JP3093890U - Rotating magnetic head device - Google Patents

Abstract

(57) [Summary] [Purpose] To stabilize the rotating operation of a rotary cylinder at low cost. [Constitution] Inner diameter D of shaft insertion hole 6 of fixed cylinder 4
Is set slightly larger than the outer diameter H of the shaft 8, and the inner peripheral surface of the shaft insertion hole 6 is cut in the circumferential direction to form a plurality of oil reservoirs 40, 41 at predetermined intervals in the vertical direction. As a result, a plurality of bearings 43, 44 are left above the oil reservoirs 40, 41, and the bearings 43, 44
The spiral oil guide groove 4 is formed on the outer peripheral surface of
5 and 46 are engraved, and the oil O is pushed up along the oil guide grooves 45 and 46 by rotation of the shaft 8 in a state where the oil O is accumulated in the oil reservoirs 40 and 41, and the pushed oil O To the bearings 43 and 44 and the shaft 8
Is supplied to the gap a between them.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

  The present invention is applicable to a rotating magnetic disk used for reproduction or recording in a magnetic tape device, for example. Related to the door device.

[0002]

[Prior art]

  Conventionally, as an example of a rotary magnetic head device, there is one described in Patent Document 1 or the like. An example of this will be described with reference to FIG. The binder 2 and the pair of upper and lower fixed cylinders 3 and 4 are concentrically arranged, and the lower fixed cylinder Between the boss portion 4a integrally formed in the central portion of the binder 4 and the rotary cylinder 2, a cylindrical roller is provided. A tally transformer 5 is arranged, and a pair of upper and lower is inserted in the shaft insertion hole 6 of the boss portion 4a. Of the oil-impregnated metal bearings 15 and 16 are arranged, and a cup-shaped thrust is provided under the boss portion 4a. When the shaft bearing 9 is externally fitted, the lower end opening of the shaft insertion hole 6 is closed and the rotation is prevented. A shaft 8 made of stainless steel, the upper end of which is fitted into the central through hole 2a of the cylinder 2, is attached to the chassis. The outer peripheral surface of the shaft 8 is inserted into the shaft insertion hole 6 so that the oil-impregnated metal bearing 15 , 16 is rotatably supported by the central fixed hole 3a of the upper fixed cylinder 3 in the vertical direction. A cylindrical earth brush 26 movably inserted is attached to the upper surface of the shaft 8 by a spring 27. By pressing the shaft 8 with a predetermined pressing force P, the lower end surface of the shaft 8 is cup-shaped. Rotated with the coil 12a supported by the last bearing 9 and attached to the upper fixed cylinder 3. A drive motor 12 including a magnet 12b attached to the cylinder 2 is provided. ing.

[0003]   In the above structure, the drive motor 12 causes the rotary cylinder 2 to center on the shaft 8. The rotating cylinder 2 and the fixed cylinders 3 and 4 which are rotated at high speed. With respect to the magnetic tape (not shown) running along the outer peripheral surface of the magnetic head 1, Information is recorded and reproduced.

[0004]

[Patent Document 1]   JP, 11-86246, A

[0005]

[Problems to be solved by the device]

  According to the above configuration, the pair of upper and lower oil-impregnated metal bearings 15 and 16 are provided in the shaft insertion hole 6 The oil-impregnated metal bearings 15 and 16 are separately fitted onto the inner peripheral surfaces of the In order to stably support the shaft 8 so that it does not wobble, The inner peripheral surface of the through hole 6 is subjected to precision machining so that the axial centers O1 of both the oil-impregnated metal bearings 15 and 16 are It is necessary to match O2 exactly, and the processing cost for precision processing is high, Moreover, the number of parts is increased because both oil-impregnated metal bearings 15 and 16 are used, Production costs are high.

[0006]   In view of the above problems, the present invention stably and accurately supports a shaft with an inexpensive structure. It is an object of the present invention to provide a rotary magnetic head device capable of performing the above.

[0007]

[Means for Solving the Problems]

  In order to achieve the above object, a device according to claim 1 has a magnetic head having a magnetic head. The cylinder and the fixed cylinder are concentrically arranged and integrated in the center of the fixed cylinder. The oil-impregnated metal bearing is arranged in the shaft insertion hole of the formed boss and The lower end of the shaft insertion hole is opened by fitting the cup-shaped thrust bearing to the outer part. Is closed and the upper end of the stainless steel chassis is fitted in the central through hole of the rotary cylinder. The shaft is inserted into the shaft insertion hole so that the outer peripheral surface of the shaft is oil-impregnated metal. The shaft is rotatably supported by bearings, and the lower end surface of the shaft is cup-shaped slide. It is supported by a strike bearing, and the drive motor allows the rotary cylinder to move through the shaft. In a rotary magnetic head device adapted to rotate to the center, the oil-impregnated metal bearing is Omitted, the inner diameter of the shaft insertion hole is set to be slightly larger than the outer diameter of the shaft. The inner peripheral surface of the shaft insertion hole is cut in the circumferential direction so that a plurality of oil reservoirs are specified in the vertical direction. By forming them at intervals, a plurality of bearing parts are left uncut above the oil reservoirs. And a spiral oil guide groove is formed on the outer peripheral surface of the shaft so as to face each bearing portion. In addition, an annular oil groove is formed on the inner peripheral surface of each bearing, While the oil is stored inside the part, the shaft is rotated to follow the spiral oil guide groove. Push up the oil, and put the pushed up oil in the gap between each bearing and shaft. Supply, a circular plate-shaped thrust bearing is used in place of the cup-shaped thrust bearing, The ring-shaped rotary transformer is attached to the annular wall portion integrally formed on the upper surface of the thrust bearing. An annular spacer for adjusting the gap between the upper and lower parts is fitted on the annular spacer, The annular recess, which is almost the same as or slightly larger than the shaft, is concentric with the shaft insertion hole on the lower surface of the boss. The thrust bearing is fixed to the lower surface of the boss, The upper surface of the last bearing is closely attached to the lower surface of the annular spacer, and The top surface is in close contact with the bottom surface of the annular recess.

