JP2002349608A - One-way clutch - Google Patents

Abstract

(57) [Problem] To provide a one-way clutch in which there is no gap between an outer ring and a core even when expanded by heat. SOLUTION: A fitting convex portion 21 is formed on a resin outer ring 20, and a fitting concave portion 23 which meshes with the fitting convex portion 21 is formed on a metal core 22. The fitting projection 21
Are provided at three locations on the inner peripheral side of the outer ring 20, and these intervals are equalized. Similarly, the fitting recess 23 is provided at three places on the outer peripheral side of the core 22, and the intervals between them are made equal. The circumferentially opposed joining surfaces 21b and 21c formed on the fitting projection 21 and the circumferentially opposed joining surfaces 23b and 23c formed on the fitting recess 23 have their extension lines extending through the center O of the core 22. I'm going to pass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which a rotating shaft and an outer ring rotate relative to a rotating shaft in one direction, and the rotating shaft and the outer ring rotate integrally with each other in another direction. One-way clutch.

[0002]

2. Description of the Related Art FIG. 5 is a view showing the entire structure of a conventional one-way clutch, and FIG. 6 is a sectional view of the conventional one-way clutch. As shown in FIGS. 5 and 6,
The one-way clutch includes an outer race 1, a core 2 incorporated inside the outer race 1, a cap 3 of the outer race 1, a needle 11, and a spring member 13. Outer ring 1
Consists of a cylindrical portion 5 and a closing portion 6 for closing one end of the cylindrical portion 5. A plurality of fitting projections 7 are formed inside the cylindrical portion 5, and a bearing hole 8 for supporting the rotating shaft 4 is provided in the closing portion 6.

The core 2 has a plurality of fitting recesses 9 formed on the outer periphery thereof so as to mesh with the fitting protrusions 7 of the outer race 1. Therefore, when the fitting projection 7 and the fitting recess 9 are engaged with each other, the core 2 can be incorporated inside the outer race 1. A shaft hole 10 for inserting the rotating shaft 4 is formed in the core 2, and a plurality of needle holes 12 for inserting the needle 11 around the shaft hole 10.
Is formed.

Further, a plurality of spring holes 14 for inserting a spring member 13 are formed in the core 2. The spring member 13 applies a spring force to the needle 11. The spring member 13 includes a plurality of spring portions 15 inserted into the spring holes 14 and an annular connecting portion 16 connecting the plurality of spring portions 15. Needle hole 1
2 and the spring hole 14 are connected while sharing a part thereof. The needle hole 12 includes an inclined surface 12 a and an end surface 12 b on the side facing the spring hole 14.

The inclined surface 12a is inclined from the spring hole 14 side toward the end surface 12b. That is, the distance from the outer peripheral surface of the rotating shaft 4 to the spring hole 14 side of the inclined surface 12a is longer than the diameter of the needle 11, and the distance from the side surface of the rotating shaft to the needle 11 is set to the end surface 12b. It is shorter than the diameter. That is, a wedge-shaped holding portion is formed by the inclined surface 12a and the outer periphery of the rotating shaft 4. In the needle hole 12 having the inclined surface 12a as described above, the spring force of the spring member 13 acts to bring the needle 11 into contact with the rotating shaft 14.

[0006] The needle 11 and the spring member 13,
The needle hole 12 and the spring hole 14 into which this is inserted are combined to form a clutch mechanism c. The cap 3 closes the other end of the cylindrical portion 5 of the outer race 1 and forms a bearing hole 17 for supporting the rotating shaft 4. In the above configuration, the core 2 is incorporated into the outer race 1, and further, the needle 11 and the spring member 13 are incorporated into the core 2. The outer ring 1 and the core 2
Cap 3 At this time, the annular convex portion 18 formed on the cap 3 is snap-fitted to the annular concave portion 19 formed on the outer race 1 so as to fit tightly.
After the cap 3 is attached to the outer ring 1, the rotating shaft 4 is inserted so as to pass through the bearing hole 8 of the outer ring 1, the shaft hole 10 of the core 2, and the bearing hole 17 of the cap 3.

