JPH08177989A - Gear changeover device - Google Patents

Abstract

PURPOSE: To surely change over the connection of gears by fitting a torsion coil spring having two arms in the cylindrical part of a planet gear moved by receiving the rotation of a first gear so that one of the arms of the torsion coil spring is adapted to abut against a rotary shaft of the first gear by the rotation of the planet gear. CONSTITUTION: When a planet gear 2 is rotated by the rotation of a gear 1, a torsion coil spring 9 fitted in the cylindrical part 10 of the planet gear 2 is also rotated together with the planet gear, while one of arms of the torsion coil spring abuts against the cylindrical part 10 of the gear 1 to stop the rotation. Then, the rotational direction of the planet gear 2 coincides with the direction of the loosening the torsion coil spring 9 as viewed from the cylindrical part 11 of the gear 1, so that the rotational force of the planet gear 2 expands a coil portion. The planet gear 2 can be moved in the direction of the arrow E by the loosening torque to engage a gear 12 and transmit the rotation thereto. Thus, the connection of the gears can be stably changed over.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear switching device using a planetary gear in a mechanism for transmitting the rotation of a motor using gears, which is used in the field of OA equipment such as copying machines and facsimiles.

[0002]

2. Description of the Related Art Conventionally, this type of technique has been carried out by utilizing a frictional force to move a planetary gear. Hereinafter, a conventional gear switching device will be described with reference to the drawings.
FIG. 8 is a top view showing the top surface of a conventional gear switching device, and FIG. 9 is a side view showing the side surface of a conventional gear switching device.

In FIGS. 8 and 9, reference numeral 21 denotes a gear that rotates by receiving rotation transmission directly or indirectly from a motor (not shown). 22 receives the rotation transmission from the gear 21 and E
It is a planetary gear that moves in the F direction or the F direction and transmits the rotation to another gear (not shown). Reference numeral 23 is a rotating shaft of the gear 21, and 24 is a rotating shaft of the planetary gear 22. Reference numeral 25 is an arm that keeps the distance between the rotary shaft 23 and the rotary shaft 24 constant. Reference numeral 26 denotes a bottom plate, which is a rotary shaft 23 of the gear 21.
Only the bottom plate 26 is supported. 27 and 28 are rings. Reference numeral 29 denotes a compression spring which is fitted into the cylindrical portion of the planetary gear 22 and is interposed between the ring 27 and the planetary gear 22, one end of which is in contact with the ring 27 and the other end of which is a side surface of the planetary gear 22. Is pressing. The compression spring 2
Since the diameter of 9 is for pressing the compression spring 29, it must be larger than the diameter β of the cylindrical portion of the planetary gear.

The operation of the prior art having the above structure will be described below. First, rotation is transmitted from a motor (not shown), and the gear 21 rotates in the direction of arrow A.
The planetary gear 22 also tries to rotate in the direction of arrow C in response to the rotation of the gear 21, but since the compression spring 29 presses the side surface of the planetary gear 22 downward, a frictional force is generated and the planetary gear 22
Can't rotate. Since the gear 21 continues to rotate in the direction of the arrow A, the planet gear 22 is acted on by a force tending to move away from the gear 21. On the other hand, the gear 21
Since the distance between the planet gear 22 and the planet gear 22 is fixed by the arm 25, the planet gear 22 cannot be separated from the gear 21.

Therefore, the planetary gear 22 moves in the direction of arrow E under the force applied by the rotation of the gear 21. The movement of the planetary gears 22 is performed around the rotating shaft 23 supported by the bottom plate 26.

When the planetary gear 22 meshes with another gear (not shown) by movement and is connected, the planetary gear 22 overcomes the frictional force of the compression spring 29 and rotates, and the rotation from the gear 21 is transmitted to the other connected gear. It will be.

Also, when the motor (not shown) transmits the reverse rotation and the gear 21 rotates in the direction of arrow B, the planetary gear 22 moves in the direction of arrow F in the same manner as in the above case, and shifts to another gear (not shown). It meshes and transmits rotation.

[0008]

However, the above-mentioned conventional structure has a problem in that it is not possible to stably switch the gear connection. That is, the planetary gear 2
Since the frictional force of the compression spring 29 is used to move 2, the rotational load torque T1 applied to the planetary gear 22 is calculated by the formula 1 according to the pressing force N of the compression spring 29, the friction coefficient μ and the action radius r. As shown in.

[0009]

(Equation 1)

As is clear from the above equation 1, the rotational load torque T1 changes under the influence of the friction coefficient μ. Since the friction coefficient μ easily changes due to secular change and the manufacturing environment of the gear mechanism, it is difficult to maintain a constant value. Therefore, it is very difficult to obtain a stable rotational load torque T1, and there is a problem that it is not possible to stably switch the gear connection by the planetary gears.

