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 comprising a magnet housing and an armature plate cooperating with the magnet housing, the magnet housing containing a permanent magnet and an energizable coil, the magnet housing having two housing parts each providing one magnetic pole. [Background technology]

[0002] Permanent magnet brakes are well known per se from the prior art and do not require separate publication verification, so see, by way of example, US Pat. No. 5,499,299, US Pat. No. 5,599,299 and US Pat. No. 5,599,299.

[0003] The corresponding permanent magnet brake has a magnet housing and an armature plate cooperating with the magnet housing. The armature plate is configured to be movable relative to the magnet housing, and can abut the magnet housing in a first position or can be spaced from the magnet housing in a second position. Typically, the armature plate is arranged on the shaft so as to be non-rotatable relative to the shaft but displaceable axially.

[0004] The magnet housing houses a permanent magnet on one hand and an energizable coil on the other hand. The energizable coil, in combination with the magnet housing, then forms an electromagnet. In a typical construction, 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, an electromagnetic field is generated that counters the magnetic field of the permanent magnet, which causes the armature plate to move away from the magnet housing due to a return spring, forming an air gap. When the armature plate is in this position, the permanent magnet brake is in an unbraked position. In this position, the shaft supporting the armature plate can rotate relative to the permanent magnet brake. In contrast, when the permanent magnet brake is in the braking position, the armature plate abuts against the magnet housing so as not to rotate relative to it, thereby fixing the shaft.

[0005] The magnet housing has two housing parts, each of which forms a magnetic pole, specifically an outer pole on one side and an inner pole on the other. In a preferred construction, as known, for example, from Patent Document 3, each of the two housing parts has a tube portion on one side and a flange portion on the other side. In this case, the two tube portions of the housing parts engage with each other to form a ring space, which serves as a coil space for accommodating a current-carrying coil. The two flange portions of the magnet housing are also spaced apart from each other, and the space between the two flange portions serves to accommodate a permanent magnet. This known construction is known, for example, from Patent Documents 1 and 3.

[0006] The above-mentioned structure has a fundamental drawback in that the permanent magnet brake cannot be released, i.e., cannot be moved to a non-braking position, in the event of a coil failure or power outage. In the event of a coil failure or power outage, a reverse electromagnetic field cannot be generated, which causes the permanent magnet to continuously abut the armature plate against the magnet housing, resulting in the permanent magnet brake being continuously in a braking position.

[0007] To overcome this problem, Patent Document 3 already proposed a so-called neutralization element, which can substantially or completely eliminate the braking action of a permanent magnet without current. The neutralization element is a ring made of a magnetically conductive material that surrounds the magnet housing and is axially displaceable relative to the magnet housing. To release a permanent magnet brake without current, the neutralization element must be positioned relative to the permanent magnet so that it is in operative connection with the permanent magnet and magnetically short-circuits it. When the neutralization element is in this position, the magnetic field of the permanent magnet is preferably formed in the direction of the neutralization element, since the travel distance through the neutralization element is much shorter than through the magnet housing and armature plate, resulting in fewer losses. In this way, the neutralization element neutralizes the magnetic effect on the armature plate, thereby releasing the brake.

[0008] When the coil is energized with the demagnetizing element in this position, a magnetic field is induced which acts on the armature plate and thus attracts it, i.e. the brake is closed when energized and the action of the coil is, so to speak, reversed.

[0009] The structure known from US Pat. No. 5,629,999 has proven itself in everyday practical use, but there is a need for improvement. The known structure necessarily requires, as a prerequisite, that the demagnetizing element be arranged in close spatial proximity to the permanent magnet in order to avoid magnetic short-circuiting. However, the corresponding structural space is not always available, and therefore the structure known from US Pat. No. 5,629,999 can only be used to a limited extent in some applications. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] European Patent Application Publication No. 3499694 [Patent Document 2] European Patent Application Publication No. 4246008 [Patent Document 3] German Utility Model No. 20208611 Summary of the Invention

[0011] With this in mind, the object of the present invention is to further develop the design of conventional permanent magnet brakes in such a way that they allow for optimized use of installation space while also allowing for manual release.

[0012] In order to achieve the above object, the present invention proposes a permanent magnet brake of the type mentioned at the outset, characterized in that one of the two housing parts has two housing part sections and a separating part that at least partially magnetically isolates the two housing part sections from each other, a magnetic flux bridge is provided that cooperates with the two housing part sections, the magnetic flux bridge is configured to be movable and can be moved from a use position to a non-use position and vice versa, and the magnetic flux bridge bridges the separating part when it is in the use position.

