JPH077909A - Cylindrical type linear motor - Google Patents

Abstract

PURPOSE:To reduce magnetic leakage by making the line of magnetic force generated by an armature coil flow through a first core section consisting of a tabular magnetic bodies laminated in the stroke direction of a movable shaft and a secound core section composed of a tabular magnetic bodies laminated in the circumferential direction of the movable shaft. CONSTITUTION:Tabular magnetic bodies 27, which have circuit holes 23, through which magnetic shafts 13a, 13b can be passed, on the inside of an armature core 21 and in which the outsides are formed in the shape of an equilateral octagon 25, are laminated in the axial direction of movable shafts (PS) 13, thus forming a plurality of first core sections 29 in slots 31 at proper intervals. The first core sections 29 are brought into contact magnetically with each piece of the peripheries of the outsides of the first core sections 29, and the tabular magnetic substance 27 are laminated on the PSs 13 in the circumferential direction, thus forming second core sections 33. Armature coils 35 wound in a ring shape are inserted into the slots 31. That is, when ACs are made to flow through the armature coils 35, magnetic fields in dotted lines are generated. The magnetic fields are moved in the axial direction of the PSs 13, thus generating thrust in the azial direction by magnets mounted on the PSs 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive shaft for industrial robots, machine tools and the like, and more particularly to a drive motor which requires linear drive as well as rotary drive.

[0002]

2. Description of the Related Art Linear motors having various structures have been conventionally used in dedicated machines such as machine tools and shearing machines. For example, as a flat plate type linear motor, there is a permanent magnet type linear synchronous motor as shown in FIG.

This permanent magnet type linear synchronous motor 101
Are provided with permanent secondary magnets 5 on the upper surface of the secondary side frame 103 so that N and S poles alternate. Then, the primary side magnetic pole pieces 107a and 107b are fixed to the primary side frame 109 while maintaining a predetermined distance X on the permanent magnet 105.

The primary windings 107a and 107b are U,
The V and W three-phase windings 111 are provided, and the interval between the primary side magnetic pole pieces 107a and 107b is fixed to the primary side frame 109 with a predetermined phase. The primary frame 109 is connected to the machine side (not shown).

In the displacement shown in FIG. 11, the permanent magnet 105 is used.
The W-phase winding 111 of the primary-side magnetic pole pieces 107a and 107b is arranged above the S pole.

The flat plate type linear motor has the above-mentioned structure and cannot be used for a driving device which requires simultaneous rotation and linear movement.

FIG. 12 shows a cylindrical linear motor.
There is a linear induction motor as shown in. In this cylindrical linear motor, a primary iron core 123 is arranged around a rod 121 made of a rod-shaped conductor, and an appropriate slot 1 is provided in the iron core.
25, and the primary coil 127 is provided in the slot.

Since the primary iron core 123 of such a cylindrical linear motor is usually formed integrally, there arises a problem that the magnetic flux generated by the primary coil has a non-uniform flow direction or the magnetic flux leaks greatly. Occurs.

[0009]

As described above,
Conventionally used cylindrical linear motors have the problems that the leakage of magnetic lines of force is large, the temperature rises due to heat generation, and the efficiency is low.

The present invention has been made to solve such a problem.

[0011]

In order to solve the above problems, the present invention provides a mover having a radially magnetized ring-shaped permanent magnet mounted on a movable shaft, and a circular hole larger inside than the outer shape of the permanent magnet. A plurality of first core portions having outer side polygonal plate-like magnetic bodies stacked in the stroke direction of the mover, and plate-like magnetic bodies around the outer periphery of the first core part of the mover. An armature core composed of a second core portion laminated in the circumferential direction; an armature coil wound in a ring shape inserted into a slot provided between the first core portion and the first core portion; The armature coil is provided with a power supply for supplying a current.

[0012]

The magnetic flux of the magnetic field generated by the armature coil is a magnetic circuit composed of plate-shaped magnetic bodies along the flow direction thereof, that is, a first magnetic body composed of plate-shaped magnetic bodies laminated in the stroke direction of the movable shaft. A magnetic circuit composed of a core portion and a second core portion made of a plate-shaped magnetic body laminated in the circumferential direction of the movable shaft flows. Therefore, there is little magnetic leakage.
The magnetic field also acts circumferentially uniformly on the movable shaft, which is provided with the radially magnetized permanent magnets contained therein. Therefore, the movable shaft receives only the thrust in the stroke direction, and the suction force does not act in the rotation direction and in the vertical and horizontal directions.

