Electromagnetic brake

Abstract

An electromagnetic brake (20) having a casing body (21) and an armature disc (25), the armature disc (25) being axially guided in the casing body (21) via a groove-projection connection (32) and having at least one guide groove (21a) and at least one associated guide projection (25a), each guide groove (21a) being arranged in the casing body (21).

Description

[Technical field]

[0001] The present invention relates to an electromagnetic brake according to the preamble of claim 1. Furthermore, the present invention relates to a method for assembling such an electromagnetic brake according to the preamble of claim 8.

[0002] An electromagnetic brake of this kind is known from Korean Patent No. 101299558. In this brake, the armature disc includes a guide projection for guiding the armature disc in the cover of the brake. The guidance of the armature disc relative to the casing body is effected via a pin which engages in a hole in the casing body or in a hole in the armature disc.

[0003] Further electromagnetic brakes are known from DE 102014001474, DE 10049168 or DE 2832723. The electromagnetic brakes described therein are mounted using a friction-coupled connection and are used, for example, in robots or elevators.

[0004] Electromagnetic brakes with axial guidance of the armature disc in a housing body are known from DE 10 2012 001 701 A1 and DE 41 09 786 A1. Here, part of the guidance is formed by a through-hole in the outer wall of the housing body in each case. In DE 10 2017 000 845 A1, the armature disc is axially guided in the housing body by a stud bolt.

[0005] A further electromagnetic brake is known from JP 05-256330.

[0006] Starting from this prior art, the object on which the present invention is based is to create an improved electromagnetic brake which is particularly simple to install.

[0007] This problem is solved by an electromagnetic brake with the features of claim 1 and by a method with the features of claim 8. Advantageous configurations of the invention are set out in the dependent claims as well as in the following description.

[0008] According to the invention, an improved electromagnetic brake with a housing body and an armature disk is created in that the housing body contains a pole core and the armature disk is axially guided in the housing body via a groove-projection connection, and is provided with at least one guide groove, preferably three guide grooves, and at least one associated guide projection, preferably three associated guide projections. In addition to the axial guidance, the guide groove of the groove-projection connection also has the function of limiting the circumferential rotatability of the armature disk in such a way that this rotatability is only permitted within the framework of the play required for the axial movement.

[0009] The casing body has a substantially hollow cylindrical and ring-like shape with an opening at the end face of the casing body and a bottom opposite the end face. The casing body is preferably formed in one piece. The material of the casing body is selected such that its rigidity is sufficient for the forces occurring during one or more braking operations and its temperature resistance is sufficient for the temperatures occurring during one or more braking operations. In addition, the material of the casing body is preferably magnetic.

[0010] The respective guide groove is preferably arranged in the housing body and is formed in particular in its housing wall. The housing wall is closed towards the outside in the region of the groove-projection connection and therefore in particular in the region of the guide groove, since the guide groove is not a through hole in the housing wall but a recess in the housing wall of the housing body. A through hole through which the guide projection can pass completely is therefore not a guide groove according to this understanding. It is also conceivable that the guide groove, in particular in the form of a recess, is arranged in the armature disk and that a corresponding projection-shaped contour is arranged in the housing body as the guide projection, which contour is preferably an integral part of the housing body and is formed in particular in the housing wall of the housing body. In both of the above-mentioned cases, the housing wall is closed towards the outside in the region of the groove-projection connection. This achieves improved protection against environmental influences. It is further advantageous that no movable elements, such as the guide projections, protrude from the housing body, so that undesirable collisions with other components can be avoided.

[0011] In order to allow the axially slidable armature disk to be guided in the housing body without tilting, preferably three guide grooves and three associated guide projections are provided. The guide grooves and the guide projections are preferably evenly distributed over the circumference of the housing body or the armature disk. The outer contour of the guide projections is formed similarly or identically to the inner contour of the guide groove, and between the outer contour of the guide projections and the inner contour of the guide groove there is sufficient clearance for the axial movement of the armature disk.

[0012] The material of the armature disc is selected so that its stiffness is sufficient to withstand the forces generated during one or more braking cycles and its temperature resistance is sufficient to withstand the temperatures generated during one or more braking cycles.

[0013] The armature disk is preferably guided axially in the housing body exclusively via the aforementioned groove-projection connection. Further guide elements, such as guide bolts or guide sleeves, are not required for guiding the armature disk in the housing body. They can therefore be omitted, which results in reduced construction and manufacturing costs. This is particularly true if the guide elements are frictionally fastened to the housing body, for example by means of screws.

[0014] Thus, unlike the prior art, the inventive electromagnetic brake allows for simplified assembly, such that the electromagnetic brake can be installed more easily in a semi-automated or fully automated manner. This advantage also applies to material-bonded connections, which allows for simple assembly in manufacturing plants designed in the sense of Industry 4.0, in particular by means of robots.

[0015] Besides the casing body and the armature disc, the electromagnetic brake preferably also comprises a coil unit, which can be excited by the coil unit and which is arranged inside the coil unit, a pole core, at least one compression spring, a brake disc and a friction disc. The coil unit, the pole core, the compression spring(s), the brake disc and the friction disc are preferably arranged in the casing body, as is the armature disc. Preferably, the coil unit, the armature disc, the brake disc and the friction disc, or at least some of them, are attached to and connected with the casing body during assembly via openings in the end faces. This also preferably applies to the compression spring(s). The pole core can be a constituent part of the casing body.

[0016] The materials of the pole core, the friction disc and the brake disc are selected such that their stiffness is sufficient to withstand the forces occurring during one or more braking cycles and their temperature resistance is sufficient to withstand the temperatures occurring during one or more braking cycles. The pole core is further made of a magnetic material so that it can be excited by the coil unit.

