JPH1092062A - Rotor of reel motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive rotor of a reel motor capable of preventing the fall-off, crack and play. SOLUTION: A 1st thrust pad 18 is provided between plural projecting parts 12c at the tip part of a hollow cylindrical part 12b of a reel base 12, and the tip part of a shaft 21 is abutted thereon. A 2nd thrust pad 19 which is mounted at the tip part of the hollow cylindrical part 12b of the reel base 12 in the state brought into contact with the 1st thrust pad 18, is provided with plural through-holes 19a to which the plural projecting parts 12c are penetrated, and its outside diameter is larger than that of the tip part of the hollow cylindrical part 12b. The sectional area of the part of plural projecting parts 12c projected from the 2nd thrust pad 19 passing through the plural through-holes 19a is made to be larger than the area of the through-hole 19a by being fused with the heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor for a reel motor used in a magnetic recording / reproducing apparatus using a tape as a recording medium of a digital audio tape recorder (DAT) or a video tape recorder (VTR). About.

[0002]

2. Description of the Related Art A reel motor has a stator and a rotor rotated by the stator. The stator has a shaft erected in the direction of the central axis. The rotor is
It is fitted into the shaft and into the reel hub. The rotor rotates the reel hub around the shaft by the rotational driving force from the stator.

Referring to FIG. 3, a conventional reel motor rotor will be described. The rotor 30 has a rotor yoke 3
1, a reel base 32, a reel claw 33, a coil spring 34, a reel cap 35, a bearing 36, a rotor magnet 37, and a ball bearing 38.
The rotor yoke 31 has a substantially flat annular shape, is disposed opposite to a stator (not shown), and is disposed in a plane perpendicular to a center axis A extending in the vertical direction in the drawing by a reel base 32 (horizontal in the case of the drawing). ) Is supported. An annular rotor magnet 37 is attached to the lower surface of the rotor yoke 31.

Referring to FIG. 4, a reel base 32 has a base 32a for horizontally supporting a rotor yoke 31 and a shaft (not shown) of a stator extending from the base 32a in a direction of a center axis A. And a hollow cylindrical portion 32b. A reel cap 35 described later is press-fitted to the outer wall of the hollow cylindrical portion 32b of the reel base 32, and the base portion 32a is provided below the hollow cylindrical portion 32b in a state of being enlarged to the periphery. . The reel base 32 and the rotor yoke 31 are integrally formed by outsert molding. Further, the hollow cylindrical portion 32b of the reel base 32 has a plurality of vertically extending (3 in the illustrated example) disposed at equal intervals (120 in the illustrated example) at intervals on the outer peripheral surface thereof.
The groove 32c is formed. As shown in FIG. 3, a ball bearing 38 is provided on the inner wall surface of the base portion 32a.
Is accommodated.

Turning to FIG. 5, the reel cap 35 is formed in a hollow cylindrical shape having a closed upper end.
It is selected so that it can be pressed into the hollow cylindrical portion 32b of the reel base 32. Also, the reel cap 35
Is a plurality of (three) protruding ridges 35a extending in the vertical direction and arranged at equal angle (120 °) intervals at the lower portion of the inner surface thereof.
It has. The ridge 35a is engaged with the groove 32c of the reel base 32 to prevent the reel base 32 from rotating around the central axis A of the reel cap 35.

As shown in FIG. 3, a bearing 36 is press-fitted into the upper portion of the inner surface of the reel cap 35. Further, as shown in FIG. 3, a reel claw 33 (described later) is slidably fitted on the outer surface of the reel cap 35 in the direction of the central axis A (vertical direction). A flange 35b for locking the reel claw 33 at a position separated from the base by a predetermined distance is formed at the upper end of the reel cap 35. The reel cap 35 has, on its outer surface, a plurality (three) of protruding ridges 35c which are arranged at equal angles (120 °) and extend in the up-down direction. The ridge 35c is for restricting rotation of the reel claw 33 around the central axis A with respect to the reel cap 35.

[0007] The reel claw 33 includes a reel cap 35.
Is pressed into the reel base 32, the reel craw 3
3 is urged upward by a coil spring 34 sandwiched between the lower end of the base 3 and the upper surface of the base 32a of the reel base 32.

