Method for making or breaking a press fit and tool

Abstract

Method for forming or disengaging a press fit between a first component (1) and a second component (2) at mating surfaces (5, 6) of the components (1, 2), wherein the press fit is an oil press fit and, for forming or disengaging this oil press fit, a channel (7) formed in the second component (2) is pressurized, through which oil is guided under pressure from a pressurized oil connection (11) between the first mating surface (5) formed on the first component (1) and the second mating surface (6) formed on the second component (2), wherein the channel (7) is defined at least sectionally by two bores (8, 9) intersecting at a point of intersection (10), one of which is subdivided by the point of intersection (10) into a first part (15) leading to the second mating surface (6) and a second part (16) opening on an outside of the second component (2). becomes,characterized in that, prior to pressurization, an elastically deformable sealing element (17) is placed at the intersection point (10) and subsequently, prior to pressurization, is pressed into the second part (16) of the bore (9) at the intersection point (10) in a sealing manner.

Description

[0001] The invention relates to a method for creating or releasing a press fit between a first component and a second component at mating surfaces of the components. Furthermore, the invention relates to a tool by implementing variants of a method for creating or releasing a press fit.

[0002] Press fits are one of the methods used to join components. In these fits, the mating surfaces of the components to be joined are designed with interference fits, resulting in an interference fit between the components after assembly. This joining technique is frequently used to connect a shaft to a hub. A variation of a press fit is the so-called oil press fit, in which the components to be joined are first elastically deformed at their mating surfaces under oil pressure, allowing them to be positioned relative to each other in their final position. Once positioned in their final position, the oil pressure is released, and the components return to their original dimensions.This displaces the oil between the mating surfaces, creating a press fit between the components. To release a press fit, the mating surfaces of the connected components must be moved apart, sometimes requiring special tools. Releasing an oil press fit can be simpler, as reapplying oil pressure and the resulting elastic deformation of the components facilitates separation.

[0003] WO 2010 / 020230 A1 describes a device for releasing press fits, specifically designed as a dismantling press used to remove wheelsets from railway vehicles by pressing wheel discs, brake discs, or gears from the axle of a wheelset. The pressing action is performed by a piston in the dismantling press.

[0004] From the standard DIN 15 055 1982-07-00 Pressure oil press connections, a method for producing and disassembling a press connection according to the preamble of claim 1 is known.

[0005] Furthermore, WO 2024 / 159 262 A1 discloses a tool comprising a first end on which a receptacle for placing a sealing element is provided, wherein the first end is connected via an elongated connecting section to a second end on which a hand part for operating the tool is provided.

[0006] Starting from the prior art described above, the object of the present invention is to implement a method for producing or dismantling a press connection of components in the form of an oil press connection, wherein the method should enable sufficient pressure application of pressurized oil to the mating surfaces of the components even if a section of a channel for supplying the pressurized oil to the mating surfaces is not sealed or only incompletely sealed in a certain area.

[0007] This problem is solved starting from the preamble of claim 1 in conjunction with its characterizing features. The subsequent dependent claims each describe advantageous embodiments of the invention. A tool used to carry out at least one variant of the method according to the invention is further the subject of claims 9 to 12.

[0008] According to the invention, a method is carried out to create or detach a press fit between a first component and a second component at mating surfaces of the components. Preferably, one component is a shaft and the other component is a hub-shaped component, in particular a hollow shaft, wherein the first component is preferably the shaft and the second component is the hub-shaped component. Most preferably, the first component is an output shaft and the second component is a hollow shaft of a railway vehicle transmission. According to the invention, the method can be used to create the press fit, but it is preferably only used to detach a press fit existing between the components.

[0009] The press fit is created or is created at mating surfaces of the two components, with one mating surface preferably located on the outer circumference of one component and the other mating surface on an inner circumference of the other component. In particular, the components are each slightly conical in the area of ​​the mating surfaces, so that the respective mating surface is thus a lateral surface of a respective conical section of the respective component.

[0010] The invention comprises the technical teaching that the press connection is an oil press connection and that, to create or release this oil press connection, a channel formed in the second component is pressurized. During pressurization, oil is guided under pressure from a pressurized oil connection through this channel between a first mating surface formed on the first component and a second mating surface formed on the second component. The channel is defined, at least in sections, by two bores intersecting at a point of intersection. One of these bores is subdivided by the point of intersection into a first part leading to the second mating surface and a second part opening onto an outer surface of the second component.Prior to pressurization, an elastically deformable sealing element is placed at the intersection point and subsequently pressed into the second part of the bore at the intersection point, sealing it before pressurization.

