Permanent magnet brake

Abstract

To provide permanent magnet brake capable of being released manually.SOLUTION: A permanent magnet brake comprises a magnet housing (2) and an armature plate (3) cooperating with the magnet housing. The magnet housing (2) houses a permanent magnet (6) and an energizable coil (7). The magnet housing (2) has two housing components (9, 10) each providing one magnetic pole. One of the two housing components (9, 10) has two housing component portions (11, 12), and a separation portion (13) that at least partially magnetically isolates the two housing component portions (11, 12) from each other. The magnet housing is provided with a magnetic flux bridge (14) cooperating with the two housing component portions (11, 12). The magnetic flux bridge is formed movably, and can move from an in-use position to an out-of-use position and vice versa. The magnetic flux bridge (14) bridges the separation portion (13) in the in-use position.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a permanent magnet brake including a magnet housing and an armature plate cooperating with the magnet housing, the magnet housing accommodating a permanent magnet and an energizable coil, and the magnet housing having two housing parts each providing one magnetic pole.

Background Art

[0002] Permanent magnet brakes are well known per se from the prior art and do not require proof by separate publications. Thus, for example, see Patent Document 1, Patent Document 2, and Patent Document 3.

[0003] Attribute-corresponding permanent magnet brakes have a magnet housing and an armature plate cooperating with the magnet housing. The armature plate is formed to be movable relative to the magnet housing and can abut against the magnet housing at a first position or be separated from the magnet housing at a second position. Typically, the armature plate is arranged non-rotatably relative to the shaft but axially displaceable.

[0004] The magnet housing accommodates a permanent magnet on one hand and an energizable coil on the other hand. In that case, the energizable coil, in combination with the magnet housing, forms an electromagnet. In a typical structural form, the armature plate is attracted to the permanent magnet and abuts against the magnet housing when the coil is not energized. When the armature plate is in this position, it is in a so-called braking position. When the coil is energized, a counter electromagnetic field is generated with respect to the magnetic field of the permanent magnet, which causes the armature plate to move away from the magnetic housing by means of a return spring and form a gap. When the armature plate is in this position, the permanent magnet brake is in a non-braking position. In this position, the shaft supporting the armature plate can rotate with respect to the permanent magnet brake. On the contrary, when the permanent magnet brake is in the braking position, at this position, since the armature plate abuts against the magnet housing in a non-rotatable manner, the shaft is fixed.

[0005] The magnet housing has two housing parts. These each form magnetic poles, precisely an outer pole on one hand and an inner pole on the other hand. In a preferred structural form, as known from, for example, Patent Document 3, the two housing parts each have, on one hand, a tube part and, on the other hand, a flange part. In that case, the two tube parts of the housing parts engage with each other to form an annular space, and this annular space is used as a coil space for accommodating the energizable coil. The two flange parts of the magnet housing are also arranged spaced apart from each other, and the space between the two flange parts is used for accommodating the permanent magnet. This known structural form becomes apparent, for example, from Patent Document 1 and Patent Document 3.

[0006] The aforementioned structure has a fundamental drawback that the permanent magnet brake cannot be released in case of a coil failure or a power outage, that is, the permanent magnet brake cannot be moved to the non-braking position. When a coil failure or a power outage occurs, a counter electromagnetic field cannot be generated, and thereby the permanent magnet continuously abuts the armature plate against the magnet housing, so that the permanent magnet brake is continuously in the braking position.

[0007] To overcome this problem, Patent Document 3 has already proposed a so-called neutralisation element that can substantially or completely eliminate the braking action of the permanent magnet without current. This neutralisation element is a ring body made of a magnetically conductive material that surrounds the magnet housing, and this ring body is axially displaceable relative to the magnet housing. To release the permanent magnet brake without current, it is necessary to position the neutralisation element relative to the permanent magnet so that the neutralisation element is operatively connected to the permanent magnet to magnetically short-circuit the permanent magnet. When the neutralisation element is in this position, the magnetic field of the permanent magnet is preferably formed in the direction of the neutralisation element because the travel distance through the neutralisation element is much shorter than that through the magnet housing and the armature plate, and thus the loss is small. To that extent, the magnetic action on the armature plate is demagnetised by the neutralisation element, thereby releasing the brake.

