JPS63277449A - Motor - Google Patents

Abstract

PURPOSE:To standardize alignment work, by magnetizing a rotor magnet while matching with phase relation of pitch of a lead screw. CONSTITUTION:A jig 121 having a structure rotatable around a rotary shaft is fixed before a rotor magnet 5 is magnetized. A referential pin 71 is secured to the jig 121, and the rotor magnet 5 is rotated while matching with the root of a lead screw 6. Under such condition, the rotor magnet 5 is magnetized such that a magnetizing yoke 50 is maintained in same positional relation with respect to the jig 121. Consequently, same phase relation can be maintained at all times between the pitch of the lead screw 6 and the magnetizing yoke 50, i.e. magnetizing domain of the rotor magnet 5, by means of the referential pin 71 secured to the jig 121, and thereby fluctuation of phase relation can be eliminated. As a result, fluctuation of alignment work is eliminated, resulting in simplification and standardization of alignment work.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic disk drive (hereinafter abbreviated as magnetic DD).
This invention relates to a structure that facilitates alignment of a reference origin when a small motor called a PM lead screw type motor is used as a positioning motor.

[Conventional technology]

Conventionally, when aligning the position reference origin of the key and r ridges of an FDD, a method was used in which the entire motor was rotated relative to the motor mounting base, and the adjustment required a considerable amount of time.

Examples of conventional techniques will be described in detail below with reference to the drawings.

FIG. 3 is a schematic diagram of a magnetic DD with transparent perspective for explaining the conventional alignment.

The PM type lead screw type motor has a rotor 5 of permanent magnets PM that are divided into multiple sections and periodically magnetized in a circumferential manner.
and a stator 4 having a plurality of pole teeth on the outside thereof. In FIG. 3, the plurality of divisions and the plurality of parts are appropriately shown, and the explanation is limited to the principle. The stator 4 has a coil 3 on its outside.
A switching signal is periodically sent to the coil 6 to periodically reverse the magnetic poles of the stator 4, and the rotor 5 is rotated by interaction with the magnetic poles of the permanent magnets.

This mechanism is the same as a general PM type motor, and will not be described in detail. A device with screws on the 6th axis during rotation of the rotor 5 is generally called a lead screw, and 6 in Fig. 3.
It is shown by .

Therefore, if you align the bottle 7 with the valley of this screw part,
The rotational motion of the rotor 50 can be transmitted to the movable table 8 as a linear motion along the guide shaft 9.

In recent years, PM type IJ-toscrew type motors have been widely used for positioning heads of magnetic DDs because of their advantages of high precision, shock resistance, and low cost.

In magnetic DDs, the positions of tracks for reading and writing data must be adjusted within a certain range of positional accuracy between devices of the same type to ensure compatibility.

For this purpose, a movable table 8 (called a carrier IJ) equipped with a head for reading and writing data is 12 in FIG.
It is precisely aligned with the reference origin 10 of the entire reference stand (frame) shown by . This work is called alignment work.

Alignment work is performed in the following steps.

First, rotate the motor appropriately and move the moving table 8 to the frame 1.
2 near the reference origin 10.

This task is made easier by using the limit switch 11 shown in FIG.

Next, a phase excitation current of the reference phase is passed through the coil 3 of the stator 4 (generally speaking, there are two or four coils 6, and depending on the combination of the directions of the currents passed through these, the phase excitation current is 0.
．． There are four types (1.2.3); for example, phase 0 can be determined as the reference phase). At this time, in accordance with the phase excitation of this reference phase, the rotor 5
rotates to a predetermined stable point and stops. Along with that,
The movable table 8 moves and stops along the guide shaft 9 attached to the frame 12 by the lead screw 6 and bit 0 rotation linear conversion. At this time, the movable table 8 is not necessarily at the predetermined reference origin 10.

In this state, the housing 2, which is integrated with the stator 4 and forms the external case of the motor, is rotated around the rotation axis by loosening the attachment part 21 to the motor mounting base 1 fixed to the frame 12. . This causes the stator 4 to rotate,
As a result, the rotor 5 rotates and the lead screw L-6 rotates, and as a result, the movable table 8 can be moved.

In this way, the moving table 8 is moved to the frame 120 reference origin 1
It can be set to 0.

The position and accuracy of the mounting portion 21 must be designed so that alignment work can be performed by finely adjusting the phase relationship of the stator 4 with respect to the rotor 5.

Note that the limit switch 11 shown in FIG. 3 is roughly adjusted in advance to assist in the alignment process, but this limit switch is also called a track zero sensor in magnetic DDs, for example. Since it has a role to be concerned about the state of the starting point of the moving platform 8, after the above alignment work is completed, it is necessary to check again whether it is at the predetermined starting point (that is, track zero) and readjust it. In other words, the individual variations in motors complicate the alignment work as well as the readjustment work of the limit switches.

FIG. 4 is a conceptual diagram showing why the above alignment work is different for each motor. In this diagram 6
7 indicates the period of the increments of the lead screw, 7 indicates the position of the bin, 5 indicates the positional relationship of the magnetized sections of the rotor, and 101 indicates the movement of the reference origin of the frame position. Here, it is assumed that the stators are set in a certain positional relationship in advance.

