JP4724962B2 - One-way clutch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a one-way clutch, and in particular, a one-way that can properly bias the sprag without causing the spring to spring even when the reaction force applied to the cage is uneven when the cage is press-fitted into the outer ring. Regarding the clutch.
[0002]
[Prior art]
When repeatedly transmitting and shutting off the power between the inner ring and the outer ring, a one-way clutch is usually arranged between the inner and outer rings. As shown in FIG. 6, the one-way clutch is usually composed of a cage 13, a spring (usually a ribbon spring is used) 14, and a sprag 15, and is formed in an annular space 20 between the outer ring 11 and the inner ring 12. Be placed. When the outer ring 11 and the inner ring 12 rotate in one direction due to the relative rotation of the outer ring 11 and the inner ring 12, the sprag 15 acts as a wedge and the outer ring 11 and the inner ring 12 rotate integrally (lock), and when rotated in the other direction, the wedge action. Is released, idles and power transmission is cut off (unlocked). In some cases, two cages, that is, an outer cage and an inner cage, are arranged to rotate relative to each other when locked and unlocked.
[0003]
FIG. 7 shows a one-way clutch composed of a cage 23 with a flange 23f, a spring 24, and a sprag 25. In the one-way clutch, the cage 23 is synchronized with the rotation of the outer ring. In many cases, 23 is interference-fitted into the outer ring (not shown). Therefore, the outer diameter of the retainer 23 (outer diameter of the flange portion 23f) is slightly larger than the inner diameter of the raceway surface of the outer ring and is press-fitted to provide a one-way clutch having a fixing force. However, there is a problem that the cage 23 is eccentric with respect to the outer ring due to the pressure caused by the press-fitting between the cage 23 and the inner peripheral surface of the outer ring, and the clearance between the sprag 25 and the pocket of the cage 23 becomes narrow. Therefore, in order to avoid such a situation, a proposal has been made (registered utility model No. 2598500) in which the flanges 23f of the retainer 23 are cut at equal intervals in the circumferential direction to provide cuts 23c. Alternatively, a configuration is disclosed in which a slightly elliptical cage is press-fitted and fixed to the outer ring so that the outer ring and the cage operate integrally (Japanese Utility Model Publication No. 6-10233).
[0004]
[Problems to be solved by the invention]
In the one-way clutch, as shown in FIG. 6, a spring 14 is arranged on the inner diameter side of the retainer 13 that holds the sprag 15, and the sprag 15 is always urged to be locked by a tongue piece 14 t of the spring 14. is doing. However, in order to operate the cage 13 in synchronization with the outer ring 11, when the cage 13 having a slightly oval shape is press-fitted into the inner peripheral surface (track surface) 11 a of the outer ring 11, in particular, the oval portion of the cage 13 Therefore, the spring 14 is greatly deformed locally toward the radial center. Therefore, the biasing force acting from the tongue piece portion 14t of the spring 14 of the sprag 15 prestressed by the tongue piece portion 14t of the spring 14 is weakened, and the sprag 15 is inclined at a position where the deformation of the spring is large. As a result, the posture is greatly inclined in the idling direction. Therefore, when the idle position is changed to the meshing position, the amount of displacement of the spring tongue 14t is increased, and the spring tongue is liable to sag, and therefore, the one-way clutch is poorly meshed. It was.
[0005]
The present invention has been made to cope with the above-described problems. Even when the interference between the cage and the outer ring is increased, the spring force of the spring tongue portion is not weakened, and an appropriate spring force is obtained. An object of the present invention is to provide a one-way clutch that maintains the synchronism between the outer ring and the cage and does not increase the cost.
[0006]
[Means for Solving the Problems]
That is, in order to solve the above-described problems, the present invention includes a cage, a spring arranged along the inner diameter side of the cage, the cage, and the spring. A one-way clutch comprising a sprag fitted in a pocket and press-fitting the retainer to the inner peripheral surface of the outer ring,
The retainer is provided with a flange that is partially oval,
It said that you have the rigidity of the portion of the spring of the position of the oval portion of the flange said retainer Indian meal allowance is the largest and the reaction force becomes the largest larger than the other positions.
[0007]
Further, in the invention according to claim 2, the portion of the spring at the position of the ellipse portion of the flange where the clamping margin of the cage is the largest and the reaction force is the largest is the one end and the other end. you wherein you have to increase the rigidity by overlapping a portion of the part.
[0008]
According to a third aspect of the present invention, the portion of the spring at the position of the ellipse portion of the flange where the clamping allowance of the cage is the largest and the reaction force is the largest is hardened by hardening the other portions. it shall be the features of the the city are.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
1 is a side view of the one-way clutch of the present invention, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is an enlarged cross-sectional view of a P portion of FIG. FIG. 4 is an enlarged view of the spring portion of FIG. 2 for explaining the overlapping portion. FIG. 5 is an overall perspective view of a spring used in the one-way clutch of the present invention.
[0010]
The one-way clutch includes a cage 3, a spring (ribbon spring) 4 disposed along the inner diameter side of the cage 3, and a sprag 5 fitted in the pockets 3 p, 3 p,. Are arranged in an annular space 10 between the outer ring 1 and the inner ring 2. The cage 3 has a flange portion 3f formed on one side. The outer peripheral surface 3e of the retainer 3 is press-fitted to the inner peripheral surface 1a (also referred to as the raceway surface 1a) of the outer ring 1, but a part of the flange portion 3f has an oval shape so as to be securely press-fitted and fixed. is there. In the following description, the case where there is one cage 3 will be described. However, the present invention can also be applied to a one-way clutch using two cages, an outer cage and an inner cage, which are commonly used. In addition, a flange portion may be formed on both sides of the cage 3, but in this case, the flange on one side has an outer diameter smaller than the diameter of the short circle.