[0008]   The above configuration corresponds to the first embodiment (see FIGS. 1 to 4), According to this, the fixed cylinder and multiple bearings are integrally molded by aluminum die casting. By doing so, the shaft centers of the bearings can be accurately aligned, and The shaft can be stably supported so as not to wobble. Also, each bearing By continuously performing the inner peripheral surface polishing process and the cutting process of each oil reservoir, Finishing of the shaft insertion hole can be done quickly and easily, and the processing cost is higher than before. Can be cheaper. Moreover, since the conventional oil-impregnated metal bearing is omitted, The number of parts is reduced by the amount omitted, resulting in lower manufacturing costs.

[0009]   A spiral oil guide groove is engraved on the outer peripheral surface of the shaft facing each bearing. , By rotating the shaft with oil stored in each oil reservoir, The oil is pushed up along the spiral oil guide groove, and the pushed up oil is applied to each bearing. Is supplied to the gap between the shaft and the shaft to form a thin film of oil, Stabilizes the rotary motion of the rotating cylinder without the risk of the shaft of the machine sticking to each bearing Can be transformed. Also, use a cutting tool such as a cutting tool to spiral on the outer peripheral surface of the shaft. -Shaped oil guide groove can be engraved quickly and easily, and the cutting cost is low.

[0010]   The important thing here is that the oil is pushed up along the oil guide groove. Therefore, the liquid level of the oil collected in the shaft insertion hole can be kept low. This causes the oil to expand at high temperature and cause the oil to expand above the shaft insertion hole. It is possible to reliably eliminate the accident of overflowing from the end opening.

[0011]   Is a small amount of oil always accumulated in the annular oil groove engraved on the inner peripheral surface of each bearing? For example, even if the rotating cylinder is rotated after being stopped for a long time, the oil in the annular oil groove may be rotated. Spread in the gaps between the bearings and the shaft, and the shaft is burned in the bearings. There is no danger of getting stuck.

[0012]   By combining the annular spacer for gap adjustment and the thrust bearing, the shaft It is possible to reliably prevent oil from leaking from the lower end opening of the insertion hole, and , Make sure that the upper surface of the annular spacer is in close contact with the bottom surface of the annular recess formed on the lower surface of the boss. In order to prevent oil leakage, only the bottom of the annular recess should be cleaned. Since it only needs to be densely machined, it is more effective than precision machining of the entire lower surface of the boss. Construction costs are low.

[0013]   Rotated by a stainless steel bar that has excellent rigidity, linearity and precision finishing of the outer peripheral surface. Since the shaft of the rolling cylinder is formed, the rotary motion of the rotating cylinder is maintained for a long time. Can be stably maintained over.

[0014]   According to a second aspect of the invention, a rotary cylinder having a magnetic head and a fixed cylinder are provided. Shafts of a boss portion that are concentrically arranged and are integrally formed in the central portion of the fixed cylinder. An oil-impregnated metal bearing is arranged in the insertion hole, and a cup-shaped thrust bearing is provided below the boss. The lower end opening of the shaft insertion hole is closed by fitting the Insert the stainless steel shaft with the upper end fitted into the central through hole of the slot into the shaft insertion hole. By passing through, the outer peripheral surface of the shaft is rotatably supported by oil-impregnated metal bearings And the lower end surface of the shaft is supported by a cup-shaped thrust bearing. The drive motor is designed to rotate the rotary cylinder around the shaft. In the rotary magnetic head unit, the stainless steel shaft-equipped rotary cylinder was replaced. A rotary cylinder with a shaft integrally molded is used to save the oil-impregnated metal bearing. The inner diameter of the shaft insertion hole is set to be slightly larger than the outer diameter of the shaft. The inner peripheral surface of the shaft insertion hole is cut in the circumferential direction so that a plurality of oil reservoirs are vertically By forming them at intervals, a plurality of bearing parts are left uncut on the upper side of each oil reservoir. And a spiral oil guide groove is engraved on the outer peripheral surface of the shaft so as to face the bearings. In addition, an annular oil groove is engraved on the inner peripheral surface of each bearing, While the oil is stored inside, the shaft is rotated and the oil is guided along the spiral oil guide groove. Oil and push the oil into the gap between each bearing and shaft. And a circular plate-shaped thrust bearing is used instead of the cup-shaped thrust bearing. The ring-shaped rotary transformer is mounted on the annular wall that is integrally projected on the upper surface of the thrust bearing. An annular spacer for adjusting the gap between the lower parts is fitted on the annular spacer. An annular recess that is almost the same as or slightly larger in diameter is concentric with the shaft insertion hole on the lower surface of the boss. The thrust bearing is attached to the lower surface of the boss to form the thrust bearing. The upper surface of the strike bearing is closely attached to the lower surface of the annular spacer, and The surface is in close contact with the bottom surface of the annular recess.

[0015]   The above configuration corresponds to the second embodiment (see FIG. 5), and Then, it is possible to obtain substantially the same effect as that described in claim 1, and particularly By integrally molding the shaft and rotary cylinder with aluminum die casting, High accuracy of rotation by accurately setting the verticality and height of the shaft with respect to the rolling cylinder A rotary cylinder with a shaft can be manufactured, and a rotary cylinder with a shaft can be manufactured. The unit is a single item, and compared to a stainless steel rotary cylinder with a shaft, Since the number of products is halved, the material cost is low.