[0013]

EXAMPLE A first example in which the present invention is applied to a drill will be described. In FIG. 6, a drill 1 is attached to a drill chuck 3, and the drill is axially driven by a linear motor 5 and rotationally driven by a rotary motor 7.
The linear motor 5 and the rotary motor 7 are connected by the connecting means 6. The connecting means 6 is composed of a linearly movable shaft provided with a rotatable means, for example, a spline shaft. Since the rotary motor 7 is of a known technique, its description is omitted below. In addition to the above, the present invention can be used as a drive motor that is attached to a robot arm and tightens nuts and bolts, or is provided in a dedicated machine tool and used as a drive motor for tap work. Hereinafter, the linear motor 5 will be described together with the present invention.

FIG. 1 is a sectional view showing the outline of the overall construction of the first embodiment of the present invention. In FIG. 1, a mover 11 is composed of magnets 13a, 1 having different ring-shaped magnetic poles as shown in FIG.
3b are arranged alternately on the movable shaft 13 in an even number. The magnets 13a and 13b are permanent magnets that are radially magnetized so that the outside has N poles or S poles, and the material thereof may be phyllite or any magnetic steel.

The armature core 21 is constructed as follows. That is, as shown in FIG.
A plate-shaped magnetic body 27 having a circular hole 23 through which a and 13b can pass and having a polygonal shape on the outside, for example, a regular octagon 25 is laminated in the axial direction of the movable shaft as shown in FIG. A plurality of 1-core portions 29 are formed with slots 31 at appropriate intervals, magnetically contacting each of the outer peripheral pieces, and a plate-like magnetic body is laminated on the shaft in the circumferential direction. The core part 33 is formed.

An armature coil 35 wound in a ring shape as shown in FIG. 4 is inserted into the slot 31 provided between the first core portion 29 and the first core portion 29. An AC power supply (not shown), for example, a three-phase AC power supply using a three-phase inverter is connected to the armature coil. Although not shown, a position detector for detecting the position of the mover 11 is provided at an appropriate position, and the detection data controls the three-phase inverter to control the current in the armature coil. You can also

Since the first embodiment is constructed as described above, it operates as follows. That is, the armature coil 3
When an alternating current is applied to 5, a magnetic field is generated as shown by the dotted line in FIG. Since this magnetic field moves in the axial direction of the movable shaft, the thrust provided in the axial direction is generated by the magnet provided on the movable shaft. Furthermore, since the armature core and the mover are provided symmetrically with respect to the axis center, the attraction force in the direction perpendicular to the axis is uniform, and there is no particular bias toward one side.
Also, no rotational force is generated. Therefore, by appropriately controlling the alternating current, the speed and the position of the movable shaft in the axial direction can be freely controlled, and the rotational direction can be externally controlled independently of the drive device.

The armature core according to the present invention is formed of a first core portion and a second core portion as shown in FIG.
Since each core portion is formed by laminating plate-shaped magnetic bodies in the direction of the flow of magnetic force lines generated by the armature coil, there is little leakage magnetic flux and magnetic resistance. Therefore, there is little energy loss and little heat generation.

FIG. 8 shows the configuration of the second embodiment of the present invention. This embodiment is almost the same as the above-mentioned first embodiment. Only the different points will be described below. The same parts are given the same numbers. In the first implementation,
As shown in FIG. 1, there is no first core portion stacked above the armature coil in the stroke direction of the mover, and when the outer diameter of the armature coil is small, a gap occurs, which is a problem. In this embodiment, a plate-shaped magnetic body having a polygonal shape in which the inner circular hole has a diameter larger than the inner diameter of the first core portion and the outer side has the same shape as the upper portion of the slot is used as shown in FIG. The third core portion 53 stacked in the stroke direction is provided outside the armature coil 51.

The present embodiment is constructed as described above, and an armature core with a small magnetic loss is constructed even when the outer diameter of the armature coil is small.

FIG. 10 shows a schematic configuration of the third embodiment of the present invention. In FIG. 10, the mover 51 includes a ring-shaped magnet 53 shown in FIG.
Are arranged. The magnet is magnetized radially, and the outside is the N pole in FIG. 10, but the outside may be the S pole.

The armature core 61 is constructed as follows. That is, a yoke core having a polygonal (octagonal in this embodiment) plate-like magnetic body on the inside has a hole into which the movable shaft can be inserted and is formed on both ends in the stroke direction. A laminated yoke portion 63 is provided, and at an appropriate position corresponding to the intermediate magnet, as shown in FIG. 11B, an inner hole having the same outer shape as that of the yoke core and an inner diameter of a diameter into which the magnet can be inserted is provided. A plurality of first core portions 65 in which plate-shaped magnetic bodies are laminated in the stroke direction are provided at appropriate spaces, and the outer shape is the same as that of the yoke and the inner shape is outside the spaces as shown in FIG. 11C. A plate-shaped magnetic body having circular holes whose diameter is larger than the inner diameter of the first core portion is laminated in the stroke direction to provide a third core portion, and further, a peripheral portion outside these laminated core portions is illustrated. 11 (F) a plate-shaped magnetic body Constituting the second core portion 69 are stacked in a circumferential direction of the movable shaft 53. The armature core 6
1 is a first core portion 65, a second core portion 67, a third core portion 69
And a yoke portion 69.