[0011] In other words, the press fit to be made or broken is designed as an oil press fit. To make or break the oil press fit, pressurized oil is introduced between the mating surfaces of the components. The oil is supplied via a pressurized oil port, which is provided with a channel running through the second component. At least one section of this channel is formed by two bores that intersect at a point within the second component. One of the bores runs between the second mating surface of the second component and an outer surface of the second component. This bore is divided into a first part and a second part by the point of intersection with the other bore. The first part connects the intersection to the second mating surface, and the second part connects the intersection to the outer surface of the second component.Before pressurizing the pressure medium connection with pressurized oil, a sealing element, which can be elastically deformed, is positioned at the intersection. After positioning, the sealing element is then pressed into the second part of the bore, also before pressurization, thus sealing the second part of the bore at the intersection.

[0012] The inventive method for forming or disengaging the press-fit connection, which is an oil press fit, has the advantage that the sealing of the second part of the bore reliably ensures that the pressurized oil is directed from the intersection point exclusively towards the second mating surface and thus between the mating surfaces of the components, thereby generating sufficient pressure to form or disengage the oil press fit. This is because the sealing element, pressed into the second part of the bore at the intersection point, prevents oil from reaching the outside of the second component.This prevents oil from escaping from the outside of the second component if the bore is otherwise missing or insufficiently sealed on the outside, which would otherwise hinder the pressure build-up required to create or release the oil press connection. The sealing element can be positioned and pressed in with minimal assembly effort, ultimately making it easy to create or release the oil press connection.

[0013] Preferably, the channel in the second component is configured solely by the two bores, wherein one bore, in particular, extends at least predominantly axially within the second component and is thus a longitudinal bore, while the other bore is preferably configured at least predominantly radially within the second component and is thus a transverse bore. The transverse bore then connects the second mating surface and the outer surface of the second component. In the preferred configuration of the second component as a hub-shaped component, particularly as a hollow shaft, this bore then extends between the second mating surface on an inner circumference of the second component and an opening on the outer surface in the form of an outer circumference of the second component.Particularly preferred is a bearing surface for a further component, especially a spur gear, formed at the opening on the outer circumference. However, the placement of this further component at the opening results in only an insufficient seal of the second part of the bore on the outside of the second component. Furthermore, the pressure medium connection is preferably configured at an opening of the longitudinal bore on an end face of the second component.

[0014] Essential to the invention is that the elastically deformable sealing element is moved to the intersection point before pressurization and then, also before pressurization, pressed into the second part of the bore in such a way that the second part of the bore is sealed at the intersection point. This allows sufficient pressure to build up in the channel if there is a missing or insufficient seal of the second part of the bore on the outside of the second component.

[0015] Preferably, the second part of the bore leads from the intersection point to an annular channel, which is designed on the second mating surface of the second component and from which the oil supplied here is directed circumferentially between the second mating surface and the first mating surface.

[0016] According to one embodiment of the invention, an elastomeric element is used as the sealing element, which is preferably a rubber or plastic element. An elastomeric element exhibits high elastic deformability, enabling it to reliably seal the second part of the bore when pressed into it. Alternatively or additionally, a spherically shaped element is used as the sealing element, providing a suitable geometry for a reliable, circumferential seal of the second part of the bore.

[0017] According to one embodiment of the invention, the sealing element is positioned at the intersection using an elongated tool. For this purpose, the sealing element is received at one end of the tool in a receptacle. After the sealing element has been positioned in the receptacle, the end of the tool is inserted into the channel from the pressure oil connection and positioned at the intersection. This has the advantage that the tool allows for precise placement of the sealing element at the intersection without damaging the sealing element before pressing it in, which could otherwise impair the sealing of the second part of the bore. The tool allows the sealing element, attached to the receptacle, to be easily inserted into the channel from the pressure oil connection side and positioned at the intersection.In particular, the sealing element is easily pressed into the tool's receptacle. Preferably, the elongated tool is rod- or lance-shaped.

[0018] In a further development of the aforementioned embodiment, the tool, after positioning its end at the intersection point, also presses the sealing element into the second part via the receptacle oriented transversely on the tool. This pressing is particularly preferably carried out using pressurized fluid, which is supplied to the tool after the end of the tool has been positioned at the intersection point. The supply of fluid pressurizes the receptacle for the sealing element on the tool, thereby transferring the sealing element from the receptacle into the second part and pressing it in.This also allows the pressing of the sealing element into the second part of the bore to be achieved with minimal effort. After the sealing element has been positioned at the intersection, the tool's receptacle for the sealing element is pressurized, thereby pressing the sealing element into the second part. In particular, the flow rate of the fluid supplied for pressing is metered via a valve in the tool, allowing the tool operator to control the pressing of the sealing element.

