JPS63103638A - Rotary unit - Google Patents

Abstract

PURPOSE:To improve the accuracy of the axial and radial vibrations of a rotary member, by a method wherein the degree of parallelism between the contacting surface of a rotor supporting member to a rotor and the contacting surface of the same to an intermediate member is improved. CONSTITUTION:When a rotor supporting member 41 is pinched between one mold and the other mold and is molded by plastic work, one mold is slanted slightly with respect to the other mold. Accordingly, both of the contacting surface of the rotor supporting member 41 to a rotor 43 and the contacting surface of the same member 41 to a disc 29 are molded while contacting with one mold when both of the rotor 43 and the contacting surface of the disc 29 to the rotor supporting member 41 are at the lower side or the inside of the rotor supporting member 41, therefore, the degree of parallelism and the degree of perpendicularity between the contacting surface of the rotor supporting member 41 to the rotor 43 and the contacting surface of the same member 41 to the disc 29 may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application J] The present invention relates to a rotating unit used in video cheap recorders, digital audio tape recorders, compact discs, 70-tuppy discs, and the like.

[Prior Art] Conventionally, as shown in FIG. 1 of JP-A-61-127919, a cylindrical hole provided in a housing has a thrust bearing surface and a cylindrical radial bearing surface. The shaft disposed in the shaped hole has a thrust surface facing the thrust bearing surface and a radial surface facing the radial bearing surface. The radial surface is provided with a groove for generating dynamic pressure for the radial bearing, and the thrust bearing surface is provided with a groove for generating dynamic pressure for the thrust bearing, although not shown.

An annular disk having a rectangular cross section is attached to the upper part of the shaft, and an annular intermediate member is attached to the upper surface of the disk by bolts. A rotor support member is attached to the lower surface of the intermediate member with bolts, and a rotor is attached to the lower surface of this rotor support member. A stator support member is attached to the lower part of the outer peripheral surface of the front housing, and a stator attached to a printed circuit board is attached to this stator support member. The stator faces the rotor in the axial direction, and a rotating drum is attached to the upper surface of the intermediate member as a rotating member.

[Problem to be Solved by the Invention J] Since the rotating drum is attached to the intermediate member attached to the disk, the parallelism and widening angle of the rotating drum to the disk are worse than the parallelism and widening angle to the intermediate member. Therefore, since the rotating drum has poor parallelism and wide angle to the shaft body, when molding the rotating drum by axial pressing, the contact surface of the rotor support member to the rotor is molded in contact with one of the molds, and the rotor support member is molded in contact with the rotor. The contact surface of the member to the intermediate member is molded in contact with the other mold. In this case, one mold is slightly inclined with respect to the other mold, so the contact surface of the rotor support member to the rotor and the contact surface of the rotor support member to the intermediate member are not parallel, and the rotor support member Since the installed rotor has a poor wide angle with respect to the shaft body, a motor with the desired performance cannot be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating unit with good axial and radial runout accuracy of rotating members and good motor performance.

[Means for solving the problem 1: The cylindrical hole provided in the housing has a thrust bearing surface and a cylindrical radial bearing surface, and the shaft body provided in the cylindrical hole faces the thrust bearing surface. It has a thrust surface and a radial surface facing the radial bearing surface. A groove for generating dynamic pressure is provided on at least one of the radial bearing surface and the radial surface, and a rotor support member is attached to at least one of the upper surface and the outer peripheral surface of the disk attached to the upper part of the sleeve body, A rotor whose inner peripheral surface has a larger diameter than the disk is attached to the rotor support member. A printed circuit board having an inner circumferential surface larger in diameter than the disk and a stator having an inner circumferential surface larger in diameter than the disk are respectively attached to the stator support member attached to the lower part of the outer circumferential surface of the housing, and the stator faces the rotor in the axial direction. are doing. A rotating member is attached to the disk.

[Action 1: Drive the 0-tor and stator lf! As a mechanism, when the sleeve body rotates, the pressure of the lubricant in the radial bearing clearance between the radial bearing surfaces increases due to the pumping action of the grooves for generating dynamic pressure, and the radial surfaces become non-contact with respect to the radial bearing surfaces. Rotates on contact.

The assembly order of the rotating unit is to first attach the disk to the sleeve body, and then insert the sleeve body with the disk attached into the cylindrical hole of the unong. Then, the stator support member is attached to the housing, and then the stator attached to the printed circuit board is attached to the stator support member from above. Then, attach the rotor support member that supports the rotor to the disk from above,
Next, attach the rotating member to the disk.

