JPH09331667A - Linear induction motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a linear induction motor, by changing the sizes of the two coil-end portions present on both the side surfaces of its primary side to select their dimensional relation adequately. SOLUTION: When an inside crossover line 6 is provided in the inner side of a lateral-U-shaped frame 4, an outside coil-end width CO1 is made smaller than an inside coil-end width CI1. Since only one primary side portion affecting the width of a secondary conductor 5 is the outside coil-end width CO1 and it is made smaller than the width CI1 by the width of the inside crossover line 6, the width of the secondary conductor 5 can be reduced. Thereby, the build of the whole of a linear motor can be made small and its price can be made low too, because the reduction of the width of the secondary conductor 5 affects largely the build and price of the whole of the linear motor when the length of the secondary conductor 5 is made large.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear induction motor, and more particularly to a linear induction motor for driving an elevator.

[0002]

2. Description of the Related Art Conventional linear induction motors used for long-stroke applications such as elevators are disclosed in, for example, Japanese Unexamined Patent Publication No.
As described in Japanese Patent No. 24772, the primary side is a movable side, the secondary conductor is laid and fixed over the entire process, and the secondary conductor is sandwiched between the two-sided primary side.
The primary side is held by a U-shaped frame. Also,
The primary side includes a coil and a core, and the coil is wound around the core so as to circulate the area of one pole in order to generate a magnetic flux. That is, the coil is wound through the slot portion of the core and the space on the side surface of the core. The coil in the space on the side surface of the core is generally called a coil end.

[0003]

By the way, the thrust of the linear motor is generated in the portion of the secondary conductor where the main magnetic flux from the primary side interlinks. Then, the main magnetic flux is generated from the core on the primary side. For this reason, it goes without saying that the coil end is a portion that does not contribute to the thrust, and it is important to reduce the size of the coil end to reduce the size of the linear motor. In the conventional example, there is no particular description about the structure of the coil end portion on the primary side, and no study on the coil end portion has been made.

The object of the present invention is to provide two sides on the primary side.
By changing the size of the two coil end portions and appropriately selecting the magnitude relationship, the size of the linear induction motor can be reduced.

[0005]

SUMMARY OF THE INVENTION The above problem is a linear induction motor having a primary side made of a magnetic material core and a coil made of a conductive material and a secondary side conductor facing each other through a gap, and having a coil end on the primary side. This can be solved by varying the dimensions of. In addition, it is a linear induction motor of both sides primary consisting of a magnetic conductor core and a primary side consisting of a coil of conductive material and a secondary conductor facing each other through a gap, the primary side being held by a U-shaped frame, This is solved by making the coil end on the back side of the U-shaped frame different from the coil end on the release side of the U-shaped frame.

Here, by increasing the coil end on the back side of the U-shaped frame, the coil end on the release side of the U-shaped frame can be reduced, and thus the width of the secondary conductor can be increased. The size of the secondary conductor can be reduced, and the size of the secondary conductor can be reduced. In addition, the coil end on the back side of the U-shaped frame can be made smaller by increasing the coil end on the release side of the U-shaped frame, which allows the U-shaped frame located on the rear surface of the primary side to be reduced. The width of the mold frame can be narrowed and the primary side can be downsized.
As a result, according to the present invention, the smallest and lowest cost linear induction motor can be obtained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a horizontal sectional view of a linear induction motor showing an embodiment of the present invention. In FIG. 1, the linear induction motor includes a magnetic material primary core 1, a conductive material coil (inner coil end 2, outer coil end 3), a U-shaped frame 4, a secondary conductor 5, and an inner connecting wire 6. Become. Here, the coil end inside the U-shaped frame 4 is referred to as the inner coil end 2, and the coil end on the release side of the U-shaped frame 4 is referred to as the outer coil end 3. The primary core 1 is installed so as to face the inner surfaces of the upper side and the lower side of the U-shaped frame 4, the coil is wound around the primary core 1, and the coil end portion, that is, the inner coil end 2 is provided from the side surface of the primary core 1. The outer coil end 3 sticks out. A secondary conductor 5 having an L-shaped cross section is arranged between the two primary cores 1. When a three-phase alternating current is applied to the coil on the primary side, the main magnetic flux links the secondary conductor 5 and the induced secondary current flows through the secondary conductor 5. The main magnetic flux moves in accordance with the frequency of the three-phase AC of the primary side coil, so that thrust is generated between the main magnetic flux and the secondary current. An electric wire for passing an alternating current is connected to the coil. Normally, a linear motor is not a single pole but has multiple poles such as 4 poles and 6 poles, and an electric wire, that is, a crossover wire that connects the coils of each pole is provided, and the starting end and the terminating end thereof are on the power source side or at a neutral point. Becomes In this embodiment, the connecting wire 6 is provided on the inner side of the U-shaped frame 4 and on the inner coil end 2.

