Magnetic jar for use in moving coil components, especially in the moving coil components of scales that operate on the principle of electromagnetic force compensation.

Abstract

This invention relates to a magnetic container for a moving coil assembly, particularly for a moving coil assembly of a scale operating according to the principle of electromagnetic force compensation, comprising: a container body (102) having an inner cavity (108) having a bottom surface (114) and a circumferential surface extending perpendicularly to the bottom surface; and a permanent magnet unit (110) having a permanent magnet (112) and a pole plate (120) disposed in the inner cavity (108) of the container body (102), wherein the permanent magnet unit (110) has a permanent magnet (112) and a pole plate (120). 0) The electrode (120) is disposed in the tank (102) in such a way that an annular gap is formed between the circumferential surface of the electrode plate (120) and the circumferential surface of the inner cavity (108) of the tank (102) to accommodate the moving coil (104) of the moving coil assembly (100; 200), wherein the permanent magnet (112) is bonded to the bottom surface (114) of the inner cavity (108) of the tank (102) with its bottom side facing the bottom surface (114), wherein the permanent magnet (112) has a thickness d K An adhesive layer is formed between the bottom surface (114) and the bottom side of the permanent magnet (112), wherein the pole plate (120) is connected to the tank (102) by means of a rigid fastening mechanism (118) in a spaced manner from the permanent magnet (112) and is thus positioned such that the bottom side of the pole plate (120) faces the top side of the permanent magnet (112), and a predetermined gap width d is formed between the bottom side of the pole plate (120) and the top side of the permanent magnet (112). L The gap.

Description

Technical Field

[0001] This invention relates to a magnetic container for a moving coil assembly, particularly a moving coil assembly of a scale that operates according to the principle of electromagnetic force compensation. Background Technology

[0002] Many embodiments of magnetic containers for moving coil assemblies, also suitable for measurement purposes, have been disclosed. In principle, such magnetic containers consist of a container body, mostly designed in a bowl shape with a flat bottom, and a circular cross-section container wall extending upwards from the bottom. The container body may also have a cover, for example, that can be threaded onto the container wall. The container wall may have holes for a boom to pass through, on which a moving coil housed within the container body is mounted. The moving coil is inserted into an annular gap formed between the inner circumferential surface of the container wall and the outer circumferential surface of a magnet unit located within the container cavity. The magnet unit here consists of a permanent magnet, typically designed as an axially magnetized toroidal magnet, and a magnetic field equalization plate located at the upper end of the permanent magnet.

[0003] When using such a magnetic container in measuring devices, such as scales operating on the principle of electromagnetic force compensation, it is necessary to maintain an extremely constant position of the pole plate relative to the zero point of the moving coil. For this purpose, it has been proven insufficient to adhere the permanent magnet to the inner bottom surface of the container with its bottom side and to attach the pole plate, for example, also to the top side of the permanent magnet. This is because changes in temperature and humidity can cause variations in the adhesive layer thickness, and consequently, variations in the axial position of the pole plate. This, in turn, adversely affects the accuracy of the measuring device.

[0004] Therefore, DE 10 2017 110 930 B4 discloses a solution that, on the one hand, maintains the position of the pole plate as constant as possible, and on the other hand, avoids changes in the magnetic field when environmental conditions (especially temperature and air humidity) change. To this end, the pole plate is connected to the bottom of the magnetic container by a rigid mechanical connection, and the permanent magnet is connected to the pole plate "detached from the mechanical connection," whereby the top side of the permanent magnet is bonded to the bottom side of the pole plate. Thus, in addition to the essentially constant position of the pole plate (which may be affected at most by minor changes due to the expansion of the mechanical connection material caused by temperature), it is also achieved that when the adhesive layer thickness changes and the resulting gap width between the pole plate and the permanent magnet changes, the gap width between the bottom side of the permanent magnet and the bottom of the container changes accordingly; that is, the total width of these two gaps remains constant. Thus, changes in environmental conditions do not significantly affect the generated magnetic field, because although the total gap width remains constant, the two gaps are filled with different media (adhesive or air).