Armature coils 71a and 71b wound in a ring shape as shown in FIG. 11E are inserted into the slots formed by the first core portion 65 and the third core portion 69. Further, a DC power supply is connected to the armature coils 71a and 71b. A plurality of DC power supplies are used to reverse the directions of the currents in the left portion 71a and the right portion 71b of the coil, or the windings of the coils are reversed so that, for example, the directions of magnetic lines of force are opposite. To be configured. Further, the DC power source can be controlled by providing a position detector that detects the position of the mover. Since the third embodiment is configured as described above, by controlling the direct current, the shaft propulsion force in the stroke direction of the armature core 61 can be controlled, and the shaft position and the shaft speed can be controlled.

[0024]

As described above, according to the present invention,
It is possible to provide a practical cylindrical linear motor that generates a small amount of heat.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the overall configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a permanent magnet used in the first embodiment.

FIG. 3 is a diagram showing a shape of a core material of a first core portion of a permanent magnet used in the first embodiment.

FIG. 4 is a diagram showing an armature coil of a permanent magnet used in the first embodiment.

FIG. 5 is a view showing a cross section of an armature core of a permanent magnet used in the first embodiment.

FIG. 6 is a diagram showing a configuration of a first embodiment using the present invention.

FIG. 7 is a diagram showing a flow of lines of magnetic force generated by an armature coil.

FIG. 8 is a diagram showing an outline of the entire configuration of a second embodiment of the present invention.

FIG. 9 is a diagram showing a core material of a third core portion used in the second embodiment.

FIG. 10 is a diagram showing an outline of the entire configuration of a third embodiment of the present invention.

FIG. 11 is a diagram showing shapes of main components used in the third embodiment.

FIG. 12: 1 of a flat plate type linear motor used conventionally
It is a figure which shows an example.

FIG. 13 is a diagram showing an example of a conventionally known cylindrical linear motor.

[Explanation of symbols]

 5 linear motor 6 connecting means 7 rotary motor 11 mover 13 movable shaft 15, 15a, 15b permanent magnet 21,61 armature core 29,63 first core part 31,69 second core part 53 third core part 35,51 , 71a, 71b Armature coil

Claims (5)

[Claims] 1. A plate-shaped magnetic body having a ring-shaped permanent magnet magnetized radially and having an even number of poles attached to a movable shaft, and a circular hole larger than the outer shape of the permanent magnet on the inner side and having a polygonal shape on the outer side. A plurality of first core portions stacked in the stroke direction of the mover, and a second core portion formed by stacking plate-shaped magnetic bodies in the outer peripheral portion of the first core portion in the circumferential direction of the mover. An armature core, a slot provided between the first core portion and the first core portion, and a ring-shaped armature coil inserted into the slot; and an AC current flowing through the armature coil. A cylindrical linear motor characterized by being equipped with a power source. 2. The armature core further has a circular hole, the inner diameter of which is larger than the outer diameter of the armature core, in the radially outer portion of the slot, and the outer shape of which is the same as that of the plate-shaped magnetic body. The cylindrical linear motor according to claim 1, wherein plate-shaped magnetic bodies are laminated in the stroke direction of the mover to provide a third core portion. 3. A mover in which a single pole is attached to a shaft of a radially magnetized ring-shaped permanent magnet, and a plate-like magnetic body having a polygonal shape on the outside and a circular hole larger than the outer shape of the permanent magnet. An armature having at least a plurality of first core portions laminated in the stroke direction of the mover, and a second core portion having magnetic plates laminated in the circumferential direction of the mover on an outer peripheral portion of the first core portion. A core, at least two or more ring-shaped armature coils inserted in a slot provided between the first core portion and the first core portion, and a DC current flowing through the armature coil to form a shaft. A cylindrical linear motor characterized in that a power source for generating magnetic fields in opposite directions is provided on the right side and the left side in the direction. 4. The cylindrical linear motor according to claim 1, wherein the movable shaft is provided with a rotary drive device. 5. The cylindrical linear motor according to claim 1, wherein a position detector for detecting the position of the mover is provided and is used as a linear servo motor.