JP2001208163A - Planetary gear mechanism and disc reproducer comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planetary gear mechanism having a mechanism not using the felt and providing the stable load torque. SOLUTION: This planetary gear mechanism is composed of a base 8, a first shaft 1a stood from the base 8, an oscillating arm 1 rotatably pivoted on the first shaft 1a, a second shaft 1b stood from the oscillating arm 1, a sun gear 3 rotatably pivoted on the first shaft 1a, a planetary gear 2 engaged with the sun gear 3 and rotatably pivoted on the second gear 1b, a groove part 3a having a wedge-shaped cross section and concentrically mounted on a lower face of the sun gear 3 or the planetary gear 2, and a triangular pyramid-shaped pin 4 inserted into a hole 1c formed on the oscillating arm 1, and energized by a spring 5 to be brought into contact with the wedge-shaped groove 3a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear for distributing a driving force to two gear mechanisms by oscillating an oscillating arm in a rotational direction by rotation of a motor or a gear or a pulley for transmitting a driving force from the motor. The present invention relates to a mechanism, and more particularly to a load torque adding mechanism for stably applying a load torque for swinging a swing arm in a rotation direction.

[0002]

2. Description of the Related Art In a planetary gear mechanism, a mechanism for applying a load torque for oscillating an oscillating arm has a felt interposed between a planetary gear and an oscillating arm that supports the planetary gear, and the felt is a planetary gear. A frictional force is obtained by urging with a spring so as to be in pressure contact with, and a load torque is applied by the frictional force.

[0003]

However, in a mechanism that obtains a load torque by a frictional force in which the felt is pressed against the planetary gear, the frictional coefficient of the felt and the planetary gear changes depending on humidity because the felt has a hygroscopic property. The load torque changes.

Further, there is a problem that lubricating oil injected into the teeth of the adjacent gears or the rotating shaft permeates the felt to lower the friction coefficient, thereby reducing the load torque.

Further, in a configuration in which small-diameter gears coaxially integrated with the planetary gear are provided on both sides of the planetary gear,
Since the area in contact with the felt is reduced, sufficient frictional force cannot be obtained, and the load torque is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a planetary gear mechanism provided with a mechanism capable of obtaining a stable load torque without using a felt, and a disk reproducing apparatus having the same.

[0007]

In order to achieve the above object, according to the present invention, a groove having a wedge-shaped cross section is provided concentrically on the lower surface of a sun gear or a planetary gear, and a swing arm is provided on the wedge-shaped groove. The pin urged by the spring from the side is brought into contact.

More specifically, the present invention provides the following mechanisms and devices. The present invention provides a base, a first shaft erected from the base, a swing arm rotatably supported on the first shaft, and a second arm erected from the swing arm. Shaft and the first
A sun gear rotatably supported on the shaft, a planetary gear meshing with the sun gear and rotatably supported on the second shaft, and provided concentrically on the lower surface of the sun gear or the planetary gear. A planetary gear mechanism, comprising: a wedge-shaped groove having a cross-sectional shape; and a pin that is inserted into a hole provided in the swing arm and is urged by a spring to abut the wedge-shaped groove.

Further, the present invention provides a tray provided with a concave portion for mounting a plurality of disks in an annular shape, a loader for rotatably supporting the tray, and an operation for loading and unloading the loader from a housing. And a loading mechanism having a planetary gear mechanism for transmitting a driving force to move the loader, wherein the planetary gear mechanism is the planetary gear mechanism according to claim 1. I will provide a.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a planetary gear mechanism according to an embodiment of the present invention and a disk reproducing apparatus having the same will be described with reference to the drawings.

FIG. 1 is a perspective view of a planetary gear mechanism according to an embodiment of the present invention, and FIG. 2 is a plan view of the planetary gear mechanism of FIG. FIG. 3 shows the BB of the planetary gear mechanism of FIG.
FIG. 4 is an enlarged detailed view of a portion S in FIG. 3. FIG. 5 is a rear view of the planetary gear mechanism of FIG.

As shown in FIG. 1, the planetary gear mechanism includes a base 8, a first shaft 1 a erected from the base 8, and a first shaft 1.
a swinging arm 1 rotatably supported on a.
, A sun gear 3 rotatably supported on the first shaft 1a, a planetary gear 2 meshed with the sun gear 3 and rotatably supported on the second shaft 1b. A groove 3a concentrically provided on the lower surface of the sun gear 3 or the planetary gear 2 and having a wedge-shaped cross section, and a triangular pyramid inserted into a cylindrical hole 1c provided in the swing arm 1 and in contact with the wedge-shaped groove 3a. It comprises a pin 4 in a shape of a circle and a spring 5 for constantly urging the pin 4 upward.

Next, the operation of the planetary gear mechanism will be described. As shown in FIG. 4, the pin 4 is always pushed up by an external force F by a spring 5 and is pressed against a wedge-shaped groove 3a provided concentrically on the lower surface of the sun gear 3. Since the vertex angle of the pin 4 is set to a value equal to the vertex angle of the wedge-shaped groove 3a, the triangular pyramid-shaped surface of the pin 4 comes into contact with the inner surface of the wedge-shaped groove 3a to obtain a frictional force. Since the rotation of the moving arm 1 is always transmitted by the pin 4, when the sun gear 3 rotates in the clockwise hand rotation direction (CW direction), the swing arm 1 rotates in the same direction, and accordingly the planetary gear 2. Also move in the same direction.