[0005] However, a drawback of this magnetic container structure is that, especially when the container is used in environments where mechanical vibration or shock may occur, the measurement accuracy is affected by the positional changes of the unit composed of the permanent magnet and pole plates relative to the container. To improve stability, additional measures such as additional support mechanisms or stabilization mechanisms are required. Summary of the Invention

[0006] In view of the prior art, the object of the present invention is to provide a magnetic container for a moving coil assembly, particularly a moving coil assembly of a scale operating according to the principle of electromagnetic force compensation, which, while maintaining a simple structure, ensures improved measurement accuracy in environments with mechanical vibration or tremors, and has better overall mechanical stability.

[0007] This invention stems from the understanding that a magnetic container of the type described in the preface for a measuring device, particularly a scale operating according to the principle of electromagnetic force compensation, can improve the achievable measurement accuracy when the mechanical structure is as insensitive as possible to acceleration, especially acceleration caused by vibration or flutter. Relatedly, the applicant has determined that in a magnetic container as described in DE10 2017 110 930 B4, the unit consisting of pole plates and permanent magnets can be held in place by a correspondingly robust rigid mechanical connection, making the entire moving coil assembly sufficiently stable against vibration and impact. To this end, this document discloses that, in addition to a support member coaxially passing through the permanent magnet, a support member is provided that additionally supports the pole plates relative to the bottom of the container and passes through or surrounds the permanent magnet without contact. However, when the volume of the permanent magnet must be reduced within a predetermined structural size due to the space requirements for the holes in the support member or the support member surrounding it, this measure results in an increase in the overall unit space requirement or a decrease in the strength of the permanent magnet.

[0008] According to the invention, the sensitivity of the mechanical connection of the magnetic can, particularly the pole plate to the bottom of the can, is reduced such that, unlike what is required by DE 10 2017 110 930 B4, the permanent magnet is not connected to the pole plate, but rather to the bottom of the can. Thus, the mass of the "swinging" suspension (the possible vibrations caused here by the particularly non-rigid mechanical connection between the pole plate and the can body or bottom of the can) is reduced because it consists only of the mass of the pole plate. According to the invention, the permanent magnet is bonded to the bottom of the can with its bottom side facing the bottom surface of the can's inner cavity.

[0009] Therefore, the electrode plate is separated from the permanent magnet, and the electrode plate should be connected to the tank by means of a rigid fastening mechanism and thus positioned such that the bottom side of the electrode plate faces the top side of the permanent magnet, and a gap with a predetermined gap width is formed between the bottom side of the electrode plate and the top side of the permanent magnet.

[0010] In this solution according to the invention, the design structure of the magnetic can used for the measuring device also achieves this: when environmental conditions (especially temperature and / or air humidity) change, causing variations in the thickness of the adhesive layer between the can bottom and the permanent magnet, the sum of the gap widths—the gap between the can bottom and the permanent magnet, and the gap between the permanent magnet and the electrode plate—remains substantially constant. The sum of the gap widths may be affected by temperature-induced length variations in the mechanically rigid connection between the can bottom and the electrode plate; however, this effect is negligible in practice.

[0011] Because the mass connected to the tank via a mechanical connection (which is clearly not entirely rigid in practice) is relatively small, there is low sensitivity to vibrations or vibrations acting on the magnetic tank. There are also advantages such as the mechanical connection being virtually undamaged by severe impacts, for example, during the transport of related measuring devices, even if the magnetic tank is subjected to severe shocks, resulting in deformation or even breakage. Furthermore, the mechanical connection can have a smaller structural size, allowing for the use of larger permanent magnets within the predetermined structural dimensions of the entire unit, or achieving a smaller overall structural size for the entire unit (consisting of the pole plates, permanent magnets, and mechanical connection).

[0012] According to the present invention, the fastening mechanism can, in principle, be designed in any way to hold and fix the position of the electrode plate. It only needs to ensure that the electrode plate is rigidly connected to the canister and therefore has sufficient rigidity for its respective application, so that vibrations or vibrations acting on the canister do not cause relative movement of the electrode plate relative to the canister. Furthermore, the fastening mechanism should be designed to ensure sufficient strength so that impacts or vibrations that may occur, especially during the transport of the relevant measuring device or magnetic canister, do not damage the magnetic canister (e.g., bending or breakage of the fastening mechanism).