[0013] According to the invention, one of the two housing parts of the magnet housing has two housing part sections and a separating part, which at least partially magnetically insulates the two housing part sections from each other, so that magnetic flux from one housing part section to the other housing part through the separating part is prevented, or at any rate minimized.

[0014] According to the invention, a magnetic flux bridge is further provided, which is configured to be movable and cooperates with the two housing parts, in which case the magnetic flux bridge is used to selectively bridge the separating part that magnetically isolates the two housing parts from each other.

[0015] The flux bridge is configured to be movable and can be moved from the use position to the non-use position and vice versa, where the flux bridge bridges the separation portion when it is in the use position and does not bridge the separation portion when it is in the non-use position.

[0016] Therefore, the user can position the flux bridge relative to the magnet housing to allow or prevent magnetic flux between two housing component parts of one housing part. Only when the flux bridge is in the use position does the separating portion that isolates the two housing component parts bridge, and magnetic flux can occur between the two housing component parts through the flux bridge. However, when the flux bridge is in the non-use position, the separating portion is not bridged, and as a result, magnetic flux between the two housing component parts is blocked.

[0017] When the permanent magnet brake is in use, the flux bridge is in the operating position. The magnetic field generated by the permanent magnet is induced across the two housing parts of the magnet housing and the armature plate, attracting the armature plate and thus placing the permanent magnet brake in a braking position, also known as a closed position. To release the permanent magnet brake, a coil housed in the magnet housing must be energized, which generates a counter electromagnetic field that separates the armature plate from the magnet housing and creates an air gap. When the armature plate is in this position, the permanent magnet brake is in a non-braking position, also known as a released position.

[0018] In the event of a coil failure and / or a loss of current, the permanent magnet brake can be manually released by moving the flux bridge from the active position to the inactive position. For this purpose, the user manually moves the flux bridge relative to the magnet housing. When the flux bridge is in the inactive position, it does not bridge the separation, thereby interrupting the magnetic flux between the two housing components that are magnetically isolated from the separation. As a result, the magnetic flux to the armature plate is also interrupted, and therefore the armature plate is no longer attracted by the magnet housing. Therefore, when the flux bridge is in the inactive position, the permanent magnet brake is in the open, or released, position.

[0019] Unlike the structure according to Patent Document 3, in the embodiment according to the invention, a magnetic short circuit is not formed with respect to the permanent magnet, but the magnetic flux to the armature plate is interrupted when necessary. This is done by moving a flux bridge relative to the magnet housing, which allows magnetic flux through the armature plate only in the case of defined braking, i.e. when it is in the use position, and not otherwise.

[0020] The structural configuration according to the present invention has the particular advantage that the arrangement of the flux bridges in the magnet housing is independent of the position of the permanent magnet. Therefore, the configuration of the separating part and the position of the associated flux bridges can be selected very freely, thereby taking into account the specific characteristics of the installation space in each individual case. This allows for increased utilization of the installation space, and therefore also allows for other construction principles for permanent magnet brakes. To this extent, the configuration according to the present invention creates considerable scope for optimized utilization of the available installation space.

[0021] The structure according to Patent Document 3 may allow the demagnetizing element described therein to short-circuit the permanent magnet, thereby reversing the action of the electromagnet. Such reversal of the action of the electromagnet is not possible with the structure according to the present invention. However, this drawback is consciously accepted, as it is outweighed by the advantage achieved by the present invention, which is that the flux bridge can be arranged in the magnet housing regardless of the position of the permanent magnet. This means that not only is there room for improvement in the utilization of installation space, but additional possibilities are also possible regarding the shape and positioning of the permanent magnet. These advantages associated with the present invention cannot be achieved in Patent Document 3 due to the structural limitations.

[0022] As a result, the configuration according to the invention allows for easy manual release, particularly in emergency situations, for example in the event of a power failure. The flux bridge contemplated by the invention provides a bypass for the magnetic flux during normal use. In the case of manual release, this bypass is interrupted by moving the flux bridge relative to the magnet housing, thereby transferring the flux bridge from its active position to its inactive position. Thus, unlike what is known from the prior art, no magnetic short-circuiting of the permanent magnets is performed, and the arrangement and configuration of the flux bridge are therefore independent of the configuration and positioning of the permanent magnets. This creates an additional degree of freedom in the design, which at the same time ensures the possibility of manual release in an emergency.

