• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a slot closure arrangement (1) with a sliding block (2) and a pressure piece (3), which extend in the direction of a longitudinal axis (5), and a prestressable spring element (4) which is located between the sliding block (2) and the pressure piece (3) is arranged. The spring element (4) is composed of at least two adjacent spring segments (6) in the direction of the longitudinal axis (5). An intermediate piece (7), which is thicker than the spring segments (6), is arranged between the two adjacent spring segments (6) in the direction of the longitudinal axis (5).
    公开号:CH710245B1
    申请号:CH01399/15
    申请日:2015-09-28
    公开日:2020-03-13
    发明作者:Meier Guido；Peitz Anastasia；Liebl Wilhelm；Schödler Claudio；Hochreutener Joel
    申请人:Abb Schweiz Ag；
    IPC主号:
    专利说明:

    Technical field
    The present invention relates to a device for fixing conductors or winding bars in slots of electrical machines or generators and a suitable device or arrangement.
    Technological background and state of the art
    On the arranged in the grooves of electrical machines conductor bars and coils, hereinafter referred to simply as windings, act under the interaction of the electrical current flowing through the windings and the magnetic field in the air gap forces changing direction. In addition, the winding should be held reliably in the slot even in the event of vibrations and signs of settling of the winding. It is therefore necessary to keep these windings in the slots essentially without play.
    Various slot closure arrangements are currently known which comprise resilient elements in order to hold the windings reliably in the electrical machine.
    The CH-A-662 911 proposes in a first embodiment to achieve the bias of the wave spring by gluing the wave spring to the pressure piece and the sliding block. In an alternative embodiment, the pre-tensioning of the corrugated spring is generated via a thermo-activatable screw connection, which is subjected to heat treatment after the positioning of the slot closure arrangement, as a result of which the pre-tensioning effect of the screw connection is to be canceled.
    [0005] EP 2 187 504 A1 discloses a further developed approach. The slot closure arrangement has a spring element which is arranged between a pressure piece and a sliding block. When the groove closure arrangement is inserted into a groove, two leaf springs of the spring element bent in the transverse direction of the groove are glued together with a thermally activated adhesive. After the groove closure arrangement has been positioned in the groove, the adhesive connection is exposed to a heat source or shock waves or electromagnetic waves or a chemical reaction in such a way that the adhesive connection is at least broken and the spring force of the spring element is restored.
    In practice, it has now been shown that the spring element according to EP 2 187 504 A1 breaks, for example, when there are strong vibrations in the operation of the electrical machine and thereby leads to a failure of the tensioning action. The spring element according to EP 2 187 504 A1 has a large number of electrically insulating, unidirectionally oriented fibers which are connected to one another by a heat-resistant resin. When the spring element is installed in the groove of the electrical machine, the spring element is aligned in such a way that the fibers extend transversely (ie in the transverse direction) to the longitudinal direction defined by the groove. The groove width extends in the direction of a transverse axis, while the groove depth defines a vertical axis. In this way, a spring element is created with which spring forces acting along the transverse axis in the direction of the vertical axis can be activated. The transverse axis and the vertical axis run in an imaginary plane, which represents a cross section of the groove and the groove closure arrangement. A maximum spring travel of the spring element is thus set approximately across the center via a line in the direction of the vertical axis.
    Summary of the invention
    It is an object of the present invention to further develop the spring element according to EP 2 187 504 A1 in such a way that the slot closure arrangement becomes more durable.
    This goal is achieved by a slot closure arrangement according to claim 1.
    [0009] In a basic embodiment, the slot lock arrangement according to the invention comprises a slot nut and a pressure piece facing a winding of an electrical machine in the assembled state. Due to their elongated shape, the sliding block and the pressure piece define a longitudinal axis or extend in the direction of the longitudinal axis. At least one spring element is arranged between the sliding block and the pressure piece. Depending on the embodiment, the spring element can be designed, for example, as a leaf spring or as a corrugated spring.
    The spring element is composed in the direction of the longitudinal axis from at least two adjacent spring segments. Because the spring element is not composed of a single spring segment, but rather of several spring segments, it is avoided in a simple yet effective manner that recesses for carrying out a fastening means for prestressing the spring element have to be passed through the spring element. Depending on the embodiment, the fastening means can comprise, for example, screws, rivets that can be torn off or the like.
    Another advantage of the large number of spring segments compared to the known, rather long spring elements is that the spring element seen in the direction of the longitudinal axis extends or contracts much less at the end during pretensioning and subsequent activation / release of the spring action. Such relatively short distances are advantageous because they hinder the preloading process and the release of the spring action less than in the known, rather long spring elements. In addition, the reduced longitudinal movement of the spring segments compared to known spring elements means that the spring segments are also mechanically stressed far less inside the spring.
    The slot closure arrangement can be easily inserted and positioned with the pretensioned state of the spring element in the groove of an electrical machine, because an installation height extending in the direction of the vertical axis is less than when the spring element is activated in the groove of the electrical machine.
    The basic embodiment is further characterized in that an intermediate piece is arranged in the direction of the longitudinal axis between the two adjacent spring segments, which is thicker than the spring segments in the direction of the vertical axis.