When the linear induction motor is constructed as described above, the following dimensional relationships are obtained. That is, as shown in FIG. 1, the core width A, the outer coil end width CO1, the inner coil end width CI1, the secondary conductor outer width BO1, the secondary conductor inner width BI1, and the U-shaped frame inner width D1 are obtained.
In addition, the constraint conditions of each configuration are as follows. The outer width BO1 of the secondary conductor is set to have a certain margin so that the outer coil end 3 and the secondary conductor 5 do not come into contact with each other, and is slightly larger than the outer coil end width CO1. On the other hand, the inner width BI1 of the secondary conductor may be about 20% of the primary core width A in order to have a cross-sectional area necessary for the secondary current to flow. Since the inner coil end width CI1 is usually about 40% of the primary core width A, the inner width BI1 of the secondary conductor is
Is not affected by the size of the inner coil end width CI1. In this embodiment, since the inner connecting wire 6 is provided inside the U-shaped frame 4, the outer coil end width CO1 is smaller than the inner coil end width CI1. As described above, since the outer coil end width CO1 is the only primary side portion that affects the width of the secondary conductor 5, the outer coil end width CO1 is reduced by the width of the inner connecting wire 6, The width of the next conductor 5 can be reduced. Therefore, when the length of the secondary conductor becomes long, the size and price of the entire linear motor are greatly affected by the secondary conductor 5. Therefore, according to the present embodiment, by reducing the width of the secondary conductor 5, This has the effect of reducing the overall size of the linear motor and reducing the price.

FIG. 2 shows the external appearance of a linear induction motor according to an embodiment of the present invention as seen obliquely from above. The secondary conductor 5
Shows the top cut away so that the primary side is visible. Here, only the portions not described in the horizontal sectional view of FIG. 1 will be described. There are a plurality of U-shaped frames 4, which fix the back surface of the primary core 1. The outer coil end 3 is
The entire side of the primary core along the length of the primary side. The inner coil end 2 is hidden and not visible in the drawing, but like the outer coil end 3, the inner coil end 2 is on the entire side surface of the primary core along the entire length of the primary side, and extends to the side closer to the U-shaped frame 4. Line 6 is provided. The connecting wire 6 is shown only on the inner coil end 2 of one of the primary cores, but it is also provided on the other primary core at a similar portion. Although not shown in FIG. 2, a linear indicating mechanism is provided in order to hold the primary side and the secondary conductor 5 in a predetermined air gap. Also,
An electric wire from the lower side of the drawing to the drive power source side such as an inverter is connected to the tip of the crossover. With such a configuration,
The primary side of the linear motor moves linearly in the vertical direction in the drawing.

FIG. 3 shows another embodiment of the present invention. In FIG. 3, a part different from FIG. 1 is that the crossover wire 7 is provided at the outer coil end 3. By configuring the linear induction motor in this way, the following dimensional relationships are obtained. That is, as shown in FIG. 3, the core width A, the outer coil end width CO2, the inner coil end width CI2, the secondary conductor outer width BO2, the secondary conductor inner width BI2, and the U-shaped frame inner width D2 are obtained. In addition, the constraint conditions of each configuration are as follows. In this embodiment, since the connecting wire 7 is provided on the outer coil end 3, the outer coil end width CO2 is larger than the inner coil end width CI2. The width of the U-shaped frame 4 depends on the width A of the attached primary core 1 and the width CI2 of the inner coil end 2. Therefore, since the inner coil end width CI2 is reduced as in the present embodiment, the width 4 of the U-shaped frame can be reduced. Therefore, when the secondary conductor 5 is not so long with respect to the length of the primary side, reducing the size of the primary side leads to downsizing and cost reduction of the entire linear motor. By reducing the size of the U-shaped frame 4 on the primary side, the overall size of the linear motor can be reduced, and the price can be reduced.

FIG. 4 shows an external appearance of a linear induction motor according to another embodiment of the present invention as seen obliquely from above. The secondary conductor 5 is shown by cutting the upper part so that the primary side can be seen. Here, only a portion not described in the horizontal sectional view of FIG. 3 will be described. There are a plurality of U-shaped frames 4, which fix the back surface of the primary core 1. Outer coil end 3
Are on the entire side of the primary core along the length of the primary.
Further, a crossover 7 is provided on the side farther from the U-shaped frame 4. Although the connecting wire 7 is shown only on the outer coil end 3 of one of the primary cores, it is also provided on the other primary core at a similar portion. Like the outer coil end 3, the inner coil end 2 is also on the entire side surface of the primary core along the entire length of the primary side. Although not shown in FIG. 4, a linear indicating mechanism is provided in order to hold the primary side and the secondary conductor 5 in a predetermined air gap. An electric wire from the lower side of the drawing to the drive power source side such as an inverter is connected to the tip of the crossover. With such a configuration, the linear motor linearly moves in the vertical direction in the figure.

