Squeeze film damper

Abstract

A squeeze film damper (10) has an inner ring (11) and an outer ring (12), wherein the inner ring (11) and the outer ring (12) can be braced and / or can be variably positioned in relation to one another. In a method for creating a squeeze film damper (10), elements of the squeeze film damper (10) are braced or positioned, wherein a first element is an inner ring (11) and a second element is an outer ring (12).

Description

[0001] Description

[0002] Squeeze oil damper

[0003] The invention relates to a squeeze oil damper and a method for producing or operating a squeeze oil damper, wherein the squeeze oil damper is used in particular in a bearing.

[0004] Squeeze oil dampers are used, for example, in electrical machines. Electrical machines include motors and generators. A squeeze oil damper, which is used in particular in conjunction with a bearing of the electrical machine, can influence the rotordynamic design of a rotating electrical machine. Particularly in the case of high-speed machines, i.e. high-speed electrical machines such as high-speed motors, the occurrence of natural frequencies of the rotor-bearing system in the operating range must be expected or taken into account within the framework of the rotordynamic machine design. This can lead to restrictions in the operation of the machines because operation at or close to natural frequencies potentially causes large vibration amplitudes, which in turn is generally undesirable due to standards or due to the operational safety aspects that must be guaranteed.If vibrations cannot be sufficiently prevented or dampened, the machines can only be used within a restricted operating speed range. The rotordynamic design, for example, is carried out specifically for the requirements of the operating speed range from a specific project or application. If this operating speed range is to be adjusted (shifted or extended), the dynamic system comprising the rotor, plain bearing and support must be readjusted. This entails a great deal of time and resources, which must be taken into account when submitting a quotation. This considerably lengthens the time required to process the quotation and is disadvantageous. In addition, a rotor-bearing system of an electrical machine with a rotor and a stator, for example, cannot be optimized with conventional plain bearings to the extent that it is highly robust against changes in the operating speed range.This may result in additional project- and / or application-specific design iterations. The rotor-bearing system can be improved with a squeeze oil damper. The bearing can be a ball bearing or a plain bearing, for example.

[0005] From US 4 453 783 A a bearing support structure is known in which the outer bearing ring is located in a support ring which is surrounded by an outer damper ring to form an oil damper chamber therebetween. At one end of the support ring there is a projecting flange to which one end of a ring of rods is attached. This rod ring surrounds the outer damper ring and is attached to the other end of the rods at the remote end of the outer damper ring. The inner end of the damper ring is supported by a mounting flange by means of a frusto-conical member having through holes for the rods.

[0006] From US 9 890 810 B2 a squeeze film damper is known which comprises a bearing housing as an inner ring arranged around a radially outer side of a bearing which rotatably supports a rotary shaft. Further, there is an outer ring arranged around a radially outer side of the bearing housing, a squeeze film formed by circulating a viscous material with fluid through a gap in a radial direction between the bearing housing and the outer ring, and a coupling pin which couples the bearing housing and the outer ring to each other. The coupling pin has a rigidity which is higher in a vertical direction than in a horizontal direction in a cross section perpendicular to an axial direction of the rotary shaft.

[0007] One object of the invention is to improve a squeeze oil damper. This object is achieved by a squeeze oil damper according to claim 1, or by an electrical machine according to claim 14, or by a method according to claim 15. Further embodiments are disclosed, for example, in claims 2 to 13, 16, and 17. Features of these embodiments, or of further embodiments and examples described below, can also be combined with one another.

[0008] A squeeze oil damper has an inner ring and an outer ring, the inner ring and the outer ring being connected by means of rods, at least one of the rings, in particular the inner ring or the outer ring, having a flange, individual rods being connected in particular to only one flange. This makes an axially compact design possible, for example. It is also possible, for example, to transmit axial forces. The rods are each designed in particular as a spring element, in particular as a bar spring. The rod has in particular a round or oval cross-section.

