JPS5840332Y2 - Kaitenjikushijisouchi - Google Patents

Description

[Detailed description of the invention] The present invention relates to a rotating shaft support device, and in particular to a rotating shaft support device.
The present invention provides a device suitable for application to a TR rotary head drum motor.

A conventional motor shaft support device of this kind will be explained with reference to FIG.

A motor shaft 1 rotates integrally with a tape guide drum (not shown), and is rotatably supported by a boss portion 4 of a casing 3 via a bearing device 2.

That is, the inner ring 2a of the bearing device 2 is fixed to a predetermined position on the motor shaft 1 by pressure (or adhesive), and the outer ring 2b is fixed to the boss portion 4 of the casing 3 by press fitting or the like.

The inner ring 2a is rotatably supported by the outer ring 2b via ball bearings 2c.

Note that a pulley 6 is fixed to the tip of the motor shaft 1.

When assembling the motor shaft support device with the structure described above,
The inner ring 2a of the bearing device 2 is press-fitted onto the motor shaft 1.

At this time, the inner ring 2a is pressed against one end of the motor shaft 1 and then pushed through to a predetermined position.

However, during this press-fitting, the inner ring 2a is easily deformed,
A positional deviation occurs between the inner ring 2a and the outer ring 2b, and as a result, the motor shaft 1 appears to be eccentric, causing a shaft wobbling phenomenon when the motor shaft 1 rotates.

Furthermore, when press-fitting the inner ring 2a, the pressing force is adjusted to position it at a predetermined position, which is time-consuming.

Furthermore, when gluing the inner ring 2a to the motor shaft 1, it is necessary to apply adhesive, etc., resulting in poor workability, and if it is moved before the adhesive dries, it will be difficult to position the inner ring 2a. There was instability, such as causing

Furthermore, whether the inner ring 2a is positioned by press-fitting or fixed by adhesive, the motor shaft 1
The machining accuracy had to be strict, and the position of other parts (for example, pulleys) had to be determined separately when they were attached to the shaft.

The present invention was devised to correct the above-mentioned defects, and includes a ring-shaped bearing inserted into the rotating shaft in a substantially non-contact state, and a cylindrical positioning member for positioning the bearing. The positioning member is inserted and fixed to the rotating shaft so as to rotate together with the rotating shaft while in contact with the bearing, and in this case, the positioning member has an axis that coincides with the axis of the rotating shaft around the rotating shaft. A rotary shaft support characterized in that a truncated conical protrusion is provided, and the positioning member is press-fitted into an inclined surface formed around the protrusion so as to contact and engage with the inner side of the bearing in a substantially ring shape. It is related to the device.

With this configuration, the bearing can be attached to the rotating shaft in a state where the bearing is extremely stable and its center is held at a predetermined position with good workability.

Next, an embodiment in which the present invention is applied to a motor for a rotary head drum of a VTR will be described with reference to the drawings.

FIG. 2 is an external view showing an example of the rotary head drum 10, and FIG. 3 is a longitudinal sectional view thereof.

First, the appearance of the rotary head drum 10 will be described.
Reference numeral 1 denotes a tape guide drum, which is composed of a rotary upper drum Ila that can freely rotate in the left-right direction and a fixed lower drum 11b, and a helical guide 12 is cut on the outer peripheral surface of the fixed lower drum 11b.

14 is a drive motor (commutator type DC motor) directly connected to the lower surface of the lower drum 11b, and 15 is a mechanism panel of the VTR main body; in this example, this panel 15
The upper flange 16a of the casing 16 (bracket) of the motor 14 is inserted into the mounting hole 15a provided at a predetermined position of the panel 15. For example, a spacer 17 is arranged between the upper surface of the panel 15 and the lower surface of the lower drum 11b. A plurality of bolts or the like are screwed into the lower circumferential portion of the lower drum 11b from the lower side to fix the entire rotary head device 0 including the motor 14.

Although the spacer 17 is arranged to tilt the axis of the guide drum 11 in a predetermined direction, it is shown as a flat plate for convenience in the illustration, and therefore the axis of the guide drum 11 is also vertical.

The rotary head device 10 of this example has two heads and one head as described above.
It is an 80' winding type, which is, as is well known, the guide drum 1.
In this method, a magnetic tape 13 is wound helically around the circumferential surface of the lower drum 11b over an angle range of 180' to record (reproduce) video at 60 fields and 30 frames/-. The lower edge of the magnetic tape 13 is guided by a helical guide 12.

