JPS63148857A - Dc linear motor - Google Patents

Abstract

PURPOSE:To improve the thrust force of a movable element and to eliminate a frictional load of a stator and the element due to its attracting force by providing a magnetic field generating auxiliary coil together with a permanent magnet at the element oppositely to the magnet, and forming the stator of a nonmagnetic material. CONSTITUTION:An auxiliary coil 1 is disposed continuously along a longitudinal direction on the surface of a yoke 68 opposed face-to-face to a permanent magnet 62 to be secured. When a current of a direction of an arrow flows in the coil 1, a magnetic path designated by an arrow is formed between the adjacent coil 1 and the yoke 68. Since it passes the same magnetic path as that of a magnetic flux generated from the magnet 62, a magnetic flux which passes an air gap between the coil 1 and a stator bracket 65 becomes the sum of both. Since a thrust force is proportional to a magnetic flux density, it further increases. Since the stator is formed of a nonmagnetic material, it will not be attracted by the movable element. This eliminates the variation in the motor characteristics due to the deformation of the stator and no frictional load appears. Accordingly, the wear of a slide section, such as rollers, bearings due to the frictional load can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a DC linear motor, and particularly to the structure of a DC IJ linear motor that can be expected to reduce frictional load and improve thrust.

(Prior Art) FIG. 4 is a schematic configuration diagram showing a conventional DCIJ near motor. In the figure, reference numeral 41 denotes a mover yoke, and a permanent magnet 42, which will be described later and is not made of a soft magnetic material and is polarized and magnetized in the longitudinal direction, is fixed to the center of the lower surface of the mover yoke 41.
Bearing portions 416, which will be described later, are fixed to the four corners on both sides of the slider yoke 41, and rollers 43, which will be described later, are fixed to the bearing portions 46.
It has a structure in which it can be rotated freely. 43 is a roller, 44 is a coil, and the coil 4.1 faces the permanent magnet 42 and is fixed to the center of the upper surface of a stator yoke 15, which will be described later. Reference numeral 45 denotes a stator yoke, which has an elongated shape and has a groove or stepped guide for guiding the roller 43. 46 is a bearing section.

Next, the operation of the conventional D CIJ near motor shown in Fig. 4 will be explained, based on Figs. 5 (a) and (b), which show only the main parts in Fig. 4 to simplify the explanation. Let me explain.

As shown in FIGS. 5(a) and 5(bl), the coil 44 is located at position 1 in the magnetic field generated by the permanent magnet 42, so when a current is passed through the coil 44, the energized coil 44 will move to Fleming's left hand. A current force according to the law works.However, since each coil 44 is fixed to the stator yoke 45,
A thrust acts as a reaction force on the permanent magnet 42, which causes the υ mover yoke 41 to move linearly in the direction of the arrow in FIG. By passing a current through a predetermined coil 44 while detecting the detection, the mover yoke 41 and the permanent magnet 42 can be moved to an arbitrary position.

However, in the conventional DC linear motor shown in FIGS. 4 and 5(a) and (b), the magnetic flux of the permanent magnet 42 passes through the stator yoke 45, that is, the stator yoke 45 is part of the magnetic path. The permanent magnet 42 and the stator yoke 4
An attractive force acts between the two.

As a result, a large frictional load is generated between the roller 13 and the bearing portion 46, and there is a drawback that the sliding portions such as the 90-ra 43 with reduced thrust are worn out.

Therefore, in order to solve these drawbacks, the present applicant has proposed a DCIJ near motor shown in Japanese Unexamined Patent Publication No. 59-67864. Another conventional example will be described below based on the drawings.

FIG. 6 is a side sectional view showing another conventional DCIJ near motor. In the figure, reference numeral 61 denotes a mover yoke, in which a permanent magnet 62, which will be described later and polarized in the longitudinal direction, is fixed to the center of the upper surface of the inner part of the mover yoke 61, and a bearing portion 66, which will be described later, is attached to the mover yoke. 61, and a roller 63, which will be described later, is rotatably attached to this bearing portion 66. 62 is a permanent magnet, 63 is a roller,
A coil 64 is arranged to face the permanent magnet 62 and is fixed to a stator bracket 65 described below. Reference numeral 65 denotes a stator bracket, which is fixed to a side frame (not shown) at both longitudinal ends (both ends in the front-rear direction with respect to the plane of the paper). 66 is a bearing portion, 67 is a pace plate made of a non-magnetic material, and 68 is a yoke.

In the DC linear motor having the above structure, since the stator side does not contain any magnetic material, the magnetic flux generated from the permanent magnet 62 is distributed between the movable yoke 61 and between the movable yoke 61 and the coil 64. Since it passes through the magnetic path formed by the gap, no attractive force is generated between the mover yoke 61 and the stator bracket 65, and a large frictional load is generated between the bearing and the rollers as in the conventional example described above. do not.

(Problems to be Solved by the Invention) However, in the conventional structure described above, as shown in FIG. 5(b) and FIG. There was a problem in that the magnetic flux density was low and the thrust was reduced.

The present invention is intended to solve this problem, and an object of the present invention is to provide a DC linear motor that has a small frictional load and can obtain a large thrust.