Referring to FIG. 6, a plurality (three) of vertically extending grooves 33a are formed on the inner surface of the reel claw 33 and are arranged at equal angle (120 °) intervals. This groove 33a is provided with a ridge 35 of the reel cap 35.
c is engaged, and rotation of the reel claw 33 around the central axis A with respect to the reel cap 35 is restricted. The reel claw 33 is provided with a recess 33b at an upper portion of its inner surface. This recess 33b is the reel cap 35
, The upward movement of the reel claw 33 is restricted. A plurality of reel crows 33 (3) extending in the vertical direction are provided at positions facing the groove portions 33a on the outer surface thereof.
The ridge portion 33c is provided. The protrusions 33c engage with clamps on a reel hub (not shown), and the rotor 30 fits into the reel hub.

According to the rotor 30 of the reel motor configured as described above, the lower portion of the inner surface of the reel cap 35 is press-fitted into the hollow cylindrical portion 32b of the reel base 32 so that the reel cap 35 is Attached to The drive control of the reeling motor causes the rotor yoke 31 and the reel base 32 to rotate around the shaft. Thereby, the reel cap 35 attached to the reel base 32 by press fitting is also driven to rotate around the shaft.

[0010] The rotor 3 of the reel motor having the above-described structure is used.
At 0, the three protruding ridges 35a formed on the inner surface of the reel cap 35 engage with the three grooves 32c provided on the outer surface of the hollow cylindrical portion 32b of the reel base 32, thereby rotating the reel cap 35. The direction is stopped. Therefore, the vertical direction of the reel cap 35 and the reel base 32 (the center axis A
The direction) is fixed only by press-fitting. The thickness of the side press-fit portion of the reel cap 35 is thinner than the other portions. Further, the pressure input to the reel cap 35 varies due to variations in molding conditions and the like. If this pressure input is too weak, the reel cap 3
5 comes off the reel base 32.
On the other hand, if the pressure input is too strong, there is a problem that the reel cap 35 is cracked and the reel cap 35 falls off the reel base 32.

The present inventors have already filed an application for solving these problems on January 31, 1995 under the name of "reel motor assembly for reel base" (Japanese Patent Application No. Hei 7-344).
No. 37).

Next, the rotor 40 of the reel motor proposed by the present inventors will be described with reference to FIG. The rotor 40 includes a rotor yoke 41, a reel base 42, a reel claw 43, a coil spring 44, a reel cap 45, a bearing 46, and a rotor magnet (not shown).
And a ball bearing (not shown). Here, the rotor yoke 41, the reel claw 43, the coil spring 44, and the bearing 46 are respectively connected to the rotor 3 shown in FIG.
Since the rotor yoke 31, the reel claw 33, the coil spring 34, and the bearing 36 have the same structure, their description will be omitted to simplify the description.

Referring to FIG. 8 and FIG.
Will be described. The reel base 42 has a base portion 42a that horizontally supports the rotor yoke 41, and a hollow cylindrical shape that extends upward from the base portion 42a along the central axis A and into which a stator shaft (not shown) can be inserted. Part 42
b. In the hollow cylindrical portion 42b of the reel base 42,
A reel cap 45 described later is press-fitted into the outer wall, and a base portion 32a is provided below the hollow cylindrical portion 42b in a state where the base portion 32a is enlarged to the periphery. The reel base 42 and the rotor yoke 41 are integrally formed by outsert molding. Further, the hollow cylindrical portion 42b of the reel base 42 has, on its outer peripheral surface, a plurality of vertically extending (in the case of FIG.
(Three) grooves 42c are formed. Although not shown, a ball bearing is housed on the inner wall surface of the base 42a as shown in FIG.