[0009] In one embodiment of the squeeze oil damper, different rods or groups of rods, which in particular follow one another in a circumferential direction, are alternately connected to different flanges, in particular on different end faces of the squeeze oil damper or of the inner ring or of the outer ring, wherein in particular a rod is only connected to one flange in each case. This means that on one side of the rod the connection is made to a flange and on the other side of the rod the connection is made to a flange-free end face. For example, one end face of a rod is positioned on one end face on a flange of one of the rings and the other end of the rod is positioned on an opposite end face in a flange gap of the other ring on its end face.

[0010] In one embodiment of the squeeze oil damper, it is integrated into a bearing in an interlocking manner. The inner ring and the outer ring have entirely or predominantly the same axial position.

[0011] In one embodiment of the squeeze oil damper:

[0012] - the inner ring and the outer ring or

[0013] - only the inner ring or

[0014] - only the outer ring has a flange. The flange(s) are, in particular, toothed. Individual rods are connected to only one of the flanges. In particular, the squeeze oil damper has axially aligned rods arranged in a circle, with rods positioned at least partially next to one another being connected to different flanges.

[0015] The connection of the rods or the rod particularly concerns one of the end regions of the rod. One end region of a rod, for example, has a thread onto which a screw can be screwed. Another end region of a rod, for example, has a head as a stop. Between the end regions of a rod, the rod, in particular, has no thread, i.e., it is free of a thread between the end regions.

[0016] In one embodiment, a squeeze oil damper having an inner ring and an outer ring has a shape in which the inner ring and the outer ring are positioned axially relative to one another by means of rods. Positioned axially relative to one another by means of rods means, in particular, independent positioning. A rod is, in particular, a component which has a round, square, oval, or other cross-section. The one rod or the plurality of rods is, in particular, designed as a rod spring or rod springs. Bar springs are, in particular, components whose elastic properties are used for a spring effect. With a fixed axial positioning of the inner ring to the outer ring, axial forces can be transmitted in this way. Axial here means along an axis and / or in the direction of an axis. The axis is, in particular, the axis of a bearing or an axis of rotation. The rods, in particular, have a thread.The thread is located in a region of the rod or rods that is free from fluctuating mechanical stress during operation, and thus, in particular, free from spring action. The rods are guided, in particular, by recesses in the outer ring.

[0017] In particular, both the inner ring and the outer ring have end faces. The rods are axially aligned and have end regions. A first end region of a rod is, for example, an end head, and a second end region has, for example, a thread, with a screw screwed onto the thread. A rod can, for example, also have a thread with a screw at each end region.

[0018] In one embodiment of the squeeze oil damper, a first end region of a rod, or of a plurality of rods, is connected to the inner ring on one end side, with the second end region of this rod being connected to the outer ring. Accordingly, a rod rests on one axial end side with one end region against the inner ring and on the other axial end side with the other end region against the outer ring. This is possible for a plurality of rods.

[0019] In one embodiment of the squeeze oil damper, individual rods or successive groups of rods are alternately connected to the inner ring or the outer ring on one end face.

[0020] In one embodiment of the squeeze oil damper, the inner ring and the outer ring can be clamped to one another, i.e. in particular clamped to one another and / or variably positioned. The variable positionability relates to the positioning of the inner ring and outer ring to one another. This positioning relates, for example, to axial positioning and / or radial positioning. In a squeeze oil damper, the inner ring and outer ring can therefore be clamped to one another and / or be variably positioned. The clamping and / or positioning is achieved in particular by an interlacing of elements for clamping and / or positioning. The inner ring or the outer ring can in particular accommodate a bearing, wherein the bearing is in particular a bearing of an electrical machine. The electrical machine is, for example, a fast-rotating electrical machine with a speed of 1000 to 30,000 rpm.The possibility of clamping or positioning makes it possible to adapt the operating speed range of a machine (electric machine). If the operating speed range needs to be adjusted (shifted or expanded), the dynamic system consisting of the rotor, plain bearing, and support must be readjusted. This can be achieved by changing the clamping and / or positioning. If the inner and outer rings are positioned relative to one another, this position can be designed such that the rings are stress-free or clamped relative to one another.

