JPS631359A - Guide mechanism for linear motor - Google Patents

Abstract

PURPOSE:To prevent a roller from slipping out of place even if a movable element performs a reciprocating rectilinear motion a large number of times, by controlling a movement of a retainer in an engagement of a rack with a pinion. CONSTITUTION:A movable element 51 of a linear pulse motor performs a reciprocating rectilinear motion in both right and left directions by prescribed steps for one pulse. In this motion, the axis of a roller 67 and a retainer 69 move by one half of a travel of the movable element 51. In said case, the shaft 74 of a pinion 70 controls a position of the retainer 69 according to a movement of the movable element 51. Said position control of the retainer 69 makes the roller 67 be indirectly controlled in its position and prevented from slipping out of place.

Description

Detailed Description of the Invention [Summary] The present invention provides a linear motor in which a rolling element held in a retainer is sandwiched between the raceway surfaces of a movable element and a stator, and the movable element is moved in a reciprocating linear manner. The purpose of this system is to prevent the position of the rolling elements from shifting as the number of reciprocations increases.By forcibly setting the position of the retainer using the rack and pinion, the position of the rolling elements is indirectly regulated. We aim to achieve our goals by doing so.

[Industrial application field]

The present invention relates to a linear motor used for driving the head of a floppy disk, etc., and in particular, regarding a rolling element for supporting a movable element whose rotating shaft is not fixed to either a movable element or a stator, as the number of reciprocating linear movements of the movable element increases. The present invention relates to a guide mechanism that can prevent misalignment.

[Conventional technology]

FIG. 4 shows an example of a conventional linear valve mode. This linear pulse motor was previously applied for by the applicant (Japanese Unexamined Patent Publication No. 60-5585) for the purpose of reducing power consumption and downsizing.
Publication No. 2). In the figure, 1 is a mover, 2 is a stator, 3 is a permanent magnet, and 4 is an exciting coil.

The mover 1 is configured by bonding a scale 6 to a substrate 5,
The scale 6 has a large number of teeth 7 extending in the X direction and formed at equal intervals with pitches t in the Y direction perpendicular to the X direction. The teeth 7 are formed by making holes in the scale 6 by etching or the like.

The stator 2 has magnetic poles 8, outside of the permanent magnet 3 and the exciting coil 4.
9, 10, and 11. Each of these magnetic poles 8.9,
10.11, teeth 12 facing the teeth 7 of the scale through a predetermined gap are formed extending at the same pitch and in the same direction as the teeth 7, and the teeth 12 of the magnetic poles 8, 9.10 are formed as magnetic poles. 1
t/2, t/4, 3t/4 for each tooth 12
It has a phase difference of The movable element 1 of this linear pulse motor performs a reciprocating rectilinear movement in the Y direction at a step amount of t/4 per 1 pulse.

In this case, wheels (rolling bearings) 13, 14 are used for gap maintenance and linear guide as a guide mechanism for the mover 1.
is provided. Each wheel is rotatably supported by a shaft 15 fixed to the stator 2 and supports the lower surface of the scale 6.
A flange 16 provided on the carriage 14 plays a role of linearly guiding the movable element 1 by engaging with a groove 17 formed in the movable element 1 and extending in the Y direction.

However, in such a structure, the unit cost of the rolling bearing is high, making the linear pulse motor expensive.

Therefore, the linear pulse smoke shown in FIGS. 5 and 6 has been proposed which has a guide mechanism that eliminates this drawback. Fifth
The figure is an exploded perspective view, and FIG. 6 is a side view showing an assembled state. In the figure, 21 is a movable element, 22 is a stator, and 23 is a guide mechanism.

The movable element 21 is constructed by adhering a scale 25 to a substrate 24, and the scale 25 is provided with a large number of teeth 26 at equal intervals on a bifurcated surface. Teeth 26 are formed by etching scale 25.

The stator 22 also includes a non-magnetic frame 27, a permanent magnet 28, an excitation coil 29, and magnetic poles 30.31, 32.3.
3, linear guide board 34, and Niria guide spring plate 3
5. Magnetic poles 30, 31, 32.
33 is provided with teeth 36, and the teeth 36 of the magnetic poles 30, 31, and 32 are t/2 and t, respectively, with respect to the teeth 36 of the magnetic pole 33.
/4, and has a phase difference of 3t/4.