The rotating upper drum 11a is fixed to the upper part of the motor shaft 18, and a pair of head structures 21 consisting of a head holder 19 and a head piece 20 are attached to the lower surface of the rotating upper drum 11a at symmetrical positions on the diameter line X (see FIG. 4). It is being

That is, each head piece 20 is connected to the upper drum 11a and the lower drum 1.
Scanning of one field is performed using both helad pieces 20, facing the drum peripheral surface through the gap between the drum and the drum 1b.

On the diameter line Y perpendicular to the X-ray X, the upper drum 11a
Symmetrical L-shaped magnetic pieces 23a and 23b are attached to the boss 22 on the lower surface of the magnetic piece 23a.

23b and the PG coil on the lower drum 11b side (not shown)
The rotational phase of each headpiece 20 during recording is detected, and the vertical synchronization signal 60 included in the video signal is detected.
The motor 14 is controlled to synchronize the rotation of the upper drum 11a with Hz as a reference, and the detection signal is recorded on the lower part of the magnetic tape and used as a control signal during reproduction.

The holder 19 of the head structure 21 is made of a non-magnetic metal plate with a printed circuit board bonded to the surface.

19a is a terminal pattern of the head coil.

Upper and lower drums 11a constitute the guide drum 11.

As shown in FIG. 2, the drums 11b are each made of a light alloy drum that is hollowed out into a tap shape. The upper large diameter portion 18a of the shaft 18 is press-fitted, and a nut is screwed into the threaded portion at the upper end and tightened.

Then, the lower end of the sleeve 24 is connected to the bottom plate 2 of the lower drum 11b.
The upper and lower drums 11a and 11b are relatively positioned on the curve by contacting the inner ring of the upper bearing 26 fitted in the center of the sleeve 24.
A rotary transformer 27 is disposed around the rotary head to supply (or extract) signals to the rotary head terminal.

Here, to briefly describe the drive motor 14 (commutator type DC motor) attached to the lower surface of the lower drum 11b, the casing 16 made of light alloy has a magnet ring 2.
8a and a magnetic path drum 28b, and a rotor 29 consisting of a laminated core 29a and a coil 29b wound around the laminated core 29a. It is fitted.

This mounting structure of the rotor 29 via the sleeve is related to the present proposal (Japanese Patent Application No. 48126035). , that is, the coil 29 of the rotor 29
This is a means for reducing motor noise by cutting off the transmission of pulsed current to the motor shaft 18 that occurs when switching the current flowing through the motor.

31 is a commutator mounted on the shaft adjacent to the sleeve 30; 31a is a contact piece arranged in the axial direction on the circumferential surface of the insulator; 32 is elastically in sliding contact from symmetrical positions on both sides of the commutator 31; These brushes 32 are arranged on a printed circuit board 33 provided inside the bottom plate 16b of the casing 16 so as to perform so-called neutral point adjustment, and are connected to a power source. .

In addition, the center part of the casing bottom plate 16b has a downward boss 1.
6c, and a lower bearing 34 is fitted inside it.

As shown in FIG. 5, a truncated conical notch 35 is formed at the lower end of the inner peripheral surface of the inner ring 34a constituting the lower bearing 34, and the outer ring 34b is fixed within the casing 16.

Note that 36 is a pole bearing.

The inner ring 34a has a substantially ring shape and is inserted into the shaft 18 in a substantially non-contact state (that is, with a slight gap).

On the other hand, a cylindrical collar 37 is press-fitted and fixed to the motor shaft 18 at the lower end of the lower bearing 34, as shown in FIG.

This collar 37 is formed into a cylindrical shape as shown in FIG. 6, and a truncated conical ring-shaped projection 38 is formed at the center of the upper surface of the collar 37, and this projection 38 is connected to the notch 3 described above.
The collar 37 is press-fitted onto the shaft 18 so as to be able to rotate together with the shaft 18 so as to contact and engage the collar 5 from below.

That is, the notch 35 and the tapered surface 38a of the protrusion 38 are
Because they are formed at the same inclination angle θ, the collar 37
This notch 3 is placed over the lower bearing 34.
It is fixed by biting into 5 from below.

In this case, since the axis of the notch 35 and the line of the protrusion 38 are necessarily aligned, the lower bearing 34 will not be displaced laterally even if it is not fixed by press-fitting or gluing as in the conventional case. It will be fixed at the center of the shaft 18 without any problem.

This is the protrusion 3 of the collar 37 that is press-fitted onto the shaft 18.
By aligning the axis of 8 with the axis of axis 18,
This can be achieved easily and reliably.