[0021] In one embodiment of the squeeze oil damper, rods are provided for connecting the inner ring to the outer ring, wherein the inner ring is, or can be, axially clamped to the outer ring by the rods, or is clampable and / or is positioned, or can be variably positioned. Different and / or identical rods can, for example, have different and / or identical cross-sections. Cross-sections are, for example, round, square, or oval. The rods can produce a spring effect. A rod is therefore a type of spring element and can therefore also be referred to as a spring rod or a spring element. A rod is also, in particular, an element for achieving clamping or positioning, in particular interlaced clamping or positioning, of the inner ring and outer ring. When the rods are pre-stressed, they are, in particular, subjected to tensile stress or pre-stress.This makes it possible to change the stiffness of the connection between the inner ring and outer ring of the squeeze oil damper. In one embodiment of the squeeze oil damper, the inner ring and / or the outer ring are an open ring and / or a closed ring, wherein open rings in particular can be joined to form a closed ring. The squeeze oil damper is therefore segmented into two half rings, for example. These segments can be joined to form a closed ring. The segments are screwed together, for example. The segmentation makes it possible, for example, to integrate a bearing into the squeeze oil damper. The squeeze oil damper, for example, completely or partially encompasses the bearing, which can be a plain bearing or a rolling bearing. The squeeze oil damper can, for example, be positioned together with the bearing in a bearing housing. In such a configuration, the squeeze oil damper becomes part of a bearing.In general, the invention relates not only to a squeeze oil damper, but also to a bearing (e.g. a rolling bearing or a plain bearing) with a squeeze oil damper.

[0022] In one embodiment of the crush oil damper, the inner ring and / or the outer ring is divisible or split. This can make integration into a bearing and / or connection to a bearing easier in particular. The inner ring or the outer ring can have a lower and an upper pitch circle, with the lower and upper pitch circles joined together forming an overall circle. The lower pitch circle is the part that faces towards a fastening of the bearing or the bearing housing or the electrical machine on a foundation (this is an example of a support or substructure) or the like. The upper pitch circle is correspondingly the part facing away from such a fastening.

[0023] In one embodiment of the squeeze oil damper, a first number of rods are provided to be able to pull the outer ring in a first axial tensile direction and a second number of rods are provided to be able to pull the outer ring in a second axial tensile direction, with rods and / or groups of rods with different potential tensile directions alternating. This alternation results in an interlacing. The tensile directions are in particular opposite and additionally axially parallel to an axis of rotation of the electrical machine or axially parallel to the axis of rotation of the bearing. The rods can form a type of spring cage with their spring action. The rods can also be circular and positioned axially parallel to the bearing axis.This makes it possible to produce a crush oil damper with an interlaced spring cage with preloaded spring elements and / or variable stiffness, wherein the design of the cage is particularly integrated into a bearing housing or a bearing such as a plain bearing, i.e. in particular surrounds it completely or partially. By interlacing the connection between the inner ring and outer ring, it is possible to achieve low internal constraining forces and thus the most ideal radial guidance possible between the rings in relation to one another without tilting. Different at least potential directions of tension between the inner ring and outer ring, which are achieved by the interlacing, can prevent tilting from the inner ring to the outer ring. Axial forces can be transmitted, in particular, with a form-fitting connection.

[0024] In one embodiment of the squeeze oil damper, the rods have a surface layer resulting from a surface coating and / or a surface treatment. The surface layer is created, for example, by nitrocarburizing a base body for the rod made of the material 42CrMo4. This ensures sufficient seizure resistance during repeated joining of rods and rings, i.e., the outer ring and the inner ring, respectively.

[0025] In one embodiment of the squeeze oil damper, the rods are made of different materials.

