P/00101 I Regulaton 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Magnetic rail brake device with asymmetric excitation coils and/or with multi-part coils The following statement is a full description of this invention, including the best method of performing it known to us: 1A Electromagnetic magnetic rail brake device with multi part coil The invention relates to a magnetic rail brake device 5 of a rail vehicle. This is divided from our earlier Australian application 2008232092 and the reader is directed to that earlier specification for aspects recited herein but not claimed. 10 Such magnetic rail brake devices are known, for example, in a permanent magnet arrangement from DE 11 23 359 B and in an electrical arrangement from FR 1 003 173 A. In FR 1 003 173 A, the force-generating main component of an electric magnetic rail brake is the 15 brake magnet. Said brake magnet is in principle an electromagnet composed of a solenoid which extends in the direction of the rail and is supported by a solenoid former, and a horseshoe-like magnet core which forms the base element or carrier element. The 20 horseshoe-shaped magnet core forms pole shoes on its side which is turned toward the vehicle rail. The direct current which flows in the solenoid produces a magnetic voltage which generates a magnetic flux in the magnet core, which magnetic flux is short circuited 25 across the rail head as soon as the brake magnet rests with its pole shoes on the rail. As a result, a magnetic attraction force comes about between the brake magnet and rail. As a result of the kinetic energy of the moving rail vehicle, the magnetic rail brake is 30 pulled along the rail by means of drivers. This gives rise to a braking force as a result of the sliding friction between the brake magnet and rail in conjunction with the magnetic attraction force. As a result of the frictional contact with the rail, 35 frictional wear is produced on the pole shoes of the brake magnet, and said frictional wear must not exceed a maximum wear value since otherwise the solenoid former is damaged.
2 In the known brake magnets, two solenoids are provided which engage vertically around the yoke of the magnet core with a respective upper part and with a respective 5 lower part. In conjunction, furthermore, pole shoes in the form of pole shoes formed opposite the magnet core as separate parts are known from EP 1 477 382 Al and pole shoes 10 formed in one piece with the magnet core are known from FR 359 101 A. In principle, two different types of magnet can be differentiated according to the structural design. 15 In a first embodiment, the brake magnet is a rigid magnet to which two magnetic pole shoes which are separated in the longitudinal direction by a nonmagnetic bar are screwed. This serves to avoid a 20 magnetic short circuit within the brake magnet. The pole shoes are formed on the end faces of the side cheeks facing the vehicle rail. Rigid magnets are usually used in local streetcar and urban railroads. 25 Furthermore, link magnets are known in which the solenoid former does not have a steel core but rather only dividing walls. Magnet elements which align themselves during the braking process in order to be able to follow unevennesses on the rail head better are 30 held in such a way that they can move to a limited degree in the chambers between the dividing walls. In this case, the pole shoes are formed on those ends of the magnet elements which are turned toward the rail. Link magnets are used on a standard basis in main-line 35 track services. With respect to the embodiments of magnetic rail brakes, reference is made to the publication 3 "Grundlagen der Bremstechnik [The bases of brake technology] ", pages 92 to 97 from Knorr-Bremse AG, Munich, 2002. 5 The magnitude of the braking force of a magnetic rail brake is dependent, inter alia, on the magnetic resistance of the magnetic circuit, i.e. the geometry and permeability, the magnetic flux, the coefficient of friction between the brake magnet and rail and the 10 state of the rail. An essential factor here is also the magnetic losses which depend decisively on the geometric design of the magnetic cross section. In view of the fact that the space available in the running gear of rail vehicles is increasingly restricted, in 15 particular in the vertical direction, a small overall height is also required. An object of the invention is therefore to develop a magnetic rail brake device of the type mentioned at the 20 beginning in such a way that it has a relatively small overall height while at the same time having a high magnetic force. Reference to any prior art in the specification is not, 25 and should not be taken as, an acknowledgment, or any form of suggestion, that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as 30 relevant by a person skilled in the art. In accordance with a first aspect of the present invention, there is provided a magnetic rail brake device of a rail vehicle, containing at least one brake 35 magnet with a solenoid former which supports at least one solenoid, and with at least one magnet core, at least two solenoid formers which are arranged parallel to one another when viewed in the longitudinal 4 direction of the brake magnet and are arranged one next to the other when viewed in a plane perpendicular to the longitudinal direction, the solenoid formers being provided with respectively separate solenoids, and, 5 when viewed in a plane perpendicular to the longitudinal direction of the brake magnet, the center axes of the at least two solenoid formers being arranged at an acute or obtuse angle with respect to a vertical center axis of the brake magnet and converging 10 or diverging with respect to the vehicle rail, characterized in that pole shoes are formed on ends of the at least one magnet core which face a vehicle rail. Advantageous developments of the invention are the 15 subject of the attached subclaims. A solenoid is to be understood in the text which follows as