Force transmission structure of superconducting electric suspension magnet
Technical Field
The invention relates to the technical field of magnetic suspension, in particular to a force transmission structure of a superconducting electric suspension magnet.
Background
The superconducting electric levitation magnet is a core component of the superconducting electric levitation train, when the train runs, the superconducting electric levitation magnet and a ground coil are electromagnetically coupled to generate electromagnetic force, and the electromagnetic force is transmitted to a train bogie through a force transmission structure of the superconducting electric levitation magnet to form propelling force, levitation force, guiding force and braking force, so that advancing, levitation, guiding and braking of the train are respectively realized.
The superconducting electric suspension magnet needs to operate in an ultralow temperature environment, and needs to be sealed in the ultralow temperature environment so as to reduce heat leakage of the system. The electromagnetic force of the superconductive electric suspension magnet is transmitted to the side plate of the train bogie from an ultra-low temperature and sealed cavity, and meanwhile, the sealing performance of the cavity is not influenced, so that higher requirements are provided for a force transmission structure of the magnet.
The force transmission structure of the existing superconducting electric suspension magnet mainly adopts a rigid connection mode and is divided into the following two modes. One is to transmit the electromagnetic force of the superconducting magnet to the cryogenic container and then to the bogie, and such a structure requires the cryogenic container to have a sufficiently high strength, which inevitably increases the cost and weight of the cryogenic container. The other is to directly transmit the electromagnetic force of the superconducting magnet to the bogie without passing through the cryogenic container, and the structure reduces the strength design requirement of the cryogenic container. However, the problem of stress concentration of the low-temperature container caused by cold contraction of the superconducting magnet exists, the stress concentration can aggravate mechanical damage of the low-temperature container, the sealing performance of the low-temperature container is further influenced, and the difficulty in realizing the detachable function of the low-temperature container is increased.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a force transmission structure of a superconducting electric suspension magnet, aiming at meeting the requirement that the superconducting electric suspension magnet directly transmits the electromagnetic force of the magnet to a bogie side plate under the condition of disassembly and assembly so as to reduce the strength requirement of the electric suspension magnet on a low-temperature container, eliminate the influence of the electromagnetic force of the superconducting magnet on the sealing property of the low-temperature container and solve the problem of stress concentration of the low-temperature container caused by cold shrinkage of the superconducting magnet.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:
a force transmission structure of a superconducting electric suspension magnet is characterized in that a bottom plate of a non-working surface of a low-temperature container is connected with the low-temperature container through a screw, and a sealing ring is pressed between the bottom plate and the low-temperature container; the bogie side plate is positioned below the low-temperature container; a superconducting coil is arranged in the superconducting electric suspension magnet; the two superconducting electric suspension magnets are arranged in the low-temperature container in a bilateral symmetry mode through a left force transmission structure and a right force transmission structure, and the right force transmission structure and the left force transmission structure are identical in structure and are in bilateral symmetry; wherein, left side power transmission structure does: the lower end of a class I mandril positioned in the center of the superconducting magnet is screwed on a bottom plate of a non-working surface of the low-temperature container, the upper end of the class I mandril is propped against the low-temperature container, a plurality of class I composite supporting rods and a plurality of class II composite supporting rods are arranged on the left side and the right side of the class I mandril in a bilateral symmetry way, the class I composite supporting rods are formed by connecting a first section of a tubular class I composite supporting rod and a second section of a rod-shaped class I composite supporting rod through screws, the upper part of the first section of the class I composite supporting rod is fixed on the superconducting magnet through screws, the lower part of the second section of the class I composite supporting rod sequentially penetrates through an opening of the bottom plate of the non-working surface of the low-temperature container and a hole on a side plate of a bogie and then is screwed with a nut, the upper end of a stainless steel corrugated pipe is welded on the opening of the bottom plate of the non-working surface of the low-temperature container, and the lower end of the class I composite supporting rod is welded on the second section of the class I composite supporting rod, the second type composite supporting rod consists of a first section of a tubular second type composite supporting rod and a second section of a second type composite supporting rod, the first section of the second type composite supporting rod is fixed between the superconducting magnet and a bottom plate of a non-working surface of the low-temperature container through screws, the lower end of a second type ejector rod is inserted into a tube body of the first section of the second type composite supporting rod and is screwed on the bottom plate of the non-working surface of the low-temperature container, the upper end of the second type ejector rod abuts against the low-temperature container, the upper end of the second section of the second type composite supporting rod is fixed on the bottom plate of the non-working surface of the low-temperature container through screws, and the lower end of the second section of the second type composite supporting rod penetrates through a hole in a side plate of the bogie downwards and then is screwed with another nut;
the force transmission structure of the superconducting electric suspension magnet is characterized in that in the force transmission structure on the left side, three first-class composite supporting rods and three second-class composite supporting rods are arranged; three I-type composite supporting rods positioned on the left side of the I-type ejector rod are arranged in an isosceles triangle form; the connecting line of the centers of the class I composite supporting rod and the class I ejector rod which are positioned at the vertex of the isosceles triangle can be crossed with the middle point of the bottom edge of the isosceles triangle.