    This intermediate piece is responsible for ensuring that the spring element in the pretensioned state of the slot closure arrangement cannot be deflected or compressed over a predefined threshold value. The threshold is dimensionally less than a maximum possible spring travel of the spring element determined by the pressure piece and the sliding block. The maximum spring travel of the spring element is determined by a contour of the sliding block facing the pressure piece and a contour of the pressure piece facing the sliding block. Correct dimensioning of the intermediate piece prevents the spring element from being excessively bent, for example in the direction of the vertical axis, during pretensioning in such a way that the connection between the fibers and the resin matrix is released, which leads to delamination of the spring element. If the spring element works on the cantilever principle, the spring element according to the present invention is therefore protected against undesired overloading and thus against delamination by arranging an intermediate piece in the direction of the longitudinal axis between the two adjacent spring segments, which is thicker in the direction of the vertical axis than the spring segments is. In cross section through the slot closure arrangement, this thickness of the intermediate piece ensures that the spring segment acting as a bending beam can only be deflected to a predefinable, permitted dimension, but no longer. In other words, the maximum deflection of the spring segment is a function of the thickness of the intermediate piece. Another advantage is that the intermediate piece of the present solution enables a more precise definition of the pretension of the spring element compared to known solutions of the prior art.
    The intermediate piece made of a pliable material is thus used as a spacer for the correct pretensioning of the slot closure system during assembly. The fact that the intermediate piece is dimensionally thicker than the spring element reliably prevents damage to the spring element as a result of overstressing due to excessive compressive forces during pretensioning. If the spring element is formed by a corrugated spring, the term "thickness of the spring element" is only to be understood as the wall thickness of the spring element and not the dimension in the direction of the vertical axis between two corrugated tips pointing in opposite directions (similar to electrical amplitude heights).
    In order to ensure that the intermediate piece falsifies the predefined pretensioning force and spring action of the spring element in the installed state in the groove of the electrical machine, the intermediate piece itself is not designed as a spring element.
    These two measures, the interrupted spring element and the specific height of the intermediate piece are responsible for the fact that, for example, the large number of electrically insulating, unidirectionally oriented fibers of the spring segments, which are connected to one another by a heat-resistant resin, in comparison with that in EP 2 187 504 A1 proposed solution are better protected against delamination of the fiber composite. Delamination means the loss of the adhesive action of the fibers to the resin matrix, which is responsible for the loss of the spring action of the strip-shaped spring element or spring segment. In other words, the intermediate piece protects the spring element in the pretensioned state of the spring element from mechanical overload, which can lead to loss or even loss of the spring action during operation of the slot closure arrangement.
    In order to achieve a defined spring tension and spring force, the sliding block is designed to be rigid in such a way that it does not deform, or at most only insignificantly, during pretensioning and in particular in the installed state in the groove.
    In comparison to the solution according to EP 2 187 504 A1, the spring segments are significantly shorter in the direction of the longitudinal axis, since they only extend to the intermediate pieces, but not in the area of the fastening means for applying the pretensioning force required for transferring the slot closure arrangement in the prestressed state. The spring force which is to be available from the spring element in the groove of the electrical machine, together with the rigidity of the sliding block, pressure piece, spring element and the mechanical strength of the fastening means, is ultimately decisive for the dimensioning and number of the fastening means. In the case of screws as fastening means, in the present application, as in EP 2 187 504 A1, this leads to a certain number of screws of a certain type (size and material) in order to accordingly convert the slot closure arrangement into the pretensioned state. The subdivision of the spring element into several spring segments leads to greater design freedom given given distances of one fastener (for example a screw) to the next fastener (for example another screw), whereby the relatively short lengths of the spring segments lead to penetrations of the spring element which cause unfavorable notch effects Carrying out the fastener can be elegantly dispensed with.
    Another advantage of an intermediate piece is that it reliably prevents unwanted displacement of the spring segments during operation of the electrical machine.
    If the maximum spring travel in the operating state of the slot closure arrangement is only relatively small, for example only in the range of fractions of a millimeter, and if the slot width is relatively narrow, for example less than 20 mm, sections of a corrugated spring (English ripple springs) can be used as the spring segments. be used. Such wave springs are known for example from EP 0 601 827 A1. In order to achieve maximum spring action in the longitudinal direction, it is advantageous if the corrugated spring is corrugated along the direction of the longitudinal axis. In other words, the distance between two adjacent shafts is measured in the direction of the longitudinal axis in this embodiment. Embodiments of wave springs show the best behavior if they have a large number of electrically insulating fibers which are oriented unidirectionally in the direction of the longitudinal axis and which are connected to one another by a heat-resistant resin.
    In the case of groove widths which are wider, for example around 35 mm and / or if larger spring travel is required in the operating state of the groove closure arrangement, an alternative embodiment of the spring element is more advantageous. In this case, the spring element is arranged between the sliding block and the pressure piece in such a way that it forms a bending beam arrangement with the pressure piece in the direction of a transverse axis extending transversely to the longitudinal axis, so that the spring element extends from the pressure piece in the direction of a transverse to the longitudinal axis and is deflectable to the vertical axis extending transversely to the transverse axis. In such cases, the spring element is leaf-spring-like, that is, flat in the manner of a leaf spring.