referring to the coil winding composed of the turns of the winding wires such as are wound onto 20 the solenoid former. This coil winding which is wound onto the solenoid former or solenoid has, when viewed in a plane perpendicular to the longitudinal extent of the brake magnet (parallel to the rail), a specific cross section which depends both on the number of 25 turns, the winding density and the diameter of the wire as well as on the geometry of the solenoid former, i.e. depends on the space made available for the coil winding. In this context, a differentiation is made between an upper part of the solenoid, which is located 30 above a yoke with respect to the rail, and a lower part which is arranged below the yoke. The longitudinal direction of the brake magnet is intended to refer to the extent of the rigid magnet or 35 of the link magnets parallel to the vehicle rail. When viewed in a plane perpendicular to the longitudinal direction of the brake magnet, the center 5 axes of the at least two solenoid farmers are arranged at an acute or obtuse angle and, for example, symmetrically with respect to a vertical center axis of the brake magnet. Furthermore, at least two solenoid 5 farmers which are arranged parallel to one another when viewed in the longitudinal direction of the brake magnet and are arranged one next to the other when viewed in a plane perpendicular to the longitudinal direction are provided with respectively separate 10 solenoids. By arranging the solenoids next to one another, the magnetic power is distributed over the width, and therefore a relatively small overall height can be achieved with the same magnetic force. 15 In addition, when viewed in a plane perpendicular to the longitudinal direction of the brake magnet, the center axes of the at least two solenoid farmers converge or diverge with respect to the vehicle rail. The inclined position of the solenoid farmers then 20 assumed with respect to the vertical center axis of the brake magnet then results in a particularly compact design. Overall, owing to the relatively small overall height of the brake magnet, lower losses occur in the magnetic circuit, the power requirements are lower and 25 the mass is lower. Furthermore, pole shoes are formed on ends of the at least one magnet core which face a vehicle rail. 30 Furthermore, the cross section of at least one of the plurality of solenoids can have, in the upper part, a smaller height and a greater width than the cross section in the lower part, the height of the cross section of the respective solenoid then being measured 35 parallel to the respective center axis of the solenoid former concerned and the width of the cross section of the solenoid being measured transversely with respect to the respective center axis of the solenoid former 6 concerned. In the region of the upper part of the solenoid, a wider embodiment of the cross section compared to the prior art is not disruptive. In contrast, for a given number of turns of the solenoid 5 winding the height of the cross section decreases in the region of the upper part, which advantageously brings about a reduction in the overall height of the brake magnet compared to the prior art while the magnetic force is the same as the prior art. On the 10 other hand, in the region of the lower part, a greater height of the cross section of the solenoid can be permitted without entailing disadvantages with respect to the overall height of the brake magnet because at said location the cheeks or the pole shoes of the 15 magnet core cannot be shortened to any desired degree owing to the need for a minimum wear height. Instead of a relatively high brake magnet for achieving a predefined braking force, said brake magnet can then be made even lower. 20 Last not least, the brake magnet can be a link magnet, with at least one solenoid former on which a plurality of magnetic magnet elements are movably held, or else also a rigid magnet. 25 Drawings The invention will be explained by way of example below with reference to the drawing. In said drawing: 30 figure 1 is a perspective illustration of a magnetic rail brake according to the prior art; figure 2 is a side view of a brake magnet from figure 1 which is embodied as a link magnet; 35 figure 3 is a cross-sectional illustration of a magnet link of a link magnet according to a preferred embodiment of the invention; 7 figure 4 is a cross-sectional illustration of a rigid magnet according to a preferred embodiment of the invention; 5 figure 5 is a cross-sectional illustration of a rigid magnet; and figure 6 is a cross-sectional illustration of a magnet 10 link of a link magnet. In the following description of the exemplary embodiments, identical or identically acting components and assemblies are identified by the same reference 15 symbols. In order to be able to adapt better to unevennesses of a rail 1, a brake magnet 2 (shown in figure 1 and figure 2) of a magnetic rail brake 4 according to the 20 prior art has, instead of a single rigid magnet, a plurality of magnet elements 6 which are held in such a way that they can move to a limited degree on a solenoid former 8 which extends in the longitudinal direction of the rail 1. This is preferably achieved by 25 virtue of the fact that the magnet elements 6 are suspended in such a way that they can pivot or swivel to a limited degree symmetrically with respect to a vertical center axis on the end faces, facing away from one another, of the solenoid former 8 in chambers which 30 are formed between dividing walls 10. The transmission of the braking forces to the solenoid former 8 is then effected via the dividing walls 10 and end pieces 14, 15 which are rigidly connected to the solenoid former 8 and which guide the brake magnet 2 satisfactorily over 35 railway switches and rail joints. The solenoid former 8 which includes a solenoid 9 which cannot be seen from the outside consequently supports the magnet elements 6 which form a magnet core of the brake magnet 2.
