Electromagnetic brake

Abstract

An electromagnetic brake (20) comprising a casing body (20) and a coil unit (26), wherein the coil unit (26) is connected to the casing body (21) by a form-fitting connection, and the coil unit (26) is connected to the casing body (21) by a snap connection (34) by a form-fitting connection, and at least one snap hook (27) of the coil unit (26) is supported on a web of the casing body (21).

Description

Technical Field

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

[0002] This type of electromagnetic brake is known from German Patent Application Publication No. 102017000845 and Japanese Unexamined Patent Application Publication No. 05-256330. In Japanese Unexamined Patent Application Publication No. 05-256330, the coil unit is connected to the casing body by an impregnating material that has been cured following injection. Furthermore, the casing body has protrusions on its inner wall, and these protrusions hold the composite of the cured impregnating material and the coil unit within the casing body.

[0003] Further electromagnetic brakes are known from German Patent No. 102012001701, German Patent Application Publication No. 4109786, German Patent No. 102014001474, German Patent No. 10049168, or German Patent No. 2832723 and Korean Patent No. 101299558.

[0004] Starting from this prior art, the problem underlying the present invention is to create an improved electromagnetic brake that can be attached particularly easily.

[0005] This problem is solved by an electromagnetic brake having the features of claim 1 and a method having the features of claim 8. Advantageous configurations of the present invention are described in the dependent claims and in the following description.

[0006] According to the present invention, the improved electromagnetic brake comprises a casing body and a coil unit, the coil unit being connected to the casing body, preferably exclusively by form-fitting, and the coil unit being connected to the casing body by form-fitting by snap connection, and at least one snap hook of the coil unit being supported on a web of the casing body.

[0007] The snap hook is dimensioned and designed in terms of materials technology such that when attaching the coil unit to the casing body, by applying a force, the casing body is elastically deformed and the snap hook engages with a groove provided in the casing body. Here, this force acts parallel to the central axis of the casing body and in the direction of the bottom of the casing body.

[0008] Unlike the prior art where, for example, a coil unit is cast into a casing body with artificial resin, in the electromagnetic brake of the present invention, the assembly can be simplified so that the electromagnetic brake can be attached more easily in a semi - automated or fully automated manner. This advantage is also obtained for friction - coupled connections. As a result, simple assembly in a manufacturing plant designed in the sense of Industry 4.0 is possible, especially using robots.

[0009] The casing body has a substantially hollow - cylindrical and ring - shaped form, which form includes an opening at the end face of the casing body and a bottom facing the end face. The casing body is preferably integrally formed. The material of the casing body is selected such that its rigidity is sufficient for the forces generated during one or multiple brakings, and its temperature resistance is sufficient for the temperatures generated during one or multiple brakings. In addition, the material of the casing body is preferably magnetic.

[0010] The coil unit preferably has a substantially ring - shaped geometry, which geometry includes a C - shaped cross - section that is open towards the outside. The coil unit is formed as a coil support and is suitable for accommodating one or more coils, or for supporting on or within the coil unit itself.

[0011] Since the coil unit has a substantially ring - shaped geometry, the coil unit preferably has at least three snap hooks. Of course, it is also conceivable that the number of snap hooks is other than this, and this number is preferably determined in consideration of the forces generated.

[0012] The snap hook can be an integral part of the coil unit. However, it is also conceivable that the snap hook is an independent component and is connected to the coil unit.

[0013] In an advantageous configuration, the coil unit is rotationally locked so as not to rotate relative to the casing body. Preferably for this purpose, one positioning projection arranged on the coil unit engages with a corresponding similarly shaped, preferably identically shaped receiving part in the casing body, thereby locking the coil unit so as not to rotate relative to the casing body. However, it is also conceivable that the corresponding receiving part is arranged in the coil unit and the corresponding positioning projection is arranged on the casing body or within the casing body.

[0014] Even more particularly advantageously, the coil unit is flexible in at least the region where the coil unit is connected to the casing body by form-fitting for ease of assembly, and is thus supported by the casing body so as to be axially movable relative to the casing body. For this purpose, the coil unit has a stepped portion on the side facing the bottom of the casing body, and the flexibility of the coil unit is achieved at least outside the stepped portion. This stepped portion is preferably arranged at a diameter substantially equal to the diameter of the ring-shaped coil unit and as far as possible away from the diameter of the coil unit where the snap hook is arranged. Outside the stepped portion, for example, in the region of the inner diameter where the snap hook is arranged, a space remains empty between the coil unit and the bottom of the casing body. By utilizing this space as a kind of spring deflection, during assembly, the coil unit can be axially pushed in the direction of the casing body due to its partial flexibility, thereby making it easier for the snap hook to engage with the groove of the casing body.

[0015] In addition to the casing body and the coil unit, the electromagnetic brake preferably includes a pole core that can be excited by the coil unit, at least one compression spring, an armature disk, a brake disk, and a friction disk. The coil unit, the pole core, the compression spring(s), the armature disk, the brake disk, and the friction disk are preferably arranged within the casing body. Preferably, the coil unit, the armature disk, the brake disk, and the friction disk, or at least some of these, are attached to and connected to the casing body via openings in the end faces during assembly. This preferably also applies to the compression spring(s). The pole core can be a component of the casing body.

[0016] The materials of the pole core, the armature disk, the brake disk, and the friction disk are selected such that their rigidity is sufficient for the forces generated during one or more brakings, and their temperature resistance is sufficient for the temperatures generated during one or more brakings. The pole core is further made of a magnetic material so that it can be excited by the coil unit.