    Experiments have shown that the spring element of a slot closure arrangement had good spring properties if it comprises a large number of electrically insulating fibers which are oriented unidirectionally in the direction of the transverse axis and which are connected to one another by a heat-resistant resin. This creates a spring element with which spring forces of the desired strength acting along the transverse axis in the direction of the vertical axis can be activated. The transverse axis and the vertical axis run in an imaginary plane, which represents a cross section of the groove and the groove closure arrangement. A maximum suspension travel is therefore set approximately in the middle of a three or four point bend along a line in the direction of the vertical axis. The fibers should be electrically insulating for the function of a slot closure arrangement according to the invention. Glass fibers and / or para-amide fibers such as Kevlar, for example, may be mentioned here as representatives of a large number of suitable materials. In the former case, the glass fiber portion of the spring element is, for example, preferably about two thirds and the resin portion is preferably about 1/3 percent by weight.
    Since the installation space available for slot closure arrangements in the groove of an electrical machine is becoming increasingly smaller, compact slot closure arrangements are preferred in systems operating according to the bending beam principle, which nevertheless have a sufficiently large spring travel of the spring element in the operating state. If a particularly flat solution is required in the direction of the vertical axis, an embodiment is available in which outer edges of the spring segments which extend in the direction of the longitudinal axis touch the sliding block, while a central region of the spring segments which is arranged between the outer edges in the direction of the transverse axis touches the pressure piece. The advantage of this solution is that the beam width can be used to the maximum.
    An optimal ratio of the spring segments per length in the longitudinal direction or in the direction of the longitudinal axis can be achieved if a length extending in the direction of the longitudinal axis of one of the spring segments is at most twice as large as a width extending in the direction of the transverse axis. The term “width” is understood as the width between the outer edges of the slot closure arrangement, which is typically defined by the maximum width of the slot nut.
    To achieve the most uniform and symmetrical spring action of the spring segments over their length in the direction of the longitudinal axis, it is advantageous if a spring segment is arranged in the direction of the longitudinal axis between two adjacent intermediate pieces. Provided that the spring element is essentially of constant thickness in the direction of the longitudinal axis, it makes sense if the two adjacent intermediate pieces are dimensionally identical when viewed in the direction of the vertical axis.
    If the assembly of the slot closure arrangement is to be facilitated, it may make sense if the intermediate piece and the two adjacent spring segments are held together with a band-like carrier extending in the direction of the longitudinal axis before the assembly of the slot closure arrangement. Combining the intermediate pieces and spring segments allows a more efficient assembly of the slot closure arrangement, because the intermediate pieces and spring segments can be preassembled into an assembly thanks to the band-like carrier. The band-like carrier can, for example, be a glass fiber reinforced product. In order to avoid the formation of undesirable crumbs as a result of decomposition of the band-like carrier in the electrical machine, durable, heat-resistant carrier solutions are preferred. In one possible embodiment, the tape-like carrier is an adhesive tape, in particular a glass fiber-reinforced adhesive tape. In any case, the band-like carrier is essentially pressure-resistant in the direction of the vertical axis and yet flexible in the transverse direction in order to be able to compensate for certain shape tolerances between the pressure piece and the sliding block. Depending on requirements, the band-like carrier can be directed towards the sliding block or the pressure piece in the assembled state of the slot closure arrangement. The adhesive tape considerably simplifies the assembly of the slot closure arrangement, since it allows a sufficiently precise arrangement of several intermediate pieces and spring segments in one work step, so that a preassembly assembly is created. This pre-assembly module can then be easily inserted between the sliding block and the pressure piece because the large number of spacers and spring segments sticks to the adhesive tape. If necessary, the large number of spacers and spring segments can also be attached to the tape-like carrier with an adhesive (e.g. an adhesive).
    Even if so-called wedge systems are desired by users because they can be easily tightened again while the electrical machine is being maintained, this is nevertheless agreed with the present invention. In this case, the pressure piece and / or the sliding block has a wedge-shaped cross section when viewed in the direction of the transverse axis.
    For biasing the spring element, a fastening means is useful, with which the pressure piece is pulled against the sliding block, so that the spring element can be compressed in the direction of the vertical axis with respect to its unloaded state. The slot closure arrangement therefore has a fastening means for prestressing the spring element before the slot closure arrangement is inserted into a slot of an electrical machine. After positioning the slot closure arrangement in the slot, the fastening means can be mechanically transferred from a first position into a controllable second position, so that the prestressing of the spring element can be released and the spring element can be activated.
    In a particularly simple embodiment, the fastening means comprises at least one screw which extends through the sliding block and the intermediate piece into a threaded hole arranged in the pressure piece. The subdivision of the spring element into spring segments prevents the unidirectionally oriented fibers of the spring element from having to be severed locally in the area of the fastening means (such as in EP 2 187 504 A1), so that harmful notch effects due to the penetration of the spring element can be avoided entirely. In the case of spring elements with unidirectionally oriented fibers, such notch effects promote breakage of the fibers in the zone of the subdivision. In addition, the present invention considerably simplifies the geometry of the spring element in comparison with the solution according to EP 2 187 504 A1, since no penetrations in the spring element are required for the implementation of a fastening means.
    The above-mentioned screw makes it possible, for example, to combine the slot closure arrangement into a set or an assembly and to hold all the components together during the preassembly. In this embodiment, the screw head or a previously screwed-on nut serves as a counter-holder for applying the required pretensioning force of the spring element in the direction of the vertical axis.
    In a geometrically particularly simple embodiment, the pressure piece has a threaded hole for receiving a threaded portion of the screw.
