JPS63171156A - Structure of secondary conductor for linear induction motor - Google Patents

Abstract

PURPOSE:To improve thrust characteristic of a linear induction motor, by making multiple secondary conductor plates multilayered in structure through an electric insulator. CONSTITUTION:A linear induction motor is composed of two sheets of the secondary conductor 1, an electric insulator 2 to insulate these conductors, stators 3, a moving piece 6, wheals 4 to hold the moving piece 6, and mounting plates 3 to mount the stators serving also as rails. Thus, with the space flux generated by the stators 3 on both sides, the eddy current inside the secondary conductor respectively independent will flow through the two sheets of the secondary conducfor fitted to the moving piece 6. Since each of the eddy current becomes the thrust by the interlinkage with the space flux, the thrust is improved as compared with a single piece of the secondary conductor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the structure of a secondary conductor of a linear induction motor.

[Prior art] Figure 3 shows, for example, our catalog L (name) 74102.
073A (created in March 1985) is a sectional view showing the structure of a conventional linear induction motor, showing a double-sided type with stators on both sides.

In the figure, (1) is a plate-shaped secondary conductor, (3) is a stator with windings wound around it, (4) is a wheel that holds a movable element, and (5) is a stator with windings wound around it.
) is a stator mounting plate that also serves as a rail, and (6) is a movable element that serves as a transport body.

Next, the operation of the linear induction motor configured as described above will be explained.

In Fig. 3, when the stator (3) is excited and a traveling wave magnetic field is generated, an eddy current is generated in the secondary conductor (1), and the magnetic field ( The secondary conductor (1) and the movable element (6) move by generating thrust by interlinking with the space magnetic flux).

In general, linear induction motors are often of the one-sided type, with only the stator (3) on one side and a steel plate on the other, but when a large thrust is required, a double-sided type as shown above is used. Ru.

[Problems to be solved by the invention] Since the conventional device is configured as described above, in order to increase the thrust force, the voltage applied to the stator (3) is increased to pass through the secondary conductor. It is necessary to increase the traveling wave magnetic flux density. However, increasing the voltage and increasing the magnetic flux density means increasing the current density in the stator coil, and from the standpoint of heat dissipation, forced ventilation must be used.
Alternatively, it is necessary to increase the stator conductor cross-sectional area. That is, the slot area is increased, and in the former case, a device for forced ventilation is required, and in the latter case, the stator becomes large.

This invention was made in order to solve the above-mentioned problems, and to obtain a structure of a secondary conductor of a linear induction motor that can improve thrust characteristics even though the current in the stator coil remains the same. With the goal.

Means for Solving Problem L] The secondary conductor of the linear induction motor according to the present invention has a multilayer structure of a plurality of secondary conductor plates with electrical insulators interposed therebetween.

[Function] Since the secondary conductor in this invention has a multilayer structure, eddy currents flow through each secondary conductor, and these eddy currents interlink with the spatial magnetic flux to generate thrust. Thrust characteristics are improved.

[Embodiment] Hereinafter, a secondary conductor structure of a linear induction motor according to an embodiment of the present invention will be explained using FIG. 1 and FIG. 2.

FIG. 1 is a perspective view showing a secondary conductor structure of a linear induction motor according to an embodiment of the present invention, and FIG. 2 is a sectional view of an actual linear induction motor using the secondary conductor structure of FIG. 1.

In Figure 1, (1) is a plate-shaped secondary conductor, (2) is a
It is covered with an electrical insulator that insulates the secondary conductor (1).

Also, in Figure 2, (1) and (2) are the same plate-shaped secondary conductors and electrical insulators as in Figure 1, (3) is the stator, and (4) is the movable element. Wheels, (5) a stator mounting plate that also serves as a rail, and (6) a movable element.

Next, the operation of the secondary conductor structure of the linear induction motor of the above embodiment will be explained.

Due to the spatial magnetic flux generated by the stators (3) on both sides, the two secondary conductors (1) attached to the mover (6)
Eddy currents flow within each independent secondary conductor. Since each of these eddy currents becomes a thrust force due to linkage with the spatial magnetic flux, the thrust force is increased compared to that of a single secondary conductor (1) in the conventional example.

However, if the thickness of each secondary conductor (1) is equal to the thickness of the secondary conductor (1) of the conventional example shown in Fig. 3, and the spatial magnetic flux density is the same as that of the conventional example, then the conventional example The thrust should be twice as large, but because of the thickness of one secondary conductor (1〉) added to the conventional example, the spatial magnetic flux density of this example is higher than that of the conventional example. Since it is slightly inferior, the thrust is not doubled, but almost doubled.

In the above embodiment, two secondary conductors (1) were used, but three or more secondary conductors (1) were used, and each secondary conductor (1)
It is also possible to insert an electrical insulator (2) between the secondary conductors (1), which improves the thrust compared to the case where there are two secondary conductors (1).

However, if you deviate from making it correspond to the stators (3) on both sides, the secondary conductor plate (1) with a multilayer structure via the electrical insulator (2) will be as shown in Figures 1 and 2. , a two-layer structure is integrated with a secondary conductor (as in the conventional example shown in Figure 3).
The difference from the one that formed 1) is obvious.

In addition, as the electrical insulator 2) between the secondary conductors (1), a thin sheet such as a polyester film is used;
There is also a space (air layer) provided to prevent metal contact between the secondary conductors (1), and an adhesive to bond the secondary conductors (1) to prevent metal contact between the secondary conductors (1). used.

Furthermore, although the above embodiment describes a double-sided linear induction motor, the secondary conductor structure of this invention can also be applied to a single-sided linear induction motor.
It is applicable.

[Effects of the Invention] As described above, according to the secondary conductor structure of the linear induction motor of the present invention, a plurality of secondary conductor plates have a multilayer structure with an electrical insulator interposed therebetween. The thrust characteristics of the linear induction motor can also be improved by changing the stator dimensions. Further, when the same thrust force is required, the stator size can be reduced, which has the effect of providing a compact and inexpensive linear induction motor.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the secondary conductor structure of a linear induction motor according to an embodiment of the present invention, Fig. 2 is a sectional view of an actual linear induction motor using the secondary conductor structure of Fig. 1, and Fig. 3 1 is a sectional view of a linear induction motor using a conventional secondary conductor structure. In the figure, (1): secondary conductor, (2): insulator, (3): stator, (6): mover, (5): stator mounting plate that also serves as rail. In addition, in the figures, the same reference numerals and the same symbols indicate the same or equivalent parts.

Claims (2)

[Claims] (1) A secondary conductor structure for a linear induction motor, characterized in that a plurality of secondary conductor plates have a multilayer structure with an electrical insulator interposed therebetween. (2) The secondary conductor structure of a linear induction motor according to claim 1, wherein the secondary conductor plate having a multilayer structure with the electrical insulator interposed therebetween has a two-layer structure.