The force transmission structure of the superconducting electric suspension magnet is characterized in that one I-type composite supporting rod positioned at the vertex of an isosceles triangle is arranged on the inner side of a superconducting coil in three I-type composite supporting rods arranged in the form of the isosceles triangle, and two I-type composite supporting rods positioned at the other two angular points of the isosceles triangle are arranged on the outer side of the superconducting coil.
The force transmission structure of the superconducting electric levitation magnet is characterized in that a shoulder on the upper part of a first section of the I-type composite supporting rod is fixed on the superconducting magnet through a screw; the second section of the type I composite supporting rod (the upper part of the second section extends into the tube body of the type I composite supporting rod, and the shoulder on the second section is fixed on the annular bottom surface of the tube body of the first section of the type I composite supporting rod by adopting a screw, the shoulders at the upper end and the lower end of the first section of the type II composite supporting rod are respectively fixed between the superconducting magnet and the bottom plate of the low-temperature container by the screw, and the second section of the type II composite supporting rod consists of an upper large-diameter cylinder and a lower small-diameter cylinder.
A force transmission structure of a superconducting electric levitation magnet is characterized in that adjacent parts of two superconducting magnets are mutually connected; the class I ejector rod and the class II ejector rod are both coated with a plurality of layers of super heat-insulating materials; the first section of the first-class composite supporting rod and the first section of the second-class composite supporting rod are both made of glass fiber materials, and the second section of the first-class composite supporting rod and the second section of the second-class composite supporting rod are both made of stainless steel materials.
Compared with the prior art, the invention has the beneficial effects that:
1. the superconducting magnet is detachable in the low-temperature container. Because the force transmission structure of the superconducting electric suspension magnet is mainly in threaded connection and is not welded, the composite support rods, the ejector rods, the low-temperature container and the like can be repeatedly disassembled and assembled, and the superconducting magnet is convenient to replace.
2. The strength requirement of the superconducting electric suspension magnet on the low-temperature container is reduced. The electromagnetic force of the superconducting magnet is directly transmitted to the bogie side plate through the composite supporting rod, and the low-temperature container cannot bear the action of larger electromagnetic force, so that the strength design requirement of the low-temperature container can be greatly reduced. Based on this, the low temperature container can be made of a material with lower density or made into an ultra-thin wall structure, so as to reduce the weight of the low temperature container.
3. The influence of the electromagnetic force of the superconducting magnet on the sealing performance of the cryogenic container is eliminated. The type I composite supporting rod penetrates through a bottom plate of a non-working surface of the low-temperature container and is sealed by the corrugated pipe, after the composite supporting rod is stressed and deformed, the deformation can be compensated by the corrugated pipe, the deformation of the low-temperature container is avoided, and therefore the sealing performance of the low-temperature container cannot be influenced when the electromagnetic force of the superconducting magnet is transmitted to a bogie side plate.