[0026] In one embodiment of the squeeze oil damper, the rods are made of a material with a higher bending fatigue strength than the material used to form the rings. In one embodiment of the squeeze oil damper, the inner ring has a U-shaped profile, with the outer ring protruding at least partially into the profile. In a further embodiment of the squeeze oil damper, the outer ring has a U-shaped profile, with the inner ring protruding at least partially into the profile. The profile is created from successive cross sections. A first cross section of a ring, for example, has a first L-shape and a subsequent second cross section of the ring has a mirrored second L-shape. The mirroring therefore results in a U-shape from two L-shapes placed on top of one another.The U-shape of a ring is not necessarily the result of a single cross-section, but rather of successive cross-sections of a ring, cast in a kind of shadow. This sequence of different cross-sections makes the interlacing possible.

[0027] This allows for a compact design. Furthermore, clamping and positioning of the inner ring to the outer ring, and vice versa, are easily possible.

[0028] In one embodiment, the inner ring has, in particular, axial end faces. The inner ring has a toothed flange on each end face. The toothing is directed radially outwards. The individual teeth are distributed over the circumference of the circular flange. The toothing can result in the L-shaped cross section of a ring. The toothing on one of the end faces is offset in its circular position from the toothing on the other end face. The toothing has holes, with a rod passing through each hole. The rod is also guided through a hole in the outer ring. The outer ring has a plurality of holes for the passage of rods, with the holes running parallel to the axis. Because the toothing on the end faces is offset, in areas of the toothing on a first end face the inner ring is pulled or positioned in a first axial direction relative to the outer ring, or vice versa, by the rods.Likewise, because the teeth on the end faces are offset, in areas of the teeth on the second end face, the inner ring is pulled or positioned by the rods toward the outer ring, or vice versa, in a second axial direction, which is opposite to the first axial direction. This achieves an interlacing, and in particular, a clamping between the inner ring and the outer ring.

[0029] In one embodiment, individual rods or groups of rods can be inserted or have been inserted alternately from the left or right (i.e. from the other end face) into the inner ring and / or the outer ring. This reciprocity makes it possible to form an interlaced spring cage. The outer ring can therefore be clamped or positioned with respect to the inner ring because the outer ring is alternately pulled or positioned axially parallel in opposite directions via circular sectors (partial circles). The positioning, in particular axial positioning, can be varied because the effective length of the rods can be shortened or lengthened by nuts if the rods are designed as screws. In one embodiment of rods which have a spring effect, the rod has a spring-effective length, whereby the spring-effective length remains the same regardless of the position-dependent effective length of the rod.

[0030] In one embodiment of the squeeze oil damper, the bearing is enclosed within the squeeze oil damper. The bearing, which is in particular a plain bearing, can, for example, be screwed to the inner ring, pressed into it, or integrated into it.

[0031] In one embodiment of the squeeze oil damper, a bearing is provided in the squeeze oil damper, wherein the bearing is in particular a plain bearing and the bearing in particular supports the rotor of an electric machine. In one embodiment of the squeeze oil damper, the squeeze oil damper is integrated or can be integrated into a bearing housing. This allows for a compact design.

[0032] In one embodiment of the squeeze oil damper, the tension and / or positioning of the inner ring and outer ring is adjustable. This can be achieved, for example, by changing the tension on the rods or changing the effective length of the rods. If the rods have a screw connection, for example, the tension on the screw can be changed. In a further embodiment, different rods can be used to adjust the tension or one or more rods can be replaced (exchanged) by one or more other rods which, in particular, have a different material and / or a different shape. For example, a cross-section with a different shape or size can be selected for the rod or rods.

[0033] In one embodiment of the squeeze oil damper, at least one rod is replaceable and / or at least one rod has a different spring action. This can, for example, positively influence the frequency response of an electrical machine, since the frequency range in which no natural vibrations occur can be expanded or adjusted.

[0034] An electrical machine, such as a synchronous machine or an asynchronous machine, has in particular a first bearing and a second bearing. The first bearing is for example on a drive side of the electrical machine, which is in particular a motor or a generator, and the second bearing is for example on an operator side of the electrical machine. At least one of the bearings has a squeeze oil damper or is combined with and / or connected thereto. The squeeze oil damper has one of the embodiments or features of the squeeze oil damper described here. According to a method for producing a squeeze oil damper, elements of the squeeze oil damper are clamped and / or variably positioned, wherein a first element is an inner ring and a second element is an outer ring. Rods can be used for clamping or positioning. The tensile load on the rods can be changed to change the clamping.Furthermore, rods can be exchanged to change the bracing, with the new rods differing from the replaced ones. The difference particularly affects the spring properties of the replaced rod. The effective length of a rod can be changed for positioning purposes.