[0013] According to one embodiment of the invention, the fastening mechanism has a support member passing through the permanent magnet, wherein the passage is made in a non-contact manner or at least in such a manner that, although there is contact, movement (e.g., sliding) between the permanent magnet and the support member is allowed without generating a significant radial clamping force that would cause a stick-slip effect when these components move relative to each other in the penetration direction. This avoids the transmission of axial (or radial) forces to the support member when the thickness of the adhesive layer between the can bottom and the permanent magnet changes, and thus when the permanent magnet moves along its axial direction (i.e., perpendicular to the can bottom), which would cause the pole plate held by the support member to move (suddenly).

[0014] According to one embodiment, the support member can be threadedly connected to the electrode plate and / or the tank body. In particular, the connection between the support member and the tank body, especially the tank bottom, can be made via a threaded connection. The connection between the electrode plate and the support member can be made, in addition to a threaded connection, by means of material joining such as welding. One-piece manufacturing of both parts is also feasible.

[0015] The support component, when manufactured as a separate element, can have an upper stop surface that mates with the bottom side of the electrode plate and an upper threaded shaft head that inserts into the threaded hole in the electrode plate. The support component can also have a lower stop surface that mates with the bottom surface of the tank's inner cavity in the same manner. The threaded connection between the lower end of the support component and the tank body can be made using a threaded shaft head provided on the lower end of the support component, which is inserted into a threaded hole in the bottom of the tank. However, the threaded connection can also be made by having a threaded hole in the bottom side of the support component, into which a screw passing through the bottom of the tank is inserted.

[0016] According to another embodiment, the support member can consist of a screw and a spacer sleeve, wherein the screw passes through the spacer sleeve. In this case, the spacer sleeve forms a stop surface that mates with the bottom side of the electrode plate or the bottom surface of the tank. The tip of the screw is inserted into a threaded hole in the bottom side of the electrode plate.

[0017] According to another embodiment, the fastening mechanism may include one or more supports (e.g., three supports evenly distributed circumferentially) that support the pole plate relative to the bottom surface of the tank cavity and are positioned on the outer circumferential surface of the permanent magnet without contact with it, or in contact with it, i.e., allowing sliding movement between the permanent magnet and the one or more supports without generating a significant radial clamping force that would cause a stick-slip effect when these components move relative to each other in the longitudinal extension direction of the one or more supports. Here, in addition to a central or coaxial support, the one or more supports may also be provided. The support can be fixed in place solely by an axial clamping force between the pole plate and the tank, particularly the bottom surface of the tank. Because the support is positioned on the outer circumferential surface of the pole plate, tilting movement of the pole plate can be effectively prevented. The one or more supports may also be connected (only) to the pole plate at their upper ends, for example, to the bottom side of the pole plate, or (only) to the tank, particularly the bottom of the tank, at their lower ends. The pole plate can be installed in this case by a simple means using screws (preferably coaxial) passing through the permanent magnet. In this case, it is not necessary to use a support member that is also the center or coaxial with the spacer.

[0018] According to one embodiment, the fastening mechanism may include a support member with a hollow cylindrical cross-section that surrounds the permanent magnet non-contactly on its outer peripheral surface (or surrounds it in contact, i.e., without transmitting large axial forces). The installation can be carried out as described above using screws (with or without additional spacers) that coaxially pass through the permanent magnet at its center. The support member may also be connected (only) to the pole plate or (only) to the bottom of the tank.

[0019] According to one embodiment, the fastening mechanism may consist only of one or more supports surrounding the permanent magnet, wherein the pole plate is secured such that it is connected to the upper end of one or more supports and the lower end of the supports is connected to the tank body, particularly the bottom of the tank. The connection between the upper or lower ends may be an inseparable connection, such as a material-bonded connection (including manufacturing the pole plate and at least one support as a single piece). It is also conceivable that the pole plate and at least one support are integrally manufactured from the same material, but this material must certainly be ferromagnetic. In this case, however, the cross-section of the at least one support should be chosen to be very small so that the magnetic reluctance can be increased sufficiently to avoid a magnetic short circuit. In a variation with supports that only surround the permanent magnet, the coaxial through-hole of the permanent magnet can be omitted, and a cylindrical, particularly cylindrical (axially magnetized) permanent magnet can be used instead of a ring magnet. Attached Figure Description

[0020] The present invention will now be explained in detail with reference to the embodiments shown in the figures. The figures show:

[0021] Figure 1 A first embodiment of the magnetic can according to the invention is shown, wherein the magnetic can has a central support member coaxially penetrating a permanent magnet, which has threaded protrusions on both sides and is thus inserted into corresponding threaded holes in the pole plate or the bottom of the can;

[0022] Figure 2 A second embodiment of the magnetic container according to the invention is shown, which has a central support member coaxially penetrating a permanent magnet and an additional support member surrounding the permanent magnet, wherein the central support member includes a spacer sleeve and a screw penetrating the spacer sleeve. Detailed Implementation

[0023] Figure 1 The moving coil assembly 100 is shown for a measuring device, particularly an electronic scale (not shown in detail) that operates according to the principle of electromagnetic force compensation.

