JPS645371B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor for a rotating magnetic head used in a rotating magnetic head mechanism of a rotating magnetic head type recording/reproducing device, and more particularly to a rotor for a rotating magnetic head mechanism including at least a rotor for a rotating magnetic head. The present invention relates to a rotor for a rotating magnetic head having a structure that eliminates the initial dynamic imbalance of the body without adding or subtracting mechanical mass.

The rotating body, including the rotating magnetic head rotor used in the rotating magnetic head mechanism of the rotating magnetic head type recording/reproducing device, suppresses dynamic vibration due to mass imbalance during steady rotation, and the magnetic recording carried by the rotating magnetic head rotor is suppressed. In order to maintain a stable mutual positional relationship between the transducer and the recording medium, it is required that the final mounted state of the rotating body has a dynamic unbalance amount below a certain tolerance value. In general, the main components of the rotating magnetic head mechanism include a rotor for the rotating magnetic head including a magnetic recording transducer for recording and reproducing, a rotating transformer, a spindle shaft, and a drive motor rotor.

Conventionally, the dynamic balance of the rotating body has been determined depending on the desired allowable unbalance amount at the time of final assembly. This has been carried out at various levels such as the final assembly of the transformer and spindle shaft or the rotating body of the rotating magnetic head mechanism. Generally speaking, among the main components of the above-mentioned rotating magnetic head mechanism, the component that causes the largest dynamic imbalance is the rotating magnetic head rotor because the rotor support is equipped with a magnetic recording transducer for recording and reproducing. big. Furthermore, the dynamic balance of the rotating body is performed in the final assembly of the rotating body of the rotating magnetic head mechanism due to the complexity of mounting the rotating magnetic head mechanism. This method is extremely difficult because it involves adding or removing mechanical mass to the rotor for the magnetic head. In view of the above-mentioned background, dynamic balancing of the rotating body of a rotating magnetic head mechanism is generally performed using an assembly of a rotor for a rotating magnetic head and a rotating transformer, or an assembly combining them with a spindle shaft. Figure 1 is well known to those skilled in the art.
FIG. 3 is a diagram showing the structure of an assembly of a rotating magnetic head rotor and a rotating transformer used in a rotating magnetic head mechanism of an IBM 3850 type mass storage device.
FIG. 2 is a view taken along the line A--A in FIG. 1. In the figure, 1 is a rotor for a rotating magnetic head including a magnetic recording transducer for recording and reproducing, 2 is a rotating transformer,
3 is a fitting portion of the spindle shaft, and 4 is a dynamic balance surface of a rotor for a rotating magnetic head. 5 is a screw hole formed in the dynamic balance surface 4 of the rotating magnetic head rotor. Conventionally, the dynamic balance of this rotating body assembly is achieved by fitting a spindle shaft actually used in the rotating magnetic head mechanism or a dedicated shaft for dynamic balancing into the spindle fitting part 3 of the rotor 1 for the rotating magnetic head. A rotor 1 for a rotating magnetic head and a rotating transformer 2 shown in FIG.
The rotating body assembly, which includes the assembly and the spindle shaft, was installed in a dynamic balance tester and rotated. Threaded rods having different masses are suitably screwed into a plurality of screw holes 5 pre-drilled at intervals in the dynamic balance surface 4 of 1 to achieve dynamic balance, thereby eliminating the unbalance of the mass of the rotating body. Furthermore, as another method for dynamic balancing of a rotating body including a rotor for a rotating magnetic head in the past, a method opposite to mechanically screwing a threaded rod into a screw hole as shown in FIG. This is a method of mechanically removing the mass of , in order to make the amount of dynamic unbalance zero. Now, the conventional method of adding or removing mechanical mass to the dynamic balance surface of the rotor for a rotating magnetic head, which is carried out in dynamic balancing of the rotating body of a rotating magnetic head mechanism including at least the rotor for a rotating magnetic head, is as follows. The disadvantage is that it takes a very long time to dynamically balance the rotating body, and the process of dynamically balancing itself is very nerve-wracking. In addition, the method of dynamic balancing by removing the mechanical mass of the dynamic balancing surface of the rotor for a rotating magnetic head is a method of dynamic balancing that requires high mechanical accuracy and precision of the rotor for a rotating magnetic head, including a magnetic recording transducer. Therefore, it is very difficult to deal with and take measures against the chips generated during mechanical mass removal. Furthermore, damage to the rotor of the rotating magnetic head caused by chips can cause fatal problems. Ideally, the dynamic balance of the rotating body of the rotating magnetic head mechanism is achieved in the final assembly of the rotating body. Above all, the method of dynamic balance by adding or removing mechanical mass on the dynamic balance surface of the rotor for a rotating magnetic head is difficult to achieve in reality as the structure of the rotating magnetic head mechanism becomes complex. The disadvantage is that it eliminates the possibility of dynamic balancing in the assembly.