[0019] In a further embodiment of the invention, the sealing element is removed from the second part after the oil press assembly has been released. If the sealing element is designed as an elastomer element, this removal can be carried out in particular using a pointed tool, such as a needle, or possibly also using the tool described above.

[0020] The invention further relates to a tool which is used in at least one of the aforementioned variants of the inventive method for producing or disassembling the oil press assembly. This tool comprises a first end with a receptacle for placing the sealing element, the first end being connected via an elongated connecting section to a second end with a handle for operating the tool. Overall, the tool is thus elongated, in that the receptacle located at the first end is connected via the elongated connecting section to the handle located at the second end.The intake and the connecting section are designed to be sufficiently narrow so that, during the execution of the inventive method, it is possible to insert the intake together with the sealing element arranged thereon and subsequently also the connecting section into the channel.

[0021] The tool recess is preferably designed as a depression into which the sealing element can be inserted, preferably pressed in, in order to accommodate the sealing element on the tool.

[0022] In particular, the receptacle is designed to lie transversely at the first end, so that the sealing element can be placed not on the front of the tool, but laterally on the receptacle.

[0023] It is an advantageous embodiment of the tool that a pressure connection for the fluid is provided at the second end. The handpiece incorporates a line that connects to this pressure connection and is linked via a tubular connecting section to an outlet line, with the outlet line opening at the receptacle. This allows pressurized fluid to be conveyed from the handpiece to the receptacle and used there to press the sealing element located at the receptacle into the second part of the bore. The fluid is preferably compressed air, although the use of oil would also be conceivable.

[0024] In a further development of the aforementioned variant, in the tool, which is conditioned for carrying out the inventive method by metering a volume flow of the fluid supplied for injection, the valve that meters the volume flow of the supplied fluid is arranged in the handpiece between the pressure connection and the line. This allows the valve to be operated easily by a single operator. Preferably, the valve is designed as a metering gun on the handpiece, which significantly simplifies operation for a single operator.

[0025] Within the scope of the invention, the tool can also be designed in such a way that the pressure connection for the supply of the fluid in the hand part is permanently connected to the tubular connecting section, so that when the pressure connection is pressurized, a supply to the receiving area also takes place permanently.

[0026] Preferably, the receptacle is designed on a cylindrical component, which is attached to a component forming the connecting section. Furthermore, the connecting section and a component of the handle are attached to one another. This results in the tool being constructed from several components, one of which forms the receptacle, one the connecting section, and one the handle. Most preferably, these components are made of metal and joined together by brazing. However, a one-piece design of the tool could also be provided.

[0027] Advantageous embodiments of the invention, which are explained below, are illustrated in the drawings. They show: Fig. 1 a sectional view of an area of ​​a press fit made between two components; Fig. 2 the area of ​​the press connection during the execution of a method according to the invention for loosening the press connection; Fig. 3 a sectional view of a tool used in the method according to a first embodiment of the invention; and Fig. 4 a sectional view of an alternative embodiment of a tool according to the invention.

[0028] Out of Fig. Figure 1 shows a sectional view of a press fit between two components, 1 and 2, specifically implemented as an oil press fit. Component 1 is an output shaft 3 of a rail vehicle, while component 2 is a hollow shaft 4 of the rail vehicle's transmission. The oil press fit consists of mating surfaces 5 and 6 of the two components, 1 and 2. Mating surface 5 is located on the outer circumference of component 1, and mating surface 6 is located on the inner circumference of the hub-like component 2.The oil press assembly was produced in a manner known in principle to those skilled in the art by introducing oil at high pressure between the mating surfaces 5 and 6, thereby causing elastic expansion of component 2 and elastic compression of component 1, whereby, after placement in the desired position and after cessation of the oil supply, the two components 1 and 2 then returned to their original dimensions and were pressed together.

[0029] For the supply of oil between the mating surfaces 5 and 6, a channel 7 is provided in component 2, defined by two bores 8 and 9 that intersect at a point 10 within component 2. Bore 8 runs axially as a longitudinal bore within component 2 and opens into a pressurized oil connection 11 on an end face of component 2, while bore 9 is designed as a transverse bore extending predominantly radially within component 2. Bore 9 opens onto the mating surface 6 of component 2 and also onto an outer circumference on which a further component 12 in the form of a spur gear 13 is mounted. Component 12 covers an opening 14 of bore 9 on the outer circumference of component 2.