[0024] The moving coil assembly 100 has a magnetic container 102 shown as its main component and a moving coil 104, which is inserted into the magnetic container and is also not shown in detail. The moving coil 104 is mounted on a component of the measuring device, such as the lever arm of an electronic scale that operates according to the principle of electromagnetic force compensation, wherein the force acting on the component may be transmitted to the moving coil at a certain lever ratio.

[0025] The magnetic container 102 has a container body 106 with an inner cavity 108, in which a magnet unit 110 is disposed. The magnetic container 102, particularly the container body 106 and the magnet unit 110, can be designed to be substantially rotationally symmetric about a rotational axis A. However, this is not necessarily required, where, in this case, axis A can be understood as the longitudinal extension direction of the relevant components. The magnet unit includes a permanent magnet 112, which in the illustrated embodiment is designed as an axially magnetized annular magnet. The annular magnet can have a circular outer periphery and a circular through-hole, as in the illustrated embodiment. The lower end (bottom) of the permanent magnet 112 is bonded to the bottom surface 114 of the inner cavity 108 of the container body 106. The adhesive layer 116 has a thickness d. K The annular magnet 112 has a central coaxial hole through which a fastening mechanism 118 for the pole plate 120 (which also belongs to the magnet unit 110) protrudes. The pole plate, like the fastening mechanism 118, is positioned within the cavity 108 of the can 106 in a manner that substantially does not contact the permanent magnet 112. The pole plate 120 is arranged above the upper end (top side) of the permanent magnet 112, wherein a gap of width d is provided between the bottom side of the pole plate and the top side of the permanent magnet. L The air gap. In the illustrated embodiment, the electrode plate 120 has a cylindrical (especially circular) shape, wherein the circumferential surface of the electrode plate 120 is flush with the circumferential surface of the permanent magnet 112 in the axial direction.

[0026] Fastening mechanism 118 in such Figure 1 In the illustrated embodiment, a support member 122 is designed to protrude through an axial hole in the permanent magnet 112 via a cylindrical region 124. At the upper and lower ends of the cylindrical region 124, the support member has threaded ends 126, wherein the lower threaded end 126 is inserted into a threaded hole in the bottom of the canister 106, and the upper threaded end 126 is inserted into a threaded hole (from the bottom side) in the electrode plate 120. The support member 122 has stop shoulders between the cylindrical region 124 and the respective threaded ends 126, the stop shoulders engaging with the bottom surface 114 of the cavity 108 of the canister 106 or the bottom side of the electrode plate 120, wherein the axial length of the cylindrical region 124 between the two stop shoulders is defined as the distance between the bottom surface 114 and the bottom side of the electrode plate 120. This distance is chosen such that the gap width d is obtained. L The predetermined value.

[0027] The permanent magnet 112 or the pole plate 120 are respectively arranged in the inner cavity 108 of the can 106 such that there is an annular gap between the outer peripheral surface of the permanent magnet 112 or the pole plate 120 and the peripheral surface of the inner cavity 108, and the moving coil 104 is inserted into this annular gap. The pole plate 120 is used here to homogenize, and especially "focus," the magnetic field generated by the permanent magnet 112 within the annular gap. Preferably, the annular gap has a constant gap width around the pole plate 120 throughout its entire range (in a plane perpendicular to the longitudinal axis of the permanent magnet or the annular magnet 112). The peripheral surface of the inner cavity 108 does not necessarily have to be strictly designed as a cylinder with a constant radius. Instead, it may prove advantageous for the peripheral surface or inner wall of the inner cavity 108 to have a protrusion, wherein the peripheral surface has a smaller radius in the region of the protrusion than above or below the protrusion.