[0017] The brake disc is preferably arranged between the axially slidable armature disc and the friction disc, and is adjusted to be rotatable and axially slidable. The at least one compression spring is arranged and adjusted such that the armature disc can slide axially toward the brake disc by the pressure of the compression springs. Meanwhile, the coil unit and the pole core are arranged and adjusted such that a tension force can be generated by the pole core electromagnetically excited by the coil unit, and the armature disc can slide axially away from the brake disc by the tension force.

[0018] The brake disc can be connected to a shaft, in particular a drive shaft, in particular an output shaft of a motor, where the casing body, the coil unit, the pole core, the compression spring, the armature disc and / or the friction disc may need to be formed in the shape of a ring, each of which has a hole or opening through which the shaft can be guided.

[0019] In a first operating state of the electromagnetic brake, i.e. during braking, the armature disc presses the brake disc against the friction disc by the compression force of at least one compression spring, braking the brake disc by a braking torque generated between the brake disc and the friction disc and / or between the brake disc and the armature disc. The friction disc and / or the armature disc preferably each have a suitable structured surface on the side facing the brake disc, so that an optimal deceleration of the brake disc during braking is ensured.

[0020] In a second operating state of the electromagnetic brake, i.e., when vented, the armature disc is positioned away from the brake disc by a tension force formed by the coil unit and the pole core that is greater than the compression force of at least one compression spring, thereby allowing free, and therefore unbraked, rotation of the brake disc.

[0021] In an advantageous configuration, the friction disc is connected to the housing body by a positive lock, preferably in bayonet type, and / or is locked against rotation relative to the housing body, such a bayonet type connection being also called a bayonet lock.

[0022] In other words, the housing body and the friction disc are each provided with a corresponding shape, which is designed and adjusted in such a way that the housing body and the friction disc can be connected in a form-locking manner. Such a form-locking, in particular a bayonet-type connection, can be established in particular by first inserting, setting, positioning, adjusting or sliding the housing body and the friction disc into one another and bringing them into engagement with one another.

[0023] A preferred embodiment of a bayonet connection, which is a preferred special type of form-fitting connection, also called a bayonet lock, will now be described in detail.

[0024] The friction disc is formed as a substantially circular, preferably ring-shaped, disc and has at least one outwardly directed projection on its periphery, by means of which the friction disc is supported in the housing body by positive lock and in a bayonet-like manner. At least two projections are necessary in order to be able to prevent the friction disc from lifting off the housing body. The friction disc preferably has three projections, which are arranged on the circumference of the friction disc at an angle of 120° each. The friction disc is thus preferably formed rotationally symmetrically, so that the projections are evenly distributed on the circumference of the friction disc. Of course, other numbers of projections are also conceivable.

[0025] The housing body has at least one recess in the region of the end face, which is followed by a receiving groove. The recess is therefore arranged in a web on the end face of the housing body, which web is formed by the outer wall of the housing body and defines the receiving groove. The housing body has such a recess and a respective subsequent receiving groove for each projection of the friction disc, i.e. preferably has three receiving grooves. Of course, a different number of recesses and respective subsequent receiving grooves is also conceivable. Here, the recess is respectively attached to the housing body at a position corresponding to the projection. The recess makes it possible to insert the friction disc or its projection into the receiving groove and thus to establish a form-locking connection between the housing body and the friction disc. The receiving grooves preferably run partially around and extend at a distance from one another into the outer wall of the housing body. Such a partial arrangement of the grooves has the advantage that the final mounting position of the friction disc in the housing body can be easily determined by the end of the groove, which is in particular closed, facing away from the recess, thereby simplifying the subsequent assembly steps. By means of its closed end, the grooves thus each define a bayonet seat, which makes it easier to find the final mounting position during assembly. Instead of providing several separate grooves for the projections of the friction disc, it is alternatively possible to provide a single groove running all around.

[0026] To establish the bayonet connection, the projection of the friction disc is first guided through the recess in the housing body. The contour of the projection of the friction disc and the contour of the recess in the housing body are matched to one another in such a way that the projection passes through the recess with sufficient play in the mounting position. In a second step, the projection of the friction disc is guided from the recess into the receiving groove in the housing body and is also slid in the direction of rotation. The friction disc and the housing body are now rotated relative to one another in the manner typical for bayonet locks. The material thickness of the projection and the width of the receiving groove are matched to one another in such a way that the projection can move in the direction of rotation in the receiving groove with sufficient play.

[0027] No further elements are required to establish the connection between the friction disc and the housing body, thus simplifying the assembly so that the electromagnetic brake can be mounted more easily in a semi-automated or fully automated manner, in contrast to the prior art, in which the connection between the friction disc and the housing body or between the friction disc and other elements of the electromagnetic brake is made frictionally connected, in particular by means of screws. This advantage is also obtained for material-bonded connections.

[0028] The friction disk is pressed against the outer web of the outer wall of the housing body, which defines the receiving groove, via the armature disk and the brake disk, by the compression force generated by at least one compression spring during braking. The friction disk is attracted to the inner web of the receiving groove by the magnetic field generated by the coil unit and the pole core and the tensile force resulting therefrom during ventilation. Although a purely form-locking connection is formed between the housing body and the friction disk during assembly of the electromagnetic brake, the friction disk is attracted or pressed against one of the webs adjacent to the receiving groove of the housing body during operation by the forces acting thereon. As a result, vibrations and thus noise occurring at the friction disk during operation of the electromagnetic brake can be reduced or even avoided.

[0029] The friction disc is locked against rotation relative to the housing body, in particular during operation of the electromagnetic brake. This prevents the friction disc from rotating after the establishment of a positive-locking connection, in particular a bayonet connection, which would lead to the disconnection of the friction disc and the housing body. In particular after the friction disc has been positioned in the receiving groove, it is not possible for the friction disc to rotate out of the receiving groove in the direction of the adjacent recess. Such a rotation could also result in the disconnection of the connection between the friction disc and the housing body if the projections and the recesses coincide. For such a rotation lock, a correspondingly shaped contour is preferably provided in the friction disc, preferably on at least one of the projections, into which the locking element engages. The rotation lock can thus be established by a positive lock between the friction disc and the locking element.