FIG. 6 shows a cross section of the one-way clutch. The operation of the above configuration will be described with reference to FIG. In FIG. 6, the rotating shaft 4 is rotated in the arrow X direction. When the rotating shaft 4 rotates in the direction of the arrow X in this manner, the rotation force and the spring force of the spring member 13 cause the needle 1 to rotate.
1 is strongly pushed in the direction of the end face 12b of the needle hole 12.
When the needle 11 is strongly pushed toward the end face 12b in this manner, the needle 11
Is completely clamped by the wedge-shaped clamping portion formed by the outer periphery of the wedge.

[0008] When the needle 11 is held between the holding portions, the pressing force of the needle 11 against the rotating shaft 4 increases, and the needle 11 locks the rotation of the rotating shaft 4. When the rotation shaft 4 is locked, the rotation shaft 4 cannot rotate relative to the core 2. When the rotary shaft 4 is further locked in the locked state and cannot rotate relative to the core 2 and the rotary shaft 4 is further rotated in the direction of arrow X, the core 2 rotates with the arrow X
Rotate in the direction.

On the other hand, when the rotating shaft 4 is rotated in the direction of the arrow Y in FIG. 6, the needle 11 is pressed in the direction of the arrow Y with this rotation. Needle 11
When the needle 11 is pressed in the direction of the arrow Y, the needle 11 bends the spring
Move in the side direction. Since the size of the needle hole 12 is larger than the diameter of the needle 11 on the spring hole 14 side, the needle 11 comes off the holding portion. That is, the needle 11 is pressed in the direction of the rotating shaft 4,
The relative rotation between the rotating shaft 4 and the core 2 is not locked. That is, the rotation of the rotating shaft 4 is kept free.

Therefore, when the rotating shaft 4 is rotated in the direction of arrow Y, the rotating shaft 4 rotates relative to the core 2. In other words, even if the rotation axis is rotated in the arrow Y direction, the core 2 does not rotate with this rotation. As described above, when the rotating shaft 4 is rotated in one direction, the one-way clutch transfers the rotating force to the core 2.
And when it is rotated in the other direction, its rotational force is not transmitted to the core 2.

In the conventional one-way clutch as described above, when the rotating shaft 4 is rotated in the direction of arrow X to pinch the needle 11, the reaction force of the needle 11 directly acts on the core 2. The reaction force at this time increases as the rotational force of the rotating shaft 4 increases. Therefore, if the strength of the core 2 is weak, the core 2 is broken depending on the magnitude of the reaction force. Therefore, in order to maintain the strength of the core 2,
Generally, it is made of metal such as iron.

On the other hand, the outer ring 1 is often made of resin, because it is easy to mold and the cost is low. In addition, a gear, a pulley, or the like is assembled and used for the outer ring 1 depending on the application. In some cases, both the outer ring 1 and the gear may be integrally formed of resin. By making the outer race 1 made of resin in this way, the number of parts can be reduced, and the cost can be reduced. As described above, the core 2 is often made of metal from the viewpoint of maintaining its strength, and the outer ring 1 is often made of resin for the purpose of reducing the number of parts and reducing costs.

[0013]

When a one-way clutch made of a different material such as a metal and a resin is exposed to a high temperature as described above, the difference in the coefficient of expansion between the metal and the resin causes a difference in the expansion coefficient between the metal and the resin.
As shown in (1), a gap is created between the core and the outer ring. If the gap is formed, the backlash between the core and the outer ring becomes large, and the transmission of the rotational force of both of them becomes out of timing. In FIG. 7, the structure of the clutch mechanism c is omitted because it is the same as that of FIG.

Further, when a gear or the like is integrally formed with the outer race 1, the occurrence of the above-mentioned gap affects the meshing of the gear. The one-way clutch may be exposed to high temperatures, for example, a clutch in a paper feed mechanism of a copying machine.

As is clear from FIG. 6, each of the fitting projection 7 and the fitting recess 9 has a gentle arc shape in cross section. If the two have a gentle arc shape as described above, the fitting concave portion 9 may get over the fitting convex portion 7 when a relative rotational force acts on the outer ring and the core. In particular, due to the difference in expansion rate as described above,
If a gap is formed between the outer race and the core, the fitting recess 9 easily goes over the fitting projection 7. As described above, when the fitting concave portion 9 gets over the fitting convex portion 7, the outer race and the core run idle.

