JPS61196752A - Traveling device for linear actuator - Google Patents

Abstract

PURPOSE:To run a shifting member along the full length of a rod in a stable state, by applying a constant pressing force to static rod sides by bearing means provided on the shifting member. CONSTITUTION:A shifting member 15 is movably provided for a permanent magnet structure 11. The shifting member 15 is provided with a substrate section 16 and an upper plate 17, and the side walls of the substrate section 16 are provided with bearing means 21. The bearing means 21 are provided with bearings butted to rods 26, 27, and in this manner, a constant pressing force is applied to the rods 26, 27. When current is fed through motor coils, then a force moving the coil side works with the magnetic flux of the permanent magnet of the permanent magnet structure 11. In this manner, the shifting member 15 is travelled via the bearing means 21 along the rods 26, 27.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a feeding device for a linear actuator used, for example, as a head drive source of a disk drive device.

[Technical background of the invention and its problems]

Conventionally, as a transfer device for this type of linear actuator, there is known a device as shown in Patent Application Publication No. 59-501135.

That is, in this device, bearing means are provided on both sides of the transfer member to which a driving force is applied by a permanent magnet structure, and by bringing the bearing means into contact with a pair of guide rods arranged in parallel, the transfer member is attached to the guide rods. It is designed so that it runs along the same line. In this case, in order to maintain a stable contact state between the bearing means and the guide rod, one of the guide rods arranged in parallel is provided on the fixed rod so as to be able to pivot freely via an arm, and the corresponding bearing means is provided with a torsion spring. A predetermined pressing force is applied to the side. In other words, by pressing one guide rod against the corresponding bearing means, the contact state between them is stabilized, and at the same time, the contact state between the other guide rod and the bearing means is also stabilized, thereby stabilizing the traveling of the transfer member. I have to.

However, since the pressing force is applied to one of the guide rods only by the spring, it is difficult to apply a uniform pressing force over the entire length of the rod. This means that not only the contact condition between the guide rod and the bearing means differs depending on the location, but also the parallelism between both guide rods becomes unstable, causing uneven running conditions of the transfer member, which causes It cannot be used as a linear actuator for disk drives that require accurate head positioning.

Therefore, conventional methods have been considered in which the guide rod side is fixed and a bearing means provided on the transfer member side has a suppressing mechanism. That is, in this device, the guide rod is fixed, and a bearing body is provided at the tip of a leaf spring as a bearing means on the transfer member side, so that the contact state between the rod and the rod is stabilized.

However, since this device uses the deflection of the leaf spring as a pressing mechanism, it is easy for the direction of compression to not match the normal direction of compression required for the bearing means due to twisting of the leaf spring, etc. This had the disadvantage that it interfered with running and made it impossible to achieve stable running. In addition, since the bearing position must be determined accurately while the leaf spring is deformed, sufficient consideration must be given to the design of the leaf spring itself, which also poses a problem in terms of parts procurement.

[Purpose of the invention]

This invention was made to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a linear actuator traveling device that can stably travel a transfer member.

[Summary of the invention]

A traveling device for a linear actuator according to the present invention is provided with at least one pair of stationary rods arranged in parallel along the transfer direction of a transfer member having a transfer drive source, and provided with a predetermined bearing means on the transfer member side. A plurality of pairs of bearings are arranged to contact the rod at an angle, and at least one of the bearings is rotatably biased toward the other bearing about an axis along the transfer direction of the transfer member. A predetermined pressing force is always applied to the rod.

〔Effect of the invention〕

According to this invention, a constant pressing force can be applied to the stationary rod by the bearing means provided on the transfer member, so if the rods are made parallel, the transfer member can be run under the same conditions over the entire length of the rod. , it is possible to obtain stable running without unevenness in such a transfer member.