[0008] When the coil is energised when the neutralisation element is in this position, a magnetic field acting on the armature plate is induced, and thus the armature plate is attracted. That is, the brake is in a closed state when energised, and thus the action of the coil is, so to speak, reversed.

[0009] The structure known from Patent Document 3 has been proven in daily practical use, but there is a need for improvement. The known structure necessarily requires, as a precondition, the placement of the neutralisation element spatially very close to the permanent magnet for magnetic short-circuiting. However, the corresponding structural space is not always available, and thus the structure known from Patent Document 3 can only be used within a limited range depending on the application.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

[0011] Based on this, the object of the present invention is to further develop the design of the conventional permanent magnet brake so as to enable the utilization of an optimized installation space and at the same time enable manual release.

[0012] In order to solve the above problems, according to the present invention, a permanent magnet brake of the type described at the beginning is proposed. In this permanent magnet brake, one of the two housing parts has two housing part portions and a separating part that at least partially magnetically insulates these two housing part portions from each other. A magnetic flux bridge that cooperates with the two housing part portions is provided, and the magnetic flux bridge is formed movably and can move from the use position to the non-use position and vice versa. The magnetic flux bridge is characterized in that it bridges the separating part when it is in the use position.

[0013] According to the present invention, one of the two housing parts of the magnet housing has two housing part portions and a separating part. In that case, the separating part at least partially magnetically insulates the two housing part portions from each other. Therefore, the magnetic flux from one housing part portion to the other housing part portion through the separating part is blocked, but is minimized anyway.

[0014] According to the present invention, a magnetic flux bridge is further provided. The magnetic flux bridge is formed movably and cooperates with the two housing part portions. In that case, the magnetic flux bridge is used to selectively bridge the separating part that magnetically insulates the two housing part portions from each other.

[0015] The magnetic flux bridge is formed movably and can move from the use position to the non-use position and vice versa. In that case, the magnetic flux bridge bridges the separation part when it is in the use position. Bridging of the separation part by the magnetic flux bridge does not occur when it is in the non-use position.

[0016] Therefore, on the user side, by positioning the magnetic flux bridge relative to the magnet housing, it is possible or not possible to enable magnetic flux between two housing part portions of one housing part. Only when the magnetic flux bridge is in the use position, the separation part insulating the two housing part portions is bridged, and magnetic flux can occur between the two housing part portions through the mediation of the magnetic flux bridge. However, when the magnetic flux bridge is in the non-use position, the bridging of the separation part does not occur, and as a result, the magnetic flux between the two housing part portions is blocked.

[0017] When the permanent magnet brake is used as specified, the magnetic flux bridge is in the use position. The magnetic field generated by the permanent magnet is induced across the two housing parts of the magnet housing and the armature plate, whereby the armature plate is attracted, and thus the permanent magnet brake is in the braking position, also called the closed position. To effect release of the permanent magnet brake, it is necessary to energize a coil housed in the magnet housing, thereby generating a reverse electromagnetic field, whereby the armature plate is separated from the magnetic housing and a gap is formed. When the armature plate is in this position, the permanent magnet brake is in the non-braking position, also called the release position.

[0018] When a coil failure and / or a no-current state occurs, the magnetic flux bridge can be manually released from the permanent magnet brake by being moved from the use position to the non-use position. For this purpose, the magnetic flux bridge is manually moved by the user with respect to the magnet housing. When the magnetic flux bridge is in the non-use position, the bridging of the separated parts is not performed, thereby interrupting the magnetic flux between the two housing component parts magnetically insulated from the separated parts. As a result, the magnetic flux to the armature plate is also interrupted, and thus the armature plate is no longer attracted by the magnet housing. Therefore, when the magnetic flux bridge is in the non-use position, the permanent magnet brake is in the open position, i.e., the released position.

[0019] Unlike the structure according to Patent Document 3, in the embodiment according to the present invention, no magnetic short circuit is formed with respect to the permanent magnet, but rather the magnetic flux to the armature plate is interrupted when necessary. This is done by moving the magnetic flux bridge with respect to the magnet housing, and the magnetic flux bridge allows the magnetic flux passing through the armature plate only in the case of regular braking, i.e., when it is in the use position, and not otherwise.