[0016]   According to a third aspect of the invention, a rotary cylinder having a magnetic head and a fixed cylinder are provided. Shafts of a boss portion that are concentrically arranged and are integrally formed in the central portion of the fixed cylinder. An oil-impregnated metal bearing is arranged in the insertion hole, and a cup-shaped thrust bearing is provided below the boss. The lower end opening of the shaft insertion hole is closed by fitting the Insert the stainless steel shaft with the upper end fitted into the central through hole of the slot into the shaft insertion hole. By passing through, the outer peripheral surface of the shaft is rotatably supported by oil-impregnated metal bearings And the lower end surface of the shaft is supported by a cup-shaped thrust bearing. The drive motor is designed to rotate the rotary cylinder around the shaft. In the rotary magnetic head unit, the stainless steel shaft-equipped rotary cylinder was replaced. A rotating cylinder with a shaft integrally molded is used to form the shaft into a hollow shape. The hollow shaft allows the mandrel to be inserted into the oil-impregnated metal bearing. Is omitted, the inner diameter of the shaft insertion hole is set to be slightly larger than the outer diameter of the shaft, The inner peripheral surface of the shaft insertion hole is cut in the circumferential direction to place a plurality of oil reservoirs in the vertical direction. By forming the bearings at regular intervals, a plurality of bearings are cut above the oil reservoirs. A spiral oil guide groove is formed on the outer peripheral surface of the shaft so as to face the bearings. At the same time, the inner peripheral surface of each bearing is engraved with an annular oil groove. Along the spiral oil guide groove by rotating the shaft while oil is stored in the reservoir. Push up the oil, and push the pushed up oil into the gap between each bearing and shaft. And a circular plate-shaped thrust bearing is used instead of the cup-shaped thrust bearing. , A ring-shaped rotary transformer on an annular wall portion integrally provided on the upper surface of the thrust bearing. An annular spacer for adjusting the gap between the upper and lower parts of the The annular recess, which is almost the same as or slightly larger than the diameter of the It is formed in the shape of a core, and by attaching the thrust bearing to the lower surface of the boss, The upper surface of the thrust bearing is closely attached to the lower surface of the annular spacer, and the annular spacer is The upper surface of the above is closely contacted with the bottom surface of the annular recess.

[0017]   The above configuration corresponds to the third embodiment (see FIG. 6), and Then, it is possible to obtain substantially the same effects as the effects according to claims 1 and 2. , In particular, since the shaft is reinforced by inserting the mandrel into the hollow shaft, For example, even if an excessive load is applied due to a vibration / drop test, the shaft will not drop. It does not disturb the straightness, and it is cheap because it only roughened the surface as a mandrel. Since the iron bar can be used as it is, the material cost is low and it is economical. is there.

[0018]   According to a fourth aspect of the present invention, a rotary cylinder having a magnetic head and a fixed cylinder are provided. Shafts of a boss portion that are concentrically arranged and are integrally formed in the central portion of the fixed cylinder. The lower end of the shaft is inserted by inserting the shaft of the rotary cylinder into the insertion hole. The surface is supported by a thrust bearing fixed to the bottom surface of the boss, Rotating magnetic head device in which a rotating cylinder is rotated around a shaft The inner diameter of the shaft insertion hole is set to be slightly larger than the outer diameter of the shaft. Then, the inner peripheral surface of the shaft insertion hole is cut in the circumferential direction so that the plurality of oil reservoirs are vertically moved. By forming the bearings at predetermined intervals, a plurality of bearings are provided above the oil reservoirs. An uncut portion which extends in the vertical direction on the outer peripheral surface of the shaft facing the bearings. There is an engraved ill guide groove, and the shaft can be used with oil stored in each oil reservoir. The oil is pushed up along the oil guide groove by rotating the It is characterized in that the gas is supplied to the gaps between the bearings and the shaft.

[0019]   According to the above configuration, the fixed cylinder and the plurality of bearings are integrally formed by aluminum die casting. By molding, the shaft centers of the bearings can be matched exactly. Therefore, it is possible to stably support the shaft so that the shaft does not run out. Also, Continuously polishing the inner surface of each bearing and cutting each oil reservoir As a result, the finishing of the shaft insertion hole can be performed quickly and easily. Processing costs can be reduced. Furthermore, the conventional oil-impregnated metal bearing is omitted. Therefore, the number of parts is reduced by the omitted amount, and the manufacturing cost is low.

[0020]   An oil guide groove extending vertically is engraved on the outer peripheral surface of the shaft facing each bearing. The shaft is rotated with oil stored in each oil reservoir. Pushes up the oil along the oil guide groove by the The oil is supplied to the gap between the receiving part and the shaft to form a thin film of oil. There is no risk of the rotating shaft burning on each bearing and Can be stabilized.

[0021]   The important thing here is that the oil is pushed up along the oil guide groove. Therefore, the liquid level of the oil collected in the shaft insertion hole can be kept low. This causes the oil to expand at high temperature and cause the oil to expand above the shaft insertion hole. It is possible to reliably eliminate the accident of overflowing from the end opening.

[0022]   A fifth aspect of the present invention is the device of the fourth aspect, wherein the oil guide groove is provided. Is spirally engraved on the outer peripheral surface of the shaft.

[0023]   According to the above configuration, a spiral oyster is attached to the outer peripheral surface of the shaft with a cutting tool such as a cutting tool. The guide groove can be engraved quickly and easily, and the cutting cost is low.

[0024]   The invention according to claim 6 is the device according to claim 4 or 5, An annular oil groove is engraved on the inner peripheral surface of the receiving portion.