[Example] Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment in which the rotating unit of the present invention is used in a video tape recorder.A housing 1 has grooves formed between a sleeve 3 and a cylindrical roller 5 fitted to the lower part of the inner peripheral surface of the sleeve 3. has been completed. The cylindrical hole 7 provided in the housing 1 has a planar thrust bearing surface 9 and cylindrical radial bearing surfaces 11 provided at two locations spaced apart in the axial direction. is the second
As shown in the figure, a groove 13 for generating dynamic pressure for a spiral thrust bearing is provided. The cylindrical hole 7 has a large diameter hole 15 that is larger in diameter than the radial bearing surface 11 between the two radial bearing surfaces 11, and this large diameter hole 15 has an upper air vent hole 1 provided in the housing 1. It communicates with the outside of the housing 1 through the opening. The bottom of the cylindrical hole 7 communicates with the outside of the housing 1 through a groove-shaped lower air vent hole 19 provided in the lower part of the inner peripheral surface of the sleeve 3 in the axial direction. The shaft body 21 disposed in the cylindrical hole 7 has a planar thrust surface 23 facing the thrust bearing surface 9 and a radial surface 25 facing the radial bearing surface 11, and has two radial surfaces 25. are each provided with a groove 27 for generating dynamic pressure for a herringbone-shaped radial bearing. The thrust bearing clearance between the thrust bearing surface 9 and the thrust surface 23 and the radial bearing clearance between the radial bearing surface 11 and the radial surface 25 are filled with oil, grease,
A lubricant such as air is present in each case. The shaft body 21
Attach an annular disk 29 to the upper part of the
A cylindrical transmission side rotary transformer 31 is attached to a large diameter portion provided at the lower part of the inner peripheral surface of the disk 29.

A cylindrical fixed rotary transformer 33 is attached to the outer peripheral surface of the housing 1, and the fixed rotary transformer 33 is located on the inner periphery of the rotating rotary transformer 31. An annular stator support member 35 is attached to the lower part of the outer peripheral surface of the housing 1 by shrink fitting, and the inner peripheral surface of the stator support member 3S is attached to a printed circuit board 37 having a larger diameter than the disk 29. A stator 39 having an inner circumferential surface larger in diameter than the disk 29 is attached to each stator 39 . A rotor support member 41 is attached to the outer circumference of the upper surface of the disk 29, and the inner circumference of the rotor support member 41 is attached to the outer circumference of the lower surface of the disk 29.
An annular rotor 43 having a diameter larger than 9 is attached. The rotor 43 faces the stator 39 in the axial direction, and a rotating drum is attached as a rotating member 45 to the inner peripheral side of the upper surface of the disk 29.

When the shaft body 21 rotates in the ellipse as described above, the thrust surface 23 rotates without contacting the thrust bearing surface 9 due to the pumping action of the groove 13 for generating dynamic pressure for the thrust bearing.
Further, the radial surface 25 rotates without contacting the radial bearing surface 11 due to the pumping action of the groove 27 for generating dynamic pressure for the radial bearing.

The order of assembly of this rotating unit is to first install disk 2.
9 is attached to the shaft body 21, and then the shaft body 21 with the disk 29 attached thereto is inserted into the cylindrical hole 7 of the housing. Then, the rotating side rotary transformer 31 is attached to the disk 29, and the fixed rotary transformer 33 is attached to the housing 1. Next, after attaching the stator support member 35 to the housing 1, the stator 39 attached to the printed circuit board 37 is attached to the stator support member from above. Then there is the disk 29 and the rotor support member 41 to which the rotor 43 is attached.
After that, the rotating member 45 is attached to the disk 29.

In addition, in this rotating unit, both the radial bearing clearance and the thrust bearing clearance between the housing 1 and the sleeve body 21 are free from dust such as dirt and foreign matter.

