JP2004156660A - Planetary gear type clutch mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planetary gear type clutch mechanism in which two or more pairs of tooth edges between a planetary gear and a standby gear are simultaneously brought into contact with each other, when the planetary gear starts to engage with the standby gear. <P>SOLUTION: A distance between tooth edges 27 and 28 of the planetary gear 2 is shorter than a distance between tooth edges 93 and 94 of the standby gear 9 such that a full tooth length of a tooth 26 of the planetary gear 2 is lower than that of a tooth 25. Therefore, even though the planetary gear 2 and the standby gear 9 start to engage in a phase so as to bring into contact with the tooth edge 27 and the tooth edge 93 respectively, each pair of adjacent teeth of the planetary gear 2 and the standby gear 9 is not brought into contact with each other such that distances of teeth edges between the planetary gear 2 and the standby gear 9. Consequently, a locking phenomenon caused by simultaneous contact between each pair of adjacent teeth between the planetary gear 2 and the standby gear 9 at the beginning of engagement is avoidable. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a clutch mechanism for switching a power transmission direction.
[0002]
[Prior art]
BACKGROUND ART A planetary gear clutch mechanism including a sun gear, a planetary gear that can revolve around the sun gear, and a standby gear that can mesh with the planetary gear by the revolving motion of the planetary gear is known (see Patent Document 1). .
[0003]
[Patent Document 1]
JP-A-8-160511
[Problems to be solved by the invention]
Such a planetary gear type clutch mechanism has the following problem when the planetary gear starts to mesh with the standby gear. When two or more tooth tips of the planetary gear and the standby gear abut at the same time, the rotation is locked, or the rotation is locked and the gear rotates from a high load, causing impulsive sound and damage to the tooth surface. There was a risk of causing problems.
[0005]
An object of the present invention is to provide a planetary gear type clutch mechanism in which two or more tooth tips of the planetary gear and the standby gear do not simultaneously contact when the planetary gear starts to mesh with the standby gear.
[0006]
[Means for Solving the Problems]
(1) A planetary gear type clutch mechanism according to the first aspect of the present invention provides a sun gear, a planet gear that meshes with the sun gear and can revolve around the sun gear, and at least can mesh with the planet gear by the revolving position of the planet gear. One standby gear, and when the planetary gear and the standby gear start to mesh with the standby gear by the revolving motion of the planetary gear, the two or more tips of the planetary gear and the standby gear It is characterized in that it does not contact at the same time.
(2) According to a second aspect of the present invention, in the planetary gear type clutch mechanism according to the first aspect, a distance between adjacent tooth tips of the planetary gear is different from a distance between adjacent tooth tips of the standby gear. It is characterized by the following.
(3) The planetary gear-type clutch mechanism according to claim 2, wherein at least two types of teeth having different total tooth lengths are provided on the teeth of the planetary gear, so that adjacent tooth tips of the planetary gear are provided. The distance between them is different from the distance between adjacent tooth tips of the standby gear.
(4) According to a fourth aspect of the present invention, in the planetary gear type clutch mechanism according to the third aspect, every other two types of teeth having different tooth pitches are provided on teeth of the planetary gear.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
――― Planetary gear type clutch mechanism ―――
An embodiment of the planetary gear type clutch mechanism according to the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a meshing state of gears when the planetary gear type clutch mechanism is viewed from the front. The planetary gear type clutch mechanism includes a sun gear 1, a planetary gear 2, and standby gears 8 and 9. FIG. 2 is a cross-sectional view of the planetary gear type clutch mechanism according to the embodiment when viewed from the side. A center shaft 61 is formed on the gear base 6. The sun shaft 11 is rotatably fitted to the center shaft 61. The connecting member 3 is fixed to the upper surface of the sun shaft 11. The sun gear 1 is rotatably fitted on the outer periphery of the sun shaft 11. The sun shaft 11 and the sun gear 1 are prevented from falling off from the center shaft 61 by the holding plate 10. A connecting member protrusion 31 is formed at the tip of the connecting member 3. When the connecting member projection 31 of the connecting member 3 that rotates about the central axis 61 abuts on the regulating members 64 and 65 formed on the gear base 6, the rotation of the connecting member 3 about the central axis 61 is achieved. Limited to a certain angle.
[0008]
A planet shaft 21 is attached to the distal end side of the connecting member 3, and the planet gear 2 is rotatably fitted to the outer periphery of the planet shaft 21. The coil spring 7 is interposed between the planet shaft 21 and the planet gear 2. When the planet shaft 21 is attached to the connecting member 3, the coil spring 7 is slightly compressed, and the restoring force causes the connecting member 3 and the planet gear 2 to be frictionally coupled to each other.