[0017] The brake disk is preferably arranged between the axially slidable armature disk and the friction disk and is rotatable and axially slidably adjustable. At least one compression spring is arranged and adjusted such that the armature disk can slide axially towards the brake disk due to their pressure. In contrast, the coil unit and the pole core are arranged and adjusted such that a tensile force can be formed by the pole core electromagnetically excited by the coil unit, and the armature disk can slide axially away from the brake disk due to this tensile force.

[0018] The brake disc can be connected to a shaft, especially a drive shaft, particularly the output shaft of a motor. Here, the casing body, coil unit, pole core, compression spring, armature disc, and friction disc, or at least some of them, each have a hole or opening through which the shaft can be guided, so that it may be necessary to form them in a ring shape.

[0019] In the 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, and the brake disc is braked by the 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, thereby ensuring optimal deceleration of the brake disc during braking.

[0020] In the second operating state of the electromagnetic brake, i.e., during ventilation, the armature disc is arranged away from the brake disc by a tensile force greater than the compression force of at least one compression spring formed by the coil unit and the pole core, so that the brake disc can rotate freely and thus without being braked.

[0021] In an advantageous configuration, the armature disk is axially guided within the casing body via the groove-projection connection, with at least one guide groove, preferably three guide grooves, and at least one respective guide projection, preferably three respective guide projections provided. In addition to the axial guidance, the guide grooves of the groove-projection connection also have the function of restricting the circumferential rotationality of the armature disk such that this rotationality is only permitted within the play margin required for axial movement. Each guide groove is preferably arranged within the casing body, particularly formed within its outer wall. The outer wall is closed outwardly in the region of the groove-projection connection, and thus particularly in the region of the guide grooves. This is because the guide grooves are depressions within the outer wall of the casing body rather than through-holes penetrating the outer wall. Therefore, a through-hole through which the guide projection can completely pass is not a guide groove according to this understanding. It is also conceivable that guide grooves in the shape of recesses are arranged on the armature disk and correspondingly shaped protrusion contours are arranged on the casing body as guide projections. In this case, this contour is preferably an integral component of the casing body, particularly formed on the outer wall of the casing body. In both cases described above, the outer wall is closed outwardly in the region of the groove-projection connection. Thereby, improved protection against environmental influences is achieved. More preferably, since movable elements such as guide projections do not protrude from the casing body, undesirable collisions with other components can be avoided.

[0022] To enable the guidance of the armature disk without inclination in the casing body, preferably three guide grooves and three guide projections are provided. The guide grooves and guide projections are preferably evenly distributed over the circumference of the casing body or the armature disk. The outer contour of the guide projection is formed to be similar in shape or of the same shape as the inner contour of the guide groove, and sufficient play is provided between the outer contour of the guide projection and the inner contour of the guide groove for axial movement of the armature disk.

[0023] The armature disk is preferably guided axially within the casing body exclusively via the aforementioned groove-projection connection. Additional guiding elements, such as guiding bolts or guiding sleeves, are not necessary for guiding the armature disk within the casing body. Thus, these can be omitted, and as a result, the structural and manufacturing costs can be reduced. This is particularly true when the guiding elements are frictionally connected to the casing body, for example, by screws. Thus, different from the prior art, the assembly can be simplified so that the electromagnetic brake can be more easily assembled semi-automatically or fully automatically. This advantage can also be obtained for material-binding connections.

[0024] Advantageously, the friction disk is connected to the casing body by form-fitting, preferably in a bayonet manner, and / or is locked so as not to rotate relative to the casing body. Such a bayonet connection is also referred to as a bayonet lock.

[0025] In other words, the casing body and the friction disk are each provided with corresponding shapes that are formed and adjusted such that the casing body and the friction disk can be connected by form-fitting. Such a form-fitting connection, particularly a bayonet connection, can be established by first inserting, setting, arranging, adjusting, or sliding the casing body and the friction disk relative to each other and then engaging them with each other.

[0026] Also referred to as a bayonet lock, a preferred configuration of the bayonet connection, which is a preferred special form of the form-fitting connection according to the present invention, will be described in detail below.

[0027] The friction disk is formed as a substantially circular and preferably ring-shaped disk, having at least one outwardly directed protrusion at its periphery, by means of which the friction disk is supported in the casing body by form-fit and bayonet-fashion. In order to avoid the friction disk lifting off from the casing body, at least two protrusions are necessary. Preferably, the friction disk has three protrusions, which are arranged around the periphery of the friction disk at an angle of 120° each. Thus, since the friction disk is preferably rotationally symmetrically formed, the protrusions are evenly distributed around the periphery of the friction disk. Of course, other numbers of protrusions are also conceivable.

[0028] The casing body has at least one notch in the region of the end face, which is followed by a receiving groove. Thus, the notch is arranged in a web on the end face of the casing body, which web is formed by the outer wall of the casing body and defines the receiving groove. The casing body has such a notch and a receiving groove following it for each protrusion of the friction disk, i.e., preferably has three receiving grooves. Of course, it is also conceivable that the number of notches and the receiving grooves following them are different. Here, the notches are each attached to the casing body at a position corresponding to the protrusion. The notch enables the friction disk or its protrusion to be inserted into the receiving groove, and thus enables the establishment of a form-fit connection between the casing body and the friction disk. The receiving grooves preferably partially encircle and extend spaced apart from each other within the outer wall of the casing body. By arranging the receiving grooves in this way partially, the position where the friction disk is finally mounted in the casing body can be easily predefined in advance by the end of the receiving groove, which is on the side opposite to the notch and in particular closed, which has the advantage of simplifying subsequent assembly steps. Thus, by its closed end, each receiving groove defines one bayonet seat, which facilitates finding the final mounting position during assembly. Instead of providing a plurality of separate receiving grooves for the protrusions of the friction disk, it is also possible to alternatively provide a single receiving groove that encircles over the entire circumference.