Therefore, after inserting the shaft body 21 into the cylindrical hole 7 of the housing while ensuring the necessary cleanliness, it is not recommended to remove the shaft body 21 from the housing 1 because this will lead to dust entering the radial bearing clearance and the thrust bearing clearance. It doesn't look like an insect. Therefore, when assembling the rotating unit, from the housing 1 to the shaft body 21
There is no need to remove it. Also disk 29
The disk 29 attached to the shaft body 21 is at a high temperature when it is shrink-fitted, but it is at room temperature when the sleeve body 21 is inserted into the cylindrical hole 7 of the housing.
This does not have a negative effect on the lubricant in the radial bearing clearance, and although dust tends to enter the upper part of the radial bearing clearance, when the shaft body 21 with the disc 29 attached is inserted into the cylindrical hole 7 of the housing, the disc Since the disk 29 serves as a cover, the disk 29 prevents dust from entering the radial bearing clearance.

Note that the rotary transformer 31 on the rotating side, the rotary transformer 33 on the stationary side, the printed circuit board 37, etc. all contain six-layer AT fat, so after the rotary transformer 31 on the rotating side is attached to the disk 29, the disk 29 is shrink-fitted to the shaft body. If the stator support member 35 is attached to the housing 1 by shrink fitting after the printed circuit board 37 is attached to the stator support member 35, the printed circuit board 37 will be damaged, which is not preferable.

In addition, when the rotor support member 41 is formed between one mold and the other mold by plastic working such as press working or forging, one mold is slightly inclined with respect to the other mold. . Therefore, if the rotor 43 and the contact surface of the disk 29 with the rotor support member 41 are both on the lower side or the inner peripheral side of the rotor support member 41, the rotor 43 of the rotor support member 41
The contact surface of the rotor support member 41 and the contact surface of the rotor support member 41 to the disk 29 are both molded in contact with one of the molds, so the contact surface of the rotor support member 41 to the rotor 43 and the contact surface of the rotor support member 41 to the disk 29 are molded. Good parallelism and perpendicularity with the contact surface to 29.

Therefore, the perpendicularity of the rotor 43 to the sleeve body 21 is good.

FIG. 13 shows another embodiment of the present invention, in which the bottom of the cylindrical hole 7 communicates with the outside of the housing 1 through a groove-shaped lower air vent hole 19 provided in the axial direction on the outer peripheral surface of the cylindrical roller 5. . Further, in the embodiment shown on the outer circumferential surface of the disk 29, the rotor support member 41 is attached to the outer circumferential surface of the disk 29 by bolts that are screwed into the outer circumferential surface. The other parts of the illustrated embodiment are constructed almost the same as the first embodiment.

FIG. 4 shows a third embodiment of the present invention, in which the lower radial surface 25 is provided with a groove 47 for generating dynamic pressure that serves both as a spiral radial bearing and as a thrust bearing.

Further, the thrust surface 23 has a spherical shape, and a circulation hole 49 communicating with the large diameter hole 15 is provided in the center of the thrust surface 23 . thrust bearing surface 9 and thrust surface 2
3 is not provided with a groove for generating dynamic pressure for the thrust bearing. Therefore, when stationary, the thrust surface 23 rotates while maintaining a very small floating amount relative to the circulation hole 49, and the radial surface 25 rotates without contacting the radial bearing surface 11.

Further, the circulation hole 49 communicates with the large diameter hole 15, and this large diameter hole 15 communicates with the outside of the housing 1 through the upper air vent hole 17. Not provided.

Further, a rotating side rotary transformer 31 is attached to the lower part of the outer peripheral surface of the disk 29, and a stationary side rotary transformer 33 disposed around the outer periphery of the rotating side rotor lance 31 is attached to the stator support member 35.

In addition, in this embodiment, the sleeve body 21 to which the disc 29 is attached
After inserting the disk into the cylindrical hole 7 of the housing, the disk 2
Attach the rotating side rotary transformer 31 to 9. Next, attach the stator support member 35 to the housing 1, and then print the fixed side opening/rotary transformer 33 whose inner circumferential surface has a larger diameter than the disk 29 and the inner circumferential surface which has a larger diameter than the fixed side rotary transformer 33 to the stator supporting member. A substrate 37 and a stator 39 whose inner peripheral surface has a larger diameter than the fixed rotary transformer 33 are attached from above. Next, after attaching the rotor support member 41 that supports the rotor 43 whose inner peripheral surface has a larger diameter than the fixed side rotary transformer 33 to the disk 29, the disk 29
Attach the rotating member 45 to. Therefore, there is no need to remove the sleeve body 21 from the housing 1 when assembling the rotating unit.

