JPS61147768A - Gap setting method of linear pulse motor - Google Patents

Abstract

PURPOSE:To maintain a gap small and reliable with a simple structure by forming rolling surfaces in the same plane as the ends of stator and movable element teeth, and interposing a stylus roll having a diameter equal to a gap size therebetween. CONSTITUTION:Teeth 18 are formed on a core 50, a coil 11 is wound to form the teeth of a stator 13, and a stationary magnetic circuit 12 is formed of the core 50 and a permanent magnet 52 and a yoke 63. The structure is contained in an engaging hole 70 of a nonmagnetic frame 17. A movable element 14 is formed by bonding a scale 19 opened with a slender hole 60 longitudinally of a base 20 in parallel to the lower surface of the base 30. The element 14 is inserted between the stators 13 by inserting-shaped retainer 26. In this case, a nonmagnetic and hard horizontal stylus roll 22 is provided in the horizontal slit hole of the retainer 26. Thus, the element 14 is readily slid by rolling the roll 22 and holding the prescribed gap.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a linear pulse motor, and particularly to a method for setting and maintaining a minute gap between the magnetic pole faces of a mover and a stator.

BACKGROUND ART Among electrical components that have been rapidly attracting attention in recent years, there is a linear pulse motor (also known as a sidewalk drive device, hereinafter abbreviated as LPM). This is being widely applied, for example, to transport a carriage in a printer or to access a head in a 70-point disc. For ease of understanding, an LPM for printers will be illustrated. As shown in FIG.
It performs parallel motion. However, 31 is paper, 40
is a type wheel, and 32 is an ink ribbon.

The LPM, which carries this carriage 30 and performs linear motion at a predetermined step amount, has a structure as shown in FIG. The coils are wound in series, and although their lead wires are not shown, they are distributed to the left and right sides of the movable element 1, and by applying positive and negative pulse signals to each, the well-known It operates based on the principle of 'Noya'. Note that 51 is a permanent magnet, 5 is a roller for supporting the movable element, and 28 is a tooth of the stator 3. In addition, ￥J6 figures (a), (b)
As shown in the figure, the permanent magnets 52 are connected to the two cores 50a.

There are also types that are included in the 50b. Mover 1
is adapted to move in the direction of arrow B over the stator 3 by a predetermined step amount. By the way, Figure 5(b) shows this L.
A front view of the PM, shown in Figure 5 (a) and Figure 5 (b) above.
This figure shows cross sections A and A' of .

This figure 5 (a), (bJ or figure 6 (a),
The mover 1 of the LPM shown in (b) has a first
The carriage 30 shown in the figure is mounted and moved, and printing is performed on the paper 31 by pressing the type against the platen 33 via the ribbon 32 and the paper 31 by an impact mechanism (not shown).

In such LPMs for printers, the stroke (movement amount) of the movable element is quite large. On the other hand, in an LPM for head access of a 70-twee disk, the stroke does not need to be very large, and may be, for example, about 1/4 of the length of the mover. And the L of the present invention
The PM is rather of the type suitable for head access on this latter 70-tip disk.

[Conventional technology]

The magnet shown in FIGS. 6(a) and 6(b) is of the type in which the permanent magnet is divided into two cores as shown at 52, as described above.

By the way, in the LPM with this structure, the mover 1 and the stator 3
The smaller the gap g between the opposing magnetic pole faces 2.4, the larger the air gap permeance, which is advantageous because the thrust and holding force become larger. However, the magnetic pole face, various members for maintaining the gap, such as the roller 5. roller shaft 6
．． There is a limit to the miniaturization of the gap g due to the machining accuracy of the stator roller contact surface 7, etc., the presence of dust during LPM operation, the workability and cost of gap adjustment, etc., so the value of the gap g is, for example, The thickness is set to 50 to 100 μm.

[Problems to be Solved by the Invention] Conventionally, the gap holding members described above are manufactured with high precision, and the roller relative to the movable element 1 is adjusted by adjusting the amount of stepped finish polishing of the bearing surface 8 of the roller shaft 6. The value of the gap g was maintained at a predetermined value by setting the height of the shaft 6. However, adjustment by polishing requires a large number of man-hours and has the drawback that the accuracy of setting the gap g cannot be expected.