[0023] According to a further feature of the present invention, the separating portion is disposed between the two housing component parts in the axial direction of the magnet housing. Therefore, the separating portion is disposed between the two housing component parts in terms of space, thereby providing magnetic insulation between the two housing component parts. Therefore, the two housing component parts are separated from each other in the axial direction of the magnet housing by the separating portion, thereby enabling mutual magnetic insulation of the two housing component parts with a simple structure.

[0024] According to a further feature of the invention, it is contemplated that the housing component portion and the separation portion are integrally formed, the separation portion having a void that magnetically separates the housing component portions from one another.

[0025] According to this preferred embodiment, the housing parts providing the housing part and the separation part are integrally formed. This allows for simple manufacturing of the housing parts. To form the separation part, cavities are introduced into the housing parts, e.g., slots in the form of elongated holes. In the case of tubular housing parts, these cavities extend in the circumferential direction of the housing part. In this case, a plurality of these cavities can be provided, with a connecting web connecting two adjacent housing part parts between two adjacent cavities. A magnetic coupling is created between the two housing part parts via these webs, but this magnetic coupling only allows for leakage flux that does not prevent manual release of the permanent-magnetic brake during normal operation. Nevertheless, it is desirable to make the web connecting the two housing part parts 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 portion and the separating part can also be formed in a multi-piece configuration. In this case, the separating part consists of a non-magnetic material, such as aluminum or plastic. In the case of a tubular housing part, the separating part can be formed, for example, as a ring. In the final assembled state, the separating part is arranged between the two housing part portions and is connected thereto, for example, glued.

[0027] The one-piece configuration of the housing parts is preferred as it simplifies manufacturing and subsequent assembly, but the multi-piece configuration has the advantage that each magnetic flux is blocked by a separating part, thus making it possible to avoid leakage flux.

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

[0029] According to this preferred embodiment, it is provided that each housing part has, on the one hand, a pipe segment and, on the other hand, a flange segment, which is arranged on the pipe segment, and which in particular extends radially, in particular perpendicularly, to the associated pipe segment, such that in the final assembled state the pipe segments of the two housing parts engage with each other and form an intermediate space which is, strictly speaking, ring-shaped and which accommodates an energizable coil in the final assembled state.

[0030] The tube segment of one housing part provides the above-mentioned parts, i.e. the housing part on the one hand and the separation part on the other hand, which overall results in a structure that is easy to manufacture and easy to assemble.

[0031] According to a further feature of the present invention, the flux bridge surrounds an associated housing part and is arranged on the housing part so as to be displaceable in the axial direction of the housing part. The housing part supporting the flux bridge is, in particular, a housing part of the magnet housing that provides the outer pole. In this case, the flux bridge surrounds a tube part of the associated housing part. The flux bridge is movable relative to the housing part, and is preferably displaceable in the axial direction of the housing part, and is, in particular, displaceably arranged on the housing part. Thus, during normal use, the flux bridge can be displaced by the user in the axial direction of the housing part, i.e., in the longitudinal direction of the housing part, thereby being able to be moved from the use position to the non-use position and vice versa. Therefore, user operation is made possible simply by simply displacing the flux bridge in the axial direction relative to the magnet housing.

[0032] According to a further feature of the invention, the flux bridge is designed to be ring-shaped and accommodate the tube segment of the associated housing part, so that the flux bridge cooperates with the tube segment of the associated housing part, and is especially ring-shaped in order to surround the tube segment, so that it can be easily gripped by the user and, as mentioned above, selectively displaced in the axial direction of the housing part.

[0033] According to a further feature of the invention, it is provided that the flux bridge comprises a support made of a non-magnetic material and a magnet body made of a magnetic material arranged on the support, the magnet body having a longitudinal extent in the axial direction of the magnet housing that exceeds the longitudinal extent of the separating portion.

[0034] Therefore, the flux bridge preferably has a support on one side and a magnet body on the other side, where the magnet body is supported by the support. In addition, the support can be grasped by the user to displace the flux bridge, thereby allowing the user to manipulate the flux bridge. The support is made of a non-magnetic material, for example a light metal, preferably aluminum, or a plastic material.