[0029] To establish a bayonet connection, first the projections of the friction disk are guided through the cutouts of the casing body. The contour of the projections of the friction disk and the contour of the cutouts in the casing body are matched to each other such that the projections have sufficient play at the mounting position to pass through the cutouts. In a second step, the projections of the friction disk are guided from the cutouts into the receiving grooves of the casing body and are additionally slid in the rotational direction. Here, the friction disk and the casing body are rotated relative to each other in a manner common for bayonet locks. The material thickness of the projections and the width of the receiving grooves are matched to each other such that the projections can move in the rotational direction within the receiving grooves with sufficient play.

[0030] No further elements are required to establish a connection between the friction disk and the casing body. Thus, unlike the prior art in which the connection between the friction disk and the casing body or between the friction disk and other elements of the electromagnetic brake is a friction connection, in particular effected by screws, the assembly can be simplified so that the electromagnetic brake can be more easily semi-automated or fully automated for installation. This advantage is also obtained for material-binding connections.

[0031] The friction disk is pressed against the outer web of the outer wall of the casing body defining the receiving groove via the armature disk and the brake disk by a compressive force formed by at least one compression spring during braking. The friction disk is attracted to the inner web of the receiving groove by a magnetic field formed by the coil unit and the pole core or the tensile force resulting therefrom during ventilation. During the assembly of the electromagnetic brake, although a connection purely by form fit is formed between the casing body and the friction disk, the friction disk is attracted to or pressed against one of the webs defining the receiving groove of the casing body by the forces acting thereon during operation. Thereby, vibrations and thus noise occurring in the friction disk during the operation of the electromagnetic brake can be reduced or even avoided.

[0032] The friction disk is locked so as not to rotate relative to the casing body, especially during the operation of the electromagnetic brake. This prevents the friction disk from rotating after the connection by form fit, especially the establishment of a bayonet connection, and thus prevents the connection between the friction disk and the casing body from coming loose. Especially after positioning the friction disk in the receiving groove, it is impossible for the friction disk to come out of the receiving groove and rotate in the direction of the adjacent notch. Such rotation may also result in the connection between the friction disk and the casing body coming loose when the protrusion and the notch coincide. Preferably, for such rotational locking, a correspondingly formed contour is provided in the friction disk, preferably on at least one of its protrusions, and a locking element is engaged with this contour. Thus, the rotational locking can be established by form fit between the friction disk and the locking element.

[0033] Advantageously, the friction disk is locked by at least one locking element so as not to rotate relative to the casing body, and the locking element is a connecting element used, for example, to flange-mount the electromagnetic brake to a component, such as a motor or a cable drum. The locking element can be, for example, a pin or a screw, which engages with the contour of the friction disk, thereby forming a rotational lock by form fit.

[0034] The locking element is preferably guided to one of the protrusions of the friction disk through a hole in the casing body and a recess forming a contour. Neither the hole in the casing body nor the recess in the protrusion of the friction disk has a thread, so that even when using a screw, a connection purely by form fit is made between the locking element and the friction disk and between the locking element and the casing body.

[0035] Depending on the expected operating load of the electromagnetic brake, it may be necessary to use multiple locking elements. In this case, for each locking element, preferably, a corresponding protrusion with a recess is provided on the friction disk. However, if the number of locking elements is smaller than the number of protrusions, it is also conceivable not to provide corresponding contours or recesses on each protrusion.

[0036] When attaching the electromagnetic brake to the components, if more connecting elements are required in some cases than for the rotational locking of the friction disk, the remaining connecting elements can be guided through the electromagnetic brake or fixed to the electromagnetic brake at a separate position independent of the friction disk or its protrusions.

[0037] The assembly of the electromagnetic brake of the present invention is performed as a whole without friction bonding or material bonding connection techniques. The electromagnetic brake can be attached exclusively via a connection by form fit. Therefore, different from the prior art, the assembly of the electromagnetic brake of the present invention can be carried out more simply. In particular, this assembly can be carried out more easily semi-automatically or fully automatically. Thereby, simple assembly in a manufacturing factory designed in the sense of Industry 4.0 is possible, especially using robots.

[0038] Furthermore, the present invention relates to a lift mechanism including the electromagnetic brake of the present invention. The electromagnetic brake can be used in this application, for example, to hold a load or to brake the drive unit of a lift mechanism provided for raising and lowering a load. For this purpose, the brake disk of the electromagnetic brake is connected to a corresponding component of the lift mechanism, that is, the drive shaft of the lift mechanism drive unit, the lift mechanism motor, or the cable drum of the lift mechanism. Here, the assembly can be carried out with the casing body directly abutting on each component. In particular, without applying the friction disk to the lift mechanism drive unit or the cable drum, especially without gaps or seals between the casing body and the component.

[0039] The lifting mechanism can usually be attached to, for example, a crane or a stationary hoist used for lifting and lowering goods. In the case of a crane, the lifted goods are horizontally moved within the crane's working range, especially at different locations from each other.

[0040] According to the present invention, the method for assembling an electromagnetic brake according to one of the foregoing embodiments is created by fitting a coil unit into a casing body such that at least one positioning projection of the coil unit for rotational locking engages with a corresponding receiving portion of the casing body and / or the coil unit is axially and form - locked to the casing body by snap - connection, and at least one snap - hook of the coil unit is supported by a web of the casing body. However, it is also conceivable that a corresponding receiving portion is arranged within the coil unit and a corresponding positioning projection is arranged on or within the casing body.