[0035] In one embodiment of the method, to change a spring action and / or a position, at least one rod is replaced and / or a preload is changed for at least one rod and / or an effective length of a rod is changed. In a screw-type design, the effective length of a rod is determined by the position of a nut. Portions of the rod that extend beyond the nut are ineffective.

[0036] In one embodiment of the method, a squeeze oil damper in one of the types described is used.

[0037] Using the squeeze oil damper described, for example, a hydrodynamic plain bearing can be retained or improved. Bearings of this type are used, for example, in electrical machines. The hydrodynamic plain bearing is retained or supplemented as a type of bearing between rotating and stationary components of a system, such as an electrical machine. In addition, another bearing, the squeeze oil damper, is inserted into the stationary components. The squeeze oil damper can therefore be understood as a bearing for a bearing, namely a rotating bearing, for an electrical machine. Using the squeeze oil damper described, improved decoupling of a rotor-bearing system from the support, e.g. the foundation on which the electrical machine is mounted, and a reduction in the influence of the oil film coefficients can be achieved.Examples of a support include a foundation, a machine frame, a machine housing, etc.

[0038] When using conventional plain bearings, the natural frequencies of the rotor-bearing system depend significantly on the speed-dependent oil film coefficients. With the additional use of a squeeze oil damper, the rotor support is made considerably softer, resulting in only a weak physical coupling between the rotor and support. Due to this weak coupling, the influence of the oil film coefficients becomes less important. The rotor increasingly behaves as if in a "free-free" bearing arrangement. This type of bearing arrangement enables large differences between the natural frequencies to be achieved, which are now also independent of the operating speed and the associated oil film coefficients.

[0039] An additional damping component and / or spring component can be introduced through the rods of the squeeze oil damper. From a physical perspective, the squeeze oil damper can be viewed as a spring-damper system. In addition to decoupling a rotor-bearing system, this also enables the damping of natural frequencies, which can be beneficial to the operating behavior of rotating machines.

[0040] The use of a metallic spring cage in crush oil dampers can make it necessary to increase the axial installation space. This can be avoided with the proposed crush oil damper thanks to the small axial installation space that can be achieved with the crush oil damper. In the crush oil damper described, the rods (bar springs) are inserted alternately from the left and right - this creates an interlaced spring cage. This arrangement is particularly useful so that the bearing does not have to be made axially longer. An axially longer design generally leads to a deterioration in rotor dynamics and greater material usage. In addition, the interlaced arrangement of the bar springs can have the advantageous property of producing a purely radial movement without tilting the bearing carrier.

[0041] In one embodiment of the squeeze-oil damper or in one embodiment of the method, the squeeze-oil damper can be centered. This represents a positioning. By selectively preloading the rods (bar springs), which is generated by an offset of the lower and upper pitch circle, the weight-related deflection of the spring cage can be avoided or compensated for, which can have a positive effect on the linear properties of the squeeze-oil damper.

[0042] In one embodiment of the squeeze oil damper or in one embodiment of the method, the spring elements, i.e. the rods, can be adjusted, whereby the spring elements, i.e. the rod springs, offer increased variability under various aspects (individually or together):

[0043] • By adjusting their number, diameter and / or contour, they can be easily modified in their stiffness while remaining well predictable in their properties,

[0044] • the design of the system provides for the demountability of the bar springs, particularly through the front-side mounting, which has the advantage that they can be replaced with other springs if necessary or if the operating conditions of the machine have changed or if an unknown fault in the system that was not previously known can be reacted to,

[0045] • Due to the design as a separate, removable component, different materials (e.g. spring steel, 50CrV4, 51CrV4, 100Cr6, 51CrMoV4, 100CrV4) and different manufacturing methods (e.g. grinding, hardening, tempering, shot peening) can be used for the springs, which are particularly suitable for use with springs; this allows for better material utilization and a smaller size of the springs.