4. The problem of stress concentration caused by cold contraction of the superconducting magnet is solved. The superconducting magnet can contract towards the center of the superconducting magnet (namely the centers of the two superconducting magnets in the figure 2 are positioned at the midpoint of the rectangular outer contour in the figure 2) in the cooling process, the contraction forces the type I composite supporting rod to deviate towards the center of the superconducting magnet, and the type I composite supporting rod is fixedly connected with the bogie side plate, so that the type I composite supporting rod can deflect around a fixed point between the type I composite supporting rod and the bogie side plate, the deflection can drive the corrugated pipe to deform, and the deformation cannot be transmitted to the low-temperature container.
In conclusion, the invention realizes the direct transmission of the electromagnetic force of the superconducting magnet to the side plate of the bogie under the condition that the superconducting electric levitation magnet is detachable, reduces the strength requirement of the superconducting electric levitation magnet on the low-temperature container, eliminates the influence of the electromagnetic force of the superconducting magnet on the sealing performance of the low-temperature container, and solves the problem of stress concentration of the low-temperature container caused by cold shrinkage of the superconducting magnet.
Drawings
Fig. 1 is a cross-sectional view of the force transfer structure of a superconducting electrodynamic levitation magnet (taken along the transverse midline of fig. 2, showing only the portion of the superconducting magnet to the left of fig. 2, i.e., fig. 1 shows only 1 superconducting magnet and 1 superconducting coil).
Fig. 2 is a front view of a force transfer structure of a superconducting electrodynamic levitation magnet.
Fig. 3 is a simulation result of the force transfer structure of the superconducting electrodynamic levitation magnet, in which (a) is a deformation amount of the low-temperature container during vacuum pumping, (b) is a stress distribution of the low-temperature container under a load condition, and (c) is a stress distribution of the force transfer structure of the superconducting electrodynamic levitation magnet under the load condition.
The device comprises a low-temperature container, a superconducting coil, a superconducting electric suspension magnet, a first section of a type I composite supporting rod, a first section of a type I ejector rod, a second section of a type II ejector rod, a first section of a type II composite supporting rod, a second section of a type I composite supporting rod, a second section of a type II composite supporting rod, a screw, a sealing ring, a corrugated pipe, 11, a second section of the type I composite supporting rod, a nut, 13, a second section of the type II composite supporting rod, 14, a bogie side plate, 15, a bottom plate of a non-working surface of the low-temperature container, and 16, a symmetrical surface of the superconducting electric suspension magnet.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and various changes may be made apparent to those skilled in the art as long as they are within the spirit and scope of the present invention defined by the appended claims, and all of the inventions using the inventive concept are protected.
As shown in fig. 1 and 2, in a force transmission structure of a superconducting electrodynamic levitation magnet, a superconducting coil 2 is arranged in a superconducting electrodynamic levitation magnet 3; the two superconducting electric suspension magnets 3 are arranged in the low-temperature container in a bilateral symmetry mode through the left force transmission structure and the right force transmission structure, and the right force transmission structure and the left force transmission structure are identical in structure and are in bilateral symmetry; wherein, left side power transmission structure does: a bottom plate 15 of the non-working surface of the low-temperature container is connected with the low-temperature container 1 through a screw 8, and a sealing ring 9 is pressed between the bottom plate 15 and the low-temperature container 1; the bogie side plate 14 is positioned below the low-temperature container; the lower end of a class I ejector rod 5 positioned in the center of the superconducting magnet 3 is screwed on a bottom plate 15 of a non-working surface of the low-temperature container, and the upper end of the type I ejector rod abuts against a top plate 1 of the low-temperature container; the multiple I-type composite supporting rods and the multiple II-type composite supporting rods are arranged on the left side and the right side of the I-type ejector rod 5 in a bilateral symmetry mode, the I-type composite supporting rods are formed by connecting a first section 4 of a tubular I-type composite supporting rod with a second section 11 of a rod-shaped I-type composite supporting rod through a screw 8, the upper portion of the first section 4 of the I-type composite supporting rod is fixed on a superconducting magnet 3 through the screw 8, the lower portion of the second section 11 of the I-type composite supporting rod downwards penetrates through an opening in a bottom plate 15 of a non-working surface of the low-temperature container and a hole in a bogie side plate 14 in sequence and then is screwed with a nut 12, the upper end of a corrugated pipe 10 is welded on the opening in the bottom plate 15 of the non-working surface of the low-temperature container, the lower end of the corrugated pipe is welded on the second section 11 of the I-type composite supporting rod, the II-type composite supporting rod is formed by a first section 7 of the tubular II-type composite supporting rod and a second section 13 of the II-type composite supporting rod, the first section 7 of the II type composite supporting rod is fixed between the superconducting magnet 3 and the bottom plate 15 of the cryogenic container through screws, the lower end of a II type ejector rod 6 is inserted into the tube body of the first section of the II type composite supporting rod and is screwed on the bottom plate 15 of the non-working surface of the cryogenic container, the upper end of the II type ejector rod abuts against the top plate 1 of the cryogenic container, the upper end of the second section 13 of the II type composite supporting rod is fixed on the bottom plate 15 of the non-working surface of the cryogenic container through screws 8, and the lower end of the II type composite supporting rod downwards penetrates through a hole in a bogie side plate 14 and then is screwed with another nut 12.