[0030] Advantageously, the friction disc is locked against rotation relative to the casing body by at least one locking element, which is preferably a connecting element used to attach the electromagnetic brake to a component, for example for flange mounting to a motor or a cable drum. The locking element can be, for example, a pin or a screw, which engages into the contour of the friction disc and thereby creates a form-locking rotational lock.

[0031] The locking element is preferably guided into one of the projections of the friction disc through a hole in the casing body and a contoured recess, neither the hole in the casing body nor the recess in the projection of the friction disc has a thread, so that a purely form-locking connection is made between the locking element and the friction disc and between the locking element and the casing body, even when screws are used.

[0032] Depending on the expected operating load of the electromagnetic brake, it may be necessary to use several locking elements. In this case, for each locking element, a corresponding projection with a recess is preferably provided on the friction disk. However, if the number of locking elements is smaller than the number of projections, it is also conceivable not to provide each projection with a corresponding contour or recess.

[0033] If more connection elements are possibly required to mount the electromagnetic brake to a component than are required for the rotation lock of the friction disc, the remaining connection elements can be guided through the electromagnetic brake at another position independent of the friction disc or its projections or fixed to the electromagnetic brake.

[0034] Advantageously, a coil unit is provided which is preferably connected to the housing body only in a form-locking manner and / or which is locked against rotation relative to the housing body.

[0035] The coil unit preferably has a substantially ring-like geometry with an outwardly open C-shaped cross section, the coil unit being formed as a coil support and suitable for accommodating or supporting one or more coils on or within the coil unit itself.

[0036] Preferably, a positioning lug arranged on the coil unit engages in a corresponding similarly shaped, preferably identically shaped, receiving part in the casing body, thereby locking the coil unit against rotation relative to the casing body, but it is also conceivable that a corresponding receiving part is arranged in the coil unit and that a corresponding positioning lug is arranged on or in the casing body.

[0037] In contrast to the prior art, where the coil unit is cast in a housing body with synthetic resin in a material-bonded manner, the electromagnetic brake according to the invention simplifies assembly so that the electromagnetic brake can be installed more easily in a semi-automated or fully automated manner, with the advantage also being achieved in comparison with frictionally-bonded connections.

[0038] In a structurally simple manner, the coil unit is connected in a form-fitting manner to the housing body by a snap connection, preferably with at least one snap hook of the coil unit being supported on a web of the housing body. The snap hook is respectively dimensioned and material-technically designed in such a way that, when the coil unit is attached to the housing body, the housing body is elastically deformed by the application of a force, the snap hook engaging in a groove provided in the housing body, the force acting here being parallel to the central axis of the housing body in the direction of the bottom of the housing body.

[0039] Since the coil unit has a substantially ring-like geometry, the coil unit preferably has at least three snap hooks, although of course other numbers of snap hooks are also conceivable, this number being preferably determined taking into account the forces that will be generated.

[0040] The snap hook may be an integral component of the coil unit, however, it is also conceivable that the snap hook is a separate component and connected to the coil unit.

[0041] Furthermore, it is particularly advantageous for the coil unit to be supported in the housing body in such a way that, for ease of assembly, the coil unit is flexible at least in the region where it is connected to the housing body by a positive fit and is therefore axially movable relative to the housing body. For this purpose, the coil unit has a step on the side facing the bottom of the housing body, so that flexibility of the coil unit is achieved at least outside the step. This step is preferably arranged on a diameter that is essentially the diameter of the ring-shaped coil unit and that is as far away as possible from the diameter of the coil unit on which the snap hook is arranged. Outside the step, for example in the region of the inner diameter on which the snap hook is arranged, a space remains between the coil unit and the bottom of the housing body. This space is used as a kind of spring deflection, so that during assembly, the coil unit can be pushed axially towards the housing body by its local flexibility, so that the snap hook can be even more easily engaged in the groove of the housing body.

[0042] The assembly of the electromagnetic brake of the present invention is entirely carried out without friction-locking or material-locking connection techniques. The electromagnetic brake can be attached exclusively via a positive-locking connection. In contrast to the prior art, the assembly of the electromagnetic brake of the present invention is therefore carried out more simply. In particular, this assembly can be carried out more simply in a semi-automated or fully automated manner. This allows for simple assembly in manufacturing plants designed in the sense of Industry 4.0, in particular by means of robots.

[0043] The invention furthermore relates to a lifting mechanism comprising an electromagnetic brake according to the invention, which in this application can be used, for example, to brake a drive of a lifting mechanism provided for holding or lifting loads. For this purpose, the brake disks of the electromagnetic brake are connected to the corresponding components of the lifting mechanism, i.e. the drive shaft of the lifting mechanism drive or the lifting mechanism motor or the cable drum of the lifting mechanism. The assembly here can take place with the casing body directly abutting on the respective component, in particular without the friction disk being applied to the lifting mechanism drive or the cable drum, in particular without any gaps or seals between the casing body and the component.

[0044] The lifting mechanism may be attached for example to a crane or a stationary hoist which is normally used to raise and lower loads and, in the case of a crane, to move the lifted load horizontally within the crane's working envelope, in particular at different locations.

[0045] According to the invention, a method for assembling an electromagnetic brake according to one of the above-mentioned embodiments is provided in that the armature disc is fitted into the housing body in such a way that at least one guide projection of the armature disc is guided in the associated guide groove of the housing body.