[0041] In an advantageous configuration, the armature disk is adapted to be fitted into the casing body such that at least one guiding projection of the armature disk is guided within a respective guiding groove of the casing body. Preferably, the step of assembling the armature disk within the casing body is performed after the above - described step of assembling the coil unit has been carried out.

[0042] Particularly advantageously, the friction disk can be inserted into the notch of the casing body and engaged using the accommodation groove adjacent to the notch by relative movement with the casing body in the rotational direction. At least one protrusion of the friction disk, preferably three protrusions, and the notch will no longer align after relative movement. In other words, the protrusion of the friction disk passes through the notch and is guided into the accommodation groove(s) of the adjacent casing body, and is guided away from the notch and into the accommodation groove(s), so that the friction disk is connected to the casing body by form fit, preferably in a bayonet type. Here, the friction disk rotates relative to the casing body such that at least the contour of the protrusion and the corresponding female contour no longer align at least axially within the notch. Subsequently, the rotational locking of the friction disk can also be established as described above. Preferably, the assembly step of the friction disk within the casing body is subsequently performed, i.e., after the above-described assembly steps of the coil unit and the armature disk have been carried out. Hereinafter, the present invention will be described based on the drawings.

Brief Description of the Drawings

[0043]

Figure 1

Figure 2

Figure 3

Figure 4a

Figure 4b

Figure 5

Figure 6

Figure 7

Figure 8a

Figure 8b

Figure 9

Figure 10

Figure 11

Figure 12

[0044] FIG. 1 shows an exemplary structure for a crane 1 in a perspective view. Crane 1 is formed as a traveling crane in the form of a single-girder double-bridge crane and has a crane girder 2 that is movably supported along a crane track (not shown). Crane girder 2 is movable by being driven, particularly electrically, by a prime mover in a substantially horizontal traveling direction F, transversely to its longitudinal direction x. For this purpose, traveling mechanisms 5, 6 that are electrically driven as examples are respectively arranged at opposite ends 3, 4 of crane girder 2, and these traveling mechanisms are respectively supported on crane rails of a single crane track (not detailed here). Crane girder 2 is provided with a crane trolley 7 that includes a hoist formed as an exemplary cable hoist, and the crane trolley is driven, particularly electrically, by a prime mover, parallel to the longitudinal direction x of crane girder 2, together with the hoist and its lift mechanism h that is also driven by a prime mover, and can travel along crane girder 2. The operation of crane 1, that is, the control of the movement and function of traveling mechanisms 5, 6, crane trolley 7 and their respective drive parts and lift mechanism h, is performed via a control switch 8, and the control switch is formed here as a suspended control switch connected by a cable. Control switch 8 is in communication connection with a control unit 9.

[0045] Crane 1 is used to lift and lower (not shown) loads at different locations from each other by lift mechanism h, and is further used to horizontally move the loads in the traveling direction F by traveling mechanisms 5, 6 and / or in the longitudinal direction x by crane trolley 7 within its working range. Lift mechanism h includes the electromagnetic brake 20 of the present invention (see, for example, FIG. 2). Electromagnetic brake 20 can be used in this application, for example, to hold a load or to brake a drive part provided for lifting and lowering a load. Brake disk 29 of electromagnetic brake 20 is connected for this purpose to the drive shaft of the lift mechanism drive part or the shaft of the wire drum of lift mechanism h.

[0046] However, such a lift mechanism h equipped with the electromagnetic brake 20 of the present invention can also be incorporated into other types of cranes or other stationary hoists, for example.

[0047] FIG. 2 is a schematic partial cross-sectional view of an embodiment of the electromagnetic brake 20 of the present invention. In addition to the casing body 21 and the friction disk 22, the electromagnetic brake 20 includes a coil unit 26, a pole core 31 disposed within the coil unit 26 and thereby excitable, at least one compression spring 30, an armature disk 25, and a brake disk 29. The friction disk 22, the coil unit 26, the pole core 31, the compression spring 30, the armature disk 25, and the brake disk 29 are arranged within the casing body 21 in the attached state as shown in the figure.

[0048] The friction disk 22 formed in a ring shape is connected to the casing body 21 by form fit via a bayonet connection 23. For this purpose, the friction disk 22 has three protrusions 22a, and these protrusions are supported in a partially circumferential receiving groove 21c attached to the casing body 21. For this purpose, the protrusions 22a are oriented to match the cutout 21b of the casing body 21, move axially into the cutout 21b, and rotate by relative movement in the subsequent rotational direction, thereby being guided into the receiving groove 21c following the cutout 21b, for example when the friction disk 22 is rotated clockwise or the casing body 21 is rotated counterclockwise.

[0049] The friction disk 22 is locked by three locking elements 100 so as not to rotate relative to the casing body 21, particularly during the operation of the electromagnetic brake 20. Thereby, after the positioning performed within the assembly frame, the friction disk 22 rotates, whereby the protrusion 22a moves in the direction from the accommodation groove 21c towards the notch 21b, and the possibility that the bayonet connection 23 between the friction disk 22 and the casing body 21 is unintentionally released can be prevented. The locking element 100 is a connecting element that is used, in particular, for flange-mounting the electromagnetic brake 20 to a component, particularly to the motor or the wire drum of the lift mechanism h. The locking element 100 shown by way of example is a screw.

[0050] Each of the locking elements 100 is guided through a through-hole portion 21e in the outer wall 21i of the casing body 21 and a recess 22b in the corresponding protrusion 22a of the friction disk 22. Since no thread is attached to either the through-hole portion 21e or the recess 22b, a connection purely by form fit is made between the locking element 100 and the friction disk 22, as well as between the locking element 100 and the casing body 21.