10 and 11, the reel cap 45 is formed in a hollow cylindrical shape having a closed upper end, and its inner diameter is relatively lightly pressed into the hollow cylindrical portion 42b of the reel base 42. Have been chosen to be
In addition, the reel cap 45 has a plurality (two in the illustrated case) of protruding ridges 45a arranged at equal angles (180 ° in the illustrated example) extending vertically in the lower portion of the inner surface thereof. ing. The protruding ridge 45a is formed in the groove 4 of the reel base 42.
2c. As shown in FIG. 7, a bearing 46 is press-fitted into the upper portion of the inner surface of the reel cap 45. Further, the reel cap 45 is provided on its outer surface as shown in FIG.
As shown in the figure, the reel claw 43 is slidably fitted in the direction of the central axis A (up and down direction). A flange 45b for locking the reel claw 43 at a position separated by a predetermined distance from the base portion 42a is formed at an upper end of the reel cap 45. The outer surface of the reel cap 45 is provided with a plurality of (three) protruding ridges 45c disposed at equal angles (120 °) and extending in the up-down direction. The ridge 45c is for restricting rotation of the reel claw 43 around the central axis A with respect to the reel cap 45.

The above configuration is the same as the configuration of the rotor 30 shown in FIGS.

Returning to FIGS. 8 and 9, the reel base 42
Further, an elastic stopper 42d extending downward from the upper end is provided in the groove 42c of the hollow cylindrical portion 42b. As shown in FIG. 9, the elastic stopper 42d is provided with elasticity by forming slits on both sides in the groove 42c, and has a claw 42e projecting outward at the lower end. I have.

Returning to FIGS. 10 and 11, the reel cap 45 has an engagement hole 45d in a ridge 45a provided on the inner surface thereof. The position of the engagement hole 45d in the vertical direction is selected so that the claw 45e of the elastic stopper 42d can be fitted into the reel base 42 when the reel cap 45 is pressed into the reel base 42.

The rotor 40 having such a configuration is assembled as follows. When attaching the reel cap 45 to the reel base 42, the reel cap 45 is first aligned with the hollow cylindrical portion 42b of the reel base 42, and the reel cap 45 is pushed downward. As a result, the reel cap 45 is pressed into the hollow cylindrical portion 42b of the reel base 42. At this time, the hollow cylindrical portion 42b of the reel base 42
4 protruding radially outward from the surface of the groove 42c
5e is deformed inward in the radial direction based on the elasticity of the projection 45a of the reel cap 45. And
The reel cap 45 is the hollow cylindrical portion 42 of the reel base 42.
b, the elastic stopper 42
The claw 42e at the lower end of d is
It faces the engaging hole 45d provided in 5a.
As a result, the claw 42e at the lower end of the elastic stopper 42d enters the engaging hole 45d by the restoring force of the elastic stopper 42d, and engages with the lower edge of the engaging hole 45d.
Thus, the attachment of the reel cap 45 to the reel base 42 is completed.

A rotor magnet (not shown) is attached to the lower surface of the rotor yoke 41, and a ball bearing (not shown) is provided on the inner wall surface of the base 42a of the reel base 42.
, The rotor 40 is configured. Accordingly, the rotor yoke 41 is controlled by the drive control of the reel motor.
Then, the reel base 42 is driven to rotate. Accordingly, the reel cap 45 attached to the reel base 42 by press fitting is also driven to rotate.

[0020]

In the rotor 40 shown in FIGS. 7 to 11, the ridges 45a formed on the inner surface of the roll cap 45 correspond to the hollow cylindrical portions 42 of the reel base 42.
By engaging in the groove 42c provided on the outer surface of the b, the rotation is prevented from rotating. However, the reel cap 45 is a hollow cylindrical portion 42b of the reel base 42.
The projections 45a are loosely engaged in the grooves 42c because the projections 45a are fixed and held by being lightly pressed into the outside. As a result, when an external force in the rotation direction is applied to the reel cap 45, the reel cap 45 slightly slides with respect to the reel base 42, that is, rattles. Therefore, for example, when an attempt is made to rotationally drive a reel of a VTR using a reel motor having such a rotor 40,
It becomes difficult to perform accurate positioning in a VTR. This is because, when the reel base 42 is to be started to rotate by the reel motor due to the inertia force of the reel, the reel cap 45 starts to rotate slightly after the rotation of the reel base 42 starts. When trying to stop the rotation of the reel base 42,
This is because the reel cap 45 stops slightly after the reel stand 42 stops.