[0025]   According to the above configuration, a small amount of oil is stored in the annular oil groove engraved on the inner peripheral surface of each bearing portion. Since it always accumulates, even when rotating a rotating cylinder after a long stop, for example , The oil in the annular oil groove spreads in the gap between each bearing and the shaft, There is no risk of the shaft sticking to the part.

[0026]   The invention according to claim 7 is the device according to any one of claims 4 to 6, The shaft is made of stainless steel, and the upper end of the stainless steel shaft is a rotating shaft. It is characterized by being fitted in the central through hole of the Linda.

[0027]   According to the above configuration, the stainless steel excellent in rigidity, linearity and precision finishing of the outer peripheral surface. Since the shaft of the rotating cylinder is formed by the rod made of less The rotary motion of the da can be stably maintained for a long period of time.

[0028]   The invention according to claim 8 is the device according to any one of claims 4 to 6, The shaft is integrally formed with the rotary cylinder. I am trying.

[0029]   According to the above configuration, the shaft and the rotary cylinder are integrally molded by aluminum die casting. By setting, the verticality and height of the shaft with respect to the rotating cylinder can be set accurately. It is possible to manufacture a rotating cylinder with a shaft with high rotation accuracy, and Rotating cylinder with shaft is made as a single item, rotating with stainless steel shaft Since the number of parts is halved compared to cylinders, material costs are low.

[0030]   A ninth aspect of the present invention is the device of the eighth aspect, wherein the shaft is By making it hollow, the mandrel is inserted in the hollow shaft. It has a feature.

[0031]   According to the above configuration, the shaft is reinforced by inserting the mandrel into the hollow shaft. Therefore, even when an excessive load is applied, for example, in a vibration / drop test, the It does not disturb the verticality of the shaft, and the surface is roughened as a mandrel. Since it is possible to use only the cheap iron bar as it is, it does not cost too much material It is economical.

[0032]   The invention according to claim 10 is the device according to any one of claims 4 to 9. , A ring-shaped rotary transformer is provided on an annular wall portion integrally provided on the upper surface of the thrust bearing. An annular spacer for adjusting the gap between the upper and lower parts of the spacer is fitted over the annular spacer. An annular recess that is almost the same as or slightly larger than the pacer has a shaft insertion hole on the bottom surface of the boss. It is formed concentrically, and by fixing the thrust bearing to the lower surface of the boss, The upper surface of the thrust bearing is brought into close contact with the lower surface of the annular spacer, and the annular space is It is characterized in that the upper surface of the groove is brought into close contact with the bottom surface of the annular recess.

[0033]   According to the above configuration, the gap adjusting annular spacer and the thrust bearing are combined. This prevents oil from leaking from the lower end opening of the shaft insertion hole. In addition, the annular spacer is formed on the bottom surface of the annular recess formed on the lower surface of the boss. The top surface is designed to be in intimate contact, and in order to prevent oil leakage, the ring Only the bottom surface of the recess needs to be precision machined, so the entire bottom surface of the boss is precision machined. Processing costs are lower than those of

[0034]

[Embodiment of device]

  1 to 4 show a rotary magnetic head device according to a first embodiment of the present invention. Therefore, the inner diameter D of the shaft insertion hole 6 is slightly larger than the outer diameter H of the shaft 8. It is set, and the upper and lower parts and the central part of the inner peripheral surface of the shaft insertion hole 6 are cut in the circumferential direction. A plurality of oil reservoirs 40, 41 and a groove 42 are formed at a predetermined interval in the vertical direction. As a result, a plurality of bearing portions 43, 44 are cut above the oil reservoirs 40, 41. A spiral oil is left on the outer peripheral surface of the shaft 8 so as to face the bearings 43 and 44. Guide grooves 45 and 46 are engraved, and the annular groove 4 is provided at the upper end of each oil guide groove 45 and 46. 5a and 46a are extended. In addition, the thrust bearing 17 is integrally projected on the upper surface. Adjust the gap G between the upper and lower parts of the ring-shaped rotary transformer 28 on the annular wall 20. An annular spacer 30 for adjusting is fitted on the outer surface of the annular spacer 30. Has a slightly larger diameter annular recess 31 formed concentrically with the shaft insertion hole 6 on the lower surface of the boss 4a. The thrust bearing 17 is fixed to the lower surface of the boss portion 4a with a screw 19. This ensures that the upper surface of the thrust bearing 17 is brought into close contact with the lower surface of the annular spacer 30. In addition, the upper surface of the annular spacer 30 is brought into close contact with the bottom surface of the annular recess 31. Furthermore, A drive motor 22 for rotating the rotary cylinder 2 is installed on the rotary cylinder 2. The magnet 22a attached to the rotor plate 23 fixed to the Stator arranged in the rotor plate 23 connected to the rotor 4 via the connecting frame 24. 25 and a coil 22b attached to the center of the stator 25. The cylindrical earth brush 26 inserted so as to be movable downward is attached to the upper end surface of the shaft 8 by a spring 27. The lower end surface of the shaft 8 is thrust by pressing with a predetermined pressing force P by It is supported by bearings 17. The configuration other than the above is the same as the configuration shown in FIG. The reference numerals are given and the description thereof is omitted.

[0035]   In the above-mentioned structure, the drive is performed with oil stored in the oil guide grooves 45, 46. By driving the dynamic motor 22 to rotate the rotary cylinder 2 and the shaft 8, , The oil O was pushed up along the spiral oil guide grooves 45, 46 and pushed up. The oil O is supplied to the gap a between the bearings 43, 44 and the shaft 8 to supply the oil O. Thin film is formed. Therefore, the rotating shaft 8 is burned on the bearings 43 and 44. It is possible to stabilize the rotational movement of the rotary cylinder 2 without any risk of it becoming attached. This Running along the outer peripheral surface of the rotating cylinder 2 and the fixed cylinder 4 which are rotated at high speed Information is recorded / reproduced by the magnetic head 1 on / from a magnetic tape (not shown). It

[0036]   What is important here is that the oil O is pushed up along the oil guide grooves 45, 46. Therefore, the liquid level height h of the oil O stored in the shaft insertion hole 6 (see FIG. 2) can be suppressed to a low level. Accidentally expands at a high temperature and overflows from the upper opening of the shaft insertion hole 6. It can be solved reliably.