[0035] However, the magnet body is formed from a magnetic material, for example from the same material forming the two housing component parts that are separated from the separation part. In order to form a ring-shaped magnetic flux bridge, both the support body and the magnet body are formed in a ring shape. In this case, the support body provides a circumferential cavity on its inner side, into which the magnet body is inserted in the final assembled state. The magnet body is therefore embedded in the support body. In this case, the cavity in the support body that accommodates the magnet body is formed on the inner circumferential side of the support body, and therefore towards the associated housing part.

[0036] When the flux bridge is in the use position, the magnet bodies are magnetically operatively connected to the two housing part parts. When the flux bridge is in this position, the separating part is bridged by the magnet bodies, so that magnetic flux is guided from one housing part part to the other housing part through the intermediary of the magnet bodies. For this reason, the magnet bodies have a longitudinal extent that exceeds the longitudinal extent of the separating part. Advantageously, it is structurally ensured that when the flux bridge is in the use position, the two housing part parts are magnetically connected to each other by the magnet bodies and the separating part that magnetically insulates the two housing part parts from each other is bridged.

[0037] According to a further feature of the invention, it is provided that the magnet housing has a travel limiter that cooperates with the flux bridge. The travel limiter advantageously serves as a stop for the flux bridge, allowing the user to reliably and verifiably set both the in-use and out-of-use positions of the flux bridge. To this end, it is preferable to form the travel limiter in such a way that the flux bridge can be brought close to the travel limiter to hit it in order to assume the in-use and out-of-use positions. This ensures simple and safe operation of the permanent magnet brake by the user.

[0038] According to a further feature of the invention, 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, which is inserted into a threaded cavity provided by the magnet housing in the final assembled state. This configuration advantageously allows for easy assembly and further disassembly, especially during repairs.

[0039] According to a further feature of the present invention, the support has an opening through which a bolt is inserted. This opening can be formed, for example, as a slot in the form of an elongated hole. This configuration has the advantage that only one bolt is required to provide both a travel limiter for the use position and a travel limiter for the non-use position. This is because, in the use position, the bolt abuts against the edge of the opening provided by the support at one end, and in the non-use position, abuts against the associated edge of the same opening at the other end. The single opening through which the bolt is inserted allows the user to selectively and safely access both the use position and the non-use position. Additionally, the above-described structure allows for easy assembly and disassembly by guiding the flux bridge across the magnet housing, then inserting the bolt through the opening provided by the support and into a cavity in the magnet housing. The flux bridge is then fixed to the magnet housing both radially and axially, and the flux bridge is allowed to be displaced axially relative to the magnet housing as described above.

[0040] Further features and advantages of the present invention will become apparent from the following description taken in conjunction with the drawings. [Brief explanation of the drawings]

[0041] [Figure 1] 1 is a schematic, partially cross-sectional side view of a permanent magnet brake according to the present invention with the flux bridge in an in-use position; [Figure 2] 2 is a schematic partial cross-sectional side view of the permanent magnet brake according to FIG. 1, with the magnetic flux shown. [Figure 3] 2 is a schematic, partially cross-sectional side view of the permanent magnet brake according to FIG. 1 when the flux bridge is in the non-use position. [Figure 4] 1 is a schematic side view of a permanent magnet brake according to the present invention with the flux bridge in the use position; FIG. [Figure 5] 1 is a schematic side view of a permanent magnet brake according to the present invention with the flux bridge in an inoperative position; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0042] FIG. 1 shows a schematic, partially cross-sectional side view of the structure of a permanent magnet brake 1 according to the present invention. The permanent magnet brake 1 comprises a magnet housing 2 and an armature plate 3 cooperating with the magnet housing, the armature plate being arranged by a hub 4 on a shaft not shown in detail in the figures so as to be non-rotatable relative to the shaft but displaceable in the axial direction 15. In the illustrated embodiment, the armature plate 3 cooperates with the hub 4 with the aid of a return spring 5.

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

[0044] The two housing parts 9 and 10 each have a pipe segment 17 or 18 and a flange segment 19 or 20, whereby the respective flange segment 19 or 20 is arranged on the associated pipe segment 17 or 18.

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

[0046] The magnet housing 2 further accommodates a permanent magnet 6, which in the final assembled state is arranged between two flange segments 19 and 20 of the housing parts 9, 10. The permanent magnet may be ring-shaped. Alternatively, several ring-shaped or segment-shaped permanent magnets 6 are provided, which are arranged one behind the other in the circumferential direction of the magnet housing 2.

