutch according to claim 1, characterized in that the geometric centers of the inserts coincide with the circumference of the inserts on the disk.

8. A friction clutch according to claim 1, characterized in that disc springs are used as an elastic element in the clamping device.

9. A friction clutch according to claim 1, characterized in that coil springs are used as an elastic element in the clamping device.

10. A friction clutch according to claim 1, characterized in that there is a thread on the cylindrical end of the hub, the cylindrical section of the hub has an additional section for installing additional friction discs, a pressure disc, a pressure housing and a pressure nut.

11. A friction clutch according to paragraph 1, or 9, or 10, characterized in that a series of stepped holes are made in the pressure housing, located along a circle of diameter equal to the diameter of the circle with pressed friction elements on the friction disks; in the holes of larger diameter, on the one hand, helical springs are installed, and in the holes of smaller diameter, on the other hand, a locking screw of the fixing device enters.

12. A friction clutch according to paragraph 1, or 9, or 10, characterized in that a series of blind holes are made in the pressure disk, into which elastic elements are inserted, located along a circle of diameter equal to the diameter of the circle of installation of the helical springs on the pressure housing.

13. A friction clutch according to claim 1, characterized in that on the movable friction discs, on the non-working surfaces of which, not participating in frictional contact, a heat-indicating paint is applied with the property of an irreversible color change when heated to a temperature of a certain value and above.

14. A friction clutch according to claim 1, characterized in that the end portion of the cylindrical portion of the flange is flared onto the outer surface of the pressure disk, making the connection of the hub and the pressure disk non-separable, and the friction disks movable.