8 In order to supply the solenoid 9 with electrical voltage, a connecting device 26 which has at least two electrical terminals 22, 24 for the positive pole and 5 minus pole of a voltage source is provided, said connecting device 26 being arranged, for example, in the upper region of a side face of the solenoid former 8, approximately in the center with respect to its longitudinal extent. The electrical terminals 22, 24 10 preferably face away from one another and extend in the longitudinal direction of the solenoid former 8. The preceding description of the prior art has the purpose of explaining the basic design of a magnetic 15 rail brake 4. In contrast to figure 1 and figure 2, which show a magnetic rail brake 4 with just one solenoid former 8 and just one solenoid 9, figure 3 illustrates a cross section of a brake magnet 2 as a link magnet in which at least two solenoid formers 8a, 20 8b, which are arranged parallel to one another when viewed in the longitudinal direction of the brake magnet 2 and are arranged one next to the other when viewed in a plane perpendicular to the longitudinal direction, are provided with respectively separate 25 solenoids 9a, 9b. The solenoids 9a, 9b which are wound onto the solenoid formers 8a, 8b can be connected separately, in series with one another or parallel to one another, i.e. the solenoid 9a which is assigned to one 8a of the solenoid formers can be separated from 30 the solenoid 9b which is assigned to the other solenoid former 8b or can be connected in series with respect to it or parallel to it. In the cross-sectional plane which is illustrated in 35 figure 3 perpendicular to the longitudinal direction of the brake magnet 2 or in the longitudinal direction of the rail, the center axes 34, 36 of the two solenoid former 8a, 8b are arranged at an acute angle a with 9 respect to a vertical center axis 38 of the brake magnet 2 and converge with respect to the rail 1, that is to say in the downward direction. Furthermore, the two solenoid formers 8a, 8b are arranged symmetrically 5 with respect to the vertical center axis 38 of the brake magnet 2. Alternatively, the center axes 34, 36 of the two coil formers 8a, 8b could also be arranged at an obtuse 10 angle with respect to the vertical center axis 38 or diverge toward the rail 1. The coil windings 9a, 9b which are not illustrated explicitly in figure 3 but are represented by their reference numbers and are composed of the turns of the winding wires are wrapped 15 around the solenoid formers 8a, 8b in a direction which is parallel to the center axes 34, 36. In the present case, the magnet core 6 is also formed so as to be symmetrical with respect to the vertical 20 center axis 38 of the brake magnet 2 and is of multi component design, here preferably two-component design, with one half 6a, 6b of the magnet core respectively having a limb 40a, 40b which projects through an opening in the solenoid former 8a, 8b in question, 25 while the limbs 40a, 40b abut one another in a plane containing the vertical center axis 38. The limbs 40a, 40b of the halves 6a, 6b of the magnet core adjoin cheeks 42a, 42b which extend parallel to one another toward the rail 1 and on whose ends facing the rail 1 30 pole shoes 16a, 16b (respectively north and south poles) of the brake magnet 2 are formed. An air gap 20 (figure 1) is then provided between the pole shoes 16a, 16b and a rail head 18 of the rail 1 as in the prior art. The pole shoes 16a, 16b are preferably composed of 35 a friction material, for example of steel, nodular cast iron or of sintered materials, and are preferably connected releasably to the cheeks 42a, 42b as separate components. A nonmagnetic, wear-resistant, impact- 10 resistant and thermally resistant intermediate strip 21 may be arranged in an intermediate space between the left-hand and right-hand pole shoes 16a, 16b (magnetic north pole or south pole) in such a way that it fills 5 the intermediate space. With respect to the longitudinal extent of the brake magnet, the halves 6a, 6b of the magnet core of each link magnet 6 movably held in a frame which is formed 10 by the solenoid formers 8a, 8b which are preferably connected to one another, so that they can adapt themselves to the unevennesses of the rail 1. In contrast, figure 4 shows the cross section of a 15 rigid magnet 2 as a brake magnet in which the magnet core 6 is preferably likewise of two-component design and is composed of two halves 6a, 6b of the magnet core which are rigidly connected to one another. The coil former 8 is not a separate component here but is rather 