    In order to keep the overall height of the slot closure arrangement in the installed state in an electrical machine, which extends in the direction of the vertical axis, as low as possible, it is advantageous if the screw can be removed from the slot closure arrangement when the spring element is released. This solution is particularly advantageous if the screws are metallic, since otherwise they cannot remain in the electrical machine because they disrupt operation.
    If the fastening means is removed from the slot closure arrangement when the second position (ie the activation / release of the spring action of the spring element) is reached, this enables an optical control of the slot closure quality in a particularly simple and economical manner. Advantages of this embodiment result in the rapid and reliable feasibility of the optical control, which does not require any additional aids.
    Removable fasteners enable the same to be economically reused for further slot closure arrangements.
    If the fastening means are removed from the electrical machine after the slot locking arrangement has been installed, the risk of fastening means or fragments thereof remaining in the electrical machine in an uncontrolled manner is further reduced in comparison with known slot locking arrangements.
    Both to reduce the risk of errors during the initial assembly beforehand and to reduce it during maintenance, for example due to an accidentally fallen out fastener, the fastener is preferably made of a non-metallic material, for example plastic.
    Particularly in those cases in which no band-like carrier is used, it can be useful if a length of the intermediate piece extending in the direction of the longitudinal axis is dimensioned such that the intermediate piece the two adjacent spring segments when the spring element is released from the pretension Groove of the electrical machine keeps positioned. In this case, the spring segments are held in the desired positioning without a fixation being absolutely necessary, since the displaceability of the spring segments during operation of the electrical machine is limited in the direction of the longitudinal axis. This can be particularly advantageous if, due to the setting behavior of the windings, certain spring segments could otherwise move relatively freely within the groove between the sliding block and the pressure piece due to insufficient spring action.
    A particularly rational and effective embodiment can be achieved if the fastening means or a placeholder extends through the intermediate piece, as has been described above.
    If the fasteners are designed in the form of removable screws, it may be useful that after the installation of the slot closure arrangement in the electrical machine, placeholders in the form of threaded plugs or the like are screwed into the holes of the screws, around the intermediate pieces and the spring segments to keep it stationary in the operation of the electrical machine. These placeholders or threaded plugs can be made, for example, from an insulating material, for example Textolite.
    Alternatively or in addition to this, embodiments can be implemented in which the intermediate piece is shaped such that it holds the two adjacent spring segments positively positioned in the groove of the electrical machine when the spring element is released. The term "form-fitting" is not understood to mean clamping, but rather in such a way that there should and should be a certain amount of play between the spring segment and the intermediate piece. In an exemplary embodiment, the intermediate piece, viewed in the direction of the vertical axis, has an H-shaped cross section, in which the legs of the H shape have the adjacent spring segments held in the required, predefinable dimension.
    Particularly when the spring element is designed in the manner of a leaf spring - that is to say in a planar manner - a plurality of spring elements can be stacked with the simplest means, if required, to form a spring pack extending in the direction of the vertical axis. The term “planar” is understood to mean a flat extension of the spring element, the spring thickness in the direction of the vertical axis being substantially less than its width in the direction of the transverse axis and length in the direction of the longitudinal axis. The fact that the spring element in unloaded, i.e. unstressed condition is essentially flat, allows use for different groove widths without the need for expensive modifications of the pressure piece and / or the sliding block. In addition, such a shape favors economical production in that a plurality of strip-like spring elements can be separated from a semi-finished plate. If the fiber composite consisting of the fibers in the direction of the vertical axis is used with low-abrasion or low-wear cover layers, this additionally makes wedging easier.
    The possibility of stacking a plurality of spring elements also enables different clamping forces to be assembled while maintaining the same basic structure of the slot closure arrangement.
    A geometrically particularly simple embodiment of the slot closure arrangement can be achieved if the intermediate piece is made of a material which has a lower bending stiffness (in the direction of the vertical axis) than the spring element. In this case, the intermediate piece is an independent component of the slot closure arrangement, such as the slot nut and the pressure piece. The task of the intermediate piece consists exclusively in being able to withstand sufficient pressure starting from the fastening means in the pretensioned state of the slot closure arrangement in order to be able to protect the spring segments from overloading. For this purpose, for example, a plastic with a low bending stiffness compared to the spring element, for example made of a thermoplastic, is suitable.
    An alternative embodiment without independent spacers can be achieved, for example, that the spacer is at least partially integrated into the sliding block and / or the pressure piece. An advantage of this embodiment lies in the number of parts that can be reduced further, which, however, leads to more complex geometries of the sliding block and / or the pressure piece.
    Finally, it should be mentioned that, on the basis of the present description, a person skilled in the art is able to carry out a combination of two or more of the features mentioned in this description, for example in order to bring about a combination of the associated effects.