An object of the present invention is to prevent the outer ring and the core from rattling in the rotational direction even when expanded by heat.
An object of the present invention is to provide a one-way clutch in which there is no deviation between the rotation center of a rotating shaft and the rotation center of an outer ring.

[0017]

According to the present invention, a rotating shaft is inserted into a core having an inclined surface formed on an inner surface, and a needle is interposed between the inclined surface and the rotating shaft.
It is assumed that a one-way clutch in which an outer ring is attached to the outside of the core, the rotation shaft and the core rotate integrally with one rotation of the rotation shaft, and the rotation is not transmitted to the other rotation.

According to a first aspect of the present invention, the core and the outer ring are made of a material whose expansion coefficient of the outer ring is larger than the expansion coefficient of the core, and a plurality of fitting recesses are formed on the outer circumference of the core and the inner circumference of the outer ring. A plurality of fitting projections are formed, and they are fitted to each other. Of the joining surfaces of the fitting recesses and the fitting projections, the joining surfaces that face each other in the circumferential direction pass substantially through the center of the core. It is characterized by being formed along a straight line.

The second invention is characterized in that a pair of a fitting concave portion and a fitting convex portion are provided at equal intervals. The third invention is characterized in that two pairs of fitting concave portions and fitting convex portions are provided on the diameter line. The fourth invention is characterized in that three or more pairs of fitting concave portions and fitting convex portions are provided.

[0020]

FIG. 1 shows a first embodiment of the present invention. As shown in FIG.
0, a fitting protrusion 21 is formed, and a metal core 22 is formed with a fitting recess 23 that meshes with the fitting protrusion 21. The fitting protrusions 21 are provided at three locations on the inner peripheral side of the outer ring 20 and the intervals between them are equalized. Similarly, the fitting recess 23 is provided at three places on the outer peripheral side of the core 22, and the intervals between them are made equal.

The outer ring 20 and the core 22 are combined so that the fitting concave portion 23 of the core 22 engages with the fitting convex portion 21 of the outer ring 20. The fitting projection 21 has joining surfaces 21a, 21b, 21c, and the fitting recess 23 has joining surfaces 23a, 23b, 23c.
When the core 22 is combined with the outer ring 20, the joining surface 21a and the joining surface 23a are joined, and the joining surface 2
1b and 23b and the joining surfaces 21c and 23c are respectively joined. Of these joining surfaces, the joining surfaces 21b, 21c and 23b, 23c are circumferentially opposed surfaces of the present invention. Joining surfaces 21b and 21c facing these circumferentially.
And 23b, 23c, the extension of which passes through the center O of the core 22.

The other components of the first embodiment are the same as in the conventional example. Therefore, the same components as those in the conventional example are denoted by the same reference numerals used in the description of the conventional example, and detailed description thereof will be omitted. FIG. 2 shows a state when a high temperature acts on the one-way clutch having the above-described configuration.

When a high temperature is applied, the outer ring 20 and the core 22 have different expansion coefficients, so that the resin outer ring 20 expands more than the metal core 22. Thus, the outer ring 20
Is greatly expanded, the fitting protrusion 21 formed on the outer race 20 is formed.
Expands in a similar manner while sliding the joining surfaces 21b and 21c facing each other in the circumferential direction and the joining surfaces 23b and 23c of the fitting concave portion 23 formed in the core 22. That is, the joining surfaces 21b and 21c of the outer ring 20 that face each other in the circumferential direction.
Is on a straight line passing through the center. Also, when the outer ring 20 expands, it expands in the diameter direction without changing the center,
Even if the joint surfaces 21b and 21c facing each other in the circumferential direction expand, they do not deviate from a straight line passing through the center.

Similarly, since the joining surfaces 23b and 23c of the core 23 which face in the circumferential direction are also along a straight line passing through the center, they do not deviate from this straight line even when expanded. Therefore, the joining surfaces 21b and 21c and the joining surfaces 23b and 23c that are circumferentially opposed to each other slide. As described above, since the joining surfaces 21b, 21c and 23b, 23c circumferentially opposed to each other do not deviate from the center line, even if the outer ring 20 and the core 22 expand, the joining surface 21
There is no gap between b, 21c and 23b, 23c. Since there is no gap between the joining surfaces 21b and 23b and the joining surfaces 21c and 23c that face each other in the circumferential direction, there is no play as in the related art. That is, there is no backlash in the rotation direction, and there is no deviation between the rotation center of the rotating shaft and the rotation center of the outer ring.