Further, in each of the rotor 30 shown in FIG. 3 and the rotor 40 shown in FIG. 7, the rotor is rotatably supported on a stator via a ball bearing 38 around a shaft. Since the shaft is erected from the bush portion of the stator, the bush portion of this stator is
The rotors 30 and 40 are supported by the inner ring of the ball bearing 38 against the magnetic attraction of the rotor magnet 37. Anyway, in rotors 30 and 40,
To rotatably support (pivot) it with respect to the stator, expensive ball bearings 38 must be used.

In the rotors 30 and 40, the reel caps 35 and 45 having a complicated structure are used as locking means for the reel crows 33 and 43, respectively.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rotor of a reel motor which can be pivotally supported on a stator using inexpensive means in view of the above-mentioned conventional problems.

Another object of the present invention is to provide a rotor of a reel motor capable of engaging a reel claw with a simple structure without slipping, cracking, and rattling.

[0025]

SUMMARY OF THE INVENTION It is difficult for the present inventors to prevent the above-mentioned detachment, cracking, and rattling as long as a reel cap is used as a locking means for a reel claw. I thought. Moreover, it is not desirable to use expensive ball bearings as a pivotal means for the stator. As a result of various studies, the present inventors have conceived a completely new locking means, and have found that this locking means also works as a pivoting means for pivotally supporting the stator.

[0026] In the rotor of the reel motor according to the present invention, a shaft erecting from the stator of the reel motor in the central axis direction is rotatably fitted and fitted into the reel hub, and the reel hub is rotated by the rotational driving force from the stator. Are rotated around the shaft.

[0027] The rotor of the reel motor according to the present invention comprises: a rotor yoke arranged to face the stator at a distance from the stator; a base for supporting the rotor yoke in a plane perpendicular to the central axis; A reel base consisting of a hollow cylindrical portion into which a shaft can be inserted and a plurality of convex portions erected at equal angular intervals apart from a tip end of the hollow cylindrical portion around a central axis; A reel claw disposed movably in the central axis direction on the outer periphery of the hollow cylindrical portion of the reel base and engaged with the reel hub; and a base between the reel claw and the base part of the reel base arranged on the reel claw. Urging means for urging in a direction away from the portion; a rotor magnet attached to a surface of the rotor yoke facing the stator; and a press-fit into a hollow cylindrical portion of the reel base to slide against the shaft. And a first thrust receiver provided between the plurality of convex portions at the tip of the hollow cylindrical portion of the reel base and in contact with the tip of the shaft; and a hollow cylindrical portion of the reel base. A second thruster having a plurality of through holes through which a plurality of projections penetrate and having an outer diameter larger than the outer diameter of the end of the hollow cylindrical portion; And a thrust receiver.

[0028]

The first thrust receiving portion is formed by melting the portions of the plurality of convex portions projecting from the second thrust receiving portion through the plurality of through holes by heat to make the cross-sectional area larger than the area of the through hole. And the second thrust receiver. The reel claw is locked at the outer circular end of the second thrust receiver. Therefore, the combination of the first and second thrust receivers caulked by the fusion of the plurality of projections serves not only as a locking means for the reel claw but also as a pivoting means for the stator.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, a rotor 10 of a reel motor according to an embodiment of the present invention has a shaft 21 erected from a stator 20 of the reel motor in a direction of a central axis A rotatably fitted therein and a reel hub. (Not shown), and rotates the reel hub around the shaft 21 by the rotational driving force from the stator 20.

The stator 20 has a shaft 21 having a central axis A
Bush reel 22 erected in the direction, and a reel board (stator board) 23 holding this bush reel 22
And an electromagnet 24 disposed on the upper surface of the reel substrate 23.

On the other hand, the rotor 10 has a rotor yoke 11
, A reel base 12, a reel claw 13, a coil spring 14, a sintered bearing 16, a rotor magnet 17, a first thrust receiver 18, and a second thrust receiver 19.

The rotor yoke 11 is opposed to the stator 20 at a distance. The rotor yoke 11 has a lower surface to which a rotor magnet 17 is attached. The rotor magnet 17 is opposed to the electromagnet 24 with a predetermined gap.