In addition, the bearing means that applies a pressing force to the rod is configured to rotate one bearing around the axis along the transfer direction of the transfer member and the other bearing side, so that the pressing force is It is possible to always match the normal pressing direction necessary for the bearing means, and in this respect as well, stable running of the transfer member can be achieved without any hindrance to the running of the transfer member.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example in which the present invention is applied to a linear actuator used as a head drive source of a disk drive device.

In the figure, reference numeral 11 denotes a permanent magnet structure, which consists of a flat E-shaped yoke 12 with pole pieces 122 and 123 arranged parallel to each other on the left and right positions of a central pole piece 121, as shown in FIG.
Permanent magnets 131 and 132 are provided on the sides facing the center pole piece 121 of the pole pieces 122 and 123 of this yoke 12, respectively.
has been established. Moreover, the pole piece 121 of such a yoke,
Attachment parts 141 and 142 to a base (not shown) are provided at the proximal and distal ends of the members 122 and 123, respectively. In this case, the mounting portion 142 constitutes a part of the yoke 12 and the yoke 1
2 is formed into a closed magnetic path with its open end closed.

A movable transfer member 15 is provided movably with respect to the permanent magnet structure 11. This transfer member 15 has a base portion 16 and a top plate 17 as shown in FIG.

Here, the base portion 16 has side walls 161 and 162 on both side edges, and these side walls 161 and 162 are connected to the notch 16, respectively.
It is divided into 3 parts at 3.

An inclination angle of 45° is provided at both ends of the outer surface of one side wall 161.
Tapered protrusions 161a and 161b of approximately 45 degrees are formed on the other side wall 162 (a tapered protrusion 162a with an inclination angle of approximately 45° is formed in the center of the outer surface of the other side wall 162). The housing 162b has a through hole in the axial direction along the side edge of the base body 16.

Furthermore, one end of the base body 16 is formed into a narrow part 165 via a step part 164, and an end wall 166 is formed at the edge of the narrow part 165. It protrudes horizontally.

Further, the base portion 16 has a groove portion 168 in the center of the plate surface for attaching the cylindrical motor coil 19, and also has a plurality of through holes 169 formed therein for weight reduction.

On the other hand, the upper plate 17 has side walls 1 of the base portion 16 on both side edges, respectively.
A pair of bearing parts 17 that form a plurality of protrusions 171 that are fitted into the notches 163 of 61 and 162 and that face each other.
2,172 stands upright.

Such a transfer member 15 is connected to the base portion 1 as shown in FIG.
Between the side walls 161 and 162 of 6, the above-mentioned permanent magnet structure 1
In this state, the center pole piece 121 of the yoke 12 is inserted into the hollow part of the cylindrical motor coil 19, and the upper plate 17 is attached to the tip of the wall 166, and the protruding part 171 of this is attached to the side wall 161, 162. It fits into each notch 163 and is assembled integrally.

By doing this, the transfer member 15 can be moved between the base portion 16 and the upper plate 1.
7ζ forms a box-shaped structure, and in this state motor coil 1
9 causes the permanent magnet structure 11 to be driven straight along the central pole piece 121 of the yoke 12. In this case, the movement range of the transfer member 15, that is, the operating stroke, is regulated by the front end of the base body 16 and the stepped portion 164.

The transfer member 15 has a pad portion 20 provided on the upper surface of the upper plate 17. This pad portion 20 is connected to the upper plate 1 as shown in FIG.
An arm 203 rotatably supports a shaft 201 on bearing portions 172, 172 of No. 7, and has a pad 202 on this shaft 201.
The proximal end of the arm 203 is fixed, and the arm 203 is rotated and biased by a coil spring 204, so that a pad 202 presses a disk (not shown) toward the head 18.