[0020] The structural form according to the present invention has the special advantage that the arrangement of the magnetic flux bridge in the magnet housing is independent of the position of the permanent magnet. Therefore, the form of the separated part and the position of the magnetic flux bridge associated therewith can be chosen very freely, thereby taking into account the characteristics specific to the installation space in individual cases. Therefore, the utilization of the installation space can be expanded, and thus other structural principles regarding the permanent magnet brake are also possible. To that extent, the form according to the present invention creates a considerable margin for the optimized utilization of the available installation space.

[0021] The structure according to Patent Document 3 may enable the action of the electromagnet to be reversed by the demagnetizing element described therein short - circuiting the permanent magnet. Such a reversal of the action of the electromagnet is not possible with the structure according to the present invention. However, this drawback is consciously accepted because the advantages achieved by the present invention, namely that the magnetic flux bridge can be arranged in the magnet housing regardless of the position of the permanent magnet, outweigh it. That is, not only is room created with regard to the use of the installation space, but also additional possibilities are made possible with regard to the form of the permanent magnet and the positioning of the permanent magnet. These advantages associated with the present invention cannot be achieved in Patent Document 3 due to structural constraints.

[0022] As a result, the form according to the present invention enables manual release to be easily carried out, especially in an emergency, for example when a power failure occurs. The magnetic flux bridge contemplated by the present invention serves as a bypass for the magnetic flux in the case of normal use. In the case of manual release, this bypass is interrupted by moving the magnetic flux bridge relative to the magnet housing and moving this magnetic flux bridge from the use position to the non - use position. Thus, unlike what is known from the prior art, no magnetic short - circuiting of the permanent magnet is carried out, and thus the arrangement and form of the magnetic flux bridge are independent of the form and positioning of the permanent magnet. This creates additional structural freedom and thereby simultaneously ensures the possibility of manual release in an emergency.

[0023] According to a further feature of the present invention, the separating part is arranged between two housing part portions in the axial direction of the magnet housing. Thus, by arranging the separating part between the two housing part portions with respect to space, magnetic insulation of the two housing part portions is achieved. Thus, in the axial direction of the magnet housing, the two housing part portions are separated from each other by the separating part, thereby enabling mutual magnetic insulation of the two housing part portions with a simple structure.

[0024] According to a further feature of the invention, the housing part section and the separating section are integrally formed, and the separating section is intended to have a cavity that magnetically separates the housing part sections from each other.

[0025] According to this preferred embodiment, the housing part providing the housing part section and the separating section is integrally formed. This enables simple manufacture of the housing part. To form the separating section, cavities are provided in the housing part, for example slots in the form of oblong holes. In the case of a tubular housing part, these cavities extend in the circumferential direction of the housing part. In that case, a plurality of these cavities can be provided, and between two successive cavities following one another, a connecting web is provided that connects two adjacent housing part sections to each other. A magnetic coupling occurs between the two housing part sections via these webs, but this magnetic coupling only allows leakage flux that does not prevent the manual release of the permanent magnet brake during normal operation as prescribed. Nevertheless, it is desirable that the webs connecting the two housing part sections are formed as small as possible, while of course ensuring sufficient stability of the corresponding housing part.

[0026] According to an alternative embodiment, the housing part having the housing part section and the separating section can also be formed in a multi-piece configuration. In this case, the separating section is made of a non-magnetic material, for example aluminum or plastic. In the case of a tubular housing part, the separating section can be formed, for example, as a ring. In the final assembled state, the separating section is arranged between the two housing part sections and is connected to them, for example glued.

[0027] The integral form of the housing part is preferred because it simplifies manufacture and subsequent assembly. However, the multi-piece configuration has the advantage that each magnetic flux can be blocked by the separating section and thus there can also be no leakage flux.

[0028] According to a further feature of the invention, each housing part has a tube segment and a flange segment arranged on the tube segment, and it is contemplated that the tube segment of one housing part provides the housing part portion and the separation portion.