Referring to FIG. 2 as well, reel base 12 is made of resin and supports (horizontally) base 12a for supporting rotor yoke 11 in a plane perpendicular to center axis A.
A hollow cylindrical portion 12b extending upward from 2a and into which the shaft 21 can be inserted, and an equal angle (60 ° in the illustrated case) separated from the distal end of the hollow cylindrical portion 12b around the central axis A.
A plurality (six in the illustrated case) of protruding portions 12 erected at intervals.
c. The reel base 12 further has, on its outer surface,
A plurality (three) of ridges 12d extending in the up-down direction and arranged at equal angle (120 °) intervals are provided. The protruding ridges 12 c are for restricting rotation of the reel claw 13 around the central axis A with respect to the reel base 12. A recess 12 e for accommodating the first thrust receiver 18 is formed at the tip of the reel base 12 inside the projection 12 c. The depth of the recess 12 e is equal to the thickness of the first thrust receiver 18.

Returning to FIG. 1, the reel claw 13 is arranged movably in the direction of the central axis A on the outer periphery of the hollow cylindrical portion 12b of the reel base 12, and engages with a reel hub (not shown). Since the detailed structure of the reel claw 13 is the same as that shown in FIG. 6, a detailed description is omitted, but a groove (not shown) with which the three ridges 12d are engaged is provided on the inner surface. ,
The upper part of the inner surface has a recess (not shown) for engaging with a second thrust receiver 19 described later, and the three ridges 13c on the outer surface. The coil spring 1 is disposed between the lower end of the reel claw 13 and the upper surface of the base 12a of the reel base 12, and urges the reel claw 13 upward away from the base 12a.

The sintered bearing 16 is press-fitted into the hollow cylindrical portion 12b of the reel base 12 and slidably contacts the shaft 21.

The first thrust receiver 18 is a disk-shaped member provided between the plurality of convex portions 12c at the tip of the hollow cylindrical portion 12b of the reel base 12. The tip of the shaft 21 contacts the lower surface of the first thrust receiver 18. The tip of the shaft 21 has a spherical shape. The second thrust receiver 19 is
The reel unit 12 is mounted in a state of being in contact with the first thrust receiver 18 at the distal end of the hollow cylindrical portion 12b. The second thrust receiver 19 has a plurality (six in the illustrated case) of through-holes 19a through which the protrusions 12c penetrate, and the outer diameter thereof is larger than the outer diameter of the distal end of the hollow cylindrical portion 12b.

First and second thrust receivers 18 and 1
9 is assembled to the reel base 12 as follows.
First, the first thrust receiver 18 is accommodated in a recess 12 e formed at the tip of the reel base 12. Next, the through hole 1
The second thrust receiver 19 is placed on the first thrust receiver 18 so that the protrusion 12c passes through 9a. Thereby, the upper surface of the first thrust receiver 18 and the second thrust receiver 1
9 and the lower surface of the second thrust receiver 19 and the outer peripheral surface other than the recess 12e at the tip of the reel base 12 are in contact with each other. In this state, the portion of the convex portion 12c protruding from the second thrust receiver 19 through the through hole 19a is melted by heat to make the cross-sectional area larger than the area of the through hole 19a. Thus, the first thrust receiver 18 and the second thrust receiver 19 are swaged. The outer peripheral end of the second thrust receiver 19 contacts the recess of the reel claw 13 to lock the reel claw 13.

The first and second thrust receivers 18 and 19 caulked by the thermal melting of the projection 12c as described above.
The combination serves as locking means for locking the reel claw 13. When the rotor 10 having such a configuration is assembled to the stator 20 of the reel motor, the stator 20
Of the shaft 21 contacts the lower surface of the first thrust receiver 18. That is, the rotor 10 is rotatably supported (pivoted) by the first thrust receiver 18 against the magnetic attraction of the rotor magnet 17. Therefore, the combination of the first and second thrust bearings 18 and 19 serves as pivot means for the stator.