[0009]
Standby gears 8 and 9 having the same number of teeth as the planetary gear 2 are rotatably fitted to standby shafts 62 and 63 formed on the gear base 6, respectively. As described later, these standby gears 8 and 9 are engaged with the planetary gear 2 revolving around the center shaft 61, so that the driving force of the sun gear 1 is transmitted via the planetary gear 2.
[0010]
As shown in FIG. 3, the teeth of the planetary gear 2 have sharpened tooth tips, and the teeth 25 have a normal height (total teeth), and the teeth 25 Low tooth teeth 26 are formed alternately. The shape of the teeth of the standby gears 8 and 9 is sharpened like the planetary gears 2, but all teeth are the same in height.
[0011]
――― Operation of planetary gear type clutch mechanism ―――
The operation of the planetary gear type clutch mechanism according to one embodiment will be described with reference to FIGS. As shown in FIG. 1, when the sun gear 1 rotates clockwise, since the planetary gear 2 is in frictional contact with the connecting member 3 by the coil spring 7, resistance occurs in the rotation of the planetary gear 2 and thereby the planetary gear 2 2 revolves clockwise together with the sun gear 1. The revolving motion of the planetary gear 2 is regulated by the contact of the connecting member projection 31 with the regulating member 64. The planetary gear 2 meshes with the standby gear 8 in the restricted position.
[0012]
When the clockwise rotation of the sun gear 1 stops and starts to rotate counterclockwise, the planetary gear 2 releases the engagement with the standby gear 2 as shown in FIG. Starts revolving counterclockwise. When the planetary gear 2 further revolves due to the further rotation of the sun gear 1 in the counterclockwise direction, the planetary gear 2 and the standby gear 9 start to mesh with each other, as shown in FIG. Thereafter, as shown in FIG. 6, the connecting member protrusion 31 comes into contact with the regulating member 65, and the switching of the standby gear to which the power is transmitted is completed.
[0013]
When the planetary gear 2 and the standby gear 9 start to engage with each other, as shown in FIG. 5, a position where the tooth tips 27 of the teeth 25 of the planetary gear 2 and the tooth tips 93 of the teeth 91 of the standby gear 9 come into contact with each other. , The planetary gear 2 and the standby gear 9 each have a sharpened tooth tip, so that the tooth tip 27 of the planetary gear 2 and the tooth tip 93 of the standby gear 9 do not come into contact with each other, Can be moved to the meshing position. Further, since the total tooth length of the teeth 26 of the planetary gear 2 is lower than the total tooth length of the teeth 25, the distance between the tooth tips 27 and 28 of the planetary gear 2 is shorter than the distance between the tooth tips 93 and 94 of the standby gear 9. . Therefore, even if the planetary gear 2 and the standby gear 9 start to mesh with each other at such a phase that they abut on the tooth tip 27 and the tooth tip 93, the distance between the tooth tips of the planetary gear 2 and the standby gear 9 is different. Two adjacent teeth of the gear 2 and the standby gear 9 do not abut simultaneously. As a result, it is possible to avoid a lock caused by two adjacent teeth of the planetary gear 2 and the standby gear 9 simultaneously abutting at the beginning of meshing.
[0014]
Similarly, when the sun gear 1 stops rotating in the counterclockwise direction and rotates in the clockwise direction, two adjacent teeth of the planetary gear 2 and the standby gear 8 similarly do not abut simultaneously.
[0015]
In the conventionally used planetary gear type clutch mechanism, when the distance between the tooth tips of the planetary gear and the standby gear is equal, two adjacent tooth tips come into contact with each other and are locked. Therefore, in the planetary gear type clutch mechanism of the above-described embodiment, locking is avoided by changing the distance between all adjacent tooth tips by changing the entire gear length of a part of the planetary gear 2. . Apart from the above-mentioned method, a method is also conceivable in which the number of teeth of each of the planetary gear and the standby gear is made different to make the distance between the tooth tips different. This is because, when the number of teeth is changed, the pitch circle diameter of the gear changes, so that the distance between the tooth tips also changes. Therefore, when comparing the two, the method of changing the tooth tip distance by changing the number of teeth shows that if the tooth number ratio is slightly changed, the change in the tooth tip distance is small, and the effect of actually preventing locking cannot be obtained. There is. Here, if the ratio of the number of teeth is largely changed to increase the change in the distance between the tooth tips, there may be various inconveniences in design such as "the one gear becomes large" and "the speed ratio changes". On the other hand, the planetary gear type clutch mechanism of the above-described embodiment is excellent in that such inconvenience does not occur and the amount of change in the distance between the tooth tips can be increased as compared with the method of changing the number of teeth. ing.
[0016]
The above-described planetary gear type clutch mechanism according to the embodiment has the following operational effects.
