JPS63153702A - Manufacture of rotary device - Google Patents

Abstract

PURPOSE:To obtain a rotary head with a stable characteristic by applying cut processing to a stator member and a stator core at the same time so as to keep the interval at a stator and a rotor side constant in a rotary transformer where a dynamic fluid bearing is arranged to a thrust gap between the stator and the rotor member. CONSTITUTION:A reference face 1a of a stator cylinder 1 and an upper face 7a of a stator core 7 are cut simultaneously to finish the interval between the reference face and the core upper face with high accuracy. Then a rotary auxiliary member 3 and rotary core 6 are finished similarly. In arranging and assembling a rotary shaft 2, a radial dynamic fluid bearing 16R and a thrust dynamic fluid bearing 16T to the stator and rotor, the transmission characteristic of rotary transformers 6, 7 is decided by the accuracy of the height H of between the reference face 1a and a magnetic head 5. Thus, part of the stator core and the stator member of the rotary transformer is processed at the same time to increase the accuracy so as to make the gap between the stator and the rotor constant thereby obtaining the rotary head of a magnetic video recording and reproducing device or the like whose characteristic is made stable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention includes a fixed member and a one-rotation member, and has a rotary transformer for transmitting signals between the rotating member and the fixed member, and has a rotary transformer that transmits signals in the thrust direction. The present invention relates to a method of manufacturing a rotating device in which a hydrodynamic bearing is disposed in at least one gap of the present invention.

[Prior Art j] This invention applies to rotating devices that require particularly high positional accuracy in the axial direction and low cost, especially rotating members such as magnetic recording and reproducing devices (hereinafter referred to as VTR), such as rotating head cylinders. A rotary head assembly having a rotary transformer for transmitting signals between a fixed member and a fixed member will be described.

FIG. 1 is a sectional view showing an example of a rotary head type assembly using a hydrodynamic bearing in a VTR. 1 is a fixed cylinder, 2 is a rotating shaft, 3 is a rotation auxiliary member, 4 is a rotating cylinder fitted into this rotation auxiliary member 3, and 5 is a magnetic head.

Further, the rotation auxiliary member 3 is provided with a rotating side core 6 of a rotary transformer, and the fixed cylinder 1 is provided with a fixed side core 7 facing the rotating side core 6. And 8～
Reference numeral 11 constitutes a motor section for rotating the rotary cylinder 4, 8 is a rotary yoke, 9 is a rotary magnet, 10 is a stator yoke, and 11 is a stator coil. Furthermore, 16R and 17R are radial dynamic pressure fluid bearings, and 16T is a thrust dynamic pressure fluid bearing.

The smaller the gap between the rotating core 6 and the stationary core 7, the higher the signal transmission efficiency. On the other hand, since both need to rotate relative to each other, a gap must be maintained in the range of several tens of microns to more than 100 microns.

[Problems to be solved by the invention] In the conventional rotating head assembly as described above,
The rotating and stationary cores of the rotary transformer, both of which have been ground, are joined with high precision, and adjustment members such as washers are used to install each core to adjust the height of the head relative to the stationary cylinder. There was a problem in that it was necessary to provide an adjustment member, and the thickness of the adjustment member also had to be changed.

This invention was made to solve this problem, and it maintains a constant distance between the rotating side and the fixed side of the rotary transformer, does not require any auxiliary members, and eliminates the need for position adjustment between the fixed member and the rotating member. , the purpose is to obtain a rotating device with stable characteristics.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, at least a portion of the fixed side core and the fixed member of the rotary transformer are simultaneously cut into a predetermined shape. It is something that forms.

[Function] Since the distance between the thrust direction fluid bearings can always be kept constant, the gap between the stationary side and the rotating side of the rotary transformer can be kept constant by the above method without using any means to adjust the positional accuracy. Therefore, the relative positional accuracy between the fixed member and the rotating member can be increased without particularly providing an adjusting member.

[Embodiment] Fig. 2 is a sectional view showing a part of the fixed side of a rotary transformer in a rotating device according to an embodiment of the present invention, and the same reference numerals as in Fig. 1 indicate the same or corresponding parts. 1 shows a state in which the fixed core 7 of the rotary transformer is bonded to the blank material of the fixed cylinder 1. H in FIG. 1 indicates the height from the bottom of the fixed cylinder 1 to the center of the magnetic head 5.

In the state shown in FIG. 2, by cutting the fixed cylinder l and the upper surface 7a of the fixed core 7 of the rotary transformer at the same time, the reference surface 1a of the fixed cylinder 1 and the upper surface 7a of the fixed core 7 of the rotary transformer are aligned in a predetermined manner. They are formed in a predetermined shape and at intervals of , making it possible to maintain extremely high accuracy. Furthermore, it is generally easier to ensure the precision relationship between the rotational auxiliary member 3 and the rotating side core 6 of the rotary transformer, and therefore the interval between the rotating side and the fixed side of the rotary transformer can be made constant.

Even when assembled as a rotating head assembly,
Since the height H of the reference surface 1a and the magnetic head 5 depends on the precision of each of the above elements, the positional precision of the magnetic head 5 with respect to the fixed cylinder is extremely high, almost no adjustment is required, and the rotary transformer is can obtain stable characteristics.

Incidentally, as in the above embodiment, not only the reference surface 1a of the fixed cylinder 1, which is the upper surface of the fixed cylinder 1 and the fixed side core IO of the rotary transformer, is simultaneously processed, but also the rotational auxiliary member 3 and the rotating side core 9 of the rotary transformer are processed simultaneously. Of course, by performing simultaneous processing with the rotary transformer, it is possible to further improve familiarity with the distance between the rotating side and the stationary side of the rotary transformer. In addition, when machining the rotary transformer portion, the accuracy is sufficiently guaranteed if the same machine and the same chuck are used for cutting or grinding. However, since the fixed cylinder 1 is made of aluminum, machining the rotary transformer part is more cost-effective than grinding, and in particular, the fixed cylinder l and the fixed core 10 of the rotary transformer are Since it is bonded, there is less chance of cracking during cutting.

In addition, in the above explanation, 16T is used as a thrust bearing.
Although we have explained the structure in which only the magnetic flux is applied, a structure in which a non-magnetic material is formed on each of the facing surfaces of the rotary transformer and a dynamic pressure generating groove is formed on at least one of the surfaces can also be used.
Effects can be obtained by performing simultaneous processing according to the present invention.

Furthermore, although the explanation so far has been about the case where the shaft rotates, it goes without saying that exactly the same effect can be obtained even when the shaft is fixed.

[Effects of the Invention] As explained above, the present invention provides the following advantages: by forming at least the fixed-side core of the rotary transformer and the joining member between the fixed-side core into a predetermined shape by simultaneous cutting,
The gap between the rotary transformer can be kept constant, the signal transmission characteristics can be stabilized, and a low-cost rotating device that does not require position adjustment can be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a rotary head assembly using a hydrodynamic bearing according to the prior art and the present invention, and FIG. 2 is a cross-sectional view showing an example of a state in which a fixed cylinder and a rotary transformer are joined according to the present invention. . In the figure. 1: Fixed cylinder 2: Rotating shaft 3: Rotation auxiliary member 4: Rotating cylinder 5: Magnetic head 6.7 Two rotary transformers

Claims (1)

[Claims] A rotating device comprising a fixed member and a rotating member, having a rotary transformer for transmitting signals between the rotating member and the fixed member, and having a hydrodynamic bearing on at least one cap in the thrust direction. A method for manufacturing a rotating device, characterized in that at least a stationary core of the rotary transformer and at least a part of the stationary member are simultaneously cut.