Further, the guide mechanism 23 includes rollers (rolling elements) 37 and 38,
A retainer 39 made of resin mold holds these rollers 37 and 38. The roller 37 is
The mover 2 is located on the upper surface (orbital surface) 40 of the frame 27.
The lower surface (orbital surface) 41 of the scale 25 of No. 1 is supported, thereby forming a predetermined gap between the end surfaces of the teeth 26 and the teeth 36. The roller 38 is engaged with a side surface 42 of the substrate 24 of the movable element 21, a linear guide substrate 34 fixed to the frame 27, and a linear guide spring plate 35, respectively.

The movable element 21 of this linear pulse motor performs a reciprocating rectilinear movement in a direction perpendicular to the plane of FIG. 6 at a step amount of t/4 per pulse. In this case, the axes of the rollers 37 and 38 and the retainer 39 move by 1/2 of the moving distance of the movable element 21. Such a mechanism is inexpensive and advantageous in applications where the stroke is relatively short compared to the size of the linear pulse motor, such as the head drive of a floppy disk.

(Problem to be solved by the invention) However, when rollers whose shafts are not fixed are used as the rolling elements of the guide mechanism, there are problems such as force applied to the rollers, vibrations of the rollers, and slight lifting of the rollers from the raceway surface. As the number of reciprocating linear movements of the mover increases, the position of the roller gradually shifts.As a result of the accumulation of this shift, when the mover advances to the end position of its stroke, the roller moves between the mover and the stator. If it comes off between the parts, the gas retainer and linear guide will no longer function.

[Means for solving problems]

The present invention provides a guide mechanism for a linear motor that can solve the above-mentioned problems.In the linear motor, a pinion rotatably supported by the retainer is provided, and the movable element and the stator A configuration in which racks that mesh with the pinion are respectively opposed to each other, or racks are provided to face each other on either the movable element or the stator and the retainer, and
A configuration is adopted in which a pinion that meshes with each rack is provided between each rack.

[Effect]

In any of the above configurations, the position of the retainer is always set according to the movement of the movable element due to the engagement of the rack and pinion. This indirectly regulates the position of the rolling elements,
The guide mechanism no longer loses its gap holding and linear guide functions as in the past.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

A first embodiment is shown in FIGS. 1 and 2.

Figure 1 is a front view showing the guide mechanism of the linear motor, Figure 2 is a front view showing the guide mechanism of the linear motor.
The figure is an exploded perspective view, and in the figure, 51 is a movable element, 52 is a stator, and 53 is a guide mechanism.

The movable element 51 and the stator 52 are substantially the same as the movable element 21 and the stator 22 shown in FIG.
6, 57 is a frame, 58 is a permanent magnet, 59 is an excitation coil, 60, 61, 62, 63 are teeth 66
64 is a linear guide board, and 65 is a linear guide spring plate.

The guide mechanism 53 includes rollers 67 and 68 (rolling elements),
It is composed of a resin molded retainer 69 that holds these rollers 67 and 68, a pinion 70, and racks 71 and 72. The pinion 70 is fixed to a shaft 74 that is rotatably supported in a groove 73 of the retainer 69, and the rack 71 and the rack 72 are attached to the lower surface of the notch 54a of the base plate 54 and the upper surface (raceway surface) 76 of the frame 57. It meshes with the pinion 70. Note that the scale 55 is provided with a notch 55a corresponding to the notch 54a.

The functions of the rollers 67 and 68 are similar to those shown in FIG. 5, and the lower surface 75 of the scale 55 is the raceway surface of the roller 67.

The movable element 51 of this linear pulse motor performs reciprocating rectilinear movement in the left-right direction in FIG. 1 at a step amount of t/4 per pulse. In this case, the shaft 74 of the pinion 70 regulates the position of the retainer 69 as the movable element 51 moves. By regulating the position of the retainer, the positions of the rollers 67 and 68 are indirectly regulated and displacement thereof is prevented. This slippage prevention effect was confirmed in an experiment in which the guide mechanism was used to reciprocate the entire stroke 3 million times.