The transfer member 15 is provided with two sets of bearing means 21 on one side wall 161 of the base portion 16 and one set on the other side wall 162, respectively. In this case, the bearing means 21 has a tapered protrusion 1 on one side wall 161 as shown in FIG.
The rotary bearings 22 and 22 having a fixed shaft 221 and a bearing body 222 are provided upright on the upper and lower slopes of the tapered projection 161b, and the rotary bearings 22 and 22 have a fixed shaft 231 and a bearing body 232 on the upper and lower slopes of the tapered projection 161b, respectively. 23.23 is installed upright. Further, on the other side wall 162 side, a rotary bearing 24 having a fixed shaft 241 and a bearing body 242 is provided upright on the upper surface of the tapered resting protrusion 162a, and the housing 162b
A rotary bearing 25 having a suppression mechanism is provided corresponding to the rotary bearing 24. The rotation bearing 25 with a suppression mechanism has a rotation shaft 251 rotatably provided in a through hole of the housing 162b. In other words, rotation axis 2
Reference numeral 51 is arranged in a direction perpendicular to the fixed axis 241 of the rotary bearing 24, in other words, along the transfer direction of the transfer member 15, and the base end is attached to the housing.
It is supported using 2. Further, this rotating shaft 251 has a notch 251a in the middle, and the bearing body 25 is inserted into this notch 251a in a direction perpendicular to the rotating shaft 251.
The proximal end of a fixed shaft 254 having a diameter of 3 is attached. Further, a torsion spring 255 is provided at the tip of the rotating shaft 251, one end of this spring 255 is locked to the base portion 16, and the other end is locked to the tip of the fixed shaft 254, so that the bearing body 253 is attached to the rotating shaft 251. The rotation bearing 24 is biased around the rotation bearing 24 side.

A pair of stationary rods 26.2 along both sides of the moving member 15
7 are installed. These stationary rods 26 and 27 guide the movement of the transfer member 15. Two sets of bearing means 21 provided on one side wall 161 side of the base portion 16 abut on one rod 26, and the other rod 27 A set of bearing means 21 provided on the other side wall 162 is brought into contact with the bearing means 21 . In this case, the two sets of bearing means 21 on one side wall 161 have rotating bearings 22 , 22 and 23 .
, 23 abut against the rod 26 at an angle of 90', and one set of bearing means 2 on the other side wall 162 side.
1, a rotary bearing 25 having a suppressing mechanism together with a rotary bearing 24 is brought into contact with a rod 27 with a predetermined pressing force. The pressing force applied by this is the one side wall 161
The rotary bearings 22, 23, 24, 25 also come into contact with the rods 26, 27 with a predetermined pressing force, and in this state the rods 26
It is now possible to travel along ゜27.

In such a linear actuator, when a current is applied to the motor coil 19, a force is applied to move the coil 19 by the magnetic flux of the permanent magnets 131, 132 of the permanent magnet structure 11. This allows the transfer member 15 to run along the rods 26, 27 via the bearing means 21, and the head 18 can be quickly moved in the direction between different tracks on the disk.

In this case, according to the configuration shown in FIG.
Since a constant suppressing force can be applied to the stationary rods 26 and 27 from the first side, if the rods 26 and 27 are arranged in parallel, the transfer member 15 can be run under the same conditions over the entire length of the rods 26 and 27. Such a transfer member 15
This means that stable running without unevenness can be achieved.

Also, this one has a pressing mechanism lζ torsion spring 255
Since the pressing force is applied by using the bearing means, the direction of the pressing force can always be made to coincide with the normal pressing direction required by the bearing means, compared to the conventional one using a leaf spring. It is possible to remove obstacles and obtain stable running.

Furthermore, compared to a leaf spring, the spring 255 itself does not require a complicated design, making it easier to procure parts.

As a result, a linear actuator using such a traveling device can be safely used in a disk drive device that requires high-speed and accurate head positioning.

Next, FIG. 4 is a perspective view showing the main parts of another embodiment of the invention.