[0029] According to this preferred embodiment, each housing part is contemplated to have on the one hand a tube segment and on the other hand a flange segment, and the flange segment is arranged on the tube segment. The flange segment extends, in particular, radially, in particular orthogonally, with respect to the associated tube segment. In that case, in the final assembled state, the tube segments of the two housing parts engage with one another and, precisely, form an intermediate space that is ring-shaped and that accommodates a coil that can be energized in the final assembled state.

[0030] The tube segment of one housing part provides the above-mentioned portions, namely, on the one hand, the housing part portion and, on the other hand, the separation portion. Thereby, as a whole, a structure that can be easily manufactured and easily assembled is obtained.

[0031] According to a further feature of the invention, it is contemplated that the magnetic flux bridge surrounds the associated housing part and is arranged on the housing part so as to be axially displaceable with respect to the housing part. The housing part that supports the magnetic flux bridge is, in particular, the housing part of the magnet housing that provides the outer pole. In that case, the magnetic flux bridge surrounds the tube portion of the associated housing part. The magnetic flux bridge is movable with respect to the housing part, and it is preferred that the magnetic flux bridge is axially displaceable with respect to the housing part and, in particular, is arranged on the housing part so as to be displaceable. Thus, in the case of proper use, the magnetic flux bridge can be displaced by the user axially, that is, in the longitudinal direction of the housing part, of the housing part, thereby moving it from the use position to the non-use position and vice versa. Thus, the operation on the user side is made possible simply, that is, by simply axially displacing the magnetic flux bridge with respect to the magnet housing.

[0032] According to a further feature of the invention, the flux bridge is formed in a ring shape and is intended to accommodate the tube segments of the associated housing parts. Thus, the flux bridge cooperates with the tube segments of the associated housing parts, which are formed in particular in a ring shape in order to surround the tube segments. Thus, it can be easily gripped by the user and, as described above, can be selectively displaced axially with respect to the housing parts.

[0033] According to a further feature of the invention, the flux bridge has a support made of a non-magnetic material and a magnet body made of a magnetic material arranged on this support, and the magnet body is intended to have a longitudinal extent that exceeds the longitudinal extent of the separated part in the axial direction of the magnet housing.

[0034] Thus, the flux bridge preferably has a support on the one hand and a magnet body on the other hand. In that case, the magnet body is supported by the support. In addition, the support is used for the user-side operation of the flux bridge by being able to be grasped by the user in order to displace the flux bridge. The support is formed from a non-magnetic material, for example a light metal, preferably aluminium, or a plastic material.

[0035] However, the magnet body is formed from a magnetic material, for example the same material as forms the two housing part portions separated from the separated part. For the purpose of forming a ring-shaped flux bridge, both the support and the magnet body are formed in a ring shape. In that case, the support provides a cavity extending over the entire circumference inside the support, into which the magnet body is inserted in the final assembled state. Thus, the magnet body is embedded in the support. In that case, the cavity of the support accommodating the magnet body is formed on the inner circumferential side of the support and thus towards the associated housing parts.

[0036] When the magnetic flux bridge is in the use position, the magnet body is magnetically operatively connected to the two housing component parts. When the magnetic flux bridge is in this position, the separation part is bridged by the magnet body, whereby the magnetic flux is induced from one housing component part to the other housing component part via the magnet body. For this reason, the magnet body has a longitudinal extent that exceeds the longitudinal extent of the separation part. Advantageously, when the magnetic flux bridge is in the use position, it is structurally ensured that the two housing component parts are magnetically connected to each other by the magnet body and the separation part that magnetically insulates the two housing component parts from each other is bridged.

[0037] According to a further feature of the invention, it is contemplated that the magnet housing has a travel limiter (Wegbegrenzer) that cooperates with the magnetic flux bridge. The travel limiter advantageously forms a stopper for the magnetic flux bridge, whereby on the user side, both the use position and the non-use position of the magnetic flux bridge can be reliably and verifiably set. To that extent, it is preferable to form the travel limiter such that the magnetic flux bridge can be moved close to it until it hits the travel limiter in order to take the use position and in order to take the non-use position. This ensures an easy and safe operation of the permanent magnet brake by the user.