B) and 1) in FIG. 4 show different starting points of the phase relationship of the increments of the lead screw and the starting point of the phase relationship of the magnetized sections of the rotor magnet.

In other words, the starting point of the lead screw phase relationship is 101
4 (a) and 1 (opening 1 are also shown, so the relationship between the bottle 7 and the trough of the lead screw is the same as in FIG. 4 (a) and opening 1). On the other hand, in Figure 4 (B), the starting point of the phase relationship of the magnetized sections of the rotor magnet is shown in Figure 4 (B).
It is shown that Δθ differs with respect to K.

In this state, if the same stator is in the same phase excitation state, the stable point of the rotor differs from the stator by Δθ in (a) and (b) of FIG. 4. Therefore, the amount =
The toscrinny will rotate and the position of the bin 7 will differ by ΔX.

From this, K, which eliminates the difference in alignment work between individual motors, is determined by determining the relationship between the starting point of the phase relationship of the increments of the lead screw and the starting point of the phase relationship of the magnetization section of the rotor magnet for all motors. It can be seen that it is sufficient to have a constant relationship between

[Problem that the invention seeks to solve]

However, according to this method, the magnetization of the motor's rotor and the mutual position of the lead screw vary from piece to piece. In this state, a series of complicated alignment operations have been performed in which the external case of the motor is rotated relative to the device to align the position with the reference origin.

After all, different work must be done for each individual motor. In addition, the adjustment range must be set assuming variations in individual motors, and in the case of small motors that require precision, the adjustment range for the alignment work described above must be set more accurately than when precision is required. It has the disadvantage that it is larger and takes time to adjust.

The present invention improves the method of magnetizing the motor rotor to reduce variations among individual motors, simplifying and standardizing the alignment work, and providing a structure that eliminates the alignment work itself depending on the required accuracy.

[Means for solving problems]

In the present invention, we have focused on the fact that alignment work for individual motors varies due to the relative relationship between the phase relationship between the magnetized sections of the motor's rotor magnet and the phase relationship between the increments of the threaded part called the lead screw. The problem was solved by magnetizing the rotor magnets in accordance with the phase relationship of the increments of the threaded part.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a plan view showing an embodiment of means for realizing the present invention.

Before being magnetized, the rotor magnet 5 is attached to a jig 121 having a structure that allows it to rotate around a rotation axis. Jig 121
A reference pin 71 is fixed to the lead rotating type,
Turn the rotor magnet so that it aligns with the valley of the -6 increments.

In this state, the rotor magnets are always magnetized in the same way relative to the jig 121 in the positional relationship of the magnetizing yoke 50.

In this way, the phase relationship of the increments of the lead screw is always made the same as the positional relationship of the magnetizing yoke 50, that is, the phase relationship of the magnetized sections of the rotor magnet, by the reference pin 71 fixed to the jig 121. This makes it possible to eliminate variations between motors.

Figure 3 is a schematic diagram of a conventional example, and the phase relationship between the rotor magnetized sections shown in this figure and the phase relationship between the notches of the lead screw can be realized using the realization means shown in Figure 1. This means that - each motor is maintained without variation.

Furthermore, in FIGS. 1, 3, and 4, the rotor and the lead screw are fixed as one body, and when the rotor rotates, the lead screw rotates (lead rotating type).

On the other hand, in the case of a structure in which a female thread is carved along the central axis of rotation of the rotor, an independent male lead screw is engaged with the female thread, and the lead screw is prevented from rotating, one rotor rotates. Then, the lead screw moves straight (lead straight movement type). In this case, the present invention may be explained above in terms of the phase relationship between the magnetized sections of the rotor magnet and the phase relationship between the notches of the female thread cut along the central axis of rotation of the rotor.

As another embodiment of the present invention, an example of a straight lead type is shown in FIG. 51 is a rotor magnet, and 61 is a lead screw.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, in a PM type motor, it is possible to eliminate the difference in alignment work between individual motors, simplify and standardize the alignment work, and limit switch. This has the effect of eliminating the need for readjustment, and further reduces the amount of time required during adjustment during alignment work, so that the positional accuracy of the mounting portion provided on the motor housing can be greatly reduced.

Depending on the accuracy required for the alignment work, the alignment work itself may be abolished and a predetermined basic position may be obtained by simply incorporating the parts.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a perspective view showing another embodiment of the present invention, FIG. 3 is a schematic diagram illustrating the alignment of a conventional magnetic DD, and FIG. FIG. 2 is an explanatory diagram illustrating variations in a conventional motor. 1...Motor mounting base, 2...No1
Uzing, 3... Stator coil, 4...
... Stator, 5.51 ... Rotor magnet, 6
．． 61... Lead screw, 7.71.
...Pin, 8...Movement base (carriage)
, 9... Guide axis, 10... Reference origin of frame 12, 11... Limit switch, 12... Reference stand (frame) for the entire device, 21...Mounting part, 50...
Magnetizing yoke, 121... Jig. 111Figure 2Figure 4

Claims (1)

[Claims] A rotor magnet that is divided into a plurality of sections and periodically magnetized in a circumferential manner, a screw carved on the rotation center axis of the rotor magnet, and a screw that is installed outside the rotor magnet, and the rotor magnet a stator having a structure in which the phase relationship can be finely adjusted with respect to the stator; A motor characterized in that it is magnetized with a phase difference relationship.