[0046] With the help of the described crush oil damper, the robustness of the rotordynamic design of the machines can be increased, thus significantly improving the application range while simultaneously reducing design effort. A space-saving arrangement of the spring cage in a standard bearing insert is possible without additional axial space. In particular, variable spring stiffness in the spring cage is also possible due to the ability to disassemble and replace the springs.

[0047] In one embodiment of the squeeze oil damper, the rods form a type of spring cage, which has bar springs arranged with their axes parallel to the rotating shaft axis. The bar springs can provide both radial and axial stiffness. The rods are replaceable. They can be replaced with the usual maintenance effort for the bearings, without having to disassemble an entire machine.

[0048] In one embodiment of the squeeze oil damper, it has at least one of the following functions or features, in particular with regard to the cage also formed by the rods:

[0049] • a radial connection with adjustable stiffness of the outer and inner rings of the squeeze oil damper by means of bar springs, in particular for o centering of the outer and inner rings and / or setting a gap that is as uniform as possible around the entire circumference by targeted pre-tensioning of individual bar springs, o radial support for static and dynamic force transmission and / or o axial support and / or positioning of the parts relative to one another; • bar springs mounted with detachable connecting means / methods in the inner and outer rings, whereby disassembly is made easier by means of a selected material pairing (e.g. 51CrV4 and CI O) and / or a provided surface layer on the springs and additional fatigue strength of the springs is achieved (e.g. by surface hardening and / or shot peening).

[0050] The features of the individual claimed or described objects or methods can be readily combined with one another. The invention is illustrated and explained in more detail below using exemplary figures. The features shown in the figures can be combined to form new embodiments without departing from the invention. Similar elements are given the same reference numerals. They show:

[0051] FIG 1 two diagrams of frequency response of electrical machines,

[0052] FIG 2 a partial cross-section of a squeeze oil damper in a bearing housing,

[0053] FIG 3 a perspective view of a squeeze oil damper,

[0054] FIG 4 shows another partial cross-section of a squeeze oil damper and

[0055] FIG 5 is a perspective view of a two-part inner ring.

[0056] The illustration in FIG 1 shows a first diagram 1 and a second diagram 2, both diagrams representing frequency behavior over a speed. The speed is plotted on an axis 3 and the frequency on an axis 4. The frequency relates to the system of rotor, bearing and support (substructure). To measure this frequency, a sensor can be attached to a rotor or a bearing housing, for example. The frequency can, however, also relate to a relative movement between the bearing and the rotor. The speed relates to the revolutions of a rotor of an electrical machine or a bearing of an electrical machine. A hatched area 5 in each of the diagrams shows an area of ​​safe behavior, so that natural frequencies are not excited. The left-hand or upper diagram 1 relates to a system which has a plain bearing. The right-hand or upper diagram 2 relates to a system which has a plain bearing.The lower diagram 2 shows a system that uses a plain bearing with a crush oil damper. It is evident that the use of the crush oil damper increases the range of safe operation of the system. The system has at least one electrical machine with a bearing-mounted rotor.

[0057] The illustration in FIG 2 shows a partial cross section of a squeeze oil damper 10 in a bearing housing 24. The squeeze oil damper 10 has an inner ring 11 and an outer ring 12. The inner ring 11 of the squeeze oil damper 10 serves as a plain bearing carrier. The plain bearing has a plain bearing segment 27 or a plurality of plain bearing segments. The plain bearing serves to mount a rotor 26 or a rotor shaft of an electrical machine, which is not shown in detail. The rotor shaft 26 has an axis 31, with a first axial direction 32 and a second axial direction 33 being shown. The inner ring 11 forms a U-shaped profile 30 by means of alternating positions of teeth on the different end faces, into which profile the outer ring 12 projects.The U-shaped profile 30 forms opposing toothed flanges 20 on the end faces 28 and 29 of the inner ring 11, which flanges 20 are offset from one another in their angular position with respect to the different end faces. The respective end flange 20 has teeth. Teeth of opposing end flanges are therefore offset over an arc of a circle, i.e. they alternate opposite one another over a circle. In this way, the outer ring 12 can be alternately pulled or variably positioned in a first direction 32 towards the inner ring 11 by a rod 13, or by a plurality of rods, as shown in Figure 3, and pulled or variably positioned in an opposite second direction 33 by a further rod (not shown in Figure 2). This results in a bracing or positioning of the inner ring 11 and outer ring 12.A squeeze oil damper gap 23 is located between the inner ring 11 and the outer ring 12. The bearing housing 24 is sealed by seals 25. Anti-rotation devices 66 and 67 are also shown.