    Brief description of the drawing
    Exemplary embodiments of the invention are shown purely schematically in the drawing. It shows:<tb> Fig. 1 <SEP> shows a spatial representation of a first embodiment of a slot lock arrangement;<tb> Fig. 2 <SEP> a section through the slot closure arrangement from FIG. 1 in the installed state in a slot of an electrical machine;<tb> Fig. 3 <SEP> a spatial representation of a second embodiment of a slot closure arrangement;<tb> Fig. 4 <SEP> a simplified top view of two intermediate pieces and a spring segment in the direction of the vertical axis according to the first embodiment according to FIG. 1;<tb> Fig. 5 <SEP> a simplified plan view of two intermediate pieces and a spring segment in the direction of the vertical axis according to a further embodiment similar to the first embodiment according to FIG. 1;<tb> Fig. 6 <SEP> a simplified plan view of two intermediate pieces and a spring segment in the direction of the vertical axis according to a further embodiment similar to the first embodiment according to FIG. 1;<tb> Fig. 7 <SEP> shows a section shown in section through the slot closure arrangement from FIG. 1 along a plane symbolized by VII-VII in the prestressed state of the spring element;<tb> Fig. 8 <SEP> shows a section shown in section through the slot closure arrangement from FIG. 7 in the activated / released state of the spring element;<tb> Fig. 9 <SEP> a section analogous to FIG. 8, but with a longitudinally corrugated wave spring as a spring segment instead of a planar spring segment, as shown in FIG. 8; and<tb> Fig. 10 <SEP> shows a longitudinal section in the direction of the longitudinal axis through a further embodiment of a slot closure arrangement after the slot closure arrangement has been re-tensioned.
    Ways of Carrying Out the Invention
    The first embodiment of a slot closure arrangement 1 according to the invention shown in FIG. 1 shows a leaf spring-like spring element 4 arranged between a slot nut 2 and a pressure piece 3 in an exploded view before the slot closure arrangement is assembled. Due to their elongated shape, the sliding block and the pressure piece define a longitudinal axis 5 or extend in the direction of the longitudinal axis 5, that is to say in the X direction. Due to the electrical requirements, the sliding block 2 and the pressure piece 3 are made of a laminate with glass fiber mats, mineral fillers and epoxy resin as a binder.
    The spring element 4 has a plurality of spring segments 6, which are physically completely independent of one another, in the direction of the longitudinal axis 5, an intermediate piece 7 is arranged between two adjacent spring segments 6, which extends in the direction of a vertical axis 8 extending transversely to the longitudinal axis 5 is thicker than the spring segments 6. As can be seen from the summary of FIG. 1 with FIG. 4, a length 9 of the intermediate piece 7 extending in the direction of the longitudinal axis 5 is dimensioned such that the intermediate piece 7 faces the two adjacent spring segments 6 due to the shape and proximity of the spring segments 6 Keeps edges 11 positioned substantially stationary in the XY plane. The spring segment 6 shown in FIG. 4 is shown in the unloaded state for the sake of simplicity. In this embodiment, a length 34 of the spring segment 7 is approximately the same size as a width 35 of the spring element 7 extending in the transverse direction 12.
    4 further shows that the electrically insulating spring segment 6 has a multiplicity of electrically insulating fibers 13 which are oriented unidirectionally in the direction of the transverse axis 12 and which are permanently connected to one another by a heat-resistant resin. This results in a flat, that is to say planar, spring element, with which spring forces of predefinable strength acting along the transverse axis 12 in the direction of the vertical axis 8 can be activated. The transverse axis extends transversely to the longitudinal axis 5 and transversely to the vertical axis 8 in the Y direction. In this embodiment of the spring segment, the electrically insulating fibers 13 are formed from a multiplicity of glass fibers 13, the glass fiber fraction of the spring segment being approximately two thirds and the resin fraction preferably being approximately 1/3 percent by weight. Other materials are of course conceivable as long as they meet the requirements placed on them.
    With reference to FIG. 1, it can also be seen that a large number of fastening means in the form of screws 14 are present for prestressing the spring element 4. When the spring element 4 is preloaded, the slot closure arrangement is in a so-called first state, while the so-called second state is reached in the groove of the electrical machine after the spring forces of the spring element 4 have been activated.
    The intermediate pieces 7 are made of a material which has a lower bending stiffness in the direction of the vertical axis 8 than the spring element 4. In this case, the intermediate pieces 7 are made of a thermoplastic. As can also be seen from FIG. 4, the intermediate pieces 7 each have an opening 15 in order to enable a screw 14 to be inserted in each case.
    Correspondingly, threaded holes 16 for engaging the screws 14 are arranged in the pressure piece in order to pull the pressure piece 3 in the direction of the vertical axis 8 against the sliding block 2 and to prestress the spring element 4. In order to achieve centering and to be able to accommodate the screws 14, the sliding block also has a number of through holes 17.
    In order to be able to optimally absorb the forces of the screws 14 which arise during the prestressing of the spring element 4, a pressure strip 18 is arranged between the heads of the screws 14 and the sliding block 2. This pressure strip 18 is removed after the insertion and positioning of the slot closure arrangement in a slot of the electrical machine together with the screws 14. The shoulders of the screws 14 facing the sliding block serve as a stop during pretensioning. For safety reasons, the screws 14 are also made of a laminate with glass fiber mats, mineral fillers and epoxy resin as a binder. Other materials are of course conceivable as long as they meet the requirements placed on them.
    The sectional view shown in FIG. 2 through the slot closure arrangement 1 from FIG. 1 in the installed state in a groove 19 of an electrical machine in the Y-Z plane. This Y-Z plane is defined by the vertical axis 8 and a transverse axis 12. 2 shows the slot closure arrangement 1 in the second state, the screws 14 having already been removed, but the pressure strip 18 is still shown in section. The second state is reached when the slot closure arrangement 1 designed as a set or pre-assembly unit is inserted, for example, into a stator slot of a generator and positioned in the direction of the longitudinal axis 5 of the slot and after the screws 14 have at least been loosened, but better still removed. In this embodiment, the screws 14 were unscrewed from the slot closure arrangement 1 after reaching the second state. When leaving a corresponding internal thread section 16 in the pressure piece 3 through the threaded section of the screw 14, predefined spring forces of the spring element 4 have been activated. Because the screw 14 is missing, a reliable control of the activation of the spring element 4 can be seen by the naked eye.