[0047] According to the invention, the tube segment 18 of the housing part 10 comprises two housing part parts 11 and 12, which are at least partially magnetically insulated from one another by a separating part 13, which is then arranged between the two housing part parts 11, 12 in the axial direction 15.

[0048] In the illustrated exemplary embodiment, the separation portion 13 is formed by a cavity 16, which separates the two housing component parts 11 and 12 from each other. 4 and 5 taken together, the housing part 10 providing the two housing part sections 11 and 12 is formed in one piece. In this case, the separating part 13 has a number of cavities 16 arranged one after the other in the circumferential direction 32. A web 33 is provided between two successive cavities 16 in the circumferential direction 32, which web connects the two housing part sections 11 and 12 to one another and enables them to be formed in one piece.

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

[0050] The flux bridge 14 has a support 21 on the one hand and a magnet body 22 on the other hand. The support 21 is made of a non-magnetic material, in particular aluminum. However, the magnet body 22 is made of a magnetic material, in particular the same material as the two housing part sections 11 and 12. As shown in FIG. 1 , the support 21 has a circumferential cavity on the housing part side, into which the magnet body 22 is inserted flush with the inner surface. In this case, the magnet body 22 has a longitudinal extent, i.e., an axial extent 15 that exceeds the extent of the cavity 16. The magnet body 22 can therefore bridge the separation section 13 by magnetically contacting both the first housing part 11 and the second housing part 12, as shown in FIG. 1 .

[0051] As will become more apparent from Figure 1, the support 21 is provided with an opening 25 which, in the final assembled state, is penetrated by a bolt 23 which is inserted at one end into a cavity 24 provided by the magnet housing 2. This bolt 23 acts as a travel limiter in the axial direction 15 for the flux bridge 14, as will be explained in more detail below.

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

[0053] The flux bridge 14 can in particular assume a so-called operative position and a so-called inoperative position. The operative position of the flux bridge 14 is shown in Figures 2 and 4. The inoperative position of the flux bridge 14 becomes clear from Figures 3 and 5.

[0054] 2 to the non-use position, for example, according to FIG. 3, and vice versa, the flux bridge 14 must be held by the user and moved in the axial direction 15 in the direction of the arrow 28 according to FIG. 2 or the arrow 29 according to FIG. 3. In doing so, the flux bridge 14 must be moved towards the bolt 23 up to a stop, as can be seen, for example, from FIG. 2 and FIG. 3. In so doing, in the use position according to FIG. 2, the flux bridge 14 rests against the bolt 23 with its opening 25 on the right side relative to the plane of the drawing according to FIG. 2. In contrast, in the non-use position according to FIG. 3, the flux bridge 14 rests against the bolt 23 with its opening 25 on the left side relative to the plane of the drawing according to FIG. 3.

[0055] In the use position of the flux bridge 14 according to Fig. 2, a magnetic flux 26 is enabled in relation to the magnetic field generated by the permanent magnet 6, as shown in Fig. 2. In this case, the magnetic flux 26 is guided through the two housing parts 9, 10 and the armature plate 3, so that the armature plate abuts the magnet housing 2. When the armature plate 3 is in this position, the permanent magnet brake 1 is in the braking position.

[0056] 2, in the braking position of the permanent magnet brake 1, the magnetic flux 26 is induced through the flux bridge 14, i.e., through the magnet bodies 22 provided by the supports 21 of the flux bridge 14. The magnet bodies 22 therefore bridge the separating portion 13.

[0057] To manually release the braking position of the permanent magnet brake 1, particularly in an emergency, for example if the power supply to the coil 7 is unavailable, the user can displace the flux bridge 14 according to the arrow 29 in FIG. 3. As a result of this displacement, the magnet bodies 22 of the flux bridge 14 are moved significantly to the right relative to the drawing plane in FIG. 3, and the separation section 13 is no longer bridged. When the flux bridge 14 is in this position, the magnetic flux 26 through the armature plate 3 is essentially no longer generated. Instead, a magnetic flux 27 is generated, as shown in FIG. 3. When the flux bridge 14 is in this position, the permanent magnet 6 no longer attracts the armature plate 3, allowing the armature plate 3 to separate from the magnet housing 2 and form an air gap 30.