[0028] The fastening mechanism 118 for the electrode 120, constituted by the support member 122, is mechanically rigid enough that, under mechanical loads within a predetermined range, there is no or at most a relative movement between the electrode 120 and the tank 106 (e.g., tilting or oscillation of the electrode about one or two mutually perpendicular axes in a horizontal plane (or a plane parallel to the bottom surface 114 of the tank 106)). This ensures that even in the event of vibration or other tremors during measurement, the position of the electrode within the tank 106 and consequently the position of the electrode relative to the moving coil 104 remains sufficiently constant, so that no influence occurs on the measurement results, or such influence is only within the predetermined error.

[0029] As explained above, any form of change in the position of the electrode plate (i.e., tilting or translational motion of the electrode plate, said motion having a component in the direction of the axis of the moving coil or permanent magnet) affects measurement accuracy. For this reason, a mechanical rigid connection between the electrode plate 120 and the tank 106 has been chosen, wherein such a mechanical rigid connection between the components, namely the electrode plate, the fastening mechanism, and the tank, can be achieved, in particular, by threaded connection, welding, or by manufacturing two of the respective components. It is to be avoided that connections are obtained solely by adhesive bonding or by using materials that undergo volume changes under environmental influences, especially temperature and humidity (e.g., due to swelling caused by moisture accumulation).

[0030] The electrode plate 120 is made of a ferromagnetic material, especially a ferromagnetic metal such as steel, while the fastening mechanism 118, especially the support member 122, should be made of a non-ferromagnetic material. This achieves magnetic isolation between the electrode plate 120 and the can 106, which is also made of a ferromagnetic material, thus preventing magnetic short circuits between these components. Therefore, a desired high field line density, i.e., a desired high magnetic flux, is obtained, particularly within the annular gap between the electrode plate 120 and the can 106.

[0031] The arrangement of magnet 112 on the bottom surface of the inner cavity 108 of the tank has advantages over the structure according to DE 10 2017 110 930 B4, namely, the mass held by the mechanically rigid fastening mechanism 118 is significantly smaller. Therefore, the fastening mechanism 118 can have a smaller or lighter size, or it can have significantly greater rigidity for the same size setting, resulting in less relative movement between the pole plate 120 and the tank 106 under the same mechanical load.

[0032] Furthermore, the aforementioned structure of the magnetic container 102 also ensures the following advantage: the gap width d between the bottom surface 114 and the bottom side of the permanent magnet 112 is... K The gap width d between the top side of the permanent magnet 112 and the bottom side of the pole plate 120 L The sum remains constant even under varying environmental conditions, especially changes in air humidity and temperature. This is because the gap width d... K The gap width d varies in one direction. L Reverse change. For example, if the gap width d... K The gap width d increases due to increased air humidity and / or temperature. L The same value is reduced. This results in the magnetic reluctance of the gap created by the adhesive layer 116 and the air layer remaining almost constant, even if the corresponding gap width changes (in the opposite direction).

[0033] Figure 2 Another embodiment of the moving coil assembly 200 is shown, in which the same or identical parts or components are used according to Figure 1 The same reference numerals are used to indicate the embodiments.

[0034] Unlike according to Figure 1 In this embodiment, the support member in the moving coil assembly 200 is constituted by a spacer sleeve 202 and a screw 204 passing through the spacer sleeve. The screw 204 protrudes through a central hole in the bottom of the canister 106, wherein the hole can be widened on the bottom side of the canister to accommodate the screw head. Here, neither element, the screw 204 nor the spacer sleeve 202, should be made of ferromagnetic material, especially ferromagnetic metal, to avoid magnetic flux paths and, consequently, magnetic short circuits. The spacer sleeve 202 should in any case be made of a material that is insensitive to changes in environmental conditions, especially changes in air humidity (which relates to changes in its volume, especially its length).

[0035] In the two-piece support embodiment, the spacer sleeve can be precisely positioned (to ensure non-contact installation relative to the permanent magnet 112) such that the screw is accurately (without gap or with a very small gap) inserted into the hole in the bottom of the can, and the spacer sleeve 202 also surrounds the screw 204 with no gap or with a very small gap. Furthermore, the end face of the spacer sleeve that mates with the bottom surface 114 or the bottom side of the pole plate 120 should be configured to be exactly perpendicular to the relevant surface, such that the spacer sleeve is positioned exactly perpendicular to the bottom surface 114 or parallel to the longitudinal axis of the screw. Alternatively or additionally, to position the spacer sleeve 202 and, consequently, the pole plate 120, a concave surface can be formed on the bottom side of the pole plate 120 and / or inside the bottom of the can, and the respective ends of the spacer sleeve 202 are inserted into the concave surface with no gap or with a very small gap. This fastening measure using concave surfaces can also be applied to other components, such as spacer 206 (see below).