[0038] According to a further feature of the invention, it is contemplated that the travel limiter is a bolt accommodated in a cavity provided by the magnet housing. Such a bolt can be configured, for example, as a threaded bolt and is inserted into a threaded cavity provided by the magnet housing in the final assembled state. Such a form advantageously enables easy assembly and further disassembly, especially during repair.

[0039] According to a further feature of the present invention, it is contemplated that the support has an opening through which a bolt is passed. This opening can be formed, for example, as a slot portion in the form of a long hole. In that case, this form has the advantage that both a movement distance limiter for the use position and a movement distance limiter for the non-use position are provided with only one bolt. This is because the bolt abuts against the edge of the opening provided by the support on one end side in the use position and against the relevant edge of the same opening on the other end side in the non-use position. With only one opening through which the bolt is passed, the user can selectively and safely and easily approach both the use position and the non-use position. In addition, the above-described structure enables easy assembly or disassembly by guiding the magnetic flux bridge across the magnet housing, then inserting the bolt through the opening provided by the support and into the cavity on the magnet housing side. Next, the magnetic flux bridge is fixed to the magnet housing both radially and axially, and the magnetic flux bridge is axially displaceable with respect to the magnet housing as described above.

[0040] Further features and advantages of the present invention will become apparent from the following description based on the drawings.

Brief Description of the Drawings

[0041]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0042] Figure 1 shows a schematic partial cross-sectional side view of the structure of the permanent magnet brake 1 according to the present invention. The permanent magnet brake 1 has a magnet housing 2 and an armature plate 3 that cooperates with this magnet housing. The armature plate is arranged non-rotatably but displaceably in the axial direction 15 relative to a shaft (not shown in detail in the figure) by a hub 4. In the illustrated embodiment, the armature plate 3 cooperates with the hub 4 via a return spring 5.

[0043] The magnet housing 2 has two housing parts, namely a housing part 9 on the one hand and a housing part 10 on the other hand. In the exemplary embodiment shown, the housing part 9 forms the inner pole of the magnet housing 2, while the housing part 10 forms the outer pole of the magnet housing 2.

[0044] The two housing parts 9 and 10 each have a tube segment 17 or 18 and a flange segment 19 or 20. In that case, each flange segment 19 or 20 is arranged on the associated tube segment 17 or 18.

[0045] The two tube segments 17 and 18 are arranged to mesh leaving a coil space 8. In that case, as shown in Figure 1, the tube segment 17 engages the tube segment 18 at the end of this tube segment opposite the flange part 19. In the final assembled state, the coil space 8 houses an electrically energizable coil 7, and the coil is operatively connected to the magnet housing 2 to form an electromagnet.

[0046] The magnet housing 2 further houses a permanent magnet 6. The permanent magnet is arranged between the two flange segments 19 and 20 of the housing parts 9 and 10 in the final assembled state. The permanent magnet may be formed in a ring shape. Alternatively, a plurality of permanent magnets 6 formed in a ring shape or segment shape are provided, and these permanent magnets are arranged one after another in the circumferential direction of the magnet housing 2.

[0047] According to the present invention, the tube segment 18 of the housing part 10 has two housing part sections 11 and 12. These are at least partially magnetically insulated from each other by a separating part 13. In that case, the separating part 13 is arranged axially 15 between the two housing part sections 11, 12.

[0048] In the illustrated exemplary embodiment, the separating part 13 is formed by a cavity 16, by means of which the two housing part sections 11 and 12 are separated from each other. As can be seen in particular when FIGS. 4 and 5 are considered together, the housing part 10 providing the two housing part sections 11 and 12 is integrally formed. In that case, the separating part 13 has a plurality of cavities 16 arranged one behind the other in the circumferential direction 32. In that case, a web 33 is provided between two cavities 16 following one another continuously in the circumferential direction 32, and this web connects the two housing part sections 11 and 12 to each other and enables an integral form.

[0049] Furthermore, as is evident in particular from FIG. 1, a magnetic flux bridge 14 is further provided. The magnetic flux bridge is formed in a ring shape in the illustrated exemplary embodiment and surrounds the housing part 10 of the magnet housing 2 in the final assembled state.