The present invention provides a gear change device capable of generating a stable rotational load torque regardless of the friction coefficient of members, assembly dimensional accuracy, and secular change, and reliably switching gears. With the goal.

[0012]

In order to solve the above-mentioned problems, according to the present invention, a torsion coil spring having two arms is fitted to the cylindrical portion of a planetary gear that moves by the rotation of a first gear. Wherein the diameter of the cylindrical portion of the planetary gear is larger than the inner diameter of the coil portion of the torsion coil spring, and one of the arms of the torsion coil spring is rotated by the rotation of the planetary gear so that the rotation axis of the first gear is It has a structure of abutting against.

[0013]

According to the present invention, when the rotation transmission is first received from the first gear, the planet gear rotates together with the torsion coil spring fitted in the cylindrical portion thereof. Next, the arm of the torsion coil spring comes into contact with the rotation shaft of the first gear, and the torsion coil spring stops rotating. At this time, since the winding direction of the coil portion of the torsion coil spring and the rotation direction of the planetary gear match with each other when viewed from the rotation axis of the first gear, the coil portion of the torsion coil spring is expanded by the rotation of the planetary gear. As a result, a loosening torque is generated and the planetary gear starts moving. As described above, the planetary gear can obtain the rotational load torque simply by fitting the torsion coil spring into the cylindrical portion thereof.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a top view showing a gear change device according to an embodiment of the present invention from above, and FIG. 2 is a side view showing a side face of the gear change device of FIG. Also, FIG.
FIGS. 4 (a), 4 (b), and 4 (c) show the relationship between the winding direction of the torsion coil spring and the rotation direction of the planetary gears. It is the figure shown.

In FIGS. 1 to 4, reference numeral 1 denotes a gear that directly or indirectly receives rotation from a motor (not shown) to rotate. Reference numeral 2 denotes a planetary gear that receives rotation transmission from the gear 1 and moves in the E direction of FIG. 3 to transmit the rotation to the gear, or moves in the F direction of FIG. 3 to transmit the rotation to the gear. Three
Is a rotating shaft of the gear 1, and 4 is a rotating shaft of the planetary gear 2. Reference numeral 5 denotes an arm that keeps the distance between the rotating shaft 3 and the rotating shaft 4 constant. Reference numeral 6 denotes a bottom plate, which is the rotating shaft 3 of the gear 1.
Only the bottom plate 6 is supported. 7 and 8 are rings. Reference numeral 9 denotes a torsion coil spring fitted in the cylindrical portion 10 of the planetary gear 2, but does not have a function of pressing the side surface of the planetary gear 2. Reference numeral 10 denotes a cylindrical portion of the planetary gear 2, and the cylindrical portion 10 has a diameter α larger than the inner diameter of the coil portion of the torsion coil spring 8. Reference numeral 11 is a cylindrical portion of the gear 1. Gears 12 and 13 rotate by receiving rotation transmission from the planetary gear 2. 15 and 1
Reference numeral 6 is a stopper member that regulates the rotation range of the arm 5.

The operation of the gear switching device configured as described above will be described below. First, when rotation is transmitted by a motor (not shown), the gear 1 rotates in the direction of arrow A as shown in FIG. The planetary gear 2 rotates in the direction of arrow C in response to the transmission of the rotation of the gear 1. here,
Since the torsion coil spring 9 does not press the side surface of the planetary gear 2 downward, the coil spring 9 does not apply a frictional force to the planetary gear 2. Therefore, the rotation of the planetary gear 2 is not hindered by the torsion coil spring 9, so that the planetary gear 2 cannot rotate.
Rotates. However, if no rotational load torque is applied to the planet gears 2, the planet gears 2 simply rotate in the same place and do not move in the arrow E direction or the arrow F direction. Therefore, in the present invention, the loosening torque is applied to the planetary gear 2 as the rotational load torque. Usually, the loosening torque is derived by the following equation.

[0018]

(Equation 2)

As is clear from the above equation, the loosening torque T2 is not affected by the friction coefficient μ, unlike the case of the torque T1. In order to give this loosening torque to the planetary gear 2, in the present invention, the torsion coil spring 9 is fitted to the cylindrical portion 10 of the planetary gear 2 as shown in FIG. That is, since the diameter of the torsion coil spring 9 is formed smaller than the diameter α of the cylindrical portion 10 of the planetary gear 2, when the torsion coil spring 9 is fitted into the cylindrical portion 10 of the planetary gear 2, the torsion coil spring 9 is initially moved to the planetary gear 2. The cylindrical portion 10 is closed. by this,
Rotational load torque is applied to the rotation of the planetary gear 2.