[0046] In an advantageous configuration, the friction disc is inserted into the cutout of the casing body and engaged by a relative movement with the casing body in the direction of rotation using a receiving groove adjacent to the cutout, with at least one projection, preferably three projections, the friction disc and the cutout no longer axially coincident after the relative movement. In other words, the friction disc is connected to the casing body by a positive fit, preferably in a bayonet manner, by guiding the projection of the friction disc through the cutout into the receiving groove(s) of the casing body adjacent thereto and away from the cutout into the receiving groove(s). The friction disc now rotates relative to the casing body such that at least the contour of the projection and the corresponding female contour no longer axially coincide in the cutout. Subsequently, a rotation lock of the friction disc can also be established, as explained above. Preferably, the assembly step of the friction disc in the casing body is carried out after the above-mentioned assembly step of the armature disc has been carried out.

[0047] Particularly preferably, the coil unit can be fitted into the housing body in such a way that at least one positioning lug of the coil unit engages in a corresponding receiving part of the housing body for the rotation lock and / or the coil unit is connected axially with the housing body in a form-locking manner by means of a snap connection. However, it is also conceivable that a corresponding receiving part is arranged in the coil unit and that a corresponding positioning lug is arranged on or in the housing body. The assembly step of the coil unit in the housing body is preferably carried out before the above-mentioned assembly steps of the armature disc and finally the friction disc. The present invention will now be described with reference to the drawings. [Brief description of the drawings]

[0048] [Figure 1] FIG. [Diagram 2] 1 is a schematic partial cross-sectional view of an embodiment of an electromagnetic brake of the present invention. FIG. [Diagram 3]FIG. 3 is a schematic exploded view of the electromagnetic brake of the present invention according to the embodiment of FIG. 2. [Figure 4a] FIG. 3 is a schematic perspective view of a casing body according to the embodiment of FIG. 2. [Figure 4b] FIG. 4 is a schematic perspective view of a further embodiment of a casing body; [Diagram 5] FIG. 3 is a schematic perspective view of a friction disc according to the embodiment of FIG. 2; [Figure 6] FIG. 3 is a schematic perspective view of an armature disk according to the embodiment of FIG. 2. [Figure 7] FIG. 3 is a schematic perspective view of a coil unit according to the embodiment of FIG. 2. [Figure 8a] FIG. 3 is a schematic cross-sectional view of the electromagnetic brake of the present invention according to the embodiment of FIG. 2. [Figure 8b] FIG. 3 is a schematic cross-sectional view of the electromagnetic brake of the present invention according to the embodiment of FIG. 2. [Figure 9] FIG. 3 is a schematic cross-sectional view of the electromagnetic brake of the present invention according to the embodiment of FIG. 2. [Figure 10] 3A to 3C are schematic perspective views showing the electromagnetic brake of the present invention according to the embodiment of FIG. 2 in different assembled states. [Figure 11] 3A to 3C are schematic perspective views showing the electromagnetic brake of the present invention according to the embodiment of FIG. 2 in different assembled states. [Figure 12] 3A to 3C are schematic perspective views showing the electromagnetic brake of the present invention according to the embodiment of FIG. 2 in different assembled states.

[0049] FIG. 1 shows an exemplary construction for a crane 1 in a perspective view. The crane 1 is configured as a traveling crane in the form of a single-girder bridge crane and has a crane girder 2 movably supported along a crane track, not shown. The crane girder 2 is movable in a substantially horizontal traveling direction F, transversely to its longitudinal direction x, driven by a prime mover, in particular electrically. For this purpose, at opposite ends 3, 4 of the crane girder 2, respectively electrically driven traveling mechanisms 5, 6 are arranged, which are supported on a crane rail (not shown in detail here) of a crane track. A crane trolley 7, which is provided with a hoist, which is configured as a cable hoist, is arranged on the crane girder 2, which can travel parallel to the longitudinal direction x of the crane girder 2 together with the hoist and its lifting mechanism h, which is also driven by a prime mover or electrically, driven by a prime mover, in particular electrically, along the crane girder 2. The operation of the crane 1, i.e. the control of the movements and functions of the traveling mechanisms 5, 6, the crane trolley 7 and their respective drives as well as the lifting mechanism h, is carried out via a control switch 8, which here is formed as a cable-connected suspended control switch. The control switch 8 is communicatively connected to a control unit 9.

[0050] The crane 1 is used to lift and lower loads (not shown) at different locations by means of a lifting mechanism h and to move the loads horizontally within its working range in a travelling direction F by means of traveling mechanisms 5, 6 and / or in a longitudinal direction x by means of a crane trolley 7. The lifting mechanism h includes an inventive electromagnetic brake 20 (see for example FIG. 2), which in this application can be used for example for braking a drive provided for holding the load or for lifting and lowering the load. A brake disk 29 of the electromagnetic brake 20 is connected for this purpose with the drive shaft of the lifting mechanism drive or with the shaft of the wire drum of the lifting mechanism h.

[0051] However, such a lifting mechanism h equipped with the electromagnetic brake 20 of the present invention can also be incorporated into other types of cranes or into other, for example stationary, hoists.

[0052] 2 is a schematic, partially cross-sectional view of one embodiment of an electromagnetic brake 20 of the present invention. In addition to the casing body 21 and the friction disc 22, the electromagnetic brake 20 includes a coil unit 26, a pole core 31 disposed within the coil unit 26 and excitable thereby, at least one compression spring 30, an armature disc 25, and a brake disc 29. The friction disc 22, the coil unit 26, the pole core 31, the compression spring 30, the armature disc 25, and the brake disc 29 are disposed within the casing body 21 in a mounted state as shown.

[0053] The friction disk 22, which is configured in the shape of a ring, is connected in a form-locking manner to the casing body 21 via a bayonet connection 23. For this purpose, the friction disk 22 has three projections 22a, which are supported in a partially circumferential receiving groove 21c attached to the casing body 21. For this purpose, the projections 22a are aligned in correspondence with the recess 21b of the casing body 21, move axially into the recess 21b and then rotate with a relative movement in the direction of rotation, so that they are guided into the receiving groove 21c which leads to the recess 21b, for example when the friction disk 22 is rotated clockwise or the casing body 21 is rotated counterclockwise.