An object of the present invention is to dynamically balance a rotating body of a rotating magnetic head mechanism including at least a rotor for a rotating magnetic head without adding or removing mechanical mass, and The various drawbacks found in the method of dynamic balancing of the rotating body of a rotating magnetic head mechanism, including the rotor for a rotating magnetic head mechanism, have been eliminated, and the dynamic balancing of the rotating body of a rotating magnetic head mechanism, including the rotor for a rotating magnetic head mechanism, has been achieved more easily, in a short time, and with high precision. In addition, it is an object of the present invention to provide a rotor for a rotating magnetic head that enables dynamic balancing even in the final assembled state of the rotating body of the rotating magnetic head mechanism.

According to the present invention, the inner ring of the annular steel ball guide track is formed on at least one side surface in the direction of the rotational axis of the rotor support body that rotates while supporting the magnetic recording transducer, and the annular steel ball guide track is formed of a shape memory alloy. A rotary magnetic head mechanism including at least a rotor for a rotary magnetic head is provided with an outer ring and holds a plurality of steel balls so as to be movable in an annular groove constituted by the inner ring and the outer ring of the steel ball guide raceway. When the rotating body is dynamically balanced, a plurality of A rotor for a rotating magnetic head is obtained, characterized in that steel balls are fixed in grooves formed by the inner ring and outer ring of the steel ball guide raceway, and dynamic balance is achieved.

The most important feature of the method of dynamically balancing a rotating body of a rotating magnetic head mechanism including at least a rotor for a rotating magnetic head according to the present invention is that it utilizes the shape memory effect of a shape memory alloy. Although it is well known, the principle of the mechanism of the shape memory effect of shape memory alloys will be briefly explained below. What shape memory alloys have in common is that they undergo thermoelastic martensitic transformation.
The phase on the high temperature side of this phase transformation is a regular lattice.

There is a close relationship with this in terms of metal crystallography. Martensitic transformation is a phase transformation in which the atoms that make up the alloy work together and move all at once over very short distances. When a metal that undergoes this transformation is cooled from a high temperature, martensitic transformation occurs at a certain temperature. If it is further cooled, it becomes 100% martensitic at a certain temperature. Shape memory alloys are created by a reverse transformation of martensitic transformation. What is reverse transformation? When the martensitic phase is heated, at a certain temperature it begins to return to the original high-temperature phase, and when further heated, it becomes 100% high-temperature "phase." ``Thermoelastic type'' refers to the temperature at which martensitic transformation begins. Refers to those with a small difference in reverse transformation start temperature. For example, the ordered lattice indicates a crystal structure in which alloy component atoms are regularly arranged like ABABA... This ordered lattice phase undergoes martensitic transformation and undergoes plastic deformation when subjected to force. When this alloy is heated, a reverse transformation occurs in which it attempts to return to its original ordered lattice phase. In terms of energy, it is better for this reverse transformation to return to the regular lattice state by reversibly
Best. This reversible change is the mechanism of the shape memory effect of shape memory alloys.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure, operation, and effects of embodiments of a rotor for a rotating magnetic head according to the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a diagram showing the structure of a rotor for a rotating magnetic head according to the present invention.

