JPH08205512A - Gap keeping mechanism of linear motor and linear motor driven roped elevator - Google Patents

Abstract

PURPOSE: To facilitate the smooth movement of the primary side of a linear motor and keep the gap of the linear motor with a high precision by a method wherein the stator of the linear motor can be moved in a direction of changing the length of the gap. CONSTITUTION: A member such as a spring which has a restoration force against a displacement is provided between the back of a front support 6 and the bent part of the end of a bracket 5 to constitute a slide mechanism 8. When a primary side 1 does not exist, a frame is so constructed as to have the distance between the secondary sides 2 on both sides larger than the distance necessary for the travel of rollers on the primary side. When the primary side 1 travelling upward exists between the secondary sides 2, the secondary sides 2 come closer to the primary side 1 by the attraction force between the primary side 1 and the secondary sides 2 and are held at the positions where they touch the rollers 4. Therefore, the gap lengths between the primary side 1 and the secondary sides 2 are determined by the precision and dimensions of attaching the rollers 4 to the primary side, so that the gap lengths can be maintained with a high precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor, and more particularly to a gap holding mechanism for stably maintaining the gap of a double-sided linear motor having two gaps.

[0002]

2. Description of the Related Art A conventional double-sided linear motor has a structure in which the gap lengths on both sides are made substantially equal to equalize the thrust force and suction force generated on the respective surfaces.
Many examples of this are shown in, for example, the document "Linear Motor Application Handbook" (Industrial Research Association, October 1986).

[0003]

In the structure of the double-sided linear motor described above, the gap length on both sides may fluctuate depending on the accuracy of machining and assembling of the linear motor, resulting in imbalance. The magnetic flux density increases and the attractive force increases on the short gap side, and the magnetic flux density decreases and the attractive force decreases on the long gap side. As a result, due to the imbalance of the suction force, the mover is drawn to the side where the gap length is short.

The above-mentioned imbalance between the gaps on both sides is unlikely to always be long in one gap, and which gap is longer or shorter depends on the position and time.

Therefore, the characteristics of the linear motor fluctuate due to the gap fluctuation, and thrust pulsation occurs.

It is an object of the present invention to obtain a double-sided linear motor in which the gap does not fluctuate and the characteristics do not fluctuate even if the machining and assembly precision is not improved.

[0007]

In a double-sided linear motor having two sets of stators arranged outside, at least one set of the stators is movable in the direction of changing the gap length, and further outside the outer edge of the guide mechanism. The linear motor has a restoring mechanism that returns to the position of the linear motor, while the movable element guides the movable element itself and a guide mechanism that keeps the gap with the stator so that the gap does not become shorter than a predetermined gap length. The above problem is solved by having a mechanism.

[0008]

Since the stator is movable in the gap length direction, the stator can be brought closer to the mover by the suction force generated between the stator and the mover, and the guide mechanism for maintaining the gap length provides a predetermined gap length. Is set to. Further, the stator on which the mover does not face is returned to a position outside the outer edge of the guide mechanism by the restoring mechanism, and does not hinder the movement of the mover.

[0009]

1 is a sectional view of a double-sided linear motor according to an embodiment of the present invention.

In the embodiment of the present invention, the stator is the secondary side and the mover is the primary side. As shown in the figure, the linear motor has secondary sides arranged on both sides, a primary side provided with a ring-shaped primary coil between them, and the secondary side is fixed,
Shown as a double-sided linear induction motor with a mover on the primary side.

The primary side moves in the vertical direction (depth direction of the paper surface).

The double-sided linear motor comprises a primary side 1 having a primary coil and two secondary sides 2 facing each other with a gap between them. The secondary side 2 is composed of a secondary conductor 2B provided with a secondary yoke 2A.

A primary side 1 of a double-sided linear motor is composed of a primary core 1A having a primary coil 1B turned around and a motor frame 3 on both sides. Rollers 4 are provided on the primary side of the motor frame 3 so as to maintain a gap between the secondary side and the primary side located above the drawing and a gap between the secondary side and the primary side located below the drawing. .

The secondary side 2 located at the bottom of the figure is connected to the front support 6, the secondary side 2 located at the top of the figure is connected to the rear support 7, and each support is connected by two sets of brackets 5. To form a square shape.

Therefore, since the square-shaped frame structure composed of the bracket and the support influences the interval on the secondary side,
The accuracy of assembly of this frame structure affects the accuracy of the gap length of the linear motor. However, since the dimensional accuracy of the primary side and the secondary side of the linear motor also affects the gap length, it is necessary to determine the size of the frame structure according to the dimensions of the frame structure of the linear motor.