(Means for Solving the Problems) In order to solve the above problems, the present invention comprises a polarized permanent magnet and a roller for smooth linear motion, each of which is attached to a predetermined position. A mover formed by combining a first yoke and a second yoke having a first electromagnet fixed to a surface facing the permanent magnet with a space facing the permanent magnet; A stator bracket is provided in the gap between the first electromagnet and the second electromagnet, and a second electromagnet is fixed to the surface facing the permanent magnet.

(Function) According to the present invention having the above configuration, the stator bracket is made of a non-magnetic material, thereby eliminating the attractive force between the permanent magnet of the mover and the stator bracket.

Furthermore, by fixing the first electromagnet to the surface of the second yoke forming the mover that faces the permanent magnet, the thrust between the mover and the stator bracket can be improved.

Therefore, the present invention can solve the above-mentioned problems, and can provide a DC linear motor that can reduce frictional load and provide a large thrust.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1(a) is an exploded perspective view showing each component of an embodiment of the present invention, FIG. 1(b) is a front sectional view of the D CIJ near motor of this embodiment, and FIG. It is a side sectional view of the DC linear motor of an example. Figure 1 (a), (b)
) and (e), the same reference numbers as in FIG. 6 indicate the same components. As a different component, ``■'' is an auxiliary coil, which is arranged and fixed in a continuous manner in the longitudinal direction on the surface of the yoke 68 facing the permanent magnet 62. Also,
The shape of the core portion (not shown) of the auxiliary coil 1 is a rectangular shape as shown for ease of manufacture, but the shape is not limited to this. Furthermore, the coil wire wound around this auxiliary coil 1 may consist of one or more coil wires, and it is sufficient that they are wound in the direction of current flow as shown in FIG. 2, which will be described later. Further, as shown in FIG. 1C, a predetermined air gap is also provided between the auxiliary coil 1 and the stator bracket 65, so that a constant air gap is always present.

Although not shown, as means for feeding power to the auxiliary coil 1, a power feeding circuit may be provided in the mover yoke 61, or power may be fed through a connecting cable. FIG. 2(a) is a plan view of the yoke 68, and FIG. 2(a) is a front sectional view of the yoke 68.
b) As shown in Figure 2 (al), when a current is passed in the direction of the arrow in the coil wire wound around the core (not shown) of the auxiliary coil l, the adjacent A magnetic path indicated by an arrow is formed between the auxiliary coil 1 and the yoke 68.

Furthermore, as shown in FIG. 3, since the magnetic flux passes through the same magnetic path as the magnetic flux generated from the permanent magnet 62, the magnetic flux penetrating the air gap is the sum of both. On the other hand, the thrust force is proportional to the magnetic flux density, so it becomes even larger. Here, the operating principle of the linear motor is the same as the conventional one, so a description thereof will be omitted. Furthermore, in this example, since the stator side does not contain any magnetic material, there is no attractive force between the mover side and the stator side, so there is no change in motor characteristics due to deformation of the stator, and there is no frictional load. Therefore, there is no wear on sliding parts such as rollers and bearings due to frictional loads.

(Effects of the Invention) As explained above, according to the present invention, the auxiliary coil for generating a magnetic field is provided in the mover together with the permanent magnet so as to face the permanent magnet, and the stator does not contain any magnetic material. By doing so, the thrust of the mover can be improved. Furthermore, since there is no suction person between the stator and the movable element, it is possible to eliminate frictional load due to suction force and wear on the sliding parts.

Further, the DC linear motor according to the present invention can be driven with minimum power consumption by changing the ratio of current flowing through the auxiliary coil and the stator coil depending on the load.

[Brief explanation of the drawing]

FIG. 1(a) is an exploded perspective view showing each component of an embodiment of the present invention, FIG. 1(b) is a front sectional view of the D CIJ near motor of this embodiment, and FIG. 1(c) is a main 2(a) is a plan view of the yoke in this embodiment, FIG. 2(b) is a front sectional view of the yoke in this embodiment, and FIG. 3 is a side sectional view of the DC linear motor in this embodiment. A diagram showing the state of the magnetic path in this example,
FIG. 4(a) is a schematic perspective view showing a conventional D CIJ near motor, FIG. 4(b) is a side sectional view showing a conventional D CIJ near motor, and FIG.
FIG. 6 is a front cross-sectional view showing the schematic configuration of D of another conventional example.
FIG. 3 is a side sectional view showing a CIJ near motor. 1... Auxiliary coil, 41.61... Mover yoke,
42.62...Permanent magnet, 43.63...Roller,
44.64... Coil, 45... Stator yoke, 4
6゜66...Bearing part, 65...Stator bracket,
67...Base Great, 68...York.

Claims (1)

[Claims] A first yoke comprising a polarized permanent magnet and a roller for smooth linear motion, each attached to a predetermined position, and a space provided in a plane facing the permanent magnet. a second electromagnet having a first electromagnet fixed to a surface facing the permanent magnet;
a mover made of a non-magnetic material, which is provided in the gap between the permanent magnet and the first electromagnet, and has a second electromagnet fixed to a surface facing the permanent magnet. A DC linear motor comprising a long stator bracket.