[0036] Although the premise above states that "the fastening mechanism 118 should be substantially non-contact with the permanent magnet 112," contact may still exist when it is designed so that there is no significant clamping force between the permanent magnet and the fastening mechanism. The clamping force should be sufficiently small to prevent stick-slip between the permanent magnet 112 and the fastening mechanism 118, such as the support member 122, when the axial position of the permanent magnet 112 changes. This is because sudden movement of the permanent magnet could occur, causing vibration and consequently distorting measurement results. Therefore, a contact arrangement can be specified instead of a completely non-contact fastening mechanism 118 arrangement with respect to the permanent magnet 112, provided that sufficient sliding capability is ensured between the opposing components, for example, through appropriate material selection and / or an additional sliding layer in the form of a liquid or gel between the contact surfaces.

[0037] In order to be based on Figure 1 and Figure 2 The installation of the aforementioned embodiment can be performed, for example, by first bonding the permanent magnet 112 to the bottom of the can 114. This can be accomplished, for example, by pre-installing a centering member instead of a support member, wherein the diameter of the centering member corresponds to the inner diameter of the notch in the permanent magnet 112. After the adhesive has hardened, the centering member can be removed and a replacement support member 122 can be installed, the outer diameter of which is smaller than the notch in the permanent magnet 112. In this way, a non-contact installation can be performed between the fastening mechanism 118 and the permanent magnet.

[0038] If contact mounting is required between the fastening mechanism 118 and the permanent magnet 112, the fastening mechanism (e.g., support 122 or even spacer 202) and screw 204 can also be used as a centering device during installation.

[0039] Alternatively, a positioning auxiliary mechanism for the permanent magnet 112 can be provided on the bottom surface of the tank 106. For example, this bottom surface could have stop surfaces that abut against the circumferential surface of the permanent magnet 112 for centering. Figure 1 As schematically shown, this stop surface can be formed by one or more protrusions 128 provided on the bottom of the can. For example, three protrusions spaced at 120º angles can be provided. Such protrusions can also extend over the entire range of the permanent magnet 112. The height of the protrusions 128 should be relatively low to avoid obstruction of the adhesive layer 116 at its thickness d. K The stick-slip effect between the permanent magnet 112 and the protrusion or its stop surface during changes. The height of such stop surface should be selected such that it overlaps with the height of the permanent magnet (i.e., the axial extension dimension of the permanent magnet) by no more than 5 to 15% in the mounted or bonded state of the permanent magnet 112.

[0040] Obviously, it is also possible to do so. Figure 2 The illustrated embodiment includes an installation auxiliary mechanism in the form of a protrusion or a stop surface.

[0041] exist Figure 2 In the illustrated embodiment, the fastening mechanism also includes at least one spacer 206. It may be connected, for example, to the electrode plate 120. The spacer 206 may be designed as a hollow column with a predetermined (preferably relatively small) wall thickness. The height or axial extension dimension of the hollow column corresponds to the spacer sleeve 202. It may also be slightly larger, so that when the screw 204 is tightened sufficiently to subject the spacer sleeve to force from both the bottom side and the bottom surface of the electrode plate 120, a preload is generated within the at least one spacer by means of the screw 204. Instead of the hollow cylindrical spacer 206, it is also apparent that multiple, for example, three spacers may be arranged circumferentially along the electrode plate, for example, at an angular spacing of 120°.

[0042] according to Figure 2 The implementation can also be modified such that a cylindrical magnet is used instead of the annular magnet 112, and the fastening mechanism 118 has only at least one support member surrounding the magnet. It can be pre-attached to the pole plate 120 before installation. This support member can, for example, be substantially designed as a hollow cylinder (e.g., Figure 2 (As shown) and has a flange extending outward along its entire circumference at its lower end, or has multiple flange areas extending outward from the lower end or bottom end. The outer periphery of the flange (in a horizontal plane or in a plane parallel to the bottom surface 114) can then be connected to the tank body, for example, by threaded connection to the bottom of the tank. The outer periphery of the flange can here be designed to serve as a centering mechanism when the electrode is installed using a support member thus formed, wherein the outer periphery of the flange mates with the inner surface of the inner cavity 108 of the tank body in such a way that there is a precisely defined (unambiguous) position with respect to the electrode and the support member.