[0030] The bore 9 is divided by the intersection 10 with the bore 8 into a first part 15 and a second part 16, wherein the first part 15 extends from the intersection 10 to the mating surface 6 of the component 2, while the second part 16 extends from the intersection 10 to the opening 14.

[0031] To release the press fit between components 1 and 2, oil must again be introduced between the mating surfaces 5 and 6 of components 1 and 2. This allows the press fit to be released by the renewed elastic deformation of the two components 1 and 2. However, a problem arises because the insufficient coverage of the opening 14 by component 12 makes it difficult or even impossible to build up the necessary pressure between the mating surfaces 5 and 6. Therefore, in a method according to the invention, prior to pressurizing the channel 7 with pressurized oil, the second part 16 of the bore 9 is sealed at the intersection 10, thus preventing oil from escaping through the opening 14.

[0032] This is done, as in Fig. As indicated in Figure 2, an elastically deformable sealing element 17 is placed at the intersection 10 of bores 8 and 9 and pressed into the second part 16 of bore 9 to create a seal. As a result, oil flowing from bore 8 via channel 7 can only flow into the first part 15 of bore 9. The sealing element 17 is designed as an elastomer and is spherical in shape.

[0033] For the placement and pressing in of the sealing element 17, a tool 18 is used in the inventive method, which is Fig. 2 shown in the course of placing the sealing element 17 at the intersection 10 and in Fig. 3 is shown individually in section. As is particularly evident in Fig. As can be seen in Figure 3, the tool 18 has a component 20 at a first end 19, which laterally forms a receptacle 21 for the sealing element 17. The receptacle 21 is defined as a recess 22 formed in the component 20. The component 20 is attached to another, tubular component 23, which is also elongated and forms a connecting section 24 of the tool 18. A connection to a second end 25 of the tool 18 is established via the connecting section 24. At this end 25, another component 26 is provided, which is attached to the component 23 and forms a handle 27 of the tool 18.

[0034] The tool 18 has an overall rod- or lance-like shape, with the individual parts 20 and 23 being dimensioned such that the tool 18 can be inserted into the bore 8, as shown in Fig. Figure 2 shows how to position the sealing element 17 at the intersection 10. Before being inserted into the bore 8 of the channel 7, the sealing element 17 is placed in the receptacle 21 and preferably pressed slightly into the recess 22. The sealing element 17 is then positioned at the intersection 10 using the tool 18, for which the end 19 of the tool 18 is inserted into the bore 8 from the pressure oil connection 11.

[0035] The sealing element 17 is pressed into the second part 16 of the bore 9 after its placement at the intersection 10, using a fluid, in particular compressed air. The fluid is directed via the tool 18 from end 25 to the receptacle 21, thereby moving the sealing element 17 out of the receptacle 21 and subsequently pressing it into the second part 16. The fluid is supplied as described in Fig. Figure 3 shows that a pressure port 28 is provided at end 25, to which a line 29, formed in the handpiece 27, opens. The latter is then connected via the tubular connecting section 24 to an outlet line 30, which opens into the receptacle 21. Thus, fluid introduced at the pressure port 28 is directed within the tool 18 to the receptacle 21, where it presses the sealing element 17 into the second part 16 of the bore 9.

[0036] After the sealing element 17 has been pressed into the second part 16, the tool 18 is moved out of the bore 8. Subsequently, the channel 7 is pressurized via the pressure oil connection 11. This pressurization between the mating surfaces 5 and 6 causes the components 1 and 2 to expand elastically, thus allowing the oil press fit to be released. Once released, the sealing element 17 can then be removed from the second part 16 of the bore 9.

[0037] In addition to releasing the oil press connection, the method can also be used, within the scope of the invention, to create an oil press connection between components 1 and 2, even if sufficient pressure build-up is not possible due to insufficient coverage of the opening 14 by component 12. In this case, the sealing element 17 is positioned at the intersection 10 via the tool 18 and pressed into the second part 16 before the pressure oil connection 11 is pressurized to create the oil press connection. After the oil press connection has been created, the sealing element 17 can then be removed again.

[0038] Finally, it also shows Fig. 4 An alternative embodiment of a tool 31, which can be used as an alternative to tool 18 for carrying out the method. Tool 31 largely corresponds to tool 18. Fig. 3, with the difference that a handpiece 32 provided at end 25 has, in addition to the component 26, a metering gun 33, via which a valve 34 of the tool 31 is formed. This valve 34 is arranged between the line 29 of the component 26 and the pressure connection 28 and allows an operator of the tool 31 to meter a volume flow of the fluid supplied to the receiving 21. Otherwise, the tool 31 corresponds to the tool 18 from Fig. 3, so that reference is made to what has been described here.