[0037]   The fixed cylinder 3 and the plurality of bearings 43 and 44 are integrally formed by aluminum die casting. By shaping, the shaft centers O3 and O4 of the bearings 43 and 44 are accurately matched. It is possible to stably support the shaft 8 so that it does not run out. be able to. Further, the inner peripheral surface of each bearing portion 43, 44 is polished and each oil reservoir portion 40 is processed. , 41 are continuously cut to finish the shaft insertion hole 6. Can be performed quickly and easily, and the processing cost can be reduced as compared with the conventional method. Furthermore, since the conventional oil-impregnated metal bearings 15 and 16 (see FIG. 7) are omitted, The number of parts is reduced by the amount omitted, and the manufacturing cost is low. Moreover, bye The spiral oil guide grooves 45, 46 can be quickly formed on the outer peripheral surface of the shaft 8 with a cutting tool such as It can be engraved quickly and easily, and the cutting cost is low.

[0038]   As an example of specific dimensions, as shown in FIG. 2, the outer diameter H of the shaft 8 is 7 mm. , The gap a between the shaft 8 and the bearing portions 43, 44 is 4 to 8 μ, and the oil reservoir portions are The depth b of 40 and 41 is 0.1 to 0.5 mm.

[0039]   As shown in FIG. 2, from the annular grooves 45a and 46a on the inner peripheral surfaces of the bearings 43 and 44, At a position slightly lower than that, an annular oil groove 48 having a depth c of, for example, about 0.05 to 0.1 mm is provided. An appropriate number (one in this embodiment) is engraved.

[0040]   According to the above configuration, a small amount of oil O is always stored in the annular oil groove 48. Even when the rotary cylinder 2 is rotated after being stopped for a long time, for example, in the annular oil groove 48, The oil O spreads in the gap a between the bearings 43, 44 and the shaft 8 and There is no risk of the shaft 8 sticking to the receiving portions 43 and 44.

[0041]   As shown in FIG. 2, the gap adjusting annular spacer 30 and the thrust bearing 17 are Depending on the combination, make sure that the oil O leaks from the lower end opening of the shaft insertion hole 6. It is possible to prevent it, and in addition, the annular recess 31 formed on the lower surface of the boss 4a The bottom surface of the annular spacer 30 is closely attached to the bottom surface to prevent oil leakage. To stop it, only the bottom surface of the annular recess 31 needs to be precision processed, The processing cost is lower than that in the case where the entire lower surface of the boss portion 4a is precision processed.

[0042]   As shown in Fig. 1, the stainless steel has excellent rigidity, linearity and precision finishing of the outer peripheral surface. Since the shaft 8 is made of a rod material made of stainless steel, the rotational movement of the rotary cylinder 2 is prevented. It can be stably maintained for a long period of time.

[0043]   FIG. 5 shows a rotary magnetic head device according to a second embodiment of the present invention. The shaft 8 and the rotary cylinder 2 are integrally molded, and are arranged on the upper surface of the rotary cylinder 2. The earth brush 26 is in contact with the placed magnetic plate 36. Configurations other than the above are shown in FIG. 1 to 4 are substantially the same as those in the first embodiment shown in FIG. The description is omitted.

[0044]   According to the above configuration, it is possible to obtain substantially the same effect as that of the first embodiment. By integrally molding the shaft 8 and the rotary cylinder 2 with aluminum die casting, The rotation of the shaft 8 with respect to the rotary cylinder 2 is accurately set in terms of verticality and height. It is possible to manufacture the rotary cylinder 2 with the shaft 8 having high accuracy, and Rotating cylinder 2 with gut 8 is a single item and is equipped with a stainless steel shaft 8. Since the number of parts is halved compared to the rolling cylinder 2, the material cost is low.

[0045]   FIG. 6 shows a rotary magnetic head device according to a third embodiment of the present invention. By forming the shaft 8 into a hollow shape, the hollow shaft 8 does not have an iron bar. Which magnetic mandrel 38 is inserted, and the earth brush 26 contacts the upper end surface of the magnetic mandrel 38. It is touched. The configuration other than the above is almost the same as that of the first embodiment shown in FIGS. Since they are the same, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0046]   According to the above configuration, it is possible to obtain substantially the same effects as those of the first and second embodiments. In addition, the magnetic mandrel 38 can be fitted into the hollow shaft 8 to be inserted therein. Since 8 is reinforced, if an excessive load is applied, for example, in a vibration / drop test. However, the verticality of the shaft 8 is not disturbed. Also, with the magnetic mandrel 38 Because it is possible to use an inexpensive iron bar just roughened the surface as it is The material cost is low and it is economical. Furthermore, the upper end surface of the magnetic mandrel 38 has an arc. The brush 26 is brought into contact with the magnetic mandrel 38 for removing static electricity. Since it is also used as a dual purpose, the number of parts is reduced by the amount that is also used, and the manufacturing cost is reduced. Can be cheaper.