[0054] The friction disk 22 is locked against rotation relative to the casing body 21 by three locking elements 100, in particular during operation of the electromagnetic brake 20. This prevents the friction disk 22 from rotating after positioning within the context of assembly, which would result in the projection 22a moving from the receiving groove 21c towards the recess 21b, and thus unintentionally releasing the bayonet connection 23 between the friction disk 22 and the casing body 21. The locking elements 100 are connecting elements which are used to attach the electromagnetic brake 20 to a component, in particular for flange-fastening to a motor or a wire drum of the lifting mechanism h. The locking elements 100 shown by way of example are screws.

[0055] The locking elements 100 are guided through respective through-holes 21e in the outer wall 21i of the casing body 21 and through recesses 22b in the associated projections 22a of the friction disk 22. Since neither the through-holes 21e nor the recesses 22b are threaded, a purely form-locking connection is made between the locking elements 100 and the friction disk 22 as well as between the locking elements 100 and the casing body 21.

[0056] The number of locking elements 100, and thus the number of recesses 22b in the projections 22a of the friction disc 22, can also be less than the number of projections 22a. If more connection elements are possibly required for mounting the electromagnetic brake 20 to a component than for the rotation locking of the friction disc 22, the remaining connection elements can be guided through the electromagnetic brake 20 at another location independent of the friction disc 22 or its projections 22a or fixed to the electromagnetic brake 20.

[0057] An axially slidable armature disc 25 is arranged on the coil unit 26. The armature disc 25 has, for example, three guide lugs 25a which are used in guide grooves 21a provided for this purpose on the inside of the exterior wall 21i of the casing body 21 for axially guiding the armature disc 25. A groove-lug connection 32 is therefore present between the armature disc 25 and the casing body 21.

[0058] The brake disc 29 is disposed between the armature disc 25 and the friction disc 22, and is adjusted to be rotatable and axially slidable. The brake disc 29 has an inner ring gear 29a, by which the brake disc 29 can be connected to a drive shaft (not shown) braked by the electromagnetic brake 20.

[0059] The at least one compression spring 30 is arranged and adjusted in such a way that their pressure allows the armature disc 25 to slide axially towards the brake disc 29. In the illustrated embodiment, six compression springs 30 are arranged evenly around the circumference of the electromagnetic brake 20 in the exterior wall 21i of the casing body 21. However, it is also conceivable that a different number of compression springs 30 are distributed, preferably evenly, around the circumference of the electromagnetic brake 20. Alternatively, a single compression spring 20 can also be arranged such that it partially or completely surrounds the pole core 31.

[0060] The coil unit 26 and the pole core 31 are arranged and adjusted such that a tensile force can be generated by the pole core 31 electromagnetically excited by the coil unit 26, and this tensile force enables the armature disc 25 to slide axially away from the brake disc 29 against the spring force of the compression spring 30(s).

[0061] In a first operating state of the electromagnetic brake 20, i.e. during braking, the armature disc 25 presses the brake disc 29 against the friction disc 22 by the compression force of the six compression springs 30, braking the brake disc 29 by a braking torque generated between the brake disc 29 and the friction disc 22 and / or between the brake disc 29 and the armature disc 25. The brake disc 29 has one or more brake pads 29b on two opposite sides of its outer diameter area (see Figures 8a and 8b). The friction disc 22 and / or the armature disc 25 preferably have a suitable structured surface on the side facing the brake disc 29, so that an optimal deceleration of the brake disc 29 is ensured during braking.

[0062] In the second operating state of the electromagnetic brake 20, i.e., during ventilation, the armature disc 25 is spaced from the brake disc 29 by a tensile force formed by the coil unit 26 and the pole core 31 that is greater than the compressive force of the six compression springs 30, allowing free, and therefore unbraked, rotation of the brake disc 29. In the second operating state, if the tensile force is sufficient, the armature disc 25 can abut against and be supported by the stepped portion 21f (see, for example, FIG. 4a) of the exterior wall 21i of the casing body 21.

[0063] The friction disc 22 is pressed against the outer web of the receiving groove 21c via the armature disc 25 and the brake disc 29 by the compressive force generated by the compression spring 30 during braking. The outer web of the receiving groove 21c defines a first opening 21m (see for example FIG. 3) of the casing body 21 facing the bottom 21k of the casing body 21. During ventilation, the friction disc 22 is attracted against the inner web of the receiving groove 21c in the direction of the bottom 21k by the magnetic field generated by the coil unit 26 and the pole core 31 and / or the tensile force resulting therefrom.

[0064] Even with the purely positive bayonet connection 23 between the housing body 21 and the friction disc 22, which is formed during assembly of the electromagnetic brake 20, the friction disc 22 is attracted or pressed against one of the webs that define the receiving groove 21c during operation by the forces acting thereon, so that vibrations and thus noise occurring at the friction disc 22 during operation of the electromagnetic brake 20 can be reduced or even avoided.

[0065] 3 is a schematic exploded view of the electromagnetic brake 20 according to the embodiment of FIG. 2. The structure of the electromagnetic brake 20 or the associated components, i.e. the housing body 21, the coil unit 26, the armature disk 25, the brake disk 29 and the friction disk 22, relative to one another in the axial direction of the electromagnetic brake 20 can be clearly seen. The aforementioned components are aligned to the central axis 33 for assembly, so that the holes 21h, 22d, 25c, 26c, 29c in all components are aligned concentrically so that, for example, a drive shaft can be attached. The aforementioned components are then placed concentrically in the housing body 21 with respect to the central axis 33, and the respective planes of the components are aligned so that the respective projections 22a, guiding projections 25a and positioning projections 26a can be inserted into the corresponding recesses 21b, guiding grooves 21a and / or receiving portions 21d of the housing body 21.

[0066] Otherwise the embodiment of FIG. 2 applies equally to the configuration shown in FIG.