[Means for solving problems]

The present invention has been made in view of the above-mentioned drawbacks of the conventional art.
The purpose of this study is to provide a method for setting gaps.

The means for achieving this is to form rolling surfaces on the same plane as the tip surfaces of the stator teeth and movable teeth, and to sandwich needle rollers having a diameter equal to the gap size between the rolling surfaces. This is what realizes the settings.

[For production]

The above LPM adjusts the tooth gap between the stator and mover by adjusting the height of the roller and roller bearing surface.

Instead, a magnetic circuit unit, which will be described later, is fitted into a frame, and a plate-shaped retainer is installed between the magnetic pole surface of the stator exposed at the top of the magnetic circuit unit and the almost flat movable element. The needle rollers are inserted into the slits provided in the retainer, and the gaps between the teeth of the stator and mover are maintained by the needle rollers. It does not have the drawback that gap setting accuracy cannot be expected despite the man-hours required for polishing and the like, and the purpose can be achieved easily and inexpensively with a simple configuration.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but before doing so, it is important to keep in mind the following
PM is 1. in Figures 5 and 6. Contrary to PM, the stator is a grooved body consisting of a core coil, a permanent magnet, and a yoke.
The point is that the base and scale, which will be described later, are not movable. Even if the stator and mover are arranged upside down in this way, the function of the LPM is no different from the conventional one shown in Figures 5 and 6. As mentioned above, this is due to the short stroke of the LPM. This is advantageous because the mass of the mover can be made smaller. For ease of understanding, the configuration in Figure 1 will be explained below with reference to the assembly diagram in Figure 9J2.

That is! As shown in FIG. 1, the core 50 is provided with teeth 18, and a coil 11 is wound around each tooth 18. These teeth 18 become the teeth of the stator 13. And 2
Each pair of cores 50 is a permanent magnet 52.
Roughly two permanent magnets 52 are connected by a yoke 63 for forming a magnetic path through which the bias magnetic flux of the permanent magnets flows, thereby forming the stator magnetic circuit 12.

Such a core 50. Coil 11. A structure consisting of a permanent magnet 52 and a nine-yoke iron 63 (stator magnet circuit unit)
is housed in a fitting hole 70 shown in Figure 2 of a frame-shaped non-magnetic frame (for example, made of austenitic stainless steel) 17, and is secured from the circumference by screws 16a. At this time, the core 50 is assembled so that the tooth tip surfaces 18a of the teeth 18 provided on the core 50 are flush with the upper surface 17a of the frame 17. Or frame top surface 17B after assembly
Surface polishing may be performed so that the upper tooth tip surface 18a and the upper tooth tip surface 18a are flush with each other.

As shown in FIG. 2, part of the mover 14 is made by attaching a scale 19 with elongated holes parallel to each other in the longitudinal direction of the base 20 by, for example, etching, to the lower surface of the base 20 with adhesive. By forming the hole into a groove 60, the non-groove portion 62 becomes the tooth 62 of the movable element 14. Both sides 21 of the scale 19 forming a part of the mover 14, where the groove 60 is not provided, are connected to the frame 17 forming the stator 13.
are brought into opposing contact with the upper surfaces 17a of both sides. In this case, a non-magnetic plate (thickness A retainer (for example, 80 μm made of austenitic stainless steel) is inserted and arranged as the retainer 26. In each of the horizontal slit holes 22 & provided in parallel on both sides of the horizontal surface 73 of the retainer 26, a non-magnetic and hard horizontal needle roller 2 is provided.
2 (the diameter is, for example, 100 μm, the length is, for example, 10 mn1)
(7) Made of tungsten).