[0047]

[Effect of device]

  According to the invention as set forth in claim 1, the fixed cylinder and the plurality of bearings are made of an aluminum die. By integrally molding by casting, the shaft centers of the bearings can be accurately aligned. By doing this, it is possible to support the shaft stably so that it does not wobble. Wear. In addition, the inner peripheral surface polishing of each bearing and the cutting of each oil reservoir are performed continuously. By doing so, it is possible to quickly and easily finish the shaft insertion hole. The processing cost can be reduced as compared with the conventional method. In addition, the conventional oil-impregnated metal bearing is omitted. Since it is omitted, the number of parts is reduced by the amount omitted and the manufacturing cost is low. Tighten.

[0048]   A spiral oil guide groove is engraved on the outer peripheral surface of the shaft facing each bearing. , By rotating the shaft with oil stored in each oil reservoir, The oil is pushed up along the spiral oil guide groove, and the pushed up oil is applied to each bearing. Is supplied to the gap between the shaft and the shaft to form a thin film of oil, Stabilizes the rotary motion of the rotating cylinder without the risk of the shaft of the machine sticking to each bearing Can be transformed. Also, use a cutting tool such as a cutting tool to spiral on the outer peripheral surface of the shaft. -Shaped oil guide groove can be engraved quickly and easily, and the cutting cost is low.

[0049]   The important thing here is that the oil is pushed up along the oil guide groove. Therefore, the liquid level of the oil collected in the shaft insertion hole can be kept low. This causes the oil to expand at high temperature and cause the oil to expand above the shaft insertion hole. It is possible to reliably eliminate the accident of overflowing from the end opening.

[0050]   Is a small amount of oil always accumulated in the annular oil groove engraved on the inner peripheral surface of each bearing? For example, even if the rotating cylinder is rotated after being stopped for a long time, the oil in the annular oil groove may be rotated. Spread in the gaps between the bearings and the shaft, and the shaft is burned in the bearings. There is no danger of getting stuck.

[0051]   By combining the annular spacer for gap adjustment and the thrust bearing, the shaft It is possible to reliably prevent oil from leaking from the lower end opening of the insertion hole, and , Make sure that the upper surface of the annular spacer is in close contact with the bottom surface of the annular recess formed on the lower surface of the boss. In order to prevent oil leakage, only the bottom of the annular recess should be cleaned. Since it only needs to be densely machined, it is more effective than precision machining of the entire lower surface of the boss. Construction costs are low.

[0052]   Rotated by a stainless steel bar that has excellent rigidity, linearity and precision finishing of the outer peripheral surface. Since the shaft of the rolling cylinder is formed, the rotary motion of the rotating cylinder is maintained for a long time. Can be stably maintained over.

[0053]   According to the invention as set forth in claim 2, an effect substantially similar to the effect as set forth in claim 1 is obtained. It is possible to use aluminum die casting for the shaft and rotary cylinder. By integrally molding, the verticality and height of the shaft with respect to the rotating cylinder can be adjusted. It is possible to manufacture a rotating cylinder with a shaft with a precisely set rotating accuracy, In addition, the rotating cylinder with shaft is a single item, and the stainless steel shaft Since the number of parts is halved compared to a rotating cylinder with a built-in rotary cylinder, the material cost is low.

[0054]   According to the device of claim 3, the same effect as the effects of claims 1 and 2 is obtained. The fruit can be obtained, and in particular, the shaft is inserted by inserting the mandrel into the hollow shaft. Since the hood is reinforced, excessive load was applied, for example, in vibration / drop tests. Even when the verticality of the shaft is not disturbed, and the surface as a mandrel Since it is possible to use an inexpensive iron bar just rough-finished as it is, material cost It does not cost much and is economical.

[0055]   According to the invention as set forth in claim 4, the fixed cylinder and the plurality of bearings are made of an aluminum die. By integrally molding by casting, the shaft centers of the bearings can be accurately aligned. By doing this, it is possible to support the shaft stably so that it does not wobble. Wear. In addition, the inner peripheral surface polishing of each bearing and the cutting of each oil reservoir are performed continuously. By doing so, it is possible to quickly and easily finish the shaft insertion hole. The processing cost can be reduced as compared with the conventional method. In addition, the conventional oil-impregnated metal bearing is omitted. Since it is omitted, the number of parts is reduced by the amount omitted and the manufacturing cost is low. Tighten.

[0056]   An oil guide groove extending vertically is engraved on the outer peripheral surface of the shaft facing each bearing. The shaft is rotated with oil stored in each oil reservoir. Pushes up the oil along the oil guide groove by the The oil is supplied to the gap between the receiving part and the shaft to form a thin film of oil. There is no risk of the rotating shaft burning on each bearing and Can be stabilized.

[0057]   The important thing here is that the oil is pushed up along the oil guide groove. Therefore, the liquid level of the oil collected in the shaft insertion hole can be kept low. This causes the oil to expand at high temperature and cause the oil to expand above the shaft insertion hole. It is possible to reliably eliminate the accident of overflowing from the end opening.

[0058]   According to the invention of claim 5, a cutting tool such as a cutting tool is used to screw the outer peripheral surface of the shaft. The spiral oil guide groove can be engraved quickly and easily, and the cutting cost is low.

[0059]   According to the invention as set forth in claim 6, a small amount is provided in the annular oil groove formed in the inner peripheral surface of each bearing portion. Since a certain amount of oil is always accumulated, for example Even if it is installed, the oil in the annular oil groove spreads in the gap between each bearing and the shaft. As a result, there is no risk of the shaft sticking to the bearings.

[0060]   According to the invention of claim 7, it is excellent in rigidity, linearity and precision finishing of the outer peripheral surface. Since the shaft of the rotating cylinder is formed by the stainless steel rod that is The rotary motion of the rotary cylinder can be stably maintained for a long period of time.