    The spring forces mentioned ensure reliable retention of an insulated winding 37 in the slot 19 by the winding 37 is pressed against a slot base 21. The spring forces are designed in accordance with the installation and operating requirements of the slot closure arrangement 1.
    Between the winding 37 and the pressure piece 3, a sliding pad 22 made of a laminate with glass fiber mats, mineral fillers and epoxy resin is arranged as a binder.
    2 that the spring element 4 or the corresponding spring segment 6 is arranged between the sliding block 2 and the pressure piece 3 in such a way that it forms a three-point bending beam arrangement with the pressure piece 3 in the direction of the transverse axis 12. As a result, the spring segment 6 can be deflected by the pressure piece 3 in the direction of the vertical axis 8. The mutually facing contours of the sliding block 2 and the pressure piece 3 were deliberately chosen to be concave or convex and coordinated with one another in such a way that the desired deflection of the spring segment 6 and thus the desired release of its spring force results in the groove 19.
    The transverse axis 12 and the vertical axis 8 run in an imaginary plane X-Y, which represents a cross section of the groove 19 and the groove closure arrangement 1. A maximum suspension travel is therefore ideally set approximately in the center in the direction of the vertical axis 8. With a groove width of approximately 35 mm, an excellent spring travel of approximately 2.5 mm was achieved with a tongue width of approximately 33 mm in the direction of the transverse axis 12 and a tongue thickness 28 of approximately 1.3 mm in the direction of the vertical axis 8.
    2 further shows that the outer edges 23 of the spring segment 6 which extend in the direction of the longitudinal axis 5 touch the sliding block in their edge region, while a transverse center region 24 of the spring segment 6 which is arranged between the outer edges 23 in the direction of the transverse axis 12 Pressure piece 3 touched.
    3 shows a second embodiment 10 of the slot closure arrangement according to the invention with a prestressed spring segment 6. Since the conceptual structure is similar to that of the first embodiment shown in FIG. 1, identical elements have been provided with the same reference symbols and elements with the same / similar effect have been provided with the same or at least similar reference symbols. Due to the analogous mode of operation of the elements of the slot closure arrangement according to the second embodiment to the first embodiment, only the differences between the two embodiments 1, 10 are discussed below. In contrast to the screw 14 known from FIG. 1, the fastening means 25 is formed in this case by a longer screw 140 and a nut 26. The fastening means 25 is mechanically transferred from a first position to a controllable second position after the groove closure arrangement has been positioned in the groove 19, so that the prestressing of the spring element 4 can be released and the spring element 4 can be activated. The threaded section of the screw 140 on the left side of the slot closure arrangement 10 also engages in the threaded hole 16 of the pressure piece 3. In this embodiment, the shoulder of the nut 26 previously screwed on serves as a counter-holder for applying the required pretensioning force of the spring element 4 in the direction of the vertical axis 8. For safety reasons, both the screw 140 and the nut 26 are likewise made of a laminate with glass fiber mats, mineral fillers and epoxy resin manufactured as a binder. Other materials are of course conceivable as long as they meet the requirements placed on them.
    In contrast to FIG. 4, the two intermediate pieces 7 and the spring segment 6 of the embodiment in FIG. 5 are connected to one another by means of a band-like carrier 27. The band-like carrier 27 is formed by a glass fiber-reinforced adhesive tape, which is likewise broken through in the area of the openings 15 of the intermediate piece 7 in order to enable the screws to be pushed through.
    In contrast to FIG. 4, the intermediate pieces 70 of the embodiment in FIG. 6 in the direction of the vertical axis 8 (that is to say in the Z direction) have an H-shaped cross section, in which the legs of the H shape have the adjacent spring segments Have it positioned in the required, pre-definable amount in a simple but effective manner. This takes place in that the intermediate pieces 70 encompass the outer edges 23 of the spring segment 6 at least in one longitudinal section.
    7 in connection with FIG. 8 shows in more detail how the thickness 29 of the intermediate pieces 7 extending in the direction of the vertical axis 8 affects the load on the spring segment 6. 7 to 9, the cutting plane extends in the X-Z direction. In particular, from FIG. 8 it can be seen that the intermediate pieces 7 are each considerably thicker in the direction of the vertical axis 8 than the spring segment 6. As a result, when the spring element is preloaded, the pressure piece can be pulled against the sliding block without hesitation, without overloading the To risk spring segments 6. The intermediate piece is designed to be pressure-resistant in such a way that it retains its thickness 29 when tightened without flowing away laterally. In this way, it is reliably avoided that the spring segment 6 is excessively bent, so that it is clamped on a slot block contour 31 facing the pressure piece 3 and a pressure piece contour 32 facing the slot block 2. 8 that the thickness 28 of the spring segment 6 is significantly smaller than the thickness 29 of the intermediate piece 7. Accordingly, even in the prestressed state according to FIG. 8, there is a sufficiently large gap 39 in the direction of the vertical axis (Z direction) free, which sufficiently protects the planar spring segment 6 against overload.