The sliding movement of the movable element in the direction of the small arrow is achieved by the rolling of the rollers 22. That is, both the top surface 17a of the frame 17 and the back surface 19a of the scale 19 serve as rolling surfaces of the same roller. Incidentally, the portion 70 between adjacent slit holes 22a in the retainer is for the purpose of maintaining the distance between the rollers at a predetermined value. Vertical slit holes 28B are also provided in the vertical portions 71 bent upward at right angles on both sides of the retainer 26, and M straight needle-shaped rollers 28, which are the same as those 22 described above, are respectively arranged in these holes.

The movable element 14 is guided in a straight line in the direction of the small arrow by a thick plate 24 and a plate spring 25, which are attached to the frame 17 forming the stator 18 with screws 16b. In this case, the vertical needle-like rollers 23 are sandwiched between the self-registering plate 24 and the leaf spring 25 and act as a rolling element in contact with both side surfaces 20a of the stator ◎ A gap g between each tooth of the stator 13 and the movable element 14 It is desirable that the gap size is small, but the roller 2 that determines this gap size
If the diameter of the rollers 2 is small, for example, 50 μm or less, the rollers 22 tend to have a liquid shape, as is clear from the well-known Hertz theory, and the retainer 26 is also thin, so the rollers ride on the retainer 26. Such inconveniences may occur. To widen the gap to a predetermined value without reducing the thrust, and increase the roller diameter and retainer thickness by that amount, use the stator.

An effective method is to use a material with high saturation magnetic flux density as the material for both teeth of the mover. Scale 19 is normal LP
Pure iron is used in M, but experiments show that permendur (iron-cobalt alloy), which has a higher saturation magnetic flux density than pure iron, is used, and the thrust when the gap g is 150 μm is as follows. The results show that the thrust is almost the same as when the diameter is 100 μm.

FIG. 3 is a diagram showing a second embodiment of the present invention, and this is not significantly different from the configuration shown in FIG. 2 above.

However, this method involves filling a non-magnetic material (e.g., epoxy resin) between the grooves 18a between the stator teeth 18 and the core 50 shown in FIG. It is something. In this way, the tooth tip surface having the width shown as ``T'' in the gIJ8 figure becomes a 7-rat surface in the direction of the arrow. For this purpose, horizontal needle rollers 22 can be rolled on this magnetic pole surface. However, in that case, the horizontal slit holes 22 provided in the retainer 26 need to be arranged near the center of the retainer. Even with this configuration, the function of the LPM shown in the side view in Figure 1 does not change in any way, and the rolling width of the horizontal needle roller as a rolling member is only the width shown as D in the figure. So,
There is no need to provide the rolling width of the needle rollers on the upper surface 17a of the frame 17. Therefore, the width W of the base 20 and the width W of the frame can be reduced, which allows the LPM to be made smaller without impairing its functionality.

〔Effect of the invention〕

As explained above, according to the present invention, the conventional LPM
It is no longer necessary to take care in machining the useful polished part, such as machining the bearing surface of the roller as a rolling member, and manufacturing becomes easy. Therefore, it becomes possible to maintain the interdental gap with high precision at low cost, and a great practical effect can be expected.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the structure of a novel LPM according to the present invention, FIG. 2 is a sketch of its assembly, FIG. Figure 5 (a), (b), Figure 6 (a), (b)
) is a diagram showing the structure of a conventional LPM. In the drawings, 11 is a coil, 13 is a stator, 14 is a mover, 16 is a screw, 18 is a magnetic pole, 20 is a base, 22 is a horizontal needle roller, and 28 is a superimposed needle roller. figure

Claims (1)

[Claims] In a motor in which the main components of the stator are a magnetic circuit unit including a core, a coil wound around the core, and a permanent magnet as living bodies, and a movable element is horizontally linearly slid on the upper part of the stator, the magnetic circuit unit is fitted into the fitting hole of the frame-like frame, and fixed so that the upper surface of the core of the magnetic circuit unit is aligned with the upper surface of the frame to form a rolling surface, and a plate-shaped retainer is arranged on the rolling surface. Needle-shaped rollers as rolling members are arranged in slits provided at a predetermined interval in the retainer, and the gap between the stator and the movable element is maintained by the diameter of the rollers. Features: Gap setting method for linear pulse motors.