FIG. 4 is a view along the line B--B in FIG. 3, showing a side view of the rotor for a rotating magnetic head of the present invention. In the figure, 6 is a rotor support, 7, 8, and 9 are elements constituting a dynamic balancing mechanism made of a shape memory alloy, which is a feature of the present invention, and 7 is an outer ring of an annular steel ball guide race made of a shape memory alloy; Reference numeral 8 denotes an inner ring of an annular steel ball guide race that is combined with an outer ring 7 of an annular steel ball guide race made of a shape memory alloy to form an annular groove that can freely move and guide a plurality of steel balls 9; It also has the function of fixing the outer ring 7 of the annular steel ball guide track made of memory alloy to the cylindrical portion 10 at one end of the rotor support 6. The annular steel ball guide track 8 is fixed, for example, to a cylindrical portion 10 at one end of the rotor support 6 by a method such as press fitting. Next, a method for dynamically balancing a rotating body of a rotating magnetic head mechanism including at least a rotor for a rotating magnetic head according to the present invention will be explained. FIG. 5 is a view showing an assembly of a rotor for a rotating magnetic head and a rotating transformer that constitute a dynamic balancing mechanism using a shape memory alloy according to the present invention, and FIG. 6 is a view taken along the line C--C in FIG. It is.

In the figure, reference numeral 11 denotes a rotor for a rotating magnetic head according to the present invention, which carries a magnetic recording transducer for recording and reproduction, although not shown. 12 is a rotating transformer. Rotor 11 for rotating magnetic head
As mentioned above, is formed by the outer ring 7 of the annular steel ball guide race, the inner ring 8 of the annular steel ball guide race, and the outer ring and inner ring of the annular steel ball guide race made of shape memory alloy at one end in the direction of the rotation axis. It is equipped with a dynamic balancing mechanism made of a shape memory alloy consisting of a plurality of steel balls 9 held in an annular groove. For example, the shape memory alloy of the outer ring 7 of the annular steel ball guide raceway is
Alloys such as Ti-Ni and Cu-Zn-Al are used. Now, when dynamically balancing the assembly of the rotating magnetic head mechanism shown in FIG. Fits a special shaft for target balance. FIG. 7 is an enlarged view of section A in FIG. 5 and shows the state before dynamic balance is taken. In this state, the plurality of steel balls 9 can freely move in the annular groove formed by the outer ring 7 of the annular steel ball guide track and the inner ring 8 of the annular steel ball guide track made of a shape memory alloy. There is. When the assembly of the rotating body of the rotating magnetic head rotor 11 and the rotating transformer 12 shown in FIG. The plurality of steel balls 9 are located at positions that cancel out the mass imbalance of the rotating body when it occurs. If a plurality of steel balls 9 are fixed in this state, the mass balance of the rotating body is maintained. FIG. 8 shows a state in which the outer ring 7 of the shape memory alloy steel ball guide track holds down a plurality of steel balls 9 when the plurality of steel balls 9 are positioned at a position that cancels out the mass imbalance of the rotating body. There is. Normally, the state shown in FIG. 7 is achieved by blowing cold air or carbon dioxide onto the outer ring of the steel ball guide raceway made of an annular shape memory alloy, thereby causing the shape memory alloy to undergo martensitic transformation. The steel balls 9 can freely move in a structure formed by the outer ring 7 of the annular shape memory alloy steel ball guide track and the inner ring 8 of the annular steel ball guide track. In the state shown in FIG. 8, when the rotating body and the plurality of steel balls 9 resonate and are in dynamic balance, the outer ring 7 of the steel ball guide track made of an annular shape memory alloy of the rotating magnetic head rotor 11 is rotated. This is achieved by blowing warm air to return the outer ring 7 of the steel ball guide raceway made of a shape memory alloy to its original shape due to the shape memory effect caused by reverse transformation of martensitic transformation, and the plurality of steel balls 9 are rotated. The body is fixed in a position where the unbalance of its mass is canceled out.