    FIG. 9 shows a variant in section analogous to FIG. 8. In contrast to the flat (planar) spring segment 6, the embodiment according to FIG. 9, however, has a spring element in the form of a longitudinally corrugated wave spring, which comprises a plurality of wave spring segments 60. The wave spring in turn has a large number of electrically insulating, unidirectionally oriented fibers which are connected to one another by a heat-resistant resin. This time, however, the fibers are aligned in the direction of the longitudinal axis 5 along the corrugation. Since a bending of the corrugated spring in the direction of the transverse axis 12 would be unfavorable, the sliding block contour 31 facing the pressure piece 30 and the pressure piece contour 32 facing the sliding block 20 are flat in this embodiment, that is to say arranged planar and parallel to one another and not as in the embodiment according to Fig. 8. The intermediate pieces 7 thereby reliably prevent the corrugated spring segment 40 from being compressed in the direction of the vertical axis (Z direction) during prestressing beyond a certain threshold value, so that the corrugated spring segment 40 can be reliably protected against damage due to excessive pressure stress and consequent delamination. FIG. 9 clearly shows that the thickness 28 of the spring segment 60 is significantly less than the thickness 29 of the intermediate piece 7. Accordingly, even in the prestressed state according to FIG. 9, there is a sufficiently large gap 39 in the direction of the vertical axis (Z direction) , which adequately protects the corrugated spring segment 60 against overload.
    FIG. 10 shows a slot closure arrangement 100 similar to that of FIG. 1 along a plane symbolized by VI-VI in a post-wedged state in a slot (not shown) of an electrical machine. The spring element 4 is again a planar spring element working according to the bending beam principle, as shown in FIGS. 7 and 8. The state shown in FIG. 10 with the pressure piece 300 and the sliding block 200 offset with respect to one another in the longitudinal direction (X direction) arises after wedging, for example in the direction of the arrow 36, on the occasion of maintenance / service on the electrical machine in order to compensate for a setting behavior of the windings. 10 further shows that the pressure piece 300 and the sliding block 200 are designed as a wedge-counter-wedge combination with an inclination angle 33 of approximately one degree (shown greatly enlarged in FIG. 10), with the pressure piece 300 on its upper side is additionally convexly curved in the direction of a vertical axis in order to allow a linear contact with the concave curved sliding block 200 on its underside. The edges caused by the curvature of the wedge surfaces are not shown for reasons of clarity. In this view, the mutually displaced internal thread sections of the threaded holes 16 and the through holes 17 are visible, which were used to carry out the fastening means at the time of the initial prestressing.
    If wedging is also required using corrugated spring segments, the sliding block contour 31 facing the pressure piece 300 and the pressure piece contour 32 facing the sliding block 200 in this embodiment are to be arranged evenly, that is to say planar and parallel to one another, as in connection with Fig. 9 described.
    Reference list
    [0068]<tb> 1, 10, 100 <SEP> slot lock arrangement<tb> 2, 20, 200 <SEP> sliding block<tb> 3, 30, 300 <SEP> pressure piece<tb> 4, 40 <SEP> spring element<tb> 5 <SEP> longitudinal axis<tb> 6, 60 <SEP> spring segment<tb> 7, 70 <SEP> intermediate piece<tb> 8 <SEP> vertical axis<tb> 9 <SEP> Length of the intermediate piece<tb> 11 <SEP> edge of the intermediate piece<tb> 12 <SEP> transverse axis<tb> 13 <SEP> fibers<tb> 14, 140 <SEP> screw<tb> 15 <SEP> opening in the intermediate piece<tb> 16 <SEP> threaded hole in the pressure piece<tb> 17 <SEP> through hole in the sliding block<tb> 18 <SEP> print strips<tb> 19 <SEP> groove<tb> 21 <SEP> groove base<tb> 22 <SEP> sliding pad<tb> 23 <SEP> outer edges of the spring segment<tb> 24 <SEP> transverse center region of the spring segment<tb> 25 <SEP> fasteners<tb> 26 <SEP> mother<tb> 27 <SEP> ribbon-like carriers<tb> 28 <SEP> spring thickness / thickness of the spring segment<tb> 29 <SEP> thickness of the intermediate piece<tb> 31 <SEP> T-nut contour / contour of the T-nut towards the pressure piece<tb> 32 <SEP> pressure piece contour<tb> 33 <SEP> inclination angle<tb> 34 <SEP> Length of the spring segment<tb> 35 <SEP> width of the spring segment<tb> 36 <SEP> wedge direction<tb> 37 <SEP> winding<tb> 39 <SEP> gap
    权利要求:
    Claims (17)
    [1]
    1. slot closure arrangement (1, 10, 100) for fixing conductors or winding bars (37) in a slot (19) of an electrical machine,comprising the slot closure arrangement (1, 10, 100)a sliding block (2, 20, 200) which extends in the direction of a longitudinal axis (5),a pressure piece (3, 30, 300) which extends in the direction of the longitudinal axis (5),and a prestressable spring element (4, 40), which is arranged between the sliding block (2, 20, 200) and the pressure piece (3, 30, 300), characterized in thatthe spring element (4, 40) in the direction of the longitudinal axis (5) is composed of at least two adjacent spring segments (6, 60) and that in the direction of the longitudinal axis (5) between each of the two adjacent spring segments (6, 60) an intermediate piece (7 , 70) is arranged, which is thicker than the spring segments (6, 60) in the direction of a vertical axis (8) extending transversely to the longitudinal axis.