[0058] According to the embodiment shown in the figures, even when the flux bridge 14 is in the non-use position, some leakage flux 31 still exists across the armature plate 3. This leakage flux 31 is caused by the webs 33, which are unavoidable for the purposes of forming the housing parts 10 integrally. However, the leakage flux 31 that occurs is so small that it does not interfere with the desired release of the permanent magnet brake 1.

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

[0060] 1 Permanent Magnet Brake 2 Magnet housing 3 Armature Plate 4 Hub 5 Spring 6. Permanent magnets 7 coils 8 Coil Space 9 Housing parts (inner pole) 10 Housing parts (outer pole) 11 Housing parts 12 Housing parts 13 Separation part 14 Flux Bridge 15 Axial direction (longitudinal direction) 16 blank spaces 17 pipe segments 18 pipe segments 19 flange segments 20 flange segments 21 Support 22 Magnet body 23 volts 24 voids 25 Aperture 26 Magnetic Flux 27 Magnetic Flux 28 Arrow 29 Arrow 30 void 31 Leakage magnetic flux 32 Circumferential direction 33 Web

Claims

1. A permanent magnet brake comprising a magnet housing (2) and an armature plate (3) cooperating with the magnet housing, the magnet housing (2) accommodating a permanent magnet (6) and a current-carrying coil (7), the magnet housing (2) having two housing parts (9, 10) each providing one magnetic pole, one of the two housing parts (9, 10) having two housing part portions (11, 12) and a separating part (13) that at least partially magnetically isolates the two housing part portions (11, 12) from each other, and the magnetic poles cooperating with the two housing part portions (11, 12) 1. A permanent magnet brake comprising: a flux bridge (14) configured to be movable and capable of moving from a use position to a non-use position and vice versa, the flux bridge (14) bridging the separating part (13) when the flux bridge is in the use position; and the magnet housing (2) having a travel distance limiter cooperating with the flux bridge (14), characterized in that the travel distance limiter is configured to be movable until it abuts against the travel distance limiter both when the flux bridge (14) is in the use position and when it is in the non-use position.

2. 2. A permanent magnet brake according to claim 1, characterized in that the separating part (13) is arranged between the two housing part sections (11, 12) in the axial direction (15) of the magnet housing (2).

3. 2. The permanent magnet brake according to claim 1, wherein the housing component portions (11, 12) and the separating portion (13) are integrally formed, and the separating portion (13) has a void (16) that magnetically separates the housing component portions (11, 12) from each other.

4. 2. A permanent magnet brake according to claim 1, characterized in that each housing part (9, 10) has a pipe segment (17, 18) and a flange segment (19, 20) arranged on said pipe segment, said pipe segment (18) of one said housing part (10) providing said housing part portion (11, 12) and said separating portion (13).

5. 2. A permanent magnet brake according to claim 1, characterized in that the 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).

6. 5. A permanent magnet brake according to claim 4, characterized in that the flux bridge (14) is formed in the shape of a ring and accommodates the tube segment (18) of the associated housing part (10).

7. 7. A permanent magnet brake according to claim 1, wherein the flux bridge (14) comprises a support (21) made of a non-magnetic material and a magnet body (22) made of a magnetic material arranged on the support, the magnet body having a longitudinal extent in the axial direction (15) of the magnet housing (2) that exceeds the longitudinal extent of the separating part (13).

8. 8. A permanent magnet brake as set forth in claim 7, wherein said support is made of aluminum.

9. A permanent magnet brake according to any one of claims 1 to 6, characterized in that the travel limiter is a bolt (23) accommodated in a cavity (24) provided by the magnet housing (2).

10. 10. A permanent magnet brake according to claim 9, characterized in that the flux bridge (14) comprises a support (21) made of a non-magnetic material and a magnet body (22) made of a magnetic material arranged on the support (21), the support (21) having an opening (25) through which the bolt passes.

11. A permanent magnet brake as described in any one of claims 1 to 6, characterized in that the flux bridge (14) has a support (21) made of a non-magnetic material and a magnet body (22) made of a magnetic material arranged on the support, the support (21) has an opening (25) penetrated by the travel distance limiter, the opening (25) is in the form of a long hole, and the flux bridge (14) abuts against the travel distance limiter at an edge on one end of the opening (25) in the use position, and abuts against the travel distance limiter at an edge on the other end of the opening (25) in the non-use position.

Images