[0067] Fig. 4a is a schematic perspective view of the casing body 21 according to the embodiment of Fig. 2. The casing body 21 has a substantially hollow cylindrical and ring-like shape with a circular base. The casing body 21 is here constructed in one piece.

[0068] The casing body 21 has a first opening 21m at its end face facing the bottom part 21k. The bottom part 21k has a second opening 21h, which is smaller compared to the first opening 21m. Through the second opening 21h, for example, the aforementioned braked drive shaft (not shown) can be guided. Furthermore, the casing body 21 has special design details which are necessary for the assembly and functioning of the electromagnetic brake 20, which are explained in the following description.

[0069] The first opening 21m extends up to and is defined by the outer wall 21i. In the region of the first opening 21m, the casing body 21 has three cutouts 21b in the outer wall 21i, which are each followed by a receiving groove 21c. The cutouts 21b are arranged in webs on the end face of the casing body 21, which are formed by the outer wall 21i and define the receiving grooves 21c. The receiving grooves 21c extend partially around and at a distance from one another into the outer wall 21i of the casing body 21. The arrangement of the partially extending receiving grooves 21c has the advantage that the position of the final mounting of the friction disc 22 in the casing body 21 can be easily predetermined by the end of the receiving groove 21c that is opposite the cutouts 21b, which simplifies the subsequent assembly steps. The recess 21 b makes it possible for the friction disk 22 to be inserted into the receiving groove 21 c and thus for a form-locking bayonet connection 23 to be established between the housing body 21 and the friction disk 22 .

[0070] The guide groove 21a for guiding the armature disk 25 is arranged so that the guide protrusions 25a of the armature disk 25 can be fitted into the guide groove 21a through the respective cutouts 21b. The armature disk 25 can be supported on the stepped portion 21f of the exterior wall 21i of the casing body 21, which connects the bottom portion 21k to the exterior wall 21i.

[0071] The pole core 31 is ring-shaped and is arranged in the casing body 21, in particular embedded in its wall or formed from it. The pole core 31, which surrounds the opening 21h in the bottom 21k, is spaced from the exterior wall 21i or step 21f of the casing body 21 so that the coil unit 26 can be arranged therebetween. The pole core 31 and the casing body 21 share the same central axis 33. In the illustrated embodiment, the pole core 31 is part of the casing body 21. The pole core 31 must be made of a magnetic material, so that in this example the entire casing body 21 is made of a magnetic material. A circumferential groove 28 is arranged on the outer diameter of the pole core 31, in which the snap hook 27 of the coil unit 26 can engage and be supported. The snap hook 27 then rests on a web 28a that defines the groove 28 when a force is generated parallel to the central axis 33 in the direction of the first opening 21m.

[0072] Casing body 21 further has a housing portion 21d within exterior wall 21i or stepped portion 21f, and positioning protrusion 26a of coil unit 26 is fitted into this housing portion to lock coil unit 26 against rotation relative to casing body 21.

[0073] The multiple blind holes 21g in the stepped portion 21f are used to accommodate the compression springs 30. They are evenly distributed around the periphery of the stepped portion 21f. In this embodiment, there are six blind holes 21g, so a total of six compression springs 30 can be installed.

[0074] A number of through-holes 21e extending parallel to the central axis 33 through the exterior wall 21i of the casing body 21 serve to guide the locking elements 100. Furthermore, each of the through-holes 21e extends through a receiving groove 21c that serves to receive the friction disc 22. The through-holes 21e do not have a thread.

[0075] 4b is a schematic perspective view of a further embodiment of the casing body 21. This embodiment differs from the embodiment shown in FIG. 4a in that a single receiving groove 21c is fitted in the casing body 21 or in its outer wall 21i in a fully circumferential manner, and not a single but several circumferential grooves 28 or circumferential webs 28a are fitted in a partially circumferential manner and spaced apart from one another for supporting the snap hooks 27.

[0076] However, embodiments are also conceivable in which only a single receiving groove 21c and a single groove 28 are provided, each extending over the entire circumference, or in which both receiving groove 21c and groove 28 extend only partially around the circumference and are spaced apart from each other. Otherwise, the embodiment shown in Fig. 4a applies analogously to the configuration shown in Fig. 4b.

[0077] FIG. 5 is a schematic perspective view of the friction disc 22 according to the embodiment of FIG. 2. The friction disc 22 is rotationally symmetrically formed and comprises three approximately semicircular outwardly directed projections 22a, which are arranged around the circumference of the friction disc 22 at an angle of 120° each. The number of projections 22a can be varied, but at least two are necessary to prevent the friction disc 22 from lifting off the casing body 21. Furthermore, it is advantageous if the projections 22a are evenly distributed around the circumference of the friction disc 22. Arranged on each projection 22a is a recess 22b, through which a locking element 100 can be inserted when mounting the electromagnetic brake 20 on another component, thereby preventing a rotation of the friction disc 22 around the central axis 33. It is also conceivable to provide no recess 22b on each projection 22a.

[0078] The friction disc 22 has a central hole which is dimensioned so that a drive shaft (not shown) to be braked can be guided therethrough. A recess 22c on the inner diameter of the friction disc 22 serves to improve the force flow in the friction disc 22 and to grip the friction disc 22 in an exact position, for example with a robot gripper, and also to position the friction disc 22 accurately in the casing body 21 even with narrow tolerances. The surface of the friction disc 22, at least on the side provided for braking contact with the brake disc 29, is correspondingly designed for optimal deceleration.

[0079] Figure 6 is a schematic perspective view of the armature disc 25 according to the embodiment of Figure 2. The armature disc 25 is rotationally symmetrically formed and comprises three approximately semicircular outwardly directed guiding projections 25a, which are each arranged at an angle of 120° on the circumference of the armature disc 25. The three guiding projections 25a make it possible to guide the armature disc 25 in the casing body 21 without tilting.