That is, the rotation of the gear 1 causes the planetary gear 2 to rotate.
When is rotated, the torsion coil spring 9 is also fitted in the cylindrical portion 10 of the planetary gear 2, and thus is rotated by being twisted. next,
When one of the arms of the torsion coil spring 9 contacts the cylindrical portion 10 of the gear 1, the rotation of the torsion coil spring 9 stops. At this time, as shown in FIG. 4 (a), the rotation direction of the planetary gear 2 and the loosening direction of the coil portion of the torsion coil spring 9 as viewed from the cylindrical portion 11 of the gear 1 coincide with each other, so that the rotation force of the planetary gear 2 is increased. Acts to widen the coil portion of the torsion coil spring 9. As a result, a loosening torque is generated. This loosening torque allows the planetary gear 2 to move in the direction of arrow E, meshes with the gear 12, and transmits its rotation.

In the planetary gear 2, the arm 5 has the stopper member 1
When it comes into contact with 5, it stops at a predetermined position and rotates, so that it meshes with the gear 12 at an appropriate distance.

Next, when the gear 1 rotates in the direction of arrow B, the planetary gear 2 rotates in the direction of arrow D as shown in FIG. At this time, since the torsion coil spring 9 is also fitted in the cylindrical portion 10 of the planetary gear 2, the torsion coil spring 9 is also suspended and rotated. Next, when the other arm of the torsion coil spring 9 comes into contact with the cylindrical portion 11 of the gear 1, the rotation of the torsion coil spring 9 is stopped. Next, since the loosening direction of the coil portion of the torsion coil spring 9 is relative to the direction of the rotational load, the planetary gear 2 as shown in FIG.
And the direction of loosening of the coil portion of the torsion coil spring 9 match. Therefore, the coil portion of the torsion coil spring 9 is expanded by the rotation of the cylindrical portion 10 of the planetary gear 2. As a result, loosening torque is generated and the planetary gear 2 moves in the direction of arrow F. In this way, when the planetary gear 2 moves in the direction of arrow F, it is connected to the gear 13 and transmits the rotation.

In the planetary gear 2, the arm 5 has the stopper member 1
By contacting 6 and stopping and rotating, it meshes with gear 13 at an appropriate distance.

As described above, according to the present invention, the arm of the torsion coil spring 9 and the cylindrical portion 11 of the gear 1 are brought into contact with each other by a simple structure in which the torsion coil spring 9 is simply fitted to the cylindrical portion 10 of the planetary gear 2. Since the loosening torque is generated in any direction to give the rotational load torque to the planetary gear 2, the gear coupling can be switched stably.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the first embodiment, the planetary gear 2 is rotated by the arm 5 and the stopper member 15,
Although the rotation range is regulated by 16, the second embodiment is such that the rotation shaft of the planetary gear 2 is rotated by the groove provided in the support plate and the rotation range is regulated.

FIG. 5 is a side view showing a side surface of a gear change device according to another embodiment of the present invention. FIG. 6 is a cross-sectional top view taken along the alternate long and short dash line A of the gear change device of FIG.
7 (a) and 7 (b) are diagrams showing a gear connection switching operation. 5 to 7, reference numerals 18 and 19 denote support plates, and the respective gears are held between the support plates 18 and 19. Reference numeral 16 is a groove that holds the rotation shaft of the planetary gear 2, and the planetary gear 2 moves along the groove 17. Further, the arc of the groove 17 on the side opposite to the gear 1 is formed so that the distance from the rotation axis of the gear 1 is always constant. The same parts as those in FIGS. 1 to 4 are designated by the same reference numerals and the description thereof will be omitted.

The operation of the second embodiment will be described below. First, the gear 1 is indicated by an arrow A as shown in FIG.
When the planetary gear 2 rotates in the direction, the planetary gear 2 rotates in the direction of arrow C in response to the transmission of the rotation of the gear 1, and the torsion coil spring 9 fitted in the cylindrical portion 10 of the planetary gear 2 also rotates. As in the case of the first embodiment, the diameter of the torsion coil spring 9 is the planetary gear 2
Since the diameter of the cylindrical portion 10 is smaller than the diameter α of the cylindrical portion 10, when the torsion coil spring 9 is fitted into the cylindrical portion 10 of the planetary gear 2, the torsion coil spring 9 is initially attached to the cylindrical portion 10 of the planetary gear 2.
It will be in the state to close.