[0051] The number of the locking elements 100, and thus the number of the notches 22b in the protrusions 22a of the friction disk 22, can also be made smaller than the number of the protrusions 22a. If, for mounting the components of the electromagnetic brake 20, more connecting elements are required in some cases than for the rotational locking of the friction disk 22, the remaining connecting elements can be guided through the electromagnetic brake 20 or fixed to the electromagnetic brake 20 at another position independent of the friction disk 22 or its protrusions 22a.

[0052] The armature disk 25 that can slide in the axial direction is disposed on the coil unit 26. The armature disk 25 has, for example, three guide protrusions 25a, and these guide protrusions are used in guide grooves 21a provided for this purpose on the inner side of the exterior wall 21i of the casing body 21 to guide the armature disk 25 in the axial direction. Accordingly, a groove-protrusion connection 32 exists between the armature disk 25 and the casing body 21.

[0053] The brake disk 29 is disposed between the armature disk 25 and the friction disk 22, and is rotatable and axially slidably adjustable. The brake disk 29 has a ring gear 29a on the inside, and the brake disk 29 can be connected by this ring gear to a drive shaft (not shown) that is braked by the electromagnetic brake 20.

[0054] At least one compression spring 30 is arranged and adjusted such that the armature disk 25 can slide axially toward the brake disk 29 by their pressure. In the illustrated embodiment, six compression springs 30 are evenly arranged within the exterior wall 21i of the casing body 21 over the periphery of the electromagnetic brake 20. However, it is also conceivable that a different number of compression springs 30 are preferably evenly distributed around 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.

[0055] The coil unit 26 and the pole core 31 are arranged and adjusted such that a tensile force can be formed by the pole core 31 electromagnetically excited by the coil unit 26, and the armature disk 25 can slide axially away from the brake disk 29 against the spring force of the compression spring(s) 30 by this tensile force.

[0056] In the first operating state of the electromagnetic brake 20, i.e., during braking, the armature disk 25 presses the brake disk 29 against the friction disk 22 by the compressive force of the six compression springs 30, and the brake disk 29 is braked by the braking torque generated between the brake disk 29 and the friction disk 22 and / or between the brake disk 29 and the armature disk 25. The brake disk 29 has one or more brake pads 29b on two opposite sides in its outer diameter region (see FIGS. 8a and 8b). The friction disk 22 and / or the armature disk 25 preferably each have a suitable structured surface on the side facing the brake disk 29, thereby ensuring optimal deceleration of the brake disk 29 during braking.

[0057] In the second operating state of the electromagnetic brake 20, i.e., during ventilation, the armature disk 25 is spaced apart from the brake disk 29 by a tensile force greater than the compressive force of the six compression springs 30 formed by the coil unit 26 and the pole core 31, so that the brake disk 29 can rotate freely and thus is not braked. In the second operating state, when the tensile force is sufficient, the armature disk 25 can abut against and be supported by the stepped portion 21f of the outer wall 21i of the casing body 21 (see FIG. 4a for example).

[0058] During braking, the friction disk 22 is pressed against the outer web of the receiving groove 21c via the armature disk 25 and the brake disk 29 by the compressive force formed by the compression spring 30. The outer web of the receiving groove 21c defines the first opening 21m of the casing body 21 (see FIG. 3 for example) that faces the bottom 21k of the casing body 21. During ventilation, the friction disk 22 is attracted to the inner web of the receiving groove 21c in the direction of the bottom 21k by the magnetic field formed by the coil unit 26 and the pole core 31 or the resulting tensile force.

[0059] Even if there is a bayonet connection 23 by a pure form fit between the casing body 21 and the friction disk 22 formed during the assembly of the electromagnetic brake 20, the friction disk 22 is attracted or pressed against one of the webs defining the receiving groove 21c by the forces acting thereon during operation. Thereby, vibrations and thus noises generated in the friction disk 22 during the operation of the electromagnetic brake 20 can be reduced or even avoided.

[0060] Figure 3 is a schematic exploded view of the electromagnetic brake 20 according to the embodiment of Figure 2. The structure or the components belonging to the electromagnetic brake 20, namely the casing body 21, the coil unit 26, the armature disk 25, the brake disk 29 and the friction disk 22, can be well understood in terms of their relative arrangement in the axial direction of the electromagnetic brake 20. Since the aforementioned components are aligned with the central axis 33 for assembly, the holes 21h, 22d, 25c, 26c, 29c in all the components are concentrically aligned so that, for example, a drive shaft can be attached. Subsequently, the aforementioned components are arranged concentrically within the casing body 21 with reference to the central axis 33, and the respective planes of the components are adapted so that the respective protrusions 22a, guide protrusions 25a, positioning protrusions 26a can be fitted into the corresponding notches 21b, guide grooves 21a and / or receiving portions 21d of the casing body 21.

[0061] In other respects, the embodiment of Figure 2 also applies equally to the form shown in Figure 3.

[0062] Figure 4a is a schematic perspective view of the casing body 21 according to the embodiment of Figure 2. The casing body 21 has a substantially hollow cylindrical and ring-shaped shape with a circular bottom surface. The casing body 21 is integrally formed here.

[0063] The casing body 21 has a first opening 21m on the end face facing the bottom 21k. The bottom 21k has a second opening 21h that is smaller than the first opening 21m. Through the second opening 21h, for example, a braking drive shaft (not shown) described above can be guided. Further, the casing body 21 has special shape details necessary for the assembly and function of the electromagnetic brake 20. These shape details will be described in the following specification.