[0043] List of reference numerals

[0044] 100 dynamic coil assembly

[0045] 102 Magnetic Jars

[0046] 104 Dynamic

[0047] 106 tanks

[0048] 108 Inner cavity

[0049] 110 Magnet Units

[0050] 112 permanent magnet

[0051] 114 Bottom

[0052] 116 Adhesive layer

[0053] 118 Fastening mechanism

[0054] 120 plate

[0055] 122 support components

[0056] 124 Cylindrical Zone

[0057] 126 threaded shaft end

[0058] 128 protrusions

[0059] 200 dynamic coil assembly

[0060] 202 Spacer Sleeve

[0061] 204 screws

[0062] 206 Spacer

[0063] d K The gap width of the adhesive layer

[0064] d L Air gap width

[0065] A. Rotation axis (longitudinal extension direction).

Claims

1. A magnetic pot for a moving coil assembly, having: (a) a pot body with an inner cavity (108) having a bottom face (114) and a peripheral face extending perpendicularly to the bottom face, and (b) a magnet unit (110) with a permanent magnet (112) and a pole plate (120) arranged in the inner cavity (108) of the pot body, the magnet unit (110) being arranged in the pot body in such a way that an annular gap for accommodating a moving coil (104) of the moving coil assembly is formed between the peripheral face of the pole plate (120) and the peripheral face of the inner cavity (108) of the pot body, characterized in that (f) the fastening means (118) comprise a bearing element which penetrates the permanent magnet (112), wherein the penetration is effected in a contactless manner or at least in such a way that, despite contact, axial movement between the permanent magnet (112) and the bearing element is permitted without a significant radial clamping force being generated which, when the components are moved relative to one another in the direction of penetration, leads to a stick-slip effect. The moving coil assembly is a moving coil assembly of a scale which operates according to the principle of electromagnetic force compensation. The bearing element (122) is screwed to the pole plate (120) and / or to the pot body. (c) wherein, The bearing element has an upper stop face which cooperates with the bottom side of the pole plate (120), and the bearing element has a lower stop face which cooperates with the bottom face (114) of the inner cavity (108) of the pot body. (d) wherein the permanent magnet (112) is bonded to the bottom surface (114) with its bottom side facing towards the bottom surface (114) of the inner cavity (108) of the tank body, wherein a glue layer having a thickness d K is formed between the bottom surface (114) and the bottom side of the permanent magnet (112), and (e) wherein the pole plate (120) is connected to the tank body in a manner spaced apart from the permanent magnet (112) by means of a rigid fastening and is positioned there in such a way that the bottom side of the pole plate (120) faces the top side of the permanent magnet (112) and a gap having a predetermined gap width d L is formed between the bottom side of the pole plate (120) and the top side of the permanent magnet (112), The bearing element is composed of a screw (204) and a spacer sleeve (202), wherein the screw (204) penetrates the spacer sleeve (202), and wherein the spacer sleeve (202) forms the upper stop face and the lower stop face. The fastening means (118) further comprise at least one support element which supports the pole plate (120) relative to the bottom face (114) of the inner cavity (108) of the pot body and which is arranged in contactless fashion or in such a way that, despite contact, sliding movement between the permanent magnet (112) and the at least one support element is permitted without a significant radial clamping force being generated which, when the permanent magnet (112) and the at least one support element are moved relative to one another in the longitudinal extension of the at least one support element, leads to a stick-slip effect, on the outer periphery of the permanent magnet (112).

2. The magnetic pot of claim 1, wherein The fastening means (118) comprise a support element which is hollow-cylindrical in cross section.

3. The magnetic pot of claim 1, wherein, The at least one support element is connected to the pole plate (120).

4. The magnetic pot of any one of claims 1 to 3, characterized in that The at least one support element is connected to the pot body.

5. The magnetic pot of claim 4, wherein ​ 6. The magnetic pot of claim 5, wherein ​ 7. The magnetic pot of claim 6, wherein ​ 8. A magnetic pot according to claim 6 or 7, characterised in that ​ 9. The magnetic pot of claim 8, wherein, ​

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