Note that, unlike a normal displacement transmission mechanism, the pinion and rack in the guide mechanism of the present invention correct and suppress the shift when the roller starts to shift. Therefore. A large amount of meshing play is provided so that the rack and pinion mesh only when the rollers become misaligned, exerting a restraining force. As a result, an excessive frictional force does not act, and the tolerance range for manufacturing and assembling the rack and pinion is widened, resulting in a simple and inexpensive mechanism.

Further, as an application example of the above-mentioned linear pulse smoke, it is also possible to create a rack by drilling holes in the scale of the mover by etching or the like, and to create a rack by rolling or the like into the frame of the stator. In this case, the pinion will be sandwiched between the mover and the stator as shown in Figures 1 and 2, and the retainer will have a groove that rotatably supports the pinion shaft as shown in Figures 1 and 2. establish. In the case of this structure, manufacturing and gluing of the rack can be omitted compared to the structure shown in FIGS. 1.2, so that the cost can be reduced.

FIG. 3 shows a second embodiment.

FIG. 3 is a front view showing the guide mechanism of the linear motor. In the figure, 81 is a movable element, 82 is a stator, and 83 is a guide mechanism.

The movable element 81 includes a substrate 84 and a scale 85, and the scale 85 is provided with teeth formed by drilling and a rack 86, respectively. The rough hook 86 can be easily formed by etching or the like simultaneously with the formation of the teeth.

The stator 82 has the same configuration as in FIG.
7 is a frame, 88 is an exciting coil, 91 (89), 90
(92) are magnetic poles each having teeth.

The guide mechanism 83 includes a roller (rolling element) 93 and a roller (rolling element) not shown corresponding to the roller 568 in FIG.
, a resin molded retainer 94 that holds these rollers, and a pinion 95. Retainer 94
A rack 96 is formed, and the pinion 95 is connected to the rack 86.
It is sandwiched between and engaged with the rack 96. The lasso 96 can be made when forming the retainer 94 with a resin mold.

In the above explanation, the scale 85 is drilled and the rasok 86 is
Although an example in which a rack is formed has been described, a rack may also be formed on the stator 82 side by rolling or the like. In this case, the pinion will be sandwiched between the rack built into the retainer (formed on the side of the mover opposite to that in FIG. 3) and the rack of the stator.

In this example, the same effect as the previous example can be achieved,
Moreover, since the production and gluing of racks can be omitted, the cost is even lower.

that's all. Although the first and second embodiments have been described, in both cases, if two retainers are connected, only one set of rack and pinion is required, which further reduces the cost.

The present invention is applicable not only to linear pulse motors but also to linear motion mechanisms using rolling elements such as other types of linear motors and mechanical stages. [Effects of the Invention] As described above, according to the present invention, the movement of the retainer is regulated by the engagement of the rack and pinion, so the movement of the rollers is indirectly regulated, and the mover is prevented from making multiple reciprocating linear movements. Roller misalignment is prevented even if

[Brief explanation of the drawing]

Fig. 1 is a front view showing a guide mechanism of a linear motor according to a first embodiment of the present invention, Fig. 2 is an exploded perspective view of the same, and Fig. 3 is a guide mechanism of a linear motor according to a second embodiment of the present invention. 4 is a perspective view showing the structure of a conventional linear motor, FIG. 5 is an exploded perspective view showing the structure of another conventional linear motor, and FIG. 6 is a side view of the same. .81 is the mover, 52.82 is the stator, 53
．． 83 is a guide mechanism, 67.68.93 is a roller (rolling element), 69.94 is a retainer, 70.95 is a pinion,
? 1, 72.86.96 is a rack, and 75.76 is a raceway surface.

Claims (2)

[Claims] (1) Raceway surface (75) of mover (51) and stator (52)
, 76), the rolling elements (
A linear motor that moves the movable element (51) in a reciprocating and rectilinear motion by sandwiching the movable element (51) and the stator ( 52), a guide mechanism for a linear motor, characterized in that racks that mesh with the pinion (70) are provided facing each other. (2) A linear system in which a rolling element (93) held by a retainer (94) is sandwiched between the raceway surfaces of a movable element (81) and a stator (82), and the movable element (81) is moved in a reciprocating and linear manner. In the motor, racks are provided to face each other on either the movable element (81) or the stator (82) and the retainer (94), and a pinion () that meshes with each rack is provided between each of the racks. 9
5) A guide mechanism for a linear motor, characterized in that it is provided with the following.