JPH0445428Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a permanent magnet linear pulse motor, in particular, in which the mover is located below the stator and moves while being attracted upwardly toward the stator. Regarding permanent magnet linear motors.

(Prior Art) FIGS. 7 and 8 are a longitudinal sectional view and a side view of a conventional permanent magnet linear motor. Stator 10
has a series of teeth on its underside and is elongated in shape with a constant width. The mover 11 has a pair of cores 4a and 4b, and teeth are provided on the upper surfaces of the four magnetic poles, and drive coils 8a, 8b, 8c, and 8d are wound thereon. Permanent magnets 5a and 5b are provided in contact with the lower surfaces of the cores 4a and 4b, and magnetically coupled with these cores, and a magnetic path plate 8 is provided on the lower surface of the permanent magnets 5a and 5b. Further, auxiliary plates 14 are fixed to both sides of the cores 4a and 4b, and a bearing 13 is interposed between these auxiliary plates 14 and the stator 10. A gap G1 is maintained. As is well known, the linear motor having this type of structure moves by a constant pitch by applying positive and negative pulse signals to the drive coils 8a to 8d at appropriate times.

However, this conventional linear pulse motor has the following drawbacks because the gap G1 between the stator 10 and the mover 11 is maintained by the bearing 13.

(1) Both ends of the slider 11 in the front and back direction are connected to the bearing 1
3, the stator 10 is bent due to the strong suction force between the stator 10 and the gap G1.
is no longer constant. As a result, the upper surfaces of the cores 4a and 4b of the stator 10 and the mover 11 may come into contact with each other.

(2) Due to the strong attraction between the stator 10 and the mover 11, the life of the bearing 13 is shortened.
Furthermore, the stator 10 wears out more.

(3) When using this linear pulse motor as an actuator for OA equipment, use an expensive wear-resistant material for the stator 10 in order to avoid generation of iron powder etc. due to wear of the stator 10 by bearings. Alternatively, it is necessary to apply abrasion-resistant plating, which is one reason for the high price.

(Problems to be solved by the invention) The purpose of the invention is to create a structure between the stator and the mover without bending the stator, without causing wear on the stator, and without generating iron particles due to wear. An object of the present invention is to provide a permanent magnet type linear pulse motor that can maintain a constant air gap.

(Means for solving the problem) The stator has raceway plates made of magnetic material on both sides thereof, which extend in the length direction facing both sides of the mover, and have grooves in the length direction inside the race plates. The mover is provided with a first pole protruding toward the raceway plate on both sides of each of the pair of cores and having a coil wound thereon, and the above-mentioned grooves are provided on both sides of the magnetic path plate toward the raceway plate. A second pole protruding into the core and having a coil wound thereon is provided so that a portion of the magnetic flux of the permanent magnet is transferred to the core, the first pole, and the first pole.
a first air gap between the pole of the raceway plate and the raceway plate, a second air gap between the lower sidewall of the raceway plate groove and the lower surface of the second pole, and a magnetic path through the magnetic path plate and back to the permanent magnet. do.

(Function) A part of the magnetic flux of the permanent magnet is transferred to the core of the mover, the first
pole, a first air gap between the first pole and the raceway plate, a raceway plate of the stator, a second air gap between the lower side wall of the groove of the raceway plate and the lower surface of the second pole, and again the magnetic field of the mover. It passes through the road plate and returns to the permanent magnet. For this reason,
In the first gap, a suction force is generated that attracts the slider toward the raceway plate, and in the second gap, a suction force that pulls the slider downward is generated.