[0058] The illustration in FIG 3 shows a perspective view of a squeeze oil damper 10. The squeeze oil damper 10 has a lower pitch circle (part) 22 and an upper pitch circle (part) 23. The lower part 22 is detachably screwed to the upper part 23. A bearing part joint 34 is formed between the parts 11 and 12. The cage formed by the rods is therefore divided into two halves by the bearing part joint 34. This can be used for easy disassembly and / or to introduce an offset and thus a preload. The visible end flange of the inner ring has teeth 20 and 21. Rods 13, 14, 15, 16 are guided through these teeth, such as tooth 20, as a group of teeth, which connect the outer ring 12 to the inner ring 11. Next to the tooth are rods 17 , 18 and 19 , which connect the inner ring 11 with the outer ring 12 from the other opposite, non-visible end face of the inner ring 11 .The rods form a spring effect and can therefore also be referred to as bar springs. The groups of rods are interlaced. The illustration in FIGS. 2 and 3 shows an example of a plain bearing insert with bearing shells and an integrated squeeze oil damper.

[0059] The illustration in Figure 4 shows a further partial cross-section of a squeeze oil damper. The illustration includes graphic axes 51 and 52. Also shown are an outer ring 12 and an inner ring 11. These are connected to one another by means of a rod 13. The inner ring 11 has a flange 68. This results in an L-shaped cross-section for the inner ring. Also shown is a first end region 43 of the rod 13 with an end head 45 and a head extension 48 and a second end region 44 with a nut 46 and a washer 47, the nut 46 being screwed onto a thread (not shown) in the end region 44. The inner ring 11 has a fit 70 in a fit region 41 for receiving the rod 13. The outer ring 12 has a fit 71 in a fit area 42 for receiving the rod 13. A spring area 40 is located between the fit areas.In this spring region 40, the rod 13 is received in a recess 50 in the outer ring 12. In this error region 40, the spring effect of the rod 13 can develop, a free space 64 being provided for this purpose. The inner ring 11 has an annular channel 69 for the supply of oil. Seals 37 and 38 are provided for sealing. The illustration also shows bearing running surfaces 53, 54 and 55, which can be formed in particular when a plain bearing is used in conjunction with the squeeze oil damper. End faces are marked by arrows 57 and 58. According to Figure 4, arrow 57 points to a left-hand end face of the inner ring 11 and arrow 56 to a right-hand end face of the outer ring 12. The left-hand standing surface of the inner ring 11 according to the figure is formed at least partially by the flange 68. Figure 4 also shows that the rod 13 connects the inner ring 11 to the outer ring 12 only via a flange.This one flange is the flange 68 of the inner ring 11 .

[0060] The illustration in Figure 5 shows a perspective view of an example of an inner ring 11, which is made in two parts. The inner ring 11 has a first part 64 and a second part 65. The parts are screwed together. The parts 64 and 65 are ring segments or ring circles. Both parts 64 and 65 form the inner ring 11, which has a flange on both end faces. On a first end face, which is marked with the arrow 57, the flange has a toothing with the teeth 58, 59 and 60. On a second end face, which is marked with the arrow 56, the further flange has a toothing with the teeth 61, 62 and 63. As can be seen from Figure 5, the teeth on one end face are offset in the circumferential direction relative to the teeth on the other end face.For example, it must be ensured that the inner ring is connected to the outer ring via a rod in such a way that this rod is connected to only one flange. This also allows, for example, good accessibility to the rods on the end faces. In the area of ​​tooth gaps in the flange of the inner ring, the rod is connected to the outer ring. This is shown, for example, in Figure 3.