FIG. 5 shows another embodiment of the present invention, which is a modification of the embodiment of FIG. Here, in addition to the embodiment of FIG. 1, the outer portion of the outer coil end 3 is formed into a shape bent to the U-shaped frame 4 side (a shape protruding rearward from the back surface of the primary core). By configuring the linear induction motor in this way, the following dimensional relationships are obtained.
That is, as shown in FIG. 5, the core width A, the outer coil end width CO3, the inner coil end width CI3, the secondary conductor outer width BO3, the secondary conductor inner width BI3, and the U-shaped frame inner width D3 are obtained. In addition, the constraint conditions of each configuration are as follows. Compared with the embodiment of FIG. 1, the outer coil end width CO
3 is further reduced, and the outer width BO3 of the secondary conductor can be further reduced accordingly. In order to withstand the suction force on the primary side,
The U-shaped frame 4 needs to have a certain thickness, and if the outer coil end 3 has a bending margin within that thickness, the width of the secondary conductor 5 can be further reduced. Further miniaturization can be realized without any trouble. It should be noted that a modification of the embodiment of FIG.
The same effect can be obtained by forming the shape bent to the side (shape protruding rearward from the back surface of the primary core).

6 and 7 show an embodiment in which the present invention is applied to a linear motor elevator. FIG. 6 shows the overall schematic structure. In FIG. 6, the linear motor elevator is
The car 9 and the counterweight 10 are connected via a rope 11, the rope 11 is passed through a pulley 12 fixed to the top of the hoistway (not shown), and the car rails 14 on both sides are fixed to the hoistway 13. To the car basket 9 via a guide roller (not shown), and the counterweight rail 15 to a counterway 10 via a guide roller (not shown).
Has a structure that can be moved up and down. A linear motor primary side 8 is provided inside the counterweight 10, and a secondary conductor 5 is laid on the hoistway 13 side over the traveling path of the counterweight 10. Primary side of linear motor 8
A propulsive force is generated by energizing the vehicle with a control panel (not shown), whereby the counterweight 10 moves up and down and is transmitted to the car 9 via the rope 11, and as a result, the car 9 moves up and down. Function as an elevator.

FIG. 7 shows the counter weight 10 portion of FIG. 6 in more detail. This is shown by cutting the counterweight 10 and the secondary conductor 5 in a ring shape at the position of the top of the linear motor primary side 8. In FIG. 7, the counterweight 10 is mainly composed of left and right portions 18 on which weights are provided, a lower portion 19 for mounting a rail brake (not shown), and an upper portion 20 for fixing the rope 11. A primary side 8 of the linear motor is provided in the frame of the counterweight 10 via a horizontal movement mechanism 16. The horizontal movement mechanism 16 is provided on the upper portion 20 and the lower portion 19 of the counterweight 10. The two primary sides 8 composed of the primary core 1 and the coil are fixed to the plurality of U-shaped frames 4 so as to face each other with a gap of the thickness of the secondary conductor 5 and an air gap. The secondary conductor 5 having an L-shaped cross section is fixed to the hoistway by the fixing member 17 so that the secondary conductor 5 is inserted between the primary sides 8. Therefore, the side of the counterweight 10 near the wall of the hoistway 13 is provided with a gap through which the vertical portion of the secondary conductor 5 can pass.

As is clear from FIGS. 6 and 7, the width of the counterweight 10 influences the distance between the counterweight guide rails 15 and the dimension of the hoistway. Therefore,
If the counterweight 10 is reduced, the size of the hoistway can be reduced. Further, since the counterweight 10 itself becomes a movable part of the linear motor, reducing the size thereof can reduce the weight of the movable part. Therefore, the output of the linear motor is reduced, and the linear motor itself can be downsized.
As described above, by applying the present invention to a linear motor elevator, the counterweight and the linear motor itself can be downsized and the cost can be reduced. Further, there is an effect that the size of the hoistway can be reduced.