[0064] The first opening 21m extends to the outer wall 21i and is defined thereby. In the region of the first opening 21m, the casing body 21 has three notches 21b within the outer wall 21i, each of which is followed by a receiving groove 21c. Here, the notches 21b are arranged in a web on the end face of the casing body 21, and this web is formed by the outer wall 21i and defines the receiving groove 21c. The receiving grooves 21c partially encircle and extend into the outer wall 21i of the casing body 21 at intervals from each other. Arranging the partially extending receiving grooves 21c has the advantage that the position where the friction disk 22 is finally mounted in the casing body 21 can be easily predefined by the end of the receiving groove 21c on the side opposite to the notch 21b, thereby simplifying subsequent assembly steps. The notches 21b enable the friction disk 22 to be fitted into the receiving groove 21c, and thus enable the establishment of a bayonet connection 23 by shape coupling between the casing body 21 and the friction disk 22.

[0065] The guide grooves 21a for guiding the armature disk 25 are arranged such that the guide protrusions 25a of the armature disk 25 can be fitted into the guide grooves 21a through the respective notches 21b. The armature disk 25 can be supported on the stepped portion 21f of the outer wall 21i of the casing body 21 that connects the bottom 21k to the outer wall 21i.

[0066] The pole core 31 is ring-shaped and is disposed within the casing body 21, particularly embedded in or formed from its wall. The pole core 31 surrounding the opening 21h at the bottom 21k is spaced apart from the outer wall 21i or the stepped portion 21f of the casing body 21, and a coil unit 26 can be disposed 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. Since the pole core 31 needs to be made of a magnetic material, in this embodiment, the entire casing body 21 is made of a magnetic material. A circumferential groove 28 is disposed on the outer diameter of the pole core 31, and the snap hook 27 of the coil unit 26 can be engaged and supported within this groove. Next, when a force is generated in the direction of the first opening 21m parallel to the central axis 33, the snap hook 27 is supported by the web 28a defining the groove 28.

[0067] The casing body 21 further has a receiving portion 21d within its outer wall 21i to the stepped portion 21f, and a positioning projection 26a of the coil unit 26 is fitted into this receiving portion to lock the coil unit 26 so that it does not rotate relative to the casing body 21.

[0068] The plurality of bottomed holes 21g in the stepped portion 21f are used to accommodate the compression springs 30. These are evenly distributed around the stepped portion 21f. Since there are six bottomed holes 21g in this embodiment, a total of six compression springs 30 can be incorporated.

[0069] The plurality of through-hole portions 21e extending through the outer wall 21i of the casing body 21 parallel to the central axis 33 are used for guiding the locking element 100. Further, each of the through-hole portions 21e extends through an accommodation groove 21c used for accommodating the friction disk 22. The through-hole portions 21e do not have threads.

[0070] Figure 4b is a schematic perspective view of a further embodiment of the casing body 21. In this embodiment, a single receiving groove 21c is provided in the casing body 21 or its outer wall 21i in a form that encircles the entire circumference, and in order to support the snap hook 27, a plurality of circumferential grooves 28 or circumferential webs 28a that are not single but rather partially circumferential and are spaced apart from each other are provided, which is different from the embodiment shown in Figure 4a.

[0071] However, embodiments are also conceivable in which only the single receiving groove 21c and the single groove 28 are each provided in a form that encircles the entire circumference, or both the receiving groove 21c and the groove 28 are each only partially circumferential and are spaced apart from each other. In other respects, the embodiment for Figure 4a is equally applicable to the form shown in Figure 4b.

[0072] Figure 5 is a schematic perspective view of the friction disk 22 according to the embodiment of Figure 2. The friction disk 22 is formed rotationally symmetrically and includes three outwardly directed protrusions 22a that are substantially semi-circular, and these protrusions are each arranged around the circumference of the friction disk 22 at an angle of 120°. The number of protrusions 22a can be changed, but at least two are necessary to avoid the friction disk 22 lifting off from the casing body 21. Furthermore, it is advantageous if the protrusions 22a are evenly distributed around the circumference of the friction disk 22. Each protrusion 22a has a recess 22b arranged therein, and by inserting the locking element 100 through this recess when attaching the electromagnetic brake 20 to another component, the rotation of the friction disk 22 about the central axis 33 can be blocked. It is also conceivable not to provide a recess 22b in each protrusion 22a.

[0073] The friction disk 22 has a hole in its center, and this hole is dimensioned such that a drive shaft (not shown) to be braked can be guided through the hole. The notch 22c at the inner diameter of the friction disk 22 improves the force flow in the friction disk 22, is used to grip the friction disk 22 at an accurate position using a robot gripper or the like, and further to accurately position the friction disk 22 within the casing body 21 even when the tolerance range is narrow. The surface of the friction disk 22 is correspondingly designed so that optimal deceleration can be achieved at least on the side surface provided for braking contact with the brake disk 29.

[0074] FIG. 6 is a schematic perspective view of the armature disk 25 according to the embodiment of FIG. 2. The armature disk 25 is formed rotationally symmetrically and includes three guide protrusions 25a that are substantially semi-circular and directed outward, and these guide protrusions are arranged around the armature disk 25 at an angle of 120° each. The three guide protrusions 25a make it possible to guide the armature disk 25 within the casing body 21 without tilting.

[0075] The armature disk 25 has a hole 25c in its center, and this hole is dimensioned such that a drive shaft (not shown) to be braked can be guided through the hole. The notch 25b at the inner diameter of the armature disk 25 improves the force flow in the armature disk 25, is used to grip the armature disk 25 at an accurate position using a robot gripper or the like, and further to accurately position the armature disk 25 within the casing body 21 even when the tolerance range is narrow. The surface of the armature disk 25 is correspondingly designed so that optimal deceleration can be achieved at least on the side surface directed toward the brake disk 29.