(Example) An example will be described with reference to FIGS. 1 to 4.
The linear motor of the present invention uses magnetic means without mechanical contact, whereas conventional ones use bearings with mechanical contact to maintain the air gap between the stator and mover. They differ in some respects. For this purpose, as shown in FIG. 1, the stator 1 is equipped with raceway plates 3 made of magnetic material on both sides of the part where the series of teeth are formed, facing both sides of the mover 2. A groove 15 having a U-shaped cross section is provided in the lower part. In addition, the mover 2 includes on both sides of each core 4a, 4b.
A pole 7 protruding toward the raceway plate 3 is provided, and a coil 16 is wound around the pole 7. On both sides of the magnetic path plate 6 in contact with the lower surface of the permanent magnet 5, poles 8 protruding into the grooves 15 toward the track plate 3 are provided, and a coil 17 is wound around the poles 8. As a result, a part of the magnetic flux of the permanent magnet 5 is transferred to the core 4, the pole 7, the gap G2 between the pole 7 and the raceway plate 3, the raceway plate 3, and the groove 1 of the raceway plate 3, as shown by the dotted line in the figure. A magnetic path is created from the air gap G3 between the lower side wall of the pole 8 and the pole 8, the pole 8, and the magnetic path plate 6 back to the permanent magnet 5. For this purpose, the air gap G2
In this case, a suction force that attracts the moving element 2 toward the track plate 3 is generated, and in the gap G3, an attractive force F3 that attracts the moving element 2 downward is generated. This suction force F
3 is opposite in direction to the attraction force F1 occurring in the gap G1 between the stator 1 and the mover 2, and as a result, the resultant attraction force to the stator 1 acting on the mover 2 is F0 =F1-3, which works to reduce the suction force F1. Ideally, F0=M・g(M
The attraction force of the gaps G3 and G2 is predetermined by the width of the gaps so that G is the mass of the moving element, and g is the gravitational acceleration, and is adjusted by the excitation currents of the coils 17 and 16. In addition, the unbalance of the attraction force F0 between the front and rear, left and right sides of the slider 2 can be adjusted by the excitation current of the four coils 17 (Fig. 3) on both sides of the magnetic path plate 6, and the front and rear of the magnetic path plate 6. The retention of the air gap G2 on the side of the child 2 can also be adjusted by the excitation current of each coil 16. A well-known gap sensor that detects these gaps is used to adjust the excitation currents of the coils 16 and 17 to maintain these gaps G2 and G3. FIG. 2 is a top view with the stator 1 removed to show the mutual relationship between the poles 7 on both sides of the cores 4a and 4b, the air gap G3, and the raceway plate 3, and FIG. 3 shows the magnetic path. This is a top view with the cores 4a and 4b removed to show the poles 8 on both sides of the plate 6. Moreover, FIG. 4 is a front view of the mover 2 with the track plate 3 removed.

5 and 6 show another embodiment of the present invention, in which poles 7a, 7b, 7c, and 7d are provided on both sides of the cores 4a and 4b of the mover 2, and the two poles on one side are For example, by creating a magnetic path in the horizontal plane of the magnetic flux shown by the dotted line in FIG. 5 using 7a and 7c, the attractive force of the air gap G2a is increased, and the air gap on the sides of the mover 2 is more securely maintained. In this case, the direction of the magnetic flux passing through the pole 7c is opposite to the direction of the magnetic flux in the vertical plane from the permanent magnet 5a, and a part of it is canceled out, but the excitation current of the coils 16a and 16c is adjusted. By doing so, the desired suction force can be obtained.

(Effect) Magnetism between the poles on both sides of the core and the stator raceway plate by forming a magnetic path for part of the magnetic flux of the permanent magnet without using a bearing to maintain the air gap between the stator and the mover. generating an attractive force and a downward magnetic attractive force between the poles on both sides of the magnetic path plate and the side walls of the raceway plate groove,
Since the magnetic attraction force and the predetermined balance between the stator and the mover are obtained, the stator does not bend and there is no mechanical wear on the stator.
No iron powder or the like is generated due to wear, and the gap between the stator and mover can be maintained constant.

[Brief explanation of the drawing]

Fig. 1 is a side view of an embodiment of the permanent magnet linear pulse motor of the present invention, Fig. 2 is a plan view of the linear pulse motor of Fig. 1 with the stator body removed, and Fig. 3 is a side view of an embodiment of the permanent magnet linear pulse motor of the present invention. The plan view of the section, Figure 4, is
A front view with the raceway plate removed, FIGS. 5 and 6 are a plan view of another embodiment of the present invention with the stator main body removed and a front view with the raceway plate removed, and FIGS. 7 and 8 are FIG. 2 is a front view and a side view of a conventional permanent magnet linear pulse motor. In the figure, 1...stator, 2...mover, 3
... Raceway plate, 4a, 4b ... Core, 5 ... Permanent magnet, 6 ... Magnetic path plate, 7 ... Pole, 8 ... Pole, 15 ... Groove, G1, G2, G3 ... Gap.

Claims (1)

[Claims for Utility Model Registration] An elongated stator of constant width with a series of teeth on the lower surface, a pair of cores with a drive coil on each magnetic pole, a permanent magnet that magnetically couples the pair of cores, and the permanent magnet. In a permanent magnet type linear motor, the stator has a magnetic path plate located on the lower surface of the magnet and a mover that moves while being attracted upwardly toward the stator. The slider includes a raceway plate made of a magnetic material that extends in the length direction facing the surface and has grooves in the length direction inside the raceway plate. It has a first pole that protrudes toward the track plate and is wound with a coil, and has second poles that protrude toward the raceway plate and into the groove on both sides of the magnetic path plate and are wound with a coil. A part of the magnetic flux of the permanent magnet is distributed to the core, the first pole,
a first gap between the first pole and the raceway plate, a second gap between the raceway plate, the lower side wall of the groove of the raceway plate and the lower surface of the second pole, and the magnetic path plate. A magnetic path returning to the permanent magnet is formed, an attractive force that attracts the moving element laterally is generated in the first gap, and an attractive force that attracts the moving element downward is generated in the second gap. A force is generated, and the sizes of the first air gap and the second air gap adjust the excitation current of the coil wound around the first pole and the coil wound around the second pole, respectively. A permanent magnet type linear motor characterized by being held in a predetermined gap by the following.