[0011]
As shown in FIG. 5, the spring 4 has substantially the same shape as the cage 3, and both sides of the annular portions 4 a, 4 a and columns connecting these annular portions (4 a, 4 a) at regular intervals in the circumferential direction. Is formed by the portion 4b, the annular portions (4a, 4a) and the column portion 4b, and the sprags 5 are disposed in the pocket portions 4p, 4p,. And a tongue piece portion 4t. The spring 4 is formed by punching a thin metal plate by pressing, and has an annular shape. However, as will be described later, the end portion and a part of the end portion are overlapped to increase the rigidity of this portion.
[0012]
As described above, when the flange portion 3f of the retainer 3 is press-fitted into the raceway surface 1a of the outer ring 1, the oval portion 3c of the flange portion of the retainer 3 shown by P portion in FIG. For this reason, the amount of displacement of the cage 3 in this portion is locally increased. Usually, in such a case, the amount of displacement of the spring 4 arranged along the inner diameter side of the cage 3 becomes small. Accordingly, the amount of displacement of the tongue piece 4t of the spring 4 biased toward the locking side of the sprag 5 is also reduced, so that the prestress acting on the sprag 5 by the tongue piece 4t is reduced. Therefore, in order to prevent such a situation, as shown in FIGS. 4 and 5, a partially overlapping portion 6 is provided in which one end 4c and the other end 4d of the spring 4 are overlapped. Thus, the rigidity (spring force) of the spring 4 is increased (FIG. 4 is a diagram in which one end and the other end are separated from each other for the explanation of the spring 4). As described above, when the rigidity (spring force) of the overlapped portion is increased, even if the displacement amount of the oval portion 3c of the retainer 3 is increased and the displacement amount of the tongue piece portion 4t of the spring 4 is decreased, the sprags are reduced. 5 can be ensured. For this reason, the sprags 5 are not greatly displaced in the idling direction, and all the sprags 5 operate in synchronism as usual even when changing from the idling position to the meshing position.
[0013]
The one-way clutch of the present invention is based on the displacement of the retainer and the tongue 4t of the spring 4 due to the reaction force when the elliptical portion 3c is press-fitted when press-fitting into the raceway surface 1a of the outer ring 1 described in the retainer 3. The urging force acting on the sprag 5 is reduced, and the sprag 5 is prevented from being excessively moved toward the free rotation side. That is, the rigidity of a part of the spring 4 is increased by forming a part of the spring 4 in a double structure in order to prevent the spring 4 from sag caused by the press-fitting of the oval part 3 c of the cage 3. In order to increase the rigidity of a part of the spring 4 in this way, in addition to a part of the double structure, the quenching condition is changed locally (the part where the press-fitting reaction force is increased). The rigidity may be increased. Furthermore, the shape of a part of the spring 4 may be changed to increase the rigidity. In addition, the identification of the maximum interference allowance of the cage 3 can be performed by using a marking such as a manufacturing symbol performed at the time of press molding, etc., so that the overlapping portion of the spring can be incorporated at an appropriate position. This is convenient because it can be reliably assembled without causing a difference in assembly time.
[0014]
【The invention's effect】
As described above in detail, according to the one-way clutch of the present invention, since the spring force of the tongue portion of the ribbon spring at the maximum position of the retainer and the outer ring is reinforced, the sag of the tongue portion is increased. Is suppressed, and therefore, meshing failure can be prevented. In addition, the one-way clutch can appropriately strengthen the spring force without increasing the cost. Furthermore, since the conventional marking can be used for identifying the maximum position of the interference margin in the cage, an increase in cost can be avoided.
[0015]
[Brief description of the drawings]
FIG. 1 is a side view of a one-way clutch of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 showing the one-way clutch of the present invention.
FIG. 3 is an enlarged cross-sectional view of a portion P in FIG. 1 showing a one-way clutch of the present invention.
FIG. 4 is an enlarged view of a ribbon spring portion constituting the one-way clutch of the present invention, and is a view for explaining overlapping portions.
FIG. 5 is an overall perspective view of a ribbon spring constituting the one-way clutch of the present invention.
FIG. 6 is a view showing a configuration of a sprag, a cage, and a ribbon spring constituting a conventional one-way clutch.
FIG. 7 is an example of a side view of a conventional one-way clutch.
[0016]
[Explanation of symbols]
1 Outer ring 1a Outer ring inner peripheral surface (track surface)
2 Inner ring 3 Cage 3p Cage pocket 4 Spring 4p Spring pocket 4t Spring tongue piece 5 Sprag 6 Spring overlap part

Claims (3)

A retainer, a spring disposed along the inner diameter side of the retainer, and a sprag fitted in the retainer and a pocket of the spring, and the retainer is press-fitted to the inner peripheral surface of the outer ring. In the one-way clutch consisting of
The retainer is provided with a flange that is partially oval,
The one-way clutch characterized in that the rigidity of the spring portion at the position of the ellipse portion of the flange where the clamping margin of the cage is the largest and the reaction force is the largest is larger than the other positions. The portion of the spring at the position of the ellipse portion of the flange where the clamping margin of the cage is the largest and the reaction force is the largest is rigid by overlapping one end and the other end. The one-way clutch according to claim 1, wherein the one-way clutch is increased. 2. The rigidity of the portion of the spring at the position of the ellipse portion of the flange where the clamping margin of the cage is the largest and the reaction force is the largest is made harder than the other portions by quenching. One-way clutch described in.

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