[0076] FIG. 7 is a schematic perspective view of the coil unit 26 according to the embodiment of FIG. 2. The coil unit 26 has a substantially ring-shaped geometry, which has a C-shaped cross-section open towards the outside. The C-shaped cross-section is formed by an upper leg 26d extending substantially horizontally, a lower leg 26f extending substantially horizontally, and a web 26e connecting the two legs 26d, 26f and extending substantially at right angles to the legs 26d, 26f.

[0077] In this embodiment, the coil unit 26 has eight snap hooks 27. However, the number of snap hooks 27 can be changed in consideration of the forces generated in both axial directions. Each snap hook 27 is dimensioned and designed in terms of material technology to be elastically deformable outward so that the snap hook 27 can engage with the groove 28 by applying a force acting in the direction of the bottom 21k of the casing body 21 parallel to the central axis 33 when the coil unit 26 is attached in the casing body 21. The snap hook 27 is an integral part of the coil unit 26. However, it is also conceivable that the snap hook 27 is an independent component and is connected to the coil unit 26.

[0078] The coil unit 26 further has a substantially semi-circular positioning projection 26a, which is used for rotational locking within the casing body 21. Further, the positioning projection 26a can be used so that each snap hook 27 is positioned in alignment with one of the grooves 28 when assembling the coil unit 26 in the casing body 21 where a plurality of grooves 28 are partially present.

[0079] The coil unit 26 is formed as a coil support and is suitable for accommodating one or more coils (not shown) necessary for exciting a magnetic field. In this case, the coil is arranged or supported within the C-shaped structure of the coil unit 26 that is open towards the outside.

[0080] Figures 8a, 8b, and 9 are schematic cross-sectional views of the electromagnetic brake 20 of the present invention according to the embodiment of FIG. 2. In FIGS. 8a and 8b, the structure of the assembled electromagnetic brake 20 can be well understood.

[0081] The casing body 21 has a recess dimensioned to correspond to the dimensions of the coil unit 26 between its outer wall 21i and the pole core 31. The recess has a play necessary for attaching the coil unit 26, but is formed so as to ensure sufficient fixation of the coil unit 26 particularly during the operation of the electromagnetic brake 20. The snap hook 27 of the coil unit 26 is supported in the groove 28 and is supported by the web 28a of the casing body 21 (see FIG. 9). Therefore, the coil unit 26 is connected to the casing body 21 only by form fit.

[0082] The armature disk 25 is disposed between the first opening 21m of the casing body 21 and the coil unit 26. The upper leg 26d of the coil unit 26 facing the first opening 21m of the casing body 21 is spaced appropriately from the stepped portion 21f so that the armature disk 25 can be placed on the stepped portion 21f. A tensile force can be formed by the pole core 31 excited by the coil unit 26, and due to this tensile force, the armature disk 25 is axially slidable away from the brake disk 29 to release the brake 20.

[0083] The six compression springs 30 are each disposed in the bottomed hole 21g. Only one of these bottomed holes 21g and the compression spring 30 are shown in FIGS. 8a and 8b. The compression spring 30 is adjusted by its compression force to axially slide the armature disk 25 toward the brake disk 29 for braking.

[0084] The friction disk 22 is disposed between the end face of the casing body 21 and the brake disk 29. The brake disk 29 disposed between the armature disk 25 slidable in the axial direction and the friction disk 22 is adjusted to be rotatable about the central axis 33 and slidable in the axial direction. The brake disk 29 has one or a plurality of brake pads 29b on two opposing sides in its outer diameter region. Thereby, optimal braking can be achieved, particularly in combination with the aforementioned surface of the friction disk 22 and / or the armature disk 25.

[0085] FIG. 9 is an enlarged view of the region composed of FIGS. 8a and 8b. From this region, the mounting situation of the coil unit 26 in the casing body 21, and the C-shaped cross-section formed by the leg portions 26d, 26f and the web 26e can be well understood. This C-shaped cross-section is open towards the outer wall 21i on the outside.

[0086] The illustrated snap hook 27 is an integral component of the coil unit 26, like the other snap hooks 27. It engages with the groove 28 and supports the coil unit 26 by the web 28e in the casing body 21. Therefore, the coil unit 26 is connected to the casing body 21 by shape coupling through the snap connection 34.

[0087] To establish the snap connection 34, the snap hook 27 is elastically deformed in the direction of the outer wall 21i of the casing body 21. In other words, the snap hook 27 is pulled radially outward when the coil unit 26 is attached, and then engages radially inward into the groove 28 of the casing body 21. For this purpose, the coil unit 26 has a slit-shaped recess extending along the web 26e in the region of the snap hook 27. The elastic deformation is particularly performed based on the force acting in the direction of the bottom 21k of the casing body 21 parallel to the central axis 33.

[0088] The coil unit 26 is supported on a stepped portion 26b on the bottom 21k of the casing body 21. The stepped portion 26b creates a space between the coil unit 26 and the casing body 21 in the region of the diameter where the snap hook 27 is disposed. The coil unit 26 is thereby axially movable with respect to the casing body 21 in the region of the snap connection 34, facilitating assembly. Thus, this space can be used as a kind of spring deflection, and the leg portion 26f of the coil unit 26 facing the bottom 21k is pushed in the direction of the bottom 21k of the casing body 21 around the stepped portion 26b used as a rotation point outside the stepped portion 26b during installation, thereby bending in this direction and, consequently, enabling the snap hook 27 to more easily engage with the groove 28 of the casing body 21. In other words, the coil unit 26 is adjusted to have flexibility or elasticity, thereby ensuring the engagement of the snap hook 27 even with poor manufacturing accuracy.