Further, the joining surfaces 21b facing in the circumferential direction,
As long as the contact 23b and the joining surfaces 21c, 23c are in contact, the fitting recess 23 does not climb over the fitting projection 21. This is because the joining surfaces 21b and 23b and the joining surface 21
This is because c and 23c are on a straight line passing through the center.

Further, as described above, when the outer race 20 expands, the fitting projection 21 slides in a direction to come out of the fitting recess 23. Therefore, when the outer race 20 expands, the fitting projection 21 fits. There is no pressure on the recess 23. Since the projection 21 and the recess 23 do not interfere with each other, the outer ring 2
It does not distort when the 0 expands. Since the outer race 20 is not distorted in this way, for example, it does not affect the meshing of a gear or the like integrated therewith.

In addition, a pair of fitting projections 21 and fitting recesses 2
Since the outer ring 20 and the outer ring 20 are provided at equal intervals, the outer ring 20 can be inflated in a well-balanced manner and guided by the fitting concave portion 23 and the fitting convex portion 21 to maintain a perfect circle. Furthermore, since the pair of the fitting projection 21 and the fitting recess 23 are provided at equal intervals as described above, when a load is applied in a direction perpendicular to the rotation axis,
Eccentricity does not occur between the core and the outer ring, and stable rotation transmission can be obtained.

In the first embodiment, a pair of fitting projections 21 and fitting recesses 23 are provided at equal intervals in the circumferential direction, but the number is not limited to three. As long as the number is two or more, any number may be used, but as the number increases, the outer ring 20 and the core 23 can be firmly fixed. Furthermore, even when the core and the outer ring thermally expand, the connection stability can be maintained in all directions of 360 degrees.

FIG. 3 shows a second embodiment, which is characterized in that two sets of a pair of fitting projections 25 and fitting recesses 27 are provided on a diameter line. Components other than this feature are the same as in the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted. In the second embodiment, the outer race 24 is made of resin and the core 2
6 is made of metal.

The fitting projection 25 has a joining surface 25.
a, 25b, 25c are formed, and the fitting recesses 27 are formed with joining surfaces 27a, 27b, 27c. Then, when the core 26 is combined with the outer race 24, the joining surface 25a and the joining surface 27a are joined, and the joining surface 2 facing in the circumferential direction is joined.
5b and 27b and the joining surfaces 25c and 27c are respectively joined. Extension lines of the circumferentially opposed joining surfaces 25b, 25c and 27b, 27c pass through the center O of the core. In other words, the joining surfaces 25b, 25c and 27b, 27c are arranged along a straight line passing substantially through the center of the core 26.

FIG. 4 shows the one-way clutch constructed as described above when a high temperature acts on the one-way clutch. The operation and effect when the high temperature acts on the one-way clutch are the same as those of the first embodiment.

In the first and second embodiments, the fitting protrusion is provided on the outer ring and the fitting recess is provided on the core. Conversely, the fitting recess is provided on the outer ring. Alternatively, a fitting projection may be provided on the core.

[0033]

According to the first invention, a plurality of fitting concave portions and a plurality of fitting convex portions are formed on the outer periphery of the core and the inner periphery of the outer race, and these are fitted to each other. Of the joining surfaces of the core and the outer ring, the joining surfaces opposed to each other in the circumferential direction are set to be along a straight line passing substantially through the center of the core. There is no backlash in the direction of rotation, and no deviation occurs between the center of rotation of the rotating shaft and the center of rotation of the outer ring. Therefore, the connection in the rotation direction between the rotation shaft and the outer ring is extremely stabilized. Also, there is no gap between the fitting recesses and the joining surfaces of the fitting projections that face each other in the circumferential direction. Since there is no gap, the transmission of the rotational force between the core and the outer ring does not have a timing shift. In addition, since there is no gap between the joining surfaces facing each other in the circumferential direction, the fitting concave portion does not go over the fitting convex portion. Therefore, the outer race and the core do not run idle.