[0050] The magnetic flux bridge 14 has, on the one hand, a support 21 and, on the other hand, a magnet body 22. In that case, the support 21 is formed of a non-magnetic material, in particular aluminum. However, the magnet body 22 is formed of a magnetic material, in particular the same material as that forming the two housing component parts 11 and 12. As shown by the illustration according to FIG. 1, the support 21 has a circumferential recess on the housing component side, and the magnet body 22 is inserted into this recess so as to be flush on the inner surface side. In that case, the magnet body 22 has a longitudinal range, that is to say, a range in the axial direction 15 that extends beyond the range of the recess 16 in the axial direction 15. Thus, by the magnet body 22, the magnet body 22 can magnetically contact both the one housing component part 11 and the other housing part 12, as shown in FIG. 1, so that the separation part 13 can be bridged.

[0051] As can be seen more clearly from FIG. 1, the support 21 has an opening 25. In the final assembled state, this opening 25 is penetrated by a bolt 23, and the bolt 23 is inserted, at one end side, into a recess 24 provided by the magnet housing 2. This bolt 23 functions as a travel distance limiter in the axial direction 15 for the magnetic flux bridge 14, as will be explained in more detail below.

[0052] The magnetic flux bridge 14 is arranged in the magnet housing 2 so as to be movable in the axial direction 15. Thus, the magnetic flux bridge 14 can move back and forth in the axial direction 15 with respect to the magnet housing 2.

[0053] In particular, the magnetic flux bridge 14 can take a so-called use position and a so-called non-use position. The use position of the magnetic flux bridge 14 is shown in FIGS. 2 and 4. The non-use position of the magnetic flux bridge 14 becomes clear from FIGS. 3 and 5.

[0054] In order to move the magnetic flux bridge 14 from, for example, the use position according to FIG. 2 to the non-use position according to FIG. 3, and vice versa, the magnetic flux bridge 14 is gripped on the user side and needs to be moved in the axial direction 15 in the direction of arrow 28 according to FIG. 2 or the direction of arrow 29 according to FIG. 3. In that case, as is apparent from FIGS. 2 and 3 for example, it is necessary to move the magnetic flux bridge 14 towards the bolt 23 to the stopper respectively. In that case, the magnetic flux bridge 14 abuts against the bolt 23 on the right side with respect to the drawing plane according to FIG. 2 by its opening 25 at the use position according to FIG. 2. In contrast, at the non-use position according to FIG. 3, the magnetic flux bridge 14 abuts against the bolt 23 on the left side with respect to the drawing plane according to FIG. 3 by its opening 25.

[0055] At the use position of the magnetic flux bridge 14 according to FIG. 2, as shown in FIG. 2, the magnetic flux 26 is enabled with respect to the magnetic field generated by the permanent magnet 6. In this case, the magnetic flux 26 is induced through the two housing parts 9, 10 and the armature plate 3, whereby the armature plate abuts against the magnet housing 2. When the armature plate 3 is in this position, the permanent magnet brake 1 is in the braking position.

[0056] As can be seen from the illustration of FIG. 2, the magnetic flux 26 is induced at the braking position of the permanent magnet brake 1 via the magnetic flux bridge 14, that is, the magnetic body 22 provided by the support 21 of the magnetic flux bridge 14. Therefore, the magnetic body 22 bridges the separation part 13.

[0057] Particularly in an emergency, for example when power supply to the coil 7 is impossible, the flux bridge 14 can be displaced by the user in accordance with the arrow 29 in Fig. 3 to enable manual release of the braking position of the permanent magnet brake 1. As a result of such a displacement movement, the magnet body 22 of the flux bridge 14 is largely moved to the right with respect to the drawing plane in Fig. 3, and the bridging of the separating part 13 is no longer carried out. When the flux bridge 14 is in this position, the magnetic flux 26 passing through the armature plate 3 basically no longer occurs. Rather, the magnetic flux 27 occurs as shown in Fig. 3. When the flux bridge 14 is in this position, the armature plate 3 is no longer attracted by the permanent magnet 6, whereby the armature plate 3 can be separated from the magnet housing 2 to form a gap 30.