Here, which of the embodiment of FIG. 1 and the embodiment of FIG. 3 of the present invention to select and apply to the linear motor elevator may be determined according to the specifications of the linear motor elevator to be applied. For example, when the up-and-down stroke is large, the length of the secondary conductor becomes long. Therefore, by adopting the embodiment of FIG. 1, it is possible to maximize the cost reduction and workability improvement by reducing the amount of the secondary conductor. be able to. On the other hand, when the ascending / descending stroke is short, or when the load of the car is large and a large thrust is required and the length of the primary side is long, the U-shaped frame on the primary side is adopted by adopting the embodiment of FIG. The counter weight can be shortened and the counter weight can be made smaller and the price can be maximized.

In the embodiment of the present invention, the L-shaped cross-section of the secondary conductor and the double-sided primary side structure are shown, but the cross-sectional shape of the secondary conductor is not limited to the L-shape. If the secondary conductor is provided between the two-sided primary side, even if it is a flat plate-shaped secondary conductor, the size of the end coil is restricted by the fixed end when fixing it at one end. ,
Further, since a U-shaped frame that connects the two primary sides is essential, the same effect can be obtained by using the same structure. Further, the linear induction motor of the present invention can be used in an escalator. Also in this case, as in the case of the elevator embodiment, by selecting the embodiment according to the specifications of the system, the secondary conductor is downsized when the secondary conductor occupies a large price, while the primary side occupies a large price. In this case, the size of the primary side can be reduced, and the price of the system can be reduced.

[0018]

As described above, according to the present invention,
In a double-sided primary linear induction motor having a primary side held by a U-shaped frame, the coil end on the release side of the U-shaped frame is increased by increasing the coil end on the back side of the U-shaped frame. Can be made smaller, and thus the width of the secondary conductor can be made narrower, and the secondary conductor can be made smaller. In addition, the coil end on the back side of the U-shaped frame can be made smaller by increasing the coil end on the release side of the U-shaped frame, which allows the U-shaped frame located on the rear surface of the primary side to be reduced. The width of the mold frame can be narrowed and the primary side can be downsized. As a result, the smallest and lowest cost linear induction motor can be obtained. Further, by applying the present invention to a linear motor elevator, it is possible to reduce the size and cost of the counterweight and the linear motor itself, and to reduce the size of the hoistway. Further, by applying the present invention to an escalator, it is possible to reduce the size of the secondary conductor when the secondary conductor occupies a large price, and to reduce the size of the primary side when the primary side occupies a large price. The system price can be reduced.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view of a linear induction motor showing an embodiment of the present invention.

FIG. 2 is an external view of an embodiment of the present invention.

FIG. 3 shows another embodiment of the present invention.

FIG. 4 is an external view of another embodiment of the present invention.

FIG. 5 shows another embodiment of the present invention.

FIG. 6 is a schematic structural diagram of a linear motor elevator using the present invention.

FIG. 7 is a structural diagram of a counterweight portion of a linear motor elevator using the present invention.

[Explanation of symbols]

 1 Primary Core 2 Inner Coil End 3 Outer Coil End 4 U-Shaped Frame 5 Secondary Conductor 6,7 Crossover 8 Linear Motor Primary Side 9 Cage 10 Counterweight 13 Hoistway

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Hiroshi Nagase Hiroshi Nagase 1070 Ichimo, Hitachinaka-shi, Ibaraki Hitachi Ltd. Mito Factory (72) Inventor Noboru Arahori 1070 Ichige, Hitachinaka-shi, Ibaraki Hitachi Ltd. Mito Factory (72) Inventor Ryoichi Naganuma 1-1-1, Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory

Claims (8)

[Claims] 1. A linear induction motor comprising a secondary side conductor facing a primary side made up of a magnetic material core and a coil made of a conductive material through a gap, wherein the coil ends on the primary side have different sizes. Characteristic linear induction motor. 2. A linear induction motor of a double-sided primary type, which comprises a primary side made of a magnetic material core and a conductive material coil, and a secondary conductor facing each other through a gap, the primary side being held by a U-shaped frame. The linear induction motor is characterized in that the coil end on the inner side of the U-shaped frame and the coil end on the release side of the U-shaped frame are made different in size. 3. The linear induction motor according to claim 2, wherein the coil end on the back side of the U-shaped frame is larger than the coil end on the release side of the U-shaped frame. 4. The linear induction motor according to claim 2, wherein the coil end on the release side of the U-shaped frame is larger than the coil end on the back side of the U-shaped frame. 5. The linear induction motor according to claim 2, wherein a crossover wire between the coils is arranged on the side where the coil end is increased. 6. The linear induction motor according to claim 3, wherein the coil end on the release side of the U-shaped frame projects rearward from the back surface of the primary core. 7. The linear induction motor according to claim 1, wherein the linear induction motor is provided on a counterweight of an elevator, and the elevator is moved. 8. The linear induction motor according to claim 1, wherein the linear induction motor is provided in an escalator as a drive source and the escalator is moved.