In the left force transmission structure, three first-class composite supporting rods and three second-class composite supporting rods are arranged; the three I-type composite supporting rods positioned on the left side of the I-type ejector rod 5 are arranged in an isosceles triangle form; the connecting line of the centers of the class I composite supporting rod and the class I mandril 5 positioned at the vertex of the isosceles triangle can be crossed with the middle point of the bottom side of the isosceles triangle.
Among the three class-I composite support rods arranged in the form of an isosceles triangle, one class-I composite support rod positioned at the vertex of the isosceles triangle is arranged on the inner side of the superconducting coil 2, and two class-I composite support rods positioned at the other two angular points of the isosceles triangle are arranged on the outer side of the superconducting coil 2.
The force transmission structure of the superconducting electric suspension magnet comprises two types of composite supporting rods, wherein the two types of composite supporting rods are uniformly arranged on the inner side and the outer side of a superconducting coil 2, a first type composite supporting rod is arranged in a region far away from a symmetrical plane 16 of the superconducting magnet 3, and a second type composite supporting rod is arranged in a region close to the symmetrical plane 16 of the superconducting magnet 3.
The composite supporting rod comprises a first type composite supporting rod and a second type composite supporting rod, the first type composite supporting rod penetrates through a bottom plate 15 of a non-working surface of the low-temperature container and is divided into two sections, a first section 4 connected with the superconducting magnet 3 is low in heat conductivity and made of high-strength glass fibers, a second section 11 connected with the bogie side plate 14 is high in mechanical strength and made of stainless steel materials, and the two sections of the first type composite supporting rod are connected through screws 8.
The II-type composite supporting rod is divided into two sections by a bottom plate 15 of a non-working surface of the low-temperature container, the first section 7 is connected with the superconducting magnet 3 and the bottom plate 15 of the low-temperature container through screws 8, the thermal conductivity of the II-type composite supporting rod is low, the II-type composite supporting rod is made of high-strength glass fibers, the second section 13 is connected with a bogie side plate 14 and the bottom plate 15 of the non-working surface of the low-temperature container through nuts 12 and the screws 8, the mechanical strength of the II-type composite supporting rod is high, and the II-type composite supporting rod is made of stainless steel.
The two types of ejector rods comprise a type I ejector rod 5 and a type II ejector rod 6, the type I ejector rod 5 is of a thin-wall structure, has low thermal conductivity, is made of high-strength glass fiber and penetrates through the center of the superconducting magnet 3. The II-type ejector rod 6 is of a slender structure and light in weight, is made of titanium alloy and is arranged in the first section 7 of the II-type composite supporting rod. Both the two types of ejector rods are coated with a plurality of layers of super heat-insulating materials (namely materials with two sides of asbestos coated with aluminum foil paper).
The low-temperature container 1 and the bottom plate 15 are made of aluminum alloy materials, and the corrugated pipe 10 is made of stainless steel materials.