[0039] Using the method according to the invention, a loosening or a production of an oil press assembly can be reliably achieved. Reference sign 1 component 2 components 3 Output axle 4 hollow shaft 5 Fitting area 6. Fitting area 7-channel 8 bore 9 bore 10 Intersection point 11. Pressure oil connection 12 components 13 Spur gear 14 Mouth Part 15 Part 16 17 Sealing element 18 tools 19 End 20 individual parts 21 recording 22 In-depth study 23 individual parts 24 Connecting section 25 End 26 individual parts 27 Handpiece 28 Pressure connection 29 Management 30 Outlet pipe 31 tools 32 Handpiece 33 Dispensing gun 34 valve

Claims

[1] Method for forming or disengaging a press fit between a first component (1) and a second component (2) at mating surfaces (5, 6) of the components (1, 2), wherein the press fit is an oil press fit and, for forming or disengaging this oil press fit, a channel (7) formed in the second component (2) is pressurized, through which oil is directed under pressure from a pressurized oil connection (11) between the first mating surface (5) formed on the first component (1) and the second mating surface (6) formed on the second component (2), wherein the channel (7) is defined at least sectionally by two bores (8, 9) intersecting at a point of intersection (10), one of which extends through the point of intersection (10) into a first part (15) leading to the second mating surface (6) and a second part opening onto an outside of the second component (2). (16) is subdividedcharacterized by , that prior to pressurization an elastically deformable sealing element (17) is placed at the intersection point (10) and subsequently pressed into the second part (16) of the bore (9) at the intersection point (10) in a sealing manner prior to pressurization. [2] Method according to claim 1, characterized by , that an elastomer element, in particular a rubber element or plastic element, is used as the sealing element (17). [3] Method according to claim 1 or 2, characterized by , that a spherically shaped element is used as the sealing element (17). [4] Method according to any one of claims 1 to 3, characterized by, that the placement of the sealing element (17) at the intersection point (10) is carried out using an elongated tool (18; 31), for which the sealing element (17) is received at one end (19) of the tool (18; 31) on a receptacle (21), the tool (18; 31) is inserted with its end (19) from the pressure oil connection (11) into the channel (7) after the placement of the sealing element (17) on the receptacle (21) and is positioned with its end (19) at the intersection point (10). [5] Method according to claim 4, characterized by , that after positioning the end (19) of the tool (18; 31) at the intersection point (10), the sealing element (17) is also pressed into the second part (16) via the receptacle (21) which is aligned transversely on the tool (18; 31) for this purpose. [6] Method according to claim 5, characterized by, that the pressing in is carried out via pressurized fluid, which for this purpose is supplied via the tool (18; 31) after the end (19) of the tool (18; 31) has been positioned at the intersection (10), whereby the supply of the fluid pressurizes the receptacle (21) of the sealing element (17) on the tool (18; 31) and thereby transfers the sealing element (17) from the receptacle (21) into the second part (16) and presses it in there. [7] Method according to claim 6, characterized by , that a volume flow of the fluid supplied for pressing is metered via a valve (34) of the tool (31). [8] Method according to any one of the preceding claims, characterized by , that the sealing element (17) is removed from the second part (16) after the oil press assembly has been manufactured or after it has been released. [9] Tool (18; 31) for carrying out the method according to claim 6, comprising a first end (19) on which a receptacle (21) for placing the sealing element (17) is provided, wherein the first end (19) is connected via an elongated connecting section (24) to a second end (25) on which a handle (27; 32) for operating the tool (18; 31) is provided, wherein the receptacle (21) is formed to lie transversely at the first end (19), characterized by , that a pressure connection (28) for the fluid is provided at the second end (25), wherein a line (29) is provided in the hand part (27; 32) which serves to connect to the pressure connection (28) and which is connected to an outlet line (30) via the tubular connecting section (24), wherein the outlet line (30) opens at the receiving (21). [10] Tool (31) according to claim 9 and further configured to carry out the method according to claim 7, characterized by, that the valve (34) which meters the volume flow of the supplied fluid is arranged in the hand part (32) between the pressure connection (28) and the line (29). [11] Tool (31) according to claim 10, characterized by , that the valve (34) is designed as a dosing gun (33) on the hand part (32). [12] Tool (18; 31) according to one of claims 9 to 11, characterized by , that the receiving (21) is designed on a cylindrical component (20) which is attached to a component (23) forming the connecting section (24), wherein the component (23) forming the connecting section (24) and a component (26) of the hand part (27; 32) are also attached to each other.

Images