[0061]   According to the invention as set forth in claim 8, the shaft and the rotary cylinder are die-cast with aluminum. The verticality and height of the shaft with respect to the rotary cylinder can be It is possible to manufacture a rotating cylinder with a shaft that has a precisely set rotational accuracy. In addition, the rotating cylinder with shaft is made as a single item, Since the number of parts is halved compared to a rotary cylinder with a blade, the material cost is low.

[0062]   According to the invention as set forth in claim 9, the mandrel is fitted into the hollow shaft to insert the shaft into the shuffle. Since the tongue is reinforced, for example, if an excessive load is applied in a vibration / drop test, etc. Even if the shaft does not disturb the verticality of the shaft, Inexpensive iron bars that have only been roughly finished can be used as they are, so material costs It does not cost much and is economical.

[0063]   According to the invention as set forth in claim 10, an annular spacer for gap adjustment and a thrust shaft are provided. When combined with a pan, oil will not leak from the bottom opening of the shaft insertion hole. It can be reliably blocked, and the bottom surface of the annular recess formed on the bottom surface of the boss portion The upper surface of the annular spacer is designed to be in close contact with it to prevent oil leakage. In this case, only the bottom surface of the annular recess needs to be precision machined, so the entire bottom surface of the boss The processing cost is lower than that of precision processing of the body.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a rotary magnetic head device according to a first embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of the main part.

FIG. 3 is an enlarged cross-sectional view of a main part of the drawing.

FIG. 4 is an exploded perspective view of the main part.

FIG. 5 is a vertical cross-sectional view showing a main part of a rotary magnetic head device according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional view showing a rotary magnetic head device according to a third embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing a conventional example.

[Explanation of symbols]

1 Magnetic Head 2 Rotating Cylinder 4 Fixed Cylinder 4a Boss 6 Shaft Insertion Hole 8 Shaft 15 Upper Oil-impregnated Metal Bearing 16 Lower Oil-impregnated Metal Bearing 17 Thrust Bearing 18 Boss Lower Surface 19 Screw 20 Annular Wall 22 Drive Motor 28 Ring Rotary Transformer 30 Annular spacer 31 Annular recess 38 Magnetic mandrel 40, 41 Oil sump 43, 44 Bearing 45, 46 Oil guide groove 48 Annular oil groove O Oil G Gap between upper and lower parts of ring-shaped rotary transformer Bearing and shaft The gap between

Claims (10)