In this embodiment, the fixed side rotary transformer 33 is attached to the stator support member 35 after the stator support member 35 attached to the housing 1 by shrink fitting reaches room temperature, so that the heat of the stator support member 35 during the shrink fit is reduced. There is no transmission to the fixed rotary transformer 33 at all. Also, the rotary transformer 31 on the rotating side of the stator support member 35
Since the circumferential groove 51 is provided on the facing surface, the influence of the heat of the stator support member 35 on the rotating side rotary transformer 31 during shrink fitting is reduced.

In the embodiment shown in FIGS. 1 to 3, the radial surface 2
5 is provided with grooves 27 and 47 for generating dynamic pressure, and grooves 27 for generating dynamic pressure in a spiral shape, a herringbone shape, etc. are provided in at least one of the radial bearing surface 11 and the radial surface 25.
．． 47 may be provided.

Moreover, both the radial bearing surface 11 and the radial surface 25 may be located at one location instead of two locations.

Further, since a rotating member 45 is attached to the isk 29 only for generating dynamic pressure for the thrust bearing on at least one of the thrust bearing surface 9 and the thrust surface 23, the rotating member 45 is attached to the disk 29.
The parallelism and perpendicularity to the rotor support member 41 of the rotor 43 and the disk 29 are both good (and the rotating member 45 has good runout accuracy in the axial and radial directions. are both on the lower side or the inner peripheral side of the rotor support member 41, so when the rotor support member 41 is formed by plastic working such as press working or forging, the contact surface of the rotor support member 41 to the rotor 43 and the rotor support member The contact surfaces of 41 to the disk 29 are molded in contact with one of the molds, and the parallelism of the contact surface of the rotor support member 41 to the rotor 43 and the contact surface of the rotor support member 41 to the disk 29 and Therefore, the rotor 43 has a good perpendicularity to the shaft body 21, so the performance of the motor is good.Furthermore, the rotor 43 whose inner peripheral surface has a larger diameter than the disk 29 is attached to the rotor support member 41, and A printed circuit board 37 whose inner circumferential surface has a larger diameter than the disk 29 and a stator 39 whose inner circumferential surface has a larger diameter than the disk 29 are respectively attached to the stator support member 35 attached to the lower part of the outer circumferential surface of the housing 1, so that the disk 29 is attached. After inserting the shaft body 21 into the cylindrical hole 7 of the housing while ensuring the necessary cleanliness, there is no need to remove the shaft body 21 from the housing 1, thereby preventing dust from entering the radial bearing clearance and the thrust bearing clearance. Furthermore, the housing 1, the shaft body 21, and the disk 29 can be transported and handled as a unit.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a rotating unit showing an embodiment of the present invention, Fig. 2 is a plan view of the thrust bearing surface of Fig.
Figure t53 and Figure ptS4 are cross-sectional views of a rotating unit showing another embodiment of the present invention. In the figure, 1 is a housing, 7 is a cylindrical hole, 9 is a thrust bearing surface, 11 is a radial bearing surface, 21 is a shaft body, 23 is a thrust surface, 25 is a radial surface, and 27.47 is a groove for generating dynamic pressure. , 29 is a disk, 35 is a stator support member, 37
39 is a printed circuit board, 39 is a stator, 41 is a rotor support member, 43 is a rotor, and 45 is a rotating member. Patent applicant NSK Ltd. Figure 1

Claims (1)

[Claims] 1. The cylindrical hole provided in the housing has a thrust bearing surface and a cylindrical radial bearing surface, and the shaft body provided in the cylindrical hole has a thrust surface opposite to the thrust bearing surface. and a radial surface facing a radial bearing surface, and a groove for generating dynamic pressure is provided in at least one of the radial bearing surface and the radial surface, and a disk attached to the upper part of the shaft body includes: A rotor support member is attached to at least one of the upper surface and the outer circumferential surface, and a rotor whose inner circumferential surface has a larger diameter than the disk is attached to the rotor support member,
A printed circuit board with an inner circumferential surface having a larger diameter than the disk and a stator whose inner circumferential surface has a larger diameter than the disk are respectively attached to the stator support member attached to the lower part of the outer circumferential surface of the housing,
A rotating unit characterized in that the stator faces the rotor in the axial direction, and a rotating member is attached to the disk. 2. The rotating unit according to claim 1, wherein at least one of the thrust bearing surface and the thrust surface has a groove for generating dynamic pressure for the thrust bearing. 3. The rotating unit according to claim 1, wherein the disk is attached to the shaft body by shrink fit, and the stator support member is attached to the housing by shrink fit.