However, the dimensions on the primary side and the secondary side naturally vary. In particular, since the secondary side is laid along the stroke of the primary side, a large amount of it is necessary, and it is quite conceivable that the dimensions of the secondary side will vary depending on the location. Therefore, in consideration of the variation in the dimensions of the primary side and the secondary side, it is also possible to set the dimension of the frame structure by setting a sufficiently large gap length so that the primary side and the secondary side do not contact at the gap part. To be

In the present invention, a slidable mechanism is provided in a part of the frame structure as a measure against the above. That is, FIG.
The bracket 5 and the front support 6 are connected at two connecting portions via the sliding mechanism 8. The operation of this part will be described below.

FIG. 2 shows a sectional view of a double-sided linear motor according to an embodiment of the present invention.

The configuration will be described only for the parts that could not be explained with reference to FIG.

In the figure, three sections, section A, section B, and section C
In each section, the secondary side of each of the two surfaces is fixed by using two sets of frame structures each including one front support 6, one back support 7, and two brackets 5. Although not shown, this frame structure is fixed to a robust structure such as a wall or floor.

A member such as a spring that generates a restoring force against a displacement is provided between the back portion of the front support 6 and the bent portion of the bracket 5 to form the sliding mechanism 8. When there is no primary side 1 as in the section A, the frame structure is set so that the interval between the secondary sides 2 on both sides is larger than the interval required for the rollers on the primary side 1 to travel.

In the section B, since the primary side 1 which is moving upward is between the secondary side 2, the suction force between the primary side 1 and the secondary side 2 connects to the front support 6 on the right side of the figure. The secondary side 2 being approached approaches the primary side 1. Then, the secondary side 2 stops at a position where it contacts the roller 4 provided on the primary side 1. Therefore, since the gap length between the primary side 1 and the secondary side 2 is determined by the mounting accuracy and size of the roller 4 on the primary side, the gap length is maintained with extremely high accuracy. Further, in the state where the primary side 1 has passed like the section A, the secondary side 2 returns to the original position by the restoring force of the spring or the like provided in the sliding mechanism 8. Therefore, even when the primary side 1 enters the section A again, the secondary side 2 has a sufficient margin, so that the primary side 1 does not rub or bite the secondary side.

As described above, according to this embodiment, the primary side is a double-sided linear motor having a secondary side longer than the primary side on the outside and the primary side moving, and the primary side can move smoothly, and the accuracy of the structure is not so high. Since the gap can be maintained accurately without increasing the height, a high-performance linear motor can be easily obtained.

FIG. 3 is a sectional view of the sliding mechanism of the embodiment of the present invention.

A front support 6 and a rear support 7 for fixing the secondary side 2 are connected by a bracket 5. The connection part between the rear support 7 and the bracket 5 is a bolt 10,
It is fixed by a nut 11. The connection between the front support 6 and the bracket 5 is provided with a long hole 9 in the rear support, through which a bolt 10 penetrates and a nut 11 is used to attach the bolt 1.
It is designed so that 0 cannot be omitted. With such a mechanism, the front support 6 can be moved only in the left-right direction in the drawing. The bracket 5 is bent at its end, and a restoring mechanism 8 is provided between the bracket 5 and the front support 6. The restoring mechanism 8 generates a stress proportional to the deformation like a spring. Therefore, the front support 6 is movable in the left-right direction in the drawing with respect to the bracket 5.

With such a mechanism, it is possible to freely move in the gap direction of the secondary side 2 fixed to the front support 6, so that the above-mentioned secondary side sliding mechanism can be easily realized.

FIG. 4 is a cross-sectional view of an embodiment of the elevator application of the present invention.

This drawing is obtained by adding a counterweight portion to the embodiment of the linear motor shown in FIG. 1, and is an example of a linear motor elevator in which the linear motor is provided on the counterweight. Only the parts different from FIG. 1 will be described below.

The counterweight frames 12 are provided on the left and right sides of the primary side, and the guide rollers 13 running on the guide rails 14 are provided on the left and right sides of the counterweight frame 12. There are three guide rollers 13 at one location, each of which travels on three traveling surfaces of the guide rail, and the counterweight 12 is guided by these. Further, as described above, the gap between the primary side and the secondary side of the linear motor is optimally maintained by the restoring mechanism 8 and the roller 4.

According to the present embodiment, the gap can be maintained with high accuracy without increasing the accuracy of the structure, so that a simple and high-performance linear motor can be incorporated into the counterweight as a drive source for the elevator, and high performance can be achieved. It is possible to inexpensively obtain a rope type elevator driven by a linear motor.

In this embodiment, the structure in which the linear motor is incorporated in the counterweight is shown, but the linear motor may be incorporated in the elevator car.