Although the embodiments of the present invention have been described in detail above, various modifications can be made without departing from the scope of the gist of the present invention. In the embodiments of the present invention, a method for dynamically balancing a rotating body of a rotating magnetic head mechanism including at least a rotor for an industrial rotating magnetic head has been described. It can also be applied to dynamic balance. Further, in the embodiments of the present invention, the case where the rotating body assembly is a dynamic balance of the rotating magnetic head rotor and the rotating transformer assembly has been mainly explained, but as the structure of the rotating magnetic head mechanism becomes more complex, Even if it is no longer possible to achieve dynamic balance by adding or removing mechanical mass to the rotor for a rotating magnetic head, if it is possible to blow hot air onto the shape memory alloy from the outside, the final balance of the rotating body of the rotating magnetic head mechanism can be improved. It is possible to perform dynamic balancing in the implementation state.

As explained above, the present invention provides a dynamic balancing mechanism made of the above-mentioned shape memory alloy at one end of the rotor for a rotating magnetic head in the direction of the rotational axis, thereby providing a rotary magnetic head for a conventional rotating magnetic head mechanism. It is possible to eliminate various problems and drawbacks found in the method of dynamic balancing of rotating bodies including rotors, that is, the method of mechanical addition and removal of mass, and it is possible to achieve rotational magnetism in a very short time, easily, and with high precision. It is possible to dynamically balance the rotating body including the rotor for the rotating magnetic head of the head mechanism, which is very effective in practice.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the structure of an assembly of a rotor for a rotating magnetic head and a rotary transformer used in a conventional rotating magnetic head mechanism, Fig. 2 is a view taken along arrow A-A in Fig. The figure shows the structure of a rotor for a rotating magnetic head according to the present invention, FIG. 4 is a view taken along the line B-B in FIG. 3, and FIG. 5 shows an assembly of a rotor for a rotating magnetic head and a rotary transformer according to the present invention. 6 is a view taken along the line C-C in FIG. 5, FIG. 7 is an enlarged view of section A in FIG. 5, and FIG. 8 is an enlarged view of section A in FIG. 5. This figure shows one state of an enlarged view, and in the figure, 1 is a rotor for a rotating magnetic head, 2 is a rotating transformer, 3 is a spindle fitting part, 4 is a dynamic balance surface, and 5 is a dynamic balance surface. 6 is a rotor support, 7 is an outer ring of an annular steel ball guide raceway made of shape memory alloy,
8 is the inner ring of the annular steel ball guide track, 9 is the steel ball, 10
1 is a cylindrical portion of a rotor support, 11 is a rotor for a rotating magnetic head according to the present invention, 12 is a rotating transformer, and 13 is a spindle fitting portion.

Claims (1)

[Claims] 1. An inner ring of an annular steel ball guide track and an outer ring of an annular steel ball guide track made of a shape memory alloy are provided on at least one side surface in the direction of the rotation axis of a rotor support that rotates while supporting a magnetic recording transducer, holding a plurality of steel balls so as to be movable in an annular groove formed by an inner ring and an outer ring of the steel ball guide race;
When the rotating body of the rotating magnetic head mechanism including at least the rotor for the rotating magnetic head is dynamically balanced, the shape memory effect due to the reverse transformation of the martensitic transformation of the shape memory alloy constituting the steel ball guide track causes the rotational body to change. A rotation characterized in that a plurality of steel balls located at positions to cancel mass imbalance are fixed in a groove formed by an inner ring and an outer ring of the steel ball guide race to achieve dynamic balance. Rotor for magnetic head.