[Scope of utility model registration request] 1. A rotary cylinder having a magnetic head and a fixed cylinder are concentrically arranged, and an oil-impregnated metal bearing is arranged in a shaft insertion hole of a boss integrally formed in a central portion of the fixed cylinder. The lower end opening of the shaft insertion hole is closed by externally fitting the cup-shaped thrust bearing to the lower part of the shaft, and the stainless steel shaft whose upper end is fitted in the central through hole of the rotary cylinder is inserted into the shaft insertion hole. The outer peripheral surface of the shaft is rotatably supported by the oil-impregnated metal bearing, and the lower end surface of the shaft is supported by the cup-shaped thrust bearing, so that the drive motor rotates the rotary cylinder about the shaft. In the rotating magnetic head device, the oil-impregnated metal bearing is omitted, and the inner diameter of the shaft insertion hole is slightly larger than the outer diameter of the shaft. The inner peripheral surface of the shaft insertion hole is circumferentially cut to form a plurality of oil reservoirs at predetermined intervals in the vertical direction, so that a plurality of bearings are provided above each oil reservoir. Left uncut, a spiral oil guide groove is engraved on the outer peripheral surface of the shaft so as to face each bearing portion, and an annular oil groove is engraved on the inner peripheral surface of each bearing portion. With the oil stored in the oil reservoir, the shaft is rotated to push the oil up along the spiral oil guide groove, and the pushed oil is supplied to the gaps between the bearings and the shaft to form the cup-shaped thrust bearing. Instead, a circular plate-shaped thrust bearing is used, and an annular spacer for adjusting the gap between the upper and lower portions of the ring-shaped rotary transformer is externally fitted to an annular wall portion integrally provided on the upper surface of the thrust bearing. Annular spacer An annular recess of approximately the same or slightly larger diameter is formed on the lower surface of the boss portion concentrically with the shaft insertion hole, and by fixing the thrust bearing to the lower surface of the boss portion, the upper surface of the thrust bearing is fixed to the annular spacer. A rotary magnetic head device characterized in that it is in close contact with the lower surface and the upper surface of the annular spacer is in close contact with the bottom surface of the annular recess. 2. A rotary cylinder having a magnetic head and a fixed cylinder are concentrically arranged, and an oil-impregnated metal bearing is arranged in a shaft insertion hole of a boss integrally formed in a central portion of the fixed cylinder. The lower end opening of the shaft insertion hole is closed by externally fitting the cup-shaped thrust bearing to the lower part of the shaft, and the stainless steel shaft whose upper end is fitted in the central through hole of the rotary cylinder is inserted into the shaft insertion hole. The outer peripheral surface of the shaft is rotatably supported by the oil-impregnated metal bearing, and the lower end surface of the shaft is supported by the cup-shaped thrust bearing, so that the drive motor rotates the rotary cylinder about the shaft. In the rotary magnetic head device described above, a rotary shaft in which a shaft is integrally molded is used instead of the rotary cylinder with a shaft made of stainless steel. A binder is used, the oil-impregnated metal bearing is omitted, the inner diameter of the shaft insertion hole is set to be slightly larger than the outer diameter of the shaft, and the inner peripheral surface of the shaft insertion hole is cut in the circumferential direction to form a plurality of oil reservoirs. Are formed at predetermined intervals in the vertical direction, a plurality of bearing portions are left uncut on the upper side of each oil reservoir portion, and a spiral oil guide groove is formed on the outer peripheral surface of the shaft so as to face each bearing portion. In addition to being engraved, an annular oil groove is engraved on the inner peripheral surface of each of the bearing portions, and while the oil is stored in each oil reservoir, the rotation of the shaft causes the oil to flow along the spiral oil guide groove. By pushing up and supplying the pushed up oil to the gaps between the bearings and the shaft, a circular plate-shaped thrust bearing is used in place of the cup-shaped thrust bearing, and an annular wall integrally projected on the upper surface of the thrust bearing. Ring-shaped An annular spacer for adjusting the gap between the upper and lower parts of the rotary transformer is externally fitted, and an annular recess having a diameter substantially the same as or slightly larger than that of the annular spacer is formed on the lower surface of the boss portion concentrically with the shaft insertion hole. By fixing the thrust bearing to the lower surface of the boss portion, the upper surface of the thrust bearing is brought into close contact with the lower surface of the annular spacer, and the upper surface of the annular spacer is brought into close contact with the bottom surface of the annular recess. Rotating magnetic head device. 3. A rotary cylinder having a magnetic head and a fixed cylinder are concentrically arranged, and an oil-impregnated metal bearing is arranged in a shaft insertion hole of a boss integrally formed in the center of the fixed cylinder. The lower end opening of the shaft insertion hole is closed by externally fitting the cup-shaped thrust bearing to the lower part of the shaft, and the stainless steel shaft whose upper end is fitted in the central through hole of the rotary cylinder is inserted into the shaft insertion hole. The outer peripheral surface of the shaft is rotatably supported by the oil-impregnated metal bearing, and the lower end surface of the shaft is supported by the cup-shaped thrust bearing, so that the drive motor rotates the rotary cylinder about the shaft. In the rotary magnetic head device described above, a rotary shaft in which a shaft is integrally molded is used instead of the rotary cylinder with a shaft made of stainless steel. A binder is used, and by forming the shaft in a hollow shape, the mandrel is inserted into the hollow shaft, the oil-impregnated metal bearing is omitted, and the inner diameter of the shaft insertion hole is set to be slightly larger than the outer diameter of the shaft. By cutting the inner peripheral surface of the shaft insertion hole in the circumferential direction to form a plurality of oil reservoirs at predetermined intervals in the vertical direction, a plurality of bearing portions are left above the oil reservoirs. A spiral oil guide groove is engraved on the outer peripheral surface of the shaft so as to face each bearing portion, and an annular oil groove is engraved on the inner peripheral surface of each bearing portion. With the oil accumulated in the parts, the shaft is rotated to push the oil up along the spiral oil guide groove, and the pushed oil is supplied to the gaps between the bearings and the shaft to replace the cup-shaped thrust bearing. Circular plate A thrust bearing is used, and an annular spacer for adjusting the gap between the upper and lower portions of the ring-shaped rotary transformer is externally fitted to an annular wall portion integrally provided on the upper surface of the thrust bearing. An annular recess with a slightly larger diameter is formed concentrically with the shaft insertion hole on the lower surface of the boss, and by fixing the thrust bearing to the lower surface of the boss, the upper surface of the thrust bearing closely contacts the lower surface of the annular spacer. The rotating magnetic head device is characterized in that the upper surface of the annular spacer is brought into close contact with the bottom surface of the annular recess. 4. A rotary cylinder having a magnetic head and a fixed cylinder are concentrically arranged, and a shaft of the rotary cylinder is inserted into a shaft insertion hole of a boss portion integrally formed in a central portion of the fixed cylinder, In a rotary magnetic head device in which a lower end surface of the shaft is supported by a thrust bearing fixed to a lower surface of a boss portion, and a rotary cylinder is rotated about a shaft by a drive motor, an inner diameter of the shaft insertion hole is It is set to be slightly larger than the outer diameter of the shaft, and the inner peripheral surface of the shaft insertion hole is cut in the circumferential direction to form a plurality of oil reservoirs at predetermined intervals in the vertical direction. A plurality of bearings are left uncut on the upper side, and an oil guide groove extending in the vertical direction is formed on the outer peripheral surface of the shaft so as to face each bearing, and It is characterized in that the oil is pushed up along the oil guide groove by the rotation of the shaft while the oil is stored in the oil reservoir and the pushed oil is supplied to the gaps between the bearings and the shaft. Rotating magnetic head device. 5. The rotary magnetic head device according to claim 4, wherein the oil guide groove is formed in a spiral shape on the outer peripheral surface of the shaft. 6. The rotary magnetic head device according to claim 4, wherein an annular oil groove is formed on the inner peripheral surface of each of the bearing portions. 7. The shaft is made of stainless steel, and the upper end of the stainless steel shaft is fitted in the central through hole of the rotary cylinder.
The rotary magnetic head device according to any one of 1. 8. The shaft according to claim 4, wherein the shaft is integrally formed with the rotary cylinder.
7. The rotary magnetic head device according to any one of 1 to 6. 9. The rotary magnetic head device according to claim 8, wherein the shaft is formed in a hollow shape, and a mandrel is fitted in the hollow shaft. 10. An annular spacer for adjusting a gap between upper and lower portions of a ring-shaped rotary transformer is externally fitted to an annular wall portion integrally provided on an upper surface of the thrust bearing,
An annular recess having a diameter substantially the same as or slightly larger than that of the annular spacer is formed on the lower surface of the boss portion concentrically with the shaft insertion hole, and the upper surface of the thrust bearing is fixed by fixing the thrust bearing to the lower surface of the boss portion. 10 is closely contacted with the lower surface of the annular spacer, and the upper surface of the annular spacer is closely contacted with the bottom surface of the annular recess.
The rotary magnetic head device according to any one of 1.