According to the second aspect of the present invention, the pair of the fitting concave portion and the fitting convex portion are provided at equal intervals, so that when a load is applied in a direction perpendicular to the rotating shaft, the core and the outer ring are connected to each other. There is no eccentricity between them, and stable rotation transmission can be obtained. According to the third aspect, since the pair of the fitting concave portion and the fitting convex portion is provided in the shape of a diameter line, even during thermal expansion, a stable coupling state can be sufficiently maintained with only two pairs. . According to the fourth invention,
Since three or more pairs of the fitting concave portion and the fitting convex portion are provided, the stability of the connection can be maintained in all directions of 360 degrees even during thermal expansion.

Further, according to the second to fourth aspects of the present invention, a pair of a plurality of fitting recesses and fitting projections are provided at equal intervals.
Even if the outer race expands more than the core, the outer race 20 can be expanded in a well-balanced manner and be kept in a perfect circle by being guided by these fitting recesses and fitting projections, and prevent eccentricity. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a state when the one-way clutch of FIG. 1 expands due to high temperature.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a state when the one-way clutch of FIG. 3 expands due to a high temperature.

FIG. 5 is a diagram showing a conventional one-way clutch.

FIG. 6 is a sectional view of FIG. 5;

FIG. 7 is a diagram showing a state when the one-way clutch of FIG. 6 expands due to a high temperature.

[Explanation of symbols]

 Reference Signs List 4 Rotation shaft 11 Needle 12a Inclined surface 20 Outer ring 21 Fitting convex portion 21b Joining surface 21c Joining surface 22 Core 23 Fitting concave portion 23b Joining surface 23c Joining surface 24 Outer ring 25 Fitting convex portion 25b Joining surface 25c Joining surface 26 Core 27 Fitting Joint recess 27b Joint surface 27c Joint surface O center

[Procedure amendment]

[Submission Date] March 11, 2002 (2002.3.1)
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

The inclined surface 12a is inclined from the spring hole 14 side toward the end surface 12b. That is, the distance from the outer circumferential surface of the rotary shaft 4 to the spring hole 14 side of the inclined surface 12a is longer than the diameter of the needle 11, and the distance from the side surface of the rotary shaft to the needle 11 is set to the end surface 12b side. It is shorter than the diameter. That is, a wedge-shaped holding portion is formed by the inclined surface 12a and the outer periphery of the rotating shaft 4. In the needle hole 12 having the inclined surface 12a as described above, the spring force of the spring member 13 acts to bring the needle 11 into contact with the rotating shaft 4 .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

[0017]

According to the present invention, a rotating shaft can be inserted into a core having an inclined surface formed on an inner surface, and a needle is interposed between the inclined surface and the rotating shaft. Put the outer ring on the outside of the core, inside the core
It is assumed that a one-way clutch in which the rotation shaft and the core rotate integrally with one rotation of the rotation shaft and the rotation is not transmitted to the other rotation while the rotation shaft is inserted .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

In the first embodiment, a pair of fitting projections 21 and fitting recesses 23 are provided at equal intervals in the circumferential direction, but the number is not limited to three. As long as the number is two or more, any number may be used, but as the number increases, the outer ring 20 and the core 22 can be firmly fixed. Furthermore, even when the core and the outer ring thermally expand, the connection stability can be maintained in all directions of 360 degrees.

[Procedure amendment 5]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 6]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (4)

[Claims] 1. A rotating shaft is inserted into a core having an inclined surface formed on an inner surface, and a needle is interposed between the inclined surface and the rotating shaft, while an outer ring is fitted outside the core. In a one-way clutch in which the rotation shaft and the core rotate integrally with one rotation of the rotation shaft and the rotation is not transmitted with respect to the other rotation, the expansion coefficient of the outer ring between the core and the outer ring is larger than that of the core. Constructed from a material larger than the coefficient, and formed with a plurality of fitting concave portions and a plurality of fitting convex portions on the outer periphery of the core and the inner periphery of the outer ring, and fitting them together, A one-way clutch in which, of the joint surfaces with the fitting protrusions, the joint surface facing in the circumferential direction is along a straight line passing substantially through the center of the core. 2. The one-way clutch according to claim 1, wherein a pair of a fitting concave portion and a fitting convex portion are provided at equal intervals. 3. The one-way clutch according to claim 1, wherein two pairs of the fitting concave portion and the fitting convex portion are provided on the diameter line. 4. The one-way clutch according to claim 1, wherein three or more pairs of a fitting concave portion and a fitting convex portion are provided.