In this case, the rotary bearing 30 having the suppressing mechanism of the bearing means 21 has the rotary shaft 30 inserted into the through hole of the housing 162b.
1 is rotatably provided. This rotary shaft 301 is disposed in a direction perpendicular to the fixed shaft 241 of the rotary bearing 24, and its intermediate portion is supported by the housing 162b using an E IJ song 02. Further, a notch 301a is provided at one end of the rotating shaft 301, and a base end of a fixed shaft 304 having a bearing body 303 is attached to the notch 301a in a direction perpendicular to the rotating shaft 301. An axial notch 301 at the other end of the
b and insert the torsion spring 305,
One end of this spring 305 is locked to the notch 301b, and the other end is locked to the base body 16, and the rotation shaft 30
1 to rotate the bearing body 303 through the bearing 24
The rotation is biased to the side. The rest is the same as in FIG. 3, and the same parts are given the same reference numerals.

In this way, since a small spring 305 can be used, the space below the rotary bearing 25 having the suppressing mechanism shown in FIG. ≧There is an advantage that the thickness of the eta can be made thinner.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications without changing the gist.

For example, although a linear actuator having a transfer member 15 provided with a permanent magnet structure 11 and a motor coil 19 has been described above, a stepping motor or other means may be used as a drive source for the transfer member. Further, although the above description has been made for a disk drive device, the present invention may also be applied to a linear actuator used for other purposes. Further, the bearing means 21 may have the left and right positions reversed, or the positions of the rotary bearing 25 having the pressing mechanism and the corresponding rotary bearing 24 may be reversed. Furthermore, the bearing means 21 may be a rotary bearing having a pressing mechanism for each set on the side where two sets are provided, and a rotary bearing without a pressing mechanism on the side where one set is provided. Further, when two sets of rotary bearings each having a pressing mechanism are provided, two sets of bearing means may be provided at opposite positions.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line A-A in Fig. 1, Fig. 3 is a perspective view of the embodiment, and Fig. 4 is a cross-sectional view of the embodiment. FIG. 7 is an exploded perspective view showing main parts of another embodiment of the invention. 11... Permanent magnet structure 12... Yoke 121-1
23...Pole pieces 131, 132...Permanent magnets 141, 142...Attachment part 15...Transfer member 16...Base part 161, 162...
- Side walls 161a, 161b, 162a...Protrusion 162b - Housing 163...Notch
164...Stepped part 165...Narrow part
166... End wall 167... Mounting stand 168
...Groove portion 169...Through hole 17...Top plate 171...Protrusion portion 172...Bearing portion 1
8...Head 19...Motor coil 20
...Pad portion 201...Shaft 202...Knot 203...Arm 204...Spring 21...Bearing means 22.23.2
4... Rotating bearing 221, 231, 24
1...Fixed shaft 222, 232, 242...
・Bearing body 25...Rotating bearing with pressing mechanism! 2.511... Rotating shaft 251a...
Notch 252...E ring 253...Bearing body 254...Rotating shaft 255...
・Spring 26.27...Rod 30...
・Rotating bearing 301...Rotating shaft 301
a... Notch part 301b... Notch part 302.
...E ring 303...Bearing body 304...
・Fixed shaft 305...Spring

Claims (2)

[Claims] (1) A transfer member having a transfer drive source, at least one pair of stationary rods arranged in parallel along the transfer direction of the transfer member, and provided on the transfer member and abutting the rods at a predetermined angle. and at least one set of bearings is rotatably biased toward the other bearing about an axis along the transfer direction of the transfer member to apply a pressing force to the rod. A traveling device for a linear actuator, comprising a bearing means as described above. (2) The bearing means acts as a bearing that applies a pressing force to the rod, and includes a rotating shaft disposed in the transfer direction of the transfer member, a fixed shaft provided perpendicularly to the rotating shaft, and a fixed shaft disposed perpendicularly to the rotating shaft. 2. The linear actuator traveling device according to claim 1, further comprising a torsion spring that applies a rotational biasing force to the bearing body through the provided bearing body and the rotating shaft.