At this time, the surface of the wedge-shaped groove 3a is
As shown in the figure, a normal load N = F / (sin (θ / 2)) (where θ: slope angle of the wedge) acts, and a frictional force R = 2 μN in the rotation direction of the planetary gear 2 (where μ: pin 4 and the wedge-shaped groove 3a).

As a result, as shown in FIG.
If the radius from the axis of a to the wedge-shaped groove 3a of the sun gear 3 is r, the load torque T = 2μ when the sun gear 3 rotates.
Nr is obtained. In other words, the value of T is equal to the swing arm 1
It is the rotational torque that has.

Further, as the value of θ approaches 0, N increases and T increases. Therefore, by adjusting the value of θ even with a relatively small spring force F, a large load torque can be obtained by the wedge effect. Can be.

When the sun gear 3 rotates in the clockwise direction (CW direction) of the clock hand, the swing arm 1 is rotated by a pin 4 abutting on a wedge-shaped groove 3a provided on the lower surface of the sun gear 3. When the force is transmitted, the planetary gear 2 rotates in the same direction, and accordingly, the planetary gear 2 also moves in the same direction.

Next, as shown in FIG. 2, when the planetary gear 2 moved in the CW direction meshes with another gear train 7a, the above-described space between the pin 4 and the wedge-shaped groove 3a is provided. like,
Although a load torque of T = 2 μNr is generated, the rotation torque of the sun gear 3 does not hinder the rotation of the sun gear 3 because the rotation torque is sufficiently small.

When the sun gear 3 is rotated in the opposite direction (CCW direction) to the rotation of the timepiece hand, the same operation is performed.
The swing arm 1 rotates in the CCW direction.

FIG. 6 is a plan view of the entire mechanism of a disk reproducing apparatus having a planetary gear mechanism according to an embodiment of the present invention. The loader 22 rotatably supports the tray 23 and is supported so as to be able to enter and exit the housing 21 as shown in FIG.
Indicates a state where the loader 22 protrudes from the housing 21. Further, the tray 23 is provided with a plurality of concave portions 23a for placing a plurality of disks in an annular shape.

FIG. 7 is a plan view of the loading mechanism when the loader 22 of the disc reproducing apparatus of FIG. 6 is taken in and out of the housing 21. FIG. 8 is a plan view of the gear portion of the loading mechanism of FIG. FIG.

On the back surface of the loader 22, a J-shaped rack 22a and a substantially J-shaped guide groove 22b spaced from the rack 22a by a predetermined distance are provided. When the loader 22 is pulled into the housing 21, the motor 41 is rotated counterclockwise. The driving force of the motor 41 is transmitted to the belt 51, the pulley 61, the transmission gear 71, and the sun gear 3 which is a part of the planetary gear mechanism.

The planetary gear 2 is a planetary gear of the sun gear 3, and is rotatably supported by a second shaft 1 b erected from the swing arm 1. Further, the planetary gear 2 is provided with a pinion 2 a on the loader 22 side.

A clockwise rotational force is transmitted to the planetary gear 2, the second shaft 1b engages with the guide groove 22b, the pinion 2a meshes with the rack 22a, and the rack 22a is
Extrude in the direction of the arrow (solid line). This allows
The loader 22 is pulled into the housing 21.

[0025]

According to the present invention, since a stable load torque can be applied with a simple structure without using a felt, the swing arm can be reliably swung in the rotation direction of the sun gear. Thus, the reliability of the planetary gear mechanism can be improved.

Further, it is not affected by humidity, is little affected by lubricating oil, and can be used for a small gear having a small friction surface.

[Brief description of the drawings]

FIG. 1 is a perspective view of a planetary gear mechanism according to an embodiment of the present invention.

FIG. 2 is a plan view of the planetary gear mechanism of FIG.

FIG. 3 is a sectional view taken along the line BB of the planetary gear mechanism of FIG. 2;

FIG. 4 is an enlarged detail view of a portion S in FIG. 3;

FIG. 5 is a back view of the planetary gear mechanism of FIG. 3;

FIG. 6 is a plan view of the entire mechanical part of the disk reproducing apparatus provided with the planetary gear mechanism according to one embodiment of the present invention.

FIG. 7 is a plan view of a loading mechanism when the loader of the disc reproducing apparatus of FIG. 6 is taken in and out of a housing.

8 is a view of a gear portion of the loading mechanism of FIG. 7 as viewed from below.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Swing arm, 1a ... 1st axis, 1b ... 2nd axis, 1
c ... hole, 2 ... planetary gear, 3 ... sun gear, 3a ... wedge-shaped groove, 4 ... pin, 5 ... spring, 8 ... base

Claims (2)

[Claims] 1. A base, a first shaft erected from the base,
A swing arm rotatably supported on the first shaft, a second shaft erecting from the swing arm, a sun gear rotatably supported on the first shaft, and a sun gear; The second gear
A planetary gear rotatably supported on a shaft, a sun gear or a planetary gear provided concentrically on a lower surface of the wedge-shaped groove portion, and a spring inserted through a hole provided in the swing arm by a spring. A planetary gear mechanism comprising: a pin that is urged to abut the wedge-shaped groove. 2. A tray provided with a concave portion on which a plurality of disks are placed in an annular shape, a loader for rotatably supporting the tray, and an operation for moving the loader in and out of the housing to move the loader. A disc reproducing apparatus having a loading mechanism provided with a planetary gear mechanism for transmitting a driving force, wherein the planetary gear mechanism is the planetary gear mechanism according to claim 1.