[0080] The armature disc 25 has a central hole 25c which is dimensioned so that a drive shaft (not shown) to be braked can be guided therethrough. A cutout 25b on the inner diameter of the armature disc 25 is used to improve the force flow in the armature disc 25 and to grip the armature disc 25 in an exact position, for example with a robot gripper, and also to position the armature disc 25 accurately in the casing body 21 even with narrow tolerances. The surface of the armature disc 25, at least on the side facing the brake disc 29, is accordingly designed for optimal deceleration.

[0081] Figure 7 is a schematic perspective view of the coil unit 26 according to the embodiment of Figure 2. The coil unit 26 has a substantially ring-like geometry with an outwardly open C-shaped cross section formed by a substantially horizontally extending upper leg 26d, a substantially horizontally extending lower leg 26f and a web 26e connecting the two legs 26d, 26f and extending substantially perpendicular to the legs 26d, 26f.

[0082] The coil unit 26 has eight snap hooks 27 in this embodiment. However, the number of snap hooks 27 can be changed taking into account the forces occurring in both axial directions. Each snap hook 27 is dimensioned and material-technically designed so that it can be elastically deformed outwardly when mounting the coil unit 26 in the casing body 21, by applying a force acting parallel to the central axis 33 in the direction of the bottom 21k of the casing body 21, so that the snap hooks 27 can engage in the grooves 28. The snap hooks 27 are an integral part of the coil unit 26. However, it is also conceivable that the snap hooks 27 are separate components and connected to the coil unit 26.

[0083] The coil unit 26 further has a substantially semicircular positioning protrusion 26a, which is used for rotation locking within the casing body 21. Furthermore, the positioning protrusion 26a can be used to position each snap hook 27 in line with one of the grooves 28 when assembling the coil unit 26 in the casing body 21, which partially has a plurality of grooves 28.

[0084] The coil unit 26 is configured as a coil support and is suitable for accommodating one or more coils (not shown) required for exciting a magnetic field, the coils being arranged or supported within the C-shaped structure of the coil unit 26, which is open towards the outside.

[0085] Figures 8a, 8b and 9 are schematic cross-sectional views of the electromagnetic brake 20 of the present invention according to the embodiment of Figure 2. In Figures 8a and 8b, the structure of the assembled electromagnetic brake 20 can be well understood.

[0086] Between its outer wall 21i and the pole core 31, the casing body 21 has a recess that is dimensioned to correspond to the dimensions of the coil unit 26. The recess is designed in such a way that when the coil unit 26 is mounted, the necessary play is present, but sufficient fixation of the coil unit 26 is guaranteed, especially during operation of the electromagnetic brake 20. The snap hooks 27 of the coil unit 26 are seated in grooves 28 and supported on webs 28a of the casing body 21 (see FIG. 9). The coil unit 26 is therefore connected to the casing body 21 only by a form-fit.

[0087] The armature disc 25 is arranged between the first opening 21m of the casing body 21 and the coil unit 26. In order to be able to rest the armature disc 25 on the step 21f, the upper leg 26d of the coil unit 26 facing the first opening 21m of the casing body 21 is spaced accordingly from the step 21f. A tensile force can be generated by the pole core 31 excited by the coil unit 26, by which the armature disc 25 can slide axially away from the brake disc 29 in order to release the brake 20.

[0088] Six compression springs 30 are disposed in the blind holes 21g, respectively. Figures 8a and 8b show only one blind hole 21g and one compression spring 30. The compression springs 30 are adjusted to slide axially on the armature disc 25 toward the brake disc 29 for braking by their compressive force.

[0089] The friction disc 22 is arranged between the end face of the casing body 21 and a brake disc 29. The brake disc 29, which is arranged between the axially slidable armature disc 25 and the friction disc 22, is adjusted to be rotatable and axially slidable about a central axis 33. The brake disc 29 has one or more brake pads 29b on two opposite sides of its outer diameter area, whereby, in particular in combination with the aforementioned surfaces of the friction disc 22 and / or the armature disc 25, optimal braking can be achieved.

[0090] Figure 9 shows an enlarged view of the area consisting of Figures 8a and 8b, from which the mounting state of the coil unit 26 in the casing body 21 can be clearly seen, as well as the C-shaped cross section formed by the legs 26d, 26f and the web 26e, which opens outwards towards the exterior wall 21i.

[0091] The illustrated snap hook 27, like the other snap hooks 27, is an integral part of the coil unit 26, engages in a groove 28 and supports the coil unit 26 on a web 28e on the casing body 21. The coil unit 26 is thus connected to the casing body 21 in a form-locking manner by means of a snap connection 34.

[0092] To establish the snap connection 34, the snap hook 27 is elastically deformed in the direction of the exterior wall 21i of the casing body 21. In other words, the snap hook 27 is pulled back radially outward when mounting the coil unit 26 and then engages radially inwardly into the groove 28 of the casing body 21. For this purpose, the coil unit 26 has in the region of the snap hook 27 a slit-like recess extending along the web 26e. The elastic deformation is effected in particular on the basis of a force acting parallel to the central axis 33 in the direction of the bottom 21k of the casing body 21.

[0093] The coil unit 26 is supported on a step 26b on the bottom 21k of the housing body 21. The step 26b leaves a space between the coil unit 26 and the housing body 21 in the region of the diameter in which the snap hook 27 is arranged. The coil unit 26 is thus axially movable relative to the housing body 21 in the region of the snap connection 34, which simplifies assembly. This space can thus be used as a kind of spring deflection, so that the leg 26f of the coil unit 26 facing the bottom 21k is pressed towards the bottom 21k of the housing body 21 outside the step 26b during assembly, around the step 26b used as a pivot point, and is thus bent in this direction, so that the snap hook 27 can be engaged more easily into the groove 28 of the housing body 21. In other words, the coil unit 26 is adjusted to be flexible or elastic, which ensures that the engagement of the snap hook 27 is guaranteed even with poor manufacturing precision.