As described above, in the present embodiment, the first and second thrust receivers which are crimped without using the reel cap having a complicated structure which has been conventionally used as the locking means of the reel claw 13 are used. A combination of 18 and 19 is used. As a result, it is possible to prevent the reel cap from coming off, cracking, or rattling. Further, since the thrust receiver is used as a pivoting means for the stator without using a conventionally used expensive pole bearing, the cost is low.

[0041]

As is apparent from the above description, in the rotor of the reel motor according to the present invention, the two thrust receivers caulked at the tip of the hollow cylindrical portion of the reel base are used.
The reel claw is locked and the stator is pivotally supported. For this reason, it is possible to prevent detachment, cracking and rattling as in the related art, and it is possible to provide an inexpensive rotor.

[Brief description of the drawings]

FIG. 1 is a diagram showing a rotor of a reel motor according to an embodiment of the present invention together with a stator, (A) is a plan view showing a part of the rotor, and (B) is a sectional view.

2A and 2B are diagrams showing a reel base used for the rotor shown in FIG. 1, wherein FIG. 2A is a plan view showing a part of the reel base, and FIG.
FIG. 3 is a sectional view in which a rotor yoke is incorporated.

FIG. 3 is a sectional view showing a rotor of a conventional reel motor.

4A and 4B are views showing a reel base used for the rotor shown in FIG. 3, wherein FIG. 4A is a plan view and FIG. 4B is a partially cutaway side view incorporating a rotor yoke.

5A and 5B are views showing a reel cap used for the rotor shown in FIG. 3, wherein FIG. 5A is a bottom view and FIG. 5B is a sectional view.

6A and 6B are diagrams showing a reel claw used for the rotor shown in FIG. 3, wherein FIG. 6A is a plan view and FIG.

FIG. 7 is a sectional view showing a rotor of a reel motor previously proposed by the present inventors;

8A and 8B are views showing a reel base used for the rotor shown in FIG. 7, wherein FIG. 8A is a bottom view and FIG. 8B is a partially cutaway side view incorporating a rotor yoke.

FIG. 9 is a perspective view showing a reel base used for the rotor shown in FIG. 7;

10A and 10B are diagrams showing a reel cap used for the rotor shown in FIG. 7, wherein FIG. 10A is a bottom view and FIG. 10B is a sectional view.

FIG. 11 is a perspective view showing a reel cap used in the rotor shown in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Rotor 11 Rotor yoke 12 Reel stand 12a Base part 12b Hollow cylindrical part 12c Convex part 13 Reel claw 14 Coil spring 16 Sintered bearing 17 Rotor magnet 18, 19 Thrust receiver 21 Shaft

Claims (1)

[Claims] A shaft, which stands from a stator of a reel motor in a central axis direction, is rotatably fitted and fitted into a reel hub, and rotates the reel hub around the shaft by rotational driving force from the stator. A rotor, a rotor yoke spaced apart from and facing the stator, a base for supporting the rotor yoke in a plane orthogonal to the central axis, and a base extending from the base in the central axis direction. A reel base including a hollow cylindrical portion into which the shaft can be inserted, and a plurality of protrusions erected at equal angular intervals apart from the distal end of the hollow cylindrical portion around the central axis; A reel claw arranged movably in the center axis direction on the outer periphery of the hollow cylindrical portion of the base and engaged with the reel hub; and between the reel claw and the base of the reel base. A biasing means disposed to bias the reel claw in a direction away from the base portion; a rotor magnet attached to a surface of the rotor yoke facing the stator; and a hollow cylindrical portion of the reel base. And a sintered bearing that is press-fitted into the shaft and slidably contacts the shaft, and is provided between the plurality of protrusions at the tip of the hollow cylindrical portion of the reel base, and the tip of the shaft is A first thrust receiver that is in contact with the first thrust receiver and a plurality of through-holes through which the plurality of protrusions penetrate; A second thrust receiver having an outer diameter larger than an outer diameter of a distal end of the hollow cylindrical portion, and a portion of the plurality of protrusions protruding from the second thrust receiver through the plurality of through holes. Is melted by heat By making the cross-sectional area larger than the area of the through hole, the first thrust receiver and the second thrust receiver are swaged, and the reel claw is locked at the outer peripheral end of the second thrust receiver. A rotor for a reel motor, characterized in that: