FR2481020A1 - Linear asynchronous motor for traction or material transport - has edge effect fields for centering secondary part under primary windings - Google Patents

Abstract

The linear motor includes a primary part which comprises two core components, each one laminated, running in mutually perpendicular directions. The cores (2) at right angles to the direction of motion (D) span the width of the secondary assembly (7,8) and have at least four slots. The cores (3) parallel to the direction of motion span the spaces between successive cores of the first type, and comprise one more section than the number of slots in the transverse cores (2). A concentrated multiphase winding (4,5) is arranged around the core teeth. The phase across the direction of motion follow the normal sequence to the centre of the core and then the reverse sequence to the opposite edge. In the direction of motion (D) all coils in any one line follow the normal phase sequence. The excitation provided by this coil and core arrangement gives the required linear motion, centering for the secondary part, and magnetic levitation.

Description

The invention relates to electric machines and in particular relates to a linear asynchronous electric motor.

 The invention can find its application in high speed surface means of transport, the crew of which moves on a magnetic suspension at speeds comprised, preferably, between 350 and 500 km / h, as well as in metallurgy of non-ferrous metals for the transport of flat-rolled products and rolled sections of non-ferrous metals, as well as castings made of non-ferrous metals, carried by a magnetic suspension following a path of any desired configuration, the levitation height can be varied within the necessary limits, which excludes mechanical deterioration of the treated surfaces.

 A linear asynchronous electric motor can be used in transporters, in the metropolitan area and in various electrical control devices whose working members perform alternating or linear movements.

 Currently, a linear asynchronous electric motor is already known.

 The magnetic circuit of the inductor of this linear asynchronous electric motor is constituted by a laminated core mounted in the direction of movement of the inductor of the linear movement asynchronous electric motor, and by a laminated core mounted perpendicular to the direction of movement of the 'inductor of the linear asynchronous electric motor, which rests by its cylinder head on the core arranged in the direction of movement of the inductor.

The multi-phase winding is only wound on the laminated core arranged in the direction of movement of the inductor of the linear asynchronous electric motor.

The secondary element of the linear motion electric motor is constituted by a current conducting part placed on a magnetic base.

In this known electric motor, the transverse stabilization of the inductor relative to the secondary element is absent.

Also known is a linear asynchronous electric motor comprising a magnetic circuit inductor produced from a first and a second group of laminated cores with a concentrated winding with several phases whose coils are arranged in rows, and a secondary element having a current conducting part placed on a magnetic base.

The laminated cores of the first group are mounted in the first direction, that is to say perpendicular to the direction of movement of the inductor and are interconnected by the laminated cores of the second group mounted in the second direction perpendicular to the first direction , that is to say in the direction of movement of the inductor of the linear asynchronous electric motor. Each coil of the multi-phase concentrated winding surrounds one of the bars of at least one of the laminated cores of the first group and one of the bars of at least one of the laminated cores of the second group, while that the coils of each row arranged in the second direction have a direct order of alternation of the phases.

 The U-shaped laminated cores of the first group are arranged in two rows; it should be noted that the U-shaped cores of each row are arranged one after the other in the second direction. The laminated sheet metal from the second group is placed between the rows of the cores from the first group, while the two others are adjacent to the latter on the outer sides. The linear asynchronous electric motor considered has no transverse stabilization of the inductor with respect to the secondary element, which considerably reduces the security of movement of the surface means of transport working at high speed.

The present invention therefore relates to a linear asynchronous electric motor whose construction and connection diagram of the coils of the concentrated winding with several phases would be designed so as to create transverse stabilization of the inductor of the linear asynchronous electric motor with respect to the secondary element.

 This object is achieved by the fact that in the linear asynchronous electric motor comprising an inductor with a magnetic circuit produced from a first and a second group of cores with tESiuiIStés and having a concentrated winding with several phases whose coils are arranged in rows , and a secondary element having a current conducting part placed on a magnetic base, the laminated cores of the first group being mounted in a first direction and being interconnected by the cores of the second group mounted in a second direction, perpendicular to the first direction , each coil of the multi-phase concentrated winding surrounding one of the bars of at least one laminated core of the first group and one of the bars of at least one laminated core of the second group, while the coils of each row arranged in the second direction have a direct order of alternation of the phases, according to the invention each laminated core of the first group has at least four e notches intended to receive the coils of the concentrated winding with several phases, each laminated core of the second group being U-shaped, the number of laminated cores of the second group between each pair of neighboring laminated cores of the first group being greater than d '' a unit with the number of notches of the laminated cores of the first group, and the coils of the concentrated winding with several phases of each row arranged in the first direction having, until the middle of the row, a direct order of alternation phases, and after said middle of the row, a reverse order of phase altenance.

It is advantageous that the dimension of the extreme laminated cores of the first group, measured in the second direction is greater than this same dimension of each of the other laminated cores of the first group, by a value equal to the dimension of the bar of the laminated core of the second group, measured in the second direction.

 The invention makes it possible to increase the safety of movement of the high-speed surface transport crew provided with an asynchronous electric motor with gnxed movement lace up to the creation of a transverse stabilization of the inductor with respect to the secondary element, as well as increasing the reliability of operation of high speed surface transport.

The invention will be better understood and other objects, details and advantages thereof will appear more clearly in the light of the explanatory description which will follow of various embodiments given solely by way of nonlimiting examples, with references to the drawings. nonlimiting annexed in which
- Figure 1 is a schematic view of an embodiment of the linear asynchronous electric motor, according to the invention;
FIG. 2 shows the distribution of the phases of the three-phase current source between the coils of the three-phase winding according to FIG. 1.

 The linear asynchronous electric motor comprises an inductor 1 (FIG. 1) with a magnetic circuit composed of a first group of laminated cores 2 and a second group of laminated cores 3, and with a concentrated winding 4 with several phases, the coils 5 are arranged in rows, and a secondary element 6 consisting of a conductive part 7 located on a magnetic base 8 and separated from the inductor 1 by a clearance S.

 Inductor 1 moves in the direction of arrow D.

The laminated cores 2 of the first group are mounted in a first direction, that is to say perpendicular to the direction of movement of the inductor 1, and are interconnected by the laminated cores 3 of the second group, which are mounted in a second direction, perpendicular to the first, that is to say in the direction of movement of the inductor 1.

 Each laminated core 2 of the first group has four notches arranged between five bars 9 and connected by a yoke 10; in the notches are placed the coils 5. Each laminated core 3 of the second group has a U shape and is composed of two bars II and a yoke 12. The number of laminated cores 3 of the second group arranged between each pair of cores 2 mutually neighboring equals five.

It is advantageous for the dimension of each of the extreme cores 2 measured in said second direction to be greater than the same dimension of each of the other cores 2 by a value equal to the dimension of the bar II of the core 3 measured in said second direction .

 As a result, the coils S of the concentrated winding 4 with several phases are identical, which in turn improves the manufacturing technology of the inductor 1.

 Each coil 5 of the concentrated winding 4 of the extreme rows arranged in said first direction surrounds one of the bars 9 of a core 2 and one of the bars II of a core 3, while each coil 5 of the concentrated winding 4 of the other rows surrounds one of the bars 9 of a core 2 and the bars 11 of the two adjacent cores 3.

 FIG. 2 shows the distribution of the phases of a three-phase voltage current source between the coils of the three-phase concentrated winding, A, B, C being conventional designations of said phases of the three-phase voltage current source.

Ft expresses the traction force of the linear asynchronous electric motor;
F1, F2 express the forces developed by the linear asynchronous electric motor in said first direction. The coils 5 (FIG. 1) of the concentrated winding 4 of each row arranged in the second direction have a direct order of alternation of the phases A, B, C (FIG. 2).