Claims

Patent claims 1. Squeeze oil damper (10) which has an inner ring (11) and an outer ring (12), wherein the inner ring (11) and the outer ring (12) are connected by means of rods (13, 14, 15, 16, 17, 18, 19), wherein at least one of the rings (11, 12) has a flange (68), wherein individual rods (13,14,15,16,17,18,19) are only connected with a flange (68).

2. Squeeze oil damper (10) according to claim 1, wherein the inner ring (11) and the outer ring (12) are connected by means of the rods (13,14,15,16,17,18,19) can be clamped axially to one another and / or variably positioned and / or wherein different bars (13,14,15,16,17,18,19) or groups of bars are alternately connected to different flanges.

3. Squeeze oil damper (10) according to claim 1 or 2, wherein rods (13,14,15,16,17,18,19) are provided for connecting the inner ring (11) to the outer ring (12), wherein the inner ring (11) is clamped to the outer ring (12) by the rods (13,14,15,16,17,18,19), in particular axially.

4. Squeeze oil damper (10) according to one of claims 1 to 3, wherein the inner ring (11) and / or the outer ring (12) are an open ring and / or a closed ring, wherein in particular open rings can be joined to form a closed ring.

5. Squeeze oil damper (10) according to one of claims 1 to 4, wherein the inner ring (11) and / or the outer ring (12) are divisible.

6. Squeeze oil damper (10) according to one of claims 1 to 5, wherein a first number of rods (13, 14, 15, 16, 17, 18, 19) pulls the outer ring (12) in a first axial pulling direction and a second number of rods (13, 14, 15, 16, 17, 18, 19) pulls the outer ring (12) in a second axial pulling direction, wherein Alternate bars (13,14,15,16,17,18,19) and / or groups of bars (13,14,15,16) (17,18,19) of different tensile directions.

7. Squeeze oil damper (10) according to one of claims 1 to 6, wherein rods (13,14,15,16,17,18,19) have a surface layer.

8. Squeeze oil damper (10) according to one of claims 1 to 7, wherein rods comprise different materials.

9. Squeeze oil damper (10) according to one of claims 1 to 8, wherein the inner ring (11) has a U-shaped profile (30) and wherein the outer ring (12) protrudes at least partially into the profile (30), or wherein the outer ring (11) has a U-shaped profile (30) and wherein the inner ring (12) protrudes at least partially into the profile (30).

10. Squeeze oil damper (10) according to one of claims 1 to 9, wherein the squeeze oil damper is provided for a bearing (27), wherein the bearing (27) is in particular a plain bearing (27).

11. Squeeze oil damper (10) according to one of claims 1 to 10, wherein the squeeze oil damper (10) can be integrated into a bearing housing (24).

12. Squeeze oil damper (10) according to one of claims 1 to 11, wherein the tension is adjustable.

13. Squeeze oil damper (10) according to one of claims 2 to 12, wherein at least one rod (13, 14, 15, 16, 17, 18, 19) is replaceable and / or wherein at least one rod (13, 14, 15, 16, 17, 18, 19) has a spring effect.

14. An electrical machine having a first bearing and a second bearing, wherein at least one bearing has a squeeze oil damper (10) according to one of claims 1 to 13.

15. Method for producing a squeeze oil damper (10), wherein elements of the squeeze oil damper (10) are clamped and / or variably positioned, wherein a first element is an inner ring (11) and a second element is an outer ring (12).

16. The method according to claim 15, wherein to change a spring effect at least one rod is replaced and / or at least in one rod (13, 14, 15, 16, 17, 18, 19) a preload is changed and / or an effective length of a rod (13, 14, 15, 16, 17, 18, 19) is changed.

17. Method according to claim 15 or 16, wherein a squeeze oil damper (10) according to one of claims 1 to 13 is used.

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