[0058] According to the embodiment shown in the figure, even when the flux bridge 14 is in the non-use position, some leakage magnetic flux 31 still exists across the armature plate 3. This leakage magnetic flux 31 is caused by the web 33, but this web is inevitable for the purpose of integrally forming the housing parts 10. However, since the generated leakage magnetic flux 31 is very small, it does not prevent the desired release of the permanent magnet brake 1.

[0059] In order to avoid the leakage magnetic flux 31, the web 33 must be omitted, which can be achieved, for example, by forming the housing parts 10 in a multi-component configuration. In this case, the separating part 13 is formed consistently in the circumferential direction 32.

Explanation of reference numerals

[0060] 1 Permanent magnet brake 2 Magnet housing 3 Armature plate 4 Hub 5 Spring 6 Permanent magnet 7 Coil 8 Coil space 9 Housing part (inner pole) 10 Housing part (outer pole) 11 Housing part 12 Housing part 13 Separation part 14 Magnetic flux bridge 15 Axial direction (longitudinal direction) 16 Void 17 Tube segment 18 Tube segment 19 Flange segment 20 Flange segment 21 Support 22 Magnet body 23 Bolt 24 Void 25 Opening 26 Magnetic flux 27 Magnetic flux 28 Arrow 29 Arrow 30 Gap 31 Leakage magnetic flux 32 Circumferential direction 33 Web

Claims

**Claim 1** A permanent magnet brake comprising a magnet housing (2) and an armature plate (3) cooperating with the magnet housing, wherein the magnet housing (2) houses a permanent magnet (6) and an energizable coil (7), and the magnet housing (2) has two housing parts (9, 10) each providing one magnetic pole. In the permanent magnet brake, one of the two housing parts (9, 10) has two housing part portions (11, 12) and a separating part (13) that at least partially magnetically insulates the two housing part portions (11, 12) from each other. A magnetic flux bridge (14) cooperating with the two housing part portions (11, 12) is provided, and the magnetic flux bridge is formed to be movable and can move from a use position to a non-use position and vice versa. The magnetic flux bridge (14) is characterized in that it bridges the separating part (13) when the magnetic flux bridge is in the use position. **Claim 2** The permanent magnet brake according to claim 1, characterized in that the separating part (13) is arranged between the two housing part portions (11, 12) in the axial direction (15) of the magnet housing (2). **Claim 3** The permanent magnet brake according to claim 1 or 2, characterized in that the housing part portions (11, 12) and the separating part (13) are integrally formed, and the separating part (13) has a cavity (16) that magnetically separates the housing part portions (11, 12) from each other. **Claim 4** The permanent magnet brake according to any one of claims 1 to 3, characterized in that each housing part (9, 10) has a tube segment (17, 18) and a flange segment (19, 20) arranged on the tube segment, and the tube segment (18) of one of the housing parts (10) provides the housing part portions (11, 12) and the separating part (13). **Claim 5** The permanent magnet brake according to any one of claims 1 to 4, characterized in that the magnetic flux bridge (14) surrounds the associated housing part (10) and is arranged on the housing part (10) so as to be displaceable in the axial direction (15) of the housing part (10). **Claim 6** The permanent magnet brake according to any one of claims 1 to 5, characterized in that the magnetic flux bridge (14) is formed in a ring shape and accommodates the tube segment (18) of the associated housing part (10).

7. The permanent magnet brake according to any one of claims 1 to 6, characterized in that the magnetic flux bridge (14) has a support (21) made of a non-magnetic material and a magnet body (22) made of a magnetic material disposed on the support, and the magnet body has a longitudinal range that exceeds the longitudinal range of the separation part (13) in the axial direction (15) of the magnet housing (2).

8. The permanent magnet brake according to claim 7, characterized in that the support is formed of aluminum.

9. The permanent magnet brake according to any one of claims 1 to 8, characterized in that the magnet housing (2) has a movement distance limiter that cooperates with the magnetic flux bridge (14).

10. The permanent magnet brake according to claim 9, characterized in that the movement distance limiter is a bolt (23) accommodated in a cavity (24) provided by the magnet housing (2).

11. The permanent magnet brake according to claim 10, characterized in that the support (21) has an opening (25) penetrated by the bolt.

Images