The coils 5 (Figure 1) of the concentrated winding 4 of each row arranged in the first direction have, until the middle of the row, a direct order of alternation of phases A, B, C (Figure 2), and after said middle, an inverse order of alternation of phases A, B, C.

The proposed linear asynchronous electric motor operates as follows. To move the inductor 1 (Figure 1) in the direction of arrow D, the three-phase concentrated winding 4 of the inductor 1 is connected to a current source with three-phase voltage, including phases A, B, C ( 2) are distributed in an appropriate manner between the coils 5 (FIG. 1) of the three-phase concentrated winding 4. Magnetic fields of displacement are thus created in the opposite direction to the displacement of the inductor 1 and resulting from the operation of the whole system of coils of the concentrated winding 4 of the inductor 1. magnetic fields are also created, moving in opposite directions and generated by the coils 5 of each row arranged in the first direction.

 The mobile magnetic fields intersect the conductive part 7 of the secondary element 6 by inducing in this part 7 electromotive forces causing the circulation, in the conductive part 7 of the secondary element 6, of vortex currents which interact with the fields. magnetic of the inductor 7 of the linear motor. As a result of the interaction of the magnetic fields moving in the opposite direction to the displacement of the inductor 1, on the one hand, and the currents in the conductive part 7 of the secondary element 6, on the other hand, it becomes creates tensile forces Ft (figure 2) acting in the second direction and levitation forces of the linear motor. During the interaction of magnetic fields moving in opposite directions on the one hand, and currents in the part conductive 7 (Figure 1) of the secondary element 6, on the other hand, appear forces F1 (Figure 2) and F2 directed in opposite directions and balancing each other without exerting an influence on the operation of the linear motor in the absence of lateral disturbances acting on the inductor 1 (figure 1).

 If, under the action of any random lateral disturbances, for example, from a strong lateral wind, there is a displacement of the inductor î in the first direction, then the balance of forces F1 (Figure 2) and F2 is disturbed, being that part of the inductor 1 (FIG. 1) is displaced beyond the secondary element 6 and, under the action of the stabilizing force which appears and which is equal to the difference of the efforts F1 (FIG. 2) and F2, the inductor 1 (FIG. 1) of the linear motor returns to its initial position, thereby regaining its balance. It should be noted that the value of the stabilizing force is proportional to the value of the force of the lateral disturbance.

 Thus, the present invention makes it possible to ensure transverse stabilization of the inductor relative to the secondary element of the linear asynchronous electric motor.

Of course, the invention is in no way limited to the embodiments described and shown which have been given only by way of example. In particular, it includes all the means constituting technical equivalents of the means described as well as their combinations if these are executed according to its spirit and implemented within the framework of protection as claimed.

Claims (2)

1.- Linear asynchronous electric motor comprising an inductor with a magnetic circuit composed of a first and a second group of laminated cores and with a concentrated winding with several phases whose coils are arranged in rows, and a secondary element consisting of conductive part placed on a magnetic base, the laminated cores of the first group being arranged in a first direction and being interconnected by the laminated cores of the second group arranged in a second direction, perpendicular to said first direction, each coil of said concentrated winding surrounding one of the bars of at least one of the cores of the first group and one of the bars of at least one of the cores of the second group, the coils of each fringe arranged in said second direction having a direct order alternating phases, characterized in that each laminated core of the first group has at least four notches in which The coils of the concentrated winding are arranged in several phases, each laminated core of the second group having a U shape, the number of laminated cores of the second group between each pair of laminated cores neighboring the first group being greater than one unit. the number of notches of the laminated cores of the first group, and the coils of the concentrated winding with several phases of each row arranged in said first direction having, up to the middle of the row, a direct order of alternation of the phases, and after said medium, a reverse order of alternation of the phases.  2.- linear asynchronous electric motor according to claim 1, characterized in that the dimension of the extreme laminated cores of the first group, measured in said second direction, is larger than the same dimension of each of the other laminated cores of said first group a value equal to the dimension of the bar of the laminated core of the second group, measured in said second direction.