The installation process of the force transmission structure of the superconducting electric suspension magnet comprises the following steps: firstly, fixing a superconducting magnet 3, and installing a first section 4 of a first class I composite supporting rod and a first section 7 of a second class II composite supporting rod on the superconducting magnet 3 through screws 8; connecting the second section 11 of the I-type composite support rod with the first section 4 thereof through a screw 8; welding one end of the stainless steel corrugated pipe 10 on the opening of the bottom plate 15 of the non-working surface of the low-temperature container; enabling the second section 11 of the first-class composite supporting rod to penetrate through the bottom plate 15 of the low-temperature container, and connecting the bottom plate 15 of the non-working surface of the low-temperature container with the first section 7 of the second-class composite supporting rod by using a screw 8; the lower ends of the first type ejector rod 5 and the second type ejector rod 6 are installed on a bottom plate 15 of a non-working surface of the low-temperature container in a threaded connection mode; welding the other end of the stainless steel corrugated pipe 10 on the second section 11 of the class I composite support rod; seventhly, connecting the second section 13 of the II-type composite supporting rod with a bottom plate 15 of the non-working surface of the low-temperature container through a screw 8; allowing the superconducting magnet 3 to move, and fixedly connecting a second section 11 of the type I composite supporting rod and a second section 13 of the type II composite supporting rod to a bogie side plate 14 by using nuts 12; ninthly, placing the sealing ring 9 between the low-temperature container 1 and the bottom plate 15, and connecting the low-temperature container 1 and the bottom plate 15 by using a screw 8. And finally, completing the installation of the force transmission structure of the superconducting electric suspension magnet.
When the superconducting magnet 3 is cooled, the fixing nuts 12 between the class I composite supporting rod and the bogie side plate 14 are loosened, and deflection of the class I composite supporting rod to the center of the superconducting magnet 3 caused by cold contraction of the superconducting magnet 3 is allowed. After the superconducting magnet 3 is cooled to the lowest temperature, the fixing nut 12 between the class I composite supporting rod and the bogie side plate 14 is screwed down, so that the class I composite supporting rod can transmit the electromagnetic force of the superconducting magnet 3 to the bogie side plate 14.
The disassembly process of the force transfer structure of the superconducting electric suspension magnet is as follows: loosening a screw 8 between a top plate 1 and a bottom plate 15 of the low-temperature container, and taking down the top plate 1 and a sealing ring 9 of the low-temperature container; loosening the screws 8 between the superconducting magnet 3 and the two types of composite supporting rods, and taking down the superconducting magnet 3; thirdly, detaching a first section 4 of the first type I composite supporting rod and a first section 7 of the second type II composite supporting rod, and detaching a first type I ejector rod 5 and a second type II ejector rod 6; loosening the fixing nuts 12 between the second section 11 of the I-type composite support rod and the second section 13 of the II-type composite support rod and the bogie side plate 14, and taking down the bottom plate 15 of the non-working surface of the low-temperature container; and fifthly, detaching the second section 13 of the II-type composite support rod from the bottom plate 15 of the low-temperature container. Because the two ends of the stainless steel corrugated pipe 10 are respectively welded on the second section 11 of the type I composite support rod and the bottom plate 15 of the non-working surface of the low-temperature container, the stainless steel corrugated pipe 10 and the second section 11 of the type I composite support rod do not need to be detached from the bottom plate 15 of the non-working surface of the low-temperature container. Thus, the disassembly of the force transmission structure of the superconducting electric suspension magnet is completed.
Fig. 3 is a simulation result of the present invention, and fig. 3 (a) shows that the maximum deformation amount of the cryogenic container after vacuum-pumping is about 1.3 mm, the maximum deformation position appears on the cryogenic container 1, and the maximum deformation is within the allowable range. Fig. 3 (b) shows that under the load condition, the maximum stress of the low-temperature container is 86 MPa, and the problem of stress concentration of the low-temperature container is effectively solved. Fig. 3 (c) shows that under the load condition, the maximum stress of the force transmission structure of the superconducting electrodynamic levitation magnet is 260 MPa, which is much smaller than the bearing capacity of the force transmission structure. In conclusion, the force transmission structure of the superconducting electric levitation magnet has great application value in a magnetic levitation train.