In the above embodiment, the linear motor is a linear induction motor, but a linear synchronous motor,
Even in a system other than an induction motor such as a linear DC motor, if a double-sided structure is provided, the same effect can be obtained by providing a similar gap holding mechanism.

Further, in the above embodiments, the gap holding mechanism of the double-sided linear motor in which the primary side is surrounded by the secondary side is shown, but the gap holding mechanism in the double-sided linear motor in which the secondary side is surrounded by the primary side has the same structure. It is possible to obtain and obtain the same effect.

[0034]

According to the present invention, a double-sided linear motor having a secondary side, which is longer than the primary side, on the outside and the primary side moves, the primary side can move smoothly, and the accuracy of the structure does not need to be improved so much. Since the gap can be maintained with high precision, a high-performance linear motor can be easily obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a side view of the embodiment of the present invention.

FIG. 3 is a sectional view of the restoring mechanism according to the embodiment of the present invention.

FIG. 4 is a sectional view of an embodiment in which the present invention is applied to an elevator.

[Explanation of symbols]

1 ... Primary side, 2 ... Secondary side, 3 ... Motor frame, 4 ... Roller,
5 ... Bracket, 6 ... Front support, 7 ... Rear support.

Claims (11)

[Claims] 1. A linear motor that comprises a stator and a mover, holds a gap between the stator and the mover, and linearly moves the mover. A gap holding mechanism for a linear motor, wherein the gap holding mechanism is movable in a direction in which the length of the gap is changed. 2. The gap holding mechanism for a linear motor according to claim 1, wherein the gap has two surfaces, and the two gap surfaces are arranged at positions where the directions of the attraction forces generated mutually are opposite to each other. 3. The gap holding mechanism for a linear motor according to claim 2, wherein the mover is shorter than the stator. 4. A gap holding mechanism for a linear motor according to claim 3, wherein said stator is arranged outside and said mover is arranged inside thereof. 5. The gap holding mechanism for a linear motor according to claim 4, wherein the movable element is provided with a primary side for feeding power. 6. A stator and a mover shorter than the stator, wherein there are two sets of the stator sandwiching the mover, and the two gap surfaces are formed between the stator and the mover. In the linear motor that moves the mover in a straight line, the direction of the attraction force is opposite, and at least one set of the stator is movable in the direction that changes the gap length, and the mover is guided to the mover. And a gap maintaining mechanism for the linear motor, which has a guide mechanism for keeping a distance from the stator so as not to become a predetermined gap length or less, and a restoring mechanism for returning the stator to a predetermined position. . 7. The stator according to claim 6, wherein the stator movable in a direction of changing the gap length is provided with a guide mechanism by a suction force between the stator and the movable element near the movable element. It comes close to contact and returns to a predetermined position by the restoring mechanism except near the face facing the mover,
The predetermined position is outside the outer edge of the guide mechanism, and is the gap holding mechanism of the linear motor. 8. A stator and a mover shorter than the stator, wherein there are two sets of the stator sandwiching the mover, and the two gaps are formed between the stator and the mover. In the linear motor that moves the mover in a straight line, the direction of the attraction force is opposite, and at least one set of the stator is movable in the direction that changes the gap length, and the mover is guided to the mover. And has a guide mechanism that keeps a distance from the stator so that the gap length does not become a predetermined gap length or less, and the stator in the portion facing the mover is guided by a suction force between the mover and the guide mechanism. A gap holding mechanism for a linear motor, which is characterized in that it comes close to the contact with and keeps that position. 9. A stator and a mover shorter than the stator, wherein there are two sets of the stator sandwiching the mover, and the two gap surfaces are formed between the stator and the mover. In the linear motor that moves the mover in a straight line in the opposite direction of the attraction force, at least one set of the stator is movable in the direction of changing the gap length, The distance between the stators on both sides of the facing portion is equal to the sum of the thickness and the gap length of the mover, and the distance between the stators on both sides of the portion not facing the mover is A gap holding mechanism for a linear motor, characterized in that it is larger than the total thickness of the mover and the gap length. 10. The core according to claim 5, 6, 7, 8 or 9, wherein the primary side comprises a core and a plurality of coils, and the coils are quadrilaterals having two long sides and two short sides. A gap holding mechanism for a linear motor, wherein the coil is arranged on the core so that each of the two long sides is located on each of the gap surfaces. 11. A linear motor in which a balance weight and a car are connected by a rope, a mover of the linear motor is provided on the balance weight, and a stator of the linear motor is provided on the hoistway side, and the car is moved up and down by the linear motor. In the drive rope type elevator,
A linear motor that has a guide mechanism that holds a gap between the stator and the mover of the linear motor, and that moves the mover in a straight line, in a direction in which the stator changes the gap length. A linear motor driven rope type elevator characterized by being movable.