(1) When the planetary gear 2 starts to mesh with the standby gear 9, it is possible to avoid locking caused by simultaneous contact between two adjacent teeth of the planetary gear 2 and the standby gear 9, and thus, abrasion of the tooth surface. And dents can be reduced, and the durability can be improved.
(2) Since the distance between the adjacent tooth tips of the planetary gear 2 is made different from the distance between the adjacent tooth tips of the standby gears 8 and 9, two adjacent teeth of the planetary gear 2 and the standby gear 9 are connected to each other. Can be reliably prevented from being caused by simultaneous contact of the locks. Thereby, the reliability of the planetary gear type clutch mechanism can be increased.
(3) The distance between the tips is changed by providing the planetary gear 2 with teeth having different tooth heights. Since there is no change in the number of teeth, there is less design change compared to a method of avoiding locking by changing the tip distance by changing the number of teeth, which is efficient in design. Further, as compared with the method of changing the distance between the tips by changing the number of teeth, the distance between the tips can be reliably changed, so that locking can be reliably avoided and the reliability of the planetary gear type clutch mechanism can be increased. .
(4) In the planetary gear 2, teeth 25 having a normal height of all teeth and teeth 26 having a lower total height than the teeth 25 are alternately formed. This simplifies the design, since only a slight change in the gear design is required, in which all the teeth have the same total tooth length.
[0017]
――― Modifications ―――
In the planetary gear type clutch mechanism of the above-described embodiment, the planetary gear 2 and the standby gears 8 and 9 have the same number of teeth, but are not limited thereto. In the planetary gear type clutch mechanism according to the above-described embodiment, the planetary gear 2 is provided with two types, one having a normal tooth height and the other having a low total tooth height, and the respective teeth are alternately arranged. However, the present invention is not limited to this. . It is also possible to further provide a tooth having a total tooth height different from that of the above-described embodiment, and to use three or more types of the total tooth height. In the planetary gear type clutch mechanism of the above-described embodiment, all the tooth lengths of some of the teeth of the planetary gear 2 are changed, but all the tooth lengths of some of the teeth of the standby gear may be changed. Further, one standby gear may be provided. The above-described embodiments and modified examples may be combined. Furthermore, the present invention is not limited to the above-described embodiment and its modifications as long as the characteristic functions of the present invention are not impaired.
[0018]
【The invention's effect】
According to the present invention, when the planetary gear starts to mesh with the standby gear, two or more tooth tips of the planetary gear and the standby gear are prevented from simultaneously abutting against each other. Wear and dents on the surface can be reduced, and durability can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a meshing state of gears when a planetary gear type clutch mechanism according to the present invention is viewed from the front.
FIG. 2 is a cross-sectional view of the planetary gear type clutch mechanism of FIG. 1 when viewed from a side.
FIG. 3 is an enlarged view of a planetary gear 2 of the planetary gear type clutch mechanism of FIG.
FIG. 4 is a view for explaining the operation of the planetary gear type clutch mechanism of FIG. 1;
FIG. 5 is a diagram for explaining the operation of the planetary gear type clutch mechanism of FIG. 1;
FIG. 6 is a diagram illustrating an operation of the planetary gear type clutch mechanism of FIG. 1;
[Explanation of symbols]
REFERENCE SIGNS LIST 1 sun gear 2 planetary gear 3 connecting member 6 gear stand 8, 9 standby gear 10 holding plate 11 sun shaft 21 planet shaft 31 connecting member protrusion 61 central shaft 62, 63 standby shaft 64, 65 regulating member

Claims (4)

Sun gear,
A planetary gear that can revolve around the sun gear meshing with the sun gear,
Having at least one standby gear that can mesh with the planetary gear by the revolving position of the planetary gear,
When the planetary gears begin to mesh with the standby gears due to the revolving motion of the planetary gears, two or more tooth tips of the planetary gears and the standby gears simultaneously contact the tooth shapes of the planetary gears and the standby gears. A planetary gear type clutch mechanism characterized in that it does not come into contact with it. The planetary gear type clutch mechanism according to claim 1,
A planetary gear type clutch mechanism, wherein a distance between adjacent tooth tips of the planetary gear is different from a distance between adjacent tooth tips of the standby gear. The planetary gear type clutch mechanism according to claim 2,
By providing at least two types of teeth having different total tooth lengths on the teeth of the planetary gear, the distance between adjacent tooth tips of the planetary gear is made different from the distance between adjacent tooth tips of the standby gear. Characteristic planetary gear clutch mechanism. The planetary gear type clutch mechanism according to claim 3,
A planetary gear type clutch mechanism, wherein every other two types of teeth having different tooth lengths are provided on every other tooth of the planetary gear.

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