Next, when one of the arms of the torsion coil spring 9 contacts the cylindrical portion 10 of the gear 1, the rotation of the torsion coil spring 9 is stopped. At this time, as shown in FIG. 4 (a), the rotation direction of the planetary gear 2 and the loosening direction of the coil portion of the torsion coil spring 9 as viewed from the cylindrical portion 11 of the gear 1 coincide with each other, so that the rotation force of the planetary gear 2 is increased. Acts to widen the coil portion of the torsion coil spring 9, and a loosening torque is generated. The planetary gear 2 is supported by the support plate 1 by this loosening torque.
Move in the direction of arrow E along the groove 17 of 8 and 19,
It meshes with 2 and transmits its rotation.

When the planetary gear 2 moves to the end of the groove 17, it stops at that position, so that it meshes with the gear 12 at an appropriate distance.

Also, when the gear 1 rotates in the direction of arrow B, the planetary gear 2 moves in the direction of arrow F and is connected to the gear 13 to transmit the rotation, as in the above case. Also at this time, the planetary gear 2 stops at that position when it moves to the other end of the groove 17, so that the planetary gear 2 meshes with the gear 13 at an appropriate distance.

As described above, according to the second embodiment, the movement range of the planetary gear 2 is restricted by the groove 17 of the support plates 18 and 19, so that the arm 5 and the stopper member 15 are different from the first embodiment. , 16 are unnecessary, and the number of parts can be reduced accordingly.

[0032]

As described above, according to the present invention, the planetary gear can be moved by generating the loosening torque by fitting the coil portion of the torsion coil spring to the cylindrical portion of the rotation shaft of the planetary gear. The effect of being able to realize a stable gear connection switching mechanism with a simple structure is eliminated, as it is no longer necessary to design a gear connection switching mechanism that takes into consideration the friction coefficient of members as in the conventional art. it can. Further, since it is not necessary to consider the friction coefficient of the member, the rotational load torque applied to the planetary gear does not change due to the friction coefficient that changes with time, and the load is stable. A high gear coupling switching mechanism can be realized.

[Brief description of drawings]

FIG. 1 is a top view showing a gear switching mechanism according to an embodiment of the present invention.

FIG. 2 is a side view showing a side surface of the gear switching mechanism of FIG.

FIG. 3 is a diagram showing a gear connection switching operation.

FIG. 4 is a diagram showing a relationship between a winding direction of a torsion coil spring and a rotation direction of a planetary gear.

FIG. 5 is a side view showing a side surface of a gear change device according to another embodiment of the present invention.

FIG. 6 is a cross-sectional top view taken along alternate long and short dash line A of the gear change device of FIG.

FIG. 7 is a diagram showing a gear coupling switching operation.

FIG. 8 is a top view showing a conventional gear switching mechanism.

FIG. 9 is a side view showing a side surface of a conventional gear switching mechanism.

[Explanation of symbols]

 1 gear 2 planetary gear 5 arm 8 torsion coil spring

Claims (5)

[Claims] 1. A first gear for transmitting rotation of a motor,
A planetary gear whose rotation is transmitted from the first gear, and a planetary gear between the rotation shaft of the planetary gear and the rotation shaft of the first gear so that the planetary gear always transmits the rotation from the first gear. A supporting means for supporting the rotation shaft of the planet gear so as to be rotatable about the rotation shaft of the first gear, and a regulation means for regulating the rotation range of the planet gear, A gear switching device comprising: a torsion coil spring fitted in a cylindrical portion of a planetary gear; and means for stopping the rotation of the torsion coil spring that abuts on an arm of the torsion coil spring and tries to rotate around the planetary gear. 2. A first gear for transmitting rotation of a motor,
A planetary gear whose rotation is transmitted from the first gear, and a planetary gear between the rotation shaft of the planetary gear and the rotation shaft of the first gear so that the planetary gear always transmits the rotation from the first gear. And a groove for moving a rotation shaft of the planetary gear by guiding a predetermined range by transmission of rotation from the first gear, and a torsion coil spring fitted in a cylindrical portion of the planetary gear. A gear switching device having means for stopping the rotation of the torsion coil spring that comes into contact with the arm of the torsion coil spring and tries to rotate around the planetary gear. 3. The gear switching device according to claim 1, wherein the support means is an arm that rotates about the rotation axis of the first gear, and the rotation axis of the planetary gear is supported by the arm. . 4. The means for stopping the rotation of the torsion coil spring is the cylindrical portion of the first gear.
Alternatively, the gear change device described in item 2. 5. The gear according to claim 1 or 2, wherein the means for stopping the rotation of the torsion coil spring is configured to abut one arm of the torsion coil spring in accordance with the rotation direction of the torsion coil spring. Switching device.