[0089] Figures 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.

[0090] FIG. 10 shows a state where only the coil unit 26 is attached to the casing body 21. In order to rotationally lock the coil unit 26, the positioning protrusion 26a disposed thereon engages with a corresponding receiving portion 21d in the casing body 21. Thus, a snap connection 34 by a pure form fit occurs between the coil unit 26 and the casing body.

[0091] In addition, FIG. 11 shows a state in which the armature disk 25 is attached to the casing body 21. The armature disk 25 is fitted into the casing body 21 such that each guide projection 25a of the armature disk 25 is guided within the guide groove 21a belonging to the casing body 21. The armature disk 25 is axially guided within the casing body 21 via the groove-projection connection 32 formed in this way. The outer contour of the guide projection 25a preferably corresponds to the inner contour of the guide groove 21a. However, sufficient clearance is provided between the outer contour of the guide projection 25a and the inner contour of the guide groove 21a for the axial movement of the armature disk 25.

[0092] In addition, FIG. 12 shows a state in which the brake disk 29 and the friction disk 22 are attached within the casing body 21. The friction disk 22 is connected to the casing body 21 in a bayonet manner by form fit for this purpose. For the bayonet connection 23, the projection 22a of the friction disk 22 is guided through the notch 21b into the receiving groove 21c of the casing body 21 and slid in the rotational direction therein. Thus, the friction disk 22 and the casing body 21 rotate relative to each other about the central axis 33. After this relative movement, the three projections 22a of the friction disk 22 and the notch 21b do not coincide axially, that is, substantially parallel to the central axis 33.

[0093] The through-hole portion 21e and the recess 22b positioned correspondingly to the projection 22a of the friction disk 22 can then guide three connecting elements when attaching the electromagnetic brake 20 to another component, and these connecting elements are all used as locking elements 100 at the same time in this case.

Explanation of reference numerals

[0094] 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 Receiving groove 21d Receiving part 21e Through-hole part 21f Step part 21g Bottomed hole 21h Second opening 21i Exterior wall 21k Bottom 21m First opening 22 Friction disk 22a Protrusion 22b Recess 22c Notch 22d Hole part 23 Bayonet connection 25 Armature disk 25a Guide protrusion 25b Notch 25c Hole part 26 Coil unit 26a Positioning protrusion 26b Step part 26c Hole part 26d Upper leg 26e Web 26f Lower leg 27 Snap hook 28 Groove 28a Web 29 Brake disk 29a Ring gear 29b Brake pad 29c Hole part 30 Compression spring 31 Pole core 32 Groove-protrusion connection 33 Central axis 34 Snap connection 100 Locking element h Lift mechanism F Travel direction x longitudinal direction

Claims

1. An electromagnetic brake comprising a casing body (21) and a coil unit (26), wherein the coil unit (26) is connected to the casing body (21) by snap connection (34) and by form fit, and at least one snap hook (27) of the coil unit (26) is supported by a web (28a) of the casing body (21). The casing body (21) is a hollow cylindrical shape including a receiving portion (21d) on its inner circumference. The coil unit (26) includes at least one positioning protrusion (26a) corresponding to the receiving portion (21d). The receiving portion (21d) of the casing body (21) engages with the at least one positioning protrusion (26a) of the coil unit (26), characterized in that the electromagnetic brake (20).

2. The electromagnetic brake (20) according to claim 1, characterized in that the coil unit (26) is locked so as not to rotate with respect to the casing body (21).

3. The electromagnetic brake (20) according to claim 1 or 2, characterized in that in the region where the coil unit (26) is connected to the casing body (21) by form fit for easy assembly, the coil unit (26) is supported by the casing body (21) so as to be axially movable with respect to the casing body.

4. An armature disk (25) is provided, and the armature disk (25) is axially guided in the casing body (21) via a groove-protrusion connection (32), and is provided with at least one guide groove (21a) and at least one corresponding guide protrusion (25a), and the guide grooves (21a) are respectively arranged in the casing body (21), characterized in that the electromagnetic brake (20) according to any one of claims 1 to 3.

5. A friction disk (22) is provided, and the friction disk (22) is connected to the casing body (21) by form fit and / or locked so as not to rotate with respect to the casing body (21), characterized in that the electromagnetic brake (20) according to any one of claims 1 to 4.

6. The friction disk (22) is locked by at least one locking element (100) so as not to rotate relative to the casing body (21), and the locking element (100) is a connecting element used for attaching the electromagnetic brake (20) to components, the electromagnetic brake (20) according to claim 5.

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

8. A method for assembling the electromagnetic brake (20) according to any one of claims 1 to 6, wherein at least one positioning projection (26a) of the coil unit (26) engages with a corresponding receiving portion (21d) of the casing body (21) for rotational locking, and / or at least one snap hook (27) of the coil unit (26) is supported by a web (28a) of the casing body (21) such that the coil unit (26) is axially shape-coupled by a snap connection (34) to the casing body (21), and the coil unit (26) is fitted into the casing body (21).

9. A method for assembling the electromagnetic brake (20) according to claim 8, wherein the armature disk (25) is fitted into the casing body (21) having a pole core (31) such that at least one guiding projection (25a) of the armature disk (25) is guided within a guiding groove (21a) belonging to the casing body (21).

10. A method for assembling the electromagnetic brake (20) according to claim 8, which cites claim 6, wherein the friction disk (22) is fitted into a notch (21b) of the casing body (21) and is engaged using a receiving groove (21c) adjacent to the notch (21b) by relative movement in the rotational direction with respect to the casing body (21), and at least one projection (22a) of the friction disk (22) and the notch (21b) do not align axially after the relative movement.

Images