Therefore, the lower end of the motor shaft 18 is simply supported by the lower bearing 34 inserted into the motor shaft 18, and its rotation is extremely smooth. There is no possibility of displacement, and no upward displacement occurs due to the sleeve 30.

The alignment collar 37 is press-fitted into the shaft 18 as described above, and even if the collar 37 is deformed by this, this has no effect on the bearing inner ring 34a, and the above-mentioned notch 3
5 and the tapered surface 38a is maintained, so there is no problem.

Also, by using this collar 37, the motor shaft 1
Positioning of the pulley 39 fixed to the lower end of the pulley 8 is also extremely easy.

That is, since the collar 37 is manufactured to match the shape of the motor 14, it is press-fitted onto the motor shaft 18 and is attached to the boss 1.
The lower surface of the collar 37 through which the collar 6c is inserted always protrudes from the lower surface of the casing 16 at a constant height.

Therefore, when positioning the pulley 39, there is no need to attach a special mark, a gauge or the like for positioning is unnecessary, and positioning can be performed automatically.

As explained above, the collar 3 is attached to the bearing inner ring 34a.
0 is engaged, there is no need to press fit the inner ring 34a as in the conventional case, and deformation of the inner ring 34a can be prevented.

Therefore, the accuracy of the inner ring 34a is maintained, and at the same time, the machining tolerance of the rotating shaft is widened, making it possible to stabilize and assemble with good workability.

Furthermore, the positioning of the pulley 39 has the secondary effect of being automatically performed by the collar 31.

Although the present invention has been described above with reference to one embodiment, it will be understood that further modifications are possible.

For example, the notch 35 of the inner ring 34a and the protrusion 3 of the collar 37
The shape of 8 can be changed in various ways.

That is, the notch 35 may be small.

In some cases, the original edge portion may be left without forming the notch 35, and this ring-shaped edge portion may be engaged with the tapered surface 38a of the protrusion 38 in a dotted state. .

Further, the collar 37 may be fixed to the shaft 18 simply by adhesion, but in this case, the same effect as in the above embodiment can be obtained, and at the same time, the inner ring 34a can be stably mounted in a predetermined position.

In other words, since the collar 37 is not fixed with adhesive, the inner ring 3
This completely eliminates the poor adhesive workability and instability of the adhesive state required for positioning 4a.

Furthermore, in addition to the pulley 39, a flywheel, gears, etc. can also be automatically positioned using the collar 37.

As described above, the present invention is such that the protrusion of the positioning member of the bearing inserted into the rotating shaft in a substantially non-contact state is brought into contact with the inside of the bearing, and the protrusion of the positioning member that rotates together with the rotating shaft is brought into contact with the inside of the bearing. Since the axis of the part and the axis of the rotating shaft are aligned, the bearing is not press-fitted onto the rotating shaft, and the center of the bearing is always aligned with the center of the rotating shaft. No deformation occurs, the bearing can be mounted accurately and stably, and the machining dimensional tolerance of the rotating shaft can be widened.

In addition, since the positioning member is press-fitted so that the protrusion of the positioning member contacts and engages with the inside of the bearing, the inside of the bearing is supported by this positioning member, and the axial position of the bearing is also determined by this member. achieved by.

In addition, the workability of assembly is improved, and other attachments can be automatically performed using the positioning member.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a bearing of a conventional rotary head device. 2 to 5 show an embodiment in which the present invention is applied to a rotary head drum motor, in which FIG. 2 is a front view of the rotary head drum, and FIG. 3 is a vertical cross-section of the rotary head drum. Figure 4 is a partial cross-sectional view taken along the line IV-IV in Figure 2,
FIG. 5 is an enlarged view of a portion of the bearing shown in FIG. 3, and FIG. 6 is a perspective view of a collar that engages with the bearing. In addition, in the symbols used in the drawings, 18 is the motor shaft;
34 is the lower bearing, 34a is the inner ring, 37 is the collar
38 is a truncated conical projection, and 39 is a pulley.

Claims (1)

[Scope of utility model registration request] A ring-shaped bearing is inserted into the rotating shaft in a substantially non-contact state, and the rotation is performed so that the cylindrical positioning member for positioning the bearing rotates together with the rotating shaft in contact with the bearing. At this time, a truncated conical protrusion having an axis that coincides with the axis of the rotary shaft is provided on the positioning member around the rotary shaft, and the slope formed around the protrusion is provided with the truncated conical protrusion. A rotary shaft support device characterized in that the positioning member is press-fitted so that the inner side of the bearing contacts and engages in a substantially ring shape.