[0094] 10, 11 and 12 are schematic perspective views showing the electromagnetic brake 20 of the present invention according to the embodiment of FIG. 2 in different assembled states.

[0095] 10 shows only the coil unit 26 mounted on the casing body 21. To rotate-lock the coil unit 26, positioning lugs 26a arranged on it engage in corresponding recesses 21d in the casing body 21. A purely form-locking snap connection 34 is thus created between the coil unit 26 and the casing body.

[0096] 11 additionally shows the mounting of the armature disk 25 on the housing body 21. The armature disk 25 is inserted into the housing body 21 in such a way that each guide projection 25a of the armature disk 25 is guided in the associated guide groove 21a of the housing body 21. The armature disk 25 is guided axially in the housing body 21 via the groove-projection connection 32 thus formed. The outer contour of the guide projection 25a preferably corresponds to the inner contour of the guide groove 21a. However, there is sufficient play between the outer contour of the guide projection 25a and the inner contour of the guide groove 21a for the armature disk 25 to move axially.

[0097] FIG. 12 additionally shows the mounting of the brake disc 29 and the friction disc 22 in the casing body 21. The friction disc 22 is connected to the casing body 21 by a positive fit and for this purpose in a bayonet manner. Due to the bayonet connection 23, the projection 22a of the friction disc 22 is guided through the recess 21b into the receiving groove 21c of the casing body 21 and slides therein in the direction of rotation. The friction disc 22 and the casing body 21 therefore rotate relative to one another about the central axis 33. After this relative movement, the three projections 22a and the recess 21b of the friction disc 22 no longer coincide axially, i.e. essentially parallel to the central axis 33.

[0098] By means of the through hole portion 21e and the recess 22b, which is correspondingly positioned in the protrusion 22a of the friction disk 22, three connecting elements can be guided when the electromagnetic brake 20 is then attached to another component, which connecting elements in this case all serve simultaneously as locking elements 100. [Explanation of symbols]

[0099] 1. Crane 2 Crane girder 3 End 4 End 5. Traveling mechanism 6 Traveling mechanism 7 Crane trolley 8 Control Switch 9. Control Unit 20 Electromagnetic brake 21 Casing body 21a Guide groove 21b Notch 21c Storage groove 21d Storage section 21e Through hole section 21f Stepped section 21g bottomed hole 21h Second opening 21i Exterior wall 21k bottom 21m First opening 22 Friction disc 22a Protrusion 22b Recess 22c Notch 22d Hole 23 Bayonet connection 25 Armature disc 25a Guide protrusion 25b Notch 25c Hole 26 Coil unit 26a Positioning protrusion 26b Stepped part 26c Hole 26d Upper leg 26e Web 26f lower leg 27 Snap Hook 28 Groove 28a Web 29 Brake disc 29a Ring gear 29b Brake pads 29c Hole 30 Compression spring 31 Pole Core 32 Groove-protrusion connection 33 Central axis 34 Snap Connection 100 Rock Elements h Lift mechanism F Travel direction x Longitudinal direction

Claims

1. An electromagnetic brake (20) having a housing body (21), an armature disk (25) and a friction disk (22), the housing body (21) including a pole core (31), the armature disk (25) being guided axially in the housing body (21) via a groove-projection connection (32) and provided with at least one guide groove (21a) and at least one associated guide projection (25a), Each of the guide grooves (21a) is disposed in the casing body (21), The friction disc (22) includes a protrusion (22a), The casing body (21) includes a notch (21b) and an accommodating groove (21c) adjacent to the notch (21b), The electromagnetic brake is characterized in that the projection (22a) has an area smaller than that of the cutout portion (21b) and is engaged with the accommodating groove (21c) so that the friction disc (22) is form-fitted to the casing body (21).

2. 2. The electromagnetic brake (20) of claim 1, wherein the friction disc (22) is locked against rotation relative to the casing body (21) by at least one locking element (100), the locking element (100) being a connecting element used to attach the electromagnetic brake (20) to a component.

3. 3. An electromagnetic brake (20) according to claim 1 or 2, characterized in that a coil unit (26) is provided which is connected to the housing body (21) by a positive lock and / or is locked against rotation relative to the housing body (21).

4. 4. An electromagnetic brake (20) according to claim 3, characterized in that the coil unit (26) is connected to the casing body (21) by a form-locking by a snap connection (34), and at least one snap hook (27) of the coil unit (26) is supported on a web (28a) of the casing body (21).

5. 5. An electromagnetic brake (20) according to claim 3 or 4, characterized in that, in order to simplify assembly, the coil unit (26) is supported in the casing body (21) in a region where it is connected to the casing body (21) by a form-fitting connection, such that the coil unit (26) is axially movable relative to the casing body.

6. A lift mechanism (h) comprising an electromagnetic brake (20) according to any one of claims 1 to 5.

7. 6. A method for assembling an electromagnetic brake (20) according to claim 1, characterized in that the armature disk (25) is fitted into the housing body (21) with a pole core (31) in such a way that at least one guiding projection (25a) of the armature disk (25) is guided in the associated guiding groove (21a) of the housing body (21).

8. 8. A method for assembling an electromagnetic brake (20) according to claim 7, characterized in that the friction disc (22) is fitted into the cutout portion (21b) of the casing body (21) and engaged using the accommodating groove (21c) by moving relative to the casing body (21) in a rotational direction, and the protrusion portion (22a) of the friction disc (22) and the cutout portion (21b) no longer coincide with each other in the axial direction after the relative movement.

9. 9. A method for assembling an electromagnetic brake (20) according to claim 7 or 8, characterized in that a coil unit (26) is fitted into the casing body (21) in such a way that at least one positioning projection (26a) of the coil unit (26) engages in a corresponding receiving portion (21d) of the casing body (21) for rotational locking and / or that the coil unit (26) is axially connected with the casing body (21) in a form-locking manner by means of a snap connection (34).

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