    [2]
    2. Slot lock arrangement according to claim 1, characterized in that the spring element is a corrugated spring (60).
    [3]
    3. Groove closure arrangement according to claim 2, characterized in that the corrugated spring (60) is corrugated along the direction of the longitudinal axis (5).
    [4]
    4. slot closure arrangement according to claim 1, characterized in that the spring element (6, 60) is arranged between the sliding block (2, 200) and the pressure piece (3, 300) that it with the pressure piece (3, 300) in the direction a transverse axis (12) extending transversely to the longitudinal axis forms a bending beam arrangement, so that the spring element (4) extends from the pressure piece (3, 300) in the direction of the vertical axis (transverse to the longitudinal axis (5) and transverse to the transverse axis (12) 8) is bendable.
    [5]
    5. slot closure arrangement according to claim 4, characterized in that the spring element (6) comprises a plurality of unidirectionally oriented, electrically insulating fibers (13) which extend in the direction of the transverse axis (12) and are connected to one another by a heat-resistant resin.
    [6]
    6. slot closure arrangement according to claim 4, characterized in that in the direction of the longitudinal axis (5) extending outer edges (23) of the spring segments (6) touch the sliding block (2, 200), while viewed in the direction of the transverse axis (12) between the Outside edges (23) arranged transverse region (24) of the spring segments (6) touches the pressure piece (3, 300).
    [7]
    7. Groove closure arrangement according to claim 1, characterized in that a length (34) extending in the direction of the longitudinal axis (5) of one of the spring segments (6, 60) is at most twice as large as a width (35) extending in the direction of the transverse axis ) of the spring segment (6, 60).
    [8]
    8. slot closure arrangement according to claim 1, characterized in that the intermediate piece (7) and the two adjacent spring segments (6) are held together with a band-like carrier (27) extending in the direction of the longitudinal axis (5).
    [9]
    9. slot closure arrangement according to claim 8, characterized in that the tape-like carrier is an adhesive tape (27), in particular a glass fiber reinforced adhesive tape.
    [10]
    10. Groove closure arrangement according to claim 4, characterized in that the pressure piece (300) has a wedge-shaped cross section when viewed in the direction of the transverse axis (12).
    [11]
    11. Groove closure arrangement according to claim 1, characterized in that the groove closure arrangement (1, 10, 100) a fastening means (25) for biasing the spring element (4, 40) before insertion of the groove closure arrangement (1, 10, 100) into the groove ( 19) of an electrical machine, the fastening means (25) being able to be mechanically transferred from a first position into an optically controllable second position after the groove closure arrangement (1, 10, 100) has been positioned in the groove (19), so that the pretensioning of the Spring element (4, 40) is detachable and the spring element (4, 40) can be activated.
    [12]
    12. Groove closure arrangement according to claim 11, characterized in that the fastening means (25) comprises at least one screw (14) which extends through the sliding block (2, 20, 200) and the intermediate piece (7) into a in the pressure piece (3, 30, 300) arranged threaded hole (16) extends.
    [13]
    13. Groove closure arrangement according to claim 1, characterized in that a length (9) of the intermediate piece (7, 70) extending in the direction of the longitudinal axis (5) is dimensioned such that in a state installed in the groove (19) of the electrical machine the slot closure arrangement, the intermediate piece (7, 70) holds the two adjacent spring segments (6, 60) positioned in the groove (19) when the spring element is released.
    [14]
    14. Groove closure arrangement according to claim 1, characterized in that the intermediate piece (70) is shaped such that, when the groove closure arrangement is installed in the groove (19) of the electrical machine, the two adjacent spring segments (6) with the pretensioning of the spring element ( 6) holds positively positioned in the groove (19).
    [15]
    15. The slot closure arrangement according to claim 1, characterized in that the spring element (6) comprises a plurality of spring elements which are planar in a relaxed state and are stacked on top of one another in the direction of the vertical axis (8).
    [16]
    16. Groove closure arrangement according to claim 1, characterized in that the intermediate piece is at least partially integrated in the sliding block and / or the pressure piece.
    [17]
    17. Groove closure arrangement according to claim 1, characterized in that the intermediate piece (7, 70) is made of a material which has a lower bending stiffness than the spring element.
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    同族专利:
    公开号 | 公开日
    DE102014114673A1|2016-04-14|
    CH710245A2|2016-04-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CH662911A5|1982-06-23|1987-10-30|Micafil Ag|METHOD FOR FIXING WINDINGS BY PRESERVED SLOT CLOSING PARTS AND DEVICE FOR IMPLEMENTING THE METHOD.|
    US5325008A|1992-12-09|1994-06-28|General Electric Company|Constrained ripple spring assembly with debondable adhesive and methods of installation|
    EP2187504B1|2008-11-18|2018-10-03|ABB Schweiz AG|Slot closing device|
    EP2662956A1|2012-05-09|2013-11-13|ABB Research Ltd.|Nut locking assembly and method for fixing winding bars in the nuts of electrical machines|
    法律状态:
    2020-03-13| PUE| Assignment|Owner name: ABB POWER GRIDS SWITZERLAND AG, CH Free format text: FORMER OWNER: ABB SCHWEIZ AG, CH |
    优先权:
    申请号 | 申请日 | 专利标题
    DE102014114673.5A|DE102014114673A1|2014-10-09|2014-10-09|Arrangement for closing grooves|
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