20 formed by faces 8a, 8b of the magnet core 6, to be more precise by faces of the halves 6a, 6b of the magnet core onto which the turns of the wire windings of the two solenoids 9a, 9b are preferably directly wound. Otherwise, the position and geometry of the solenoids 25 9a, 9b and of the solenoid formers 8a, 8b corresponds to the description of the preceding exemplary embodiment. Fig. 5 shows the cross section through a rigid magnet 2 30 in which the preferably single-piece magnet core 6 is formed in the shape of a horseshoe, and a yoke 28 and cheeks 42a, 42b which project away from the latter and extend parallel to one another are formed, the pole shoes 16a, 16b (respectively north and south poles) of 35 the brake magnet 2 being formed on the ends of said cheeks 42a, 42b which face the rail 1. The air gap 20 is then provided between the pole shoes 16a, 16b and the rail head 18 of the rail 1 (see figure 1). The pole 11 shoes 16a, 16b are preferably composed, as in the preceding exemplary embodiment, of a frictional material, for example of steel, nodular cast iron or of sintered materials. As in the preceding exemplary 5 embodiments, a nonmagnetic, wear-resistant, impact-resistant and thermally resistant intermediate strip 21 can be arranged in an intermediate space between the left-hand and the right-hand pole shoes 7.1, 7.2 (magnetic north pole or south pole) in such a 10 way that it fills the intermediate space. The solenoid 9 engages vertically around the yoke 28 with an upper part 30 and with a lower part 32 which is arranged between the cheeks 42a, 42b. In this context, 15 the cross section of the solenoid 9 has, in the upper part 30, a smaller height h and a greater width b than the cross section in the lower part 32, the height h of the cross section of the solenoid 9 being measured parallel to a vertical center axis 38 of the brake 20 magnet 2 and the width b of the cross section of the solenoid 9 being measured transversely with respect to a vertical center axis 38 of the brake magnet 2. For the purpose of implementation, for example the 25 number of layers of coil wire turns of the solenoid 9 which lie one on top of the other is lower in the region of the upper part 30 than in the region of the lower part 32. In particular, the cross section of the solenoid 9 in the upper part 30 is formed essentially 30 in the shape of a rectangle with the longer side perpendicular with respect to the vertical center axis 38 of the brake magnet 2, and the cross section of the solenoid 9 in the lower part 32 is formed essentially in a square shape. The cross-sectional faces of the 35 solenoid 9 are preferably of essentially the same size in the upper part 30 and in the lower part 32. According to a further embodiment which is shown in 12 figure 6, the principle of the asymmetric coil 9 according to figure 5 can also be implemented in a link magnet 2. In this case, the solenoid former 8 is of corresponding design. 5 An asymmetric design of the coil 9, i.e. a different width b and height h of the coil 9 in the upper part 30 and in the lower part 32 is also obtained if the yoke 28 has a convex, that is to say upwardly rounded or 10 bent shape when viewed in the direction facing away from the rail 1. This is because the width b in the upper part 30 is then automatically greater than the width b in the lower part 32. 15 According to a further embodiment (not illustrated here), the embodiments according to figure 3 and figure 4 can be combined with the embodiments according to figure 5 and figure 6 by virtue of the fact that the cross section of at least one of the solenoids 9a, 9b 20 of figure 3 or figure 4 has, in the upper part 30, a smaller height h and a greater width b than the cross section in the lower part 32, in this case the height h of the cross section of the respective solenoid 9a, 9b being measured parallel to the respective center axis 25 34, 36 of the solenoid former 8a, 8b in question and the width b of the cross section of the solenoid 9a, 9b being measured transversely with respect to the respective center axis 34, 36 of the solenoid former 8a, 8b in question.
13 List of reference numerals 1 Rail 2 Brake magnet 5 4 Magnetic rail brake 6 Magnet elements; magnet core 8 Solenoid former/magnetic circuit 9 Solenoid 10 Dividing walls 10 12 Screwed connection 14 End piece 15 End piece 16 Pole shoes 18 Rail head 15 20 Air gap 21 Intermediate strip 22 Electrical terminal 24 Electrical terminal 26 Connecting device 20 28 Yoke 30 Upper part 32 Lower part 34 Center axis 36 Center axis 25 38 Center axis 40 Limb 42 Cheeks