JP2007192370A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-way clutch rotated at an inner ring which has low frictional torque between a sprag and raceway ring at the time of non-power transmission. <P>SOLUTION: An inner retainer 5 is synchronously rotated with an inner ring 2 by fixing the inner ring 2 as a rotary ring with a pin. A projecting section 10 of the sprag inwardly projecting from the inner retainer 5 is formed at an inner section in a radial direction rather than the inner retainer 5 at both ends of the sprag 3 in an axial direction while the sprag 3 is stored in a pocket 8 of the inner retainer 5. The outward edge face 11 of the projecting section 10 in a radial direction has an approximately convex arc shape outwardly in a radial direction. The movement of the sprag 3 inwardly in a radial direction is prevented so that the edge face 11 keeps in contact with the end face 13 of the inner retainer 5 inwardly in a radial direction in a freely rotating state. Thus, the sprag 3 can be prevented from being in contact with an outer ring 1 in a freely rotating state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a one-way clutch.

  Conventionally, as a one-way clutch, a sprag held by a retainer (a retainer fixed to the outer ring) that rotates synchronously with the outer ring between an inner ring that is a fixed ring and an outer ring that is a rotating ring. There is something that is arranged. This one-way clutch causes the sprag to float up from the inner ring by centrifugal force caused by the rotation of the sprag accompanying the rotation of the outer ring during non-power transmission (drifting), and friction caused by contact between the sprag and the inner ring. The torque is reduced.

However, in the type in which the sprag is held by the cage fixed to the outer ring, when the inner ring is a rotating ring and the outer ring is a fixed ring, the sprag is not subjected to centrifugal force due to the rotation of the inner ring. At the time of transmission, there is a problem that the sprags held by the cage always slide with respect to the inner ring. For this reason, there is a problem that the friction torque between the sprag and the inner ring is increased, and the fuel consumption of an automobile having a one-way clutch is large.
JP 7-35163 A

  Accordingly, an object of the present invention is to provide a one-way clutch for rotating an inner ring that has a small friction torque between a sprag and a raceway during non-power transmission.

In order to solve the above problems, the one-way clutch of the present invention is
An outer ring that is a fixed ring and has an inner peripheral engagement surface;
An inner ring that is a rotating wheel and has an outer peripheral engagement surface;
A sprag disposed between the inner peripheral engagement surface and the outer peripheral engagement surface;
A pocket for accommodating the sprag; and a sprag restraining portion for supporting the sprag so as to be swingable and preventing the sprag from contacting the outer ring in an idle state, and the inner ring And a cage adapted to rotate synchronously with each other.

  The inner ring is defined as a member having an outer peripheral engagement surface that engages with the sprag. For example, in the case of a one-way clutch of a type in which the outer peripheral surface of the rotating shaft and a sprag are engaged at the locked position, the rotating shaft is an inner ring.

  According to the present invention, the retainer rotates synchronously with the inner ring, which is a rotating wheel, so that the sprags held by the retainer rotate synchronously with the inner ring accompanying the rotation of the inner ring. Can be made. Accordingly, since the centrifugal force caused by the rotation of the inner ring of the sprag in the circumferential direction can be applied to the sprag, the sprag can be easily tilted, and the sprag engagement at the lock position can be improved.

  In addition, according to the present invention, since the sprag is provided with a sprag restraining portion that prevents the sprag from coming into contact with the outer ring in the idle state, the sprag is rotated synchronously with the inner ring in order to improve the engagement at the lock position. By doing so, even if the sprag tries to move outward in the radial direction by centrifugal force, the sprag restraint portion can restrict the movement of the sprag in the radial direction so that the sprag contacts the outer ring in the idle state. Can be prevented. Therefore, no friction torque is generated between the sprag and the outer ring in the idle state, and the fuel consumption of an automobile or the like having this one-way clutch can be significantly reduced.

  Moreover, the one-way clutch of one embodiment has a structure in which the cage is formed between the pillar portions where the two annular portions are connected by a plurality of pillar portions and the pockets are opposed to each other. The sprags have both end faces in the thickness direction protruding from the respective end faces in the normal direction of the end faces, and the shape of the radially outer portion of the edge face is substantially convex outward in the radial direction. The two ring-shaped protrusions that are formed in a circular arc shape and that prevent the sprag restraining portion from moving outward in the radial direction of the sprag by contacting the radially outer portion of the edge surface. This is an end face in the radial direction of the part.

  According to the embodiment, since the radially inner end surfaces of the two annular portions are in contact with the substantially arc-shaped portion of the edge surface, the edge surface The substantially arc-shaped portion is not positioned outward in the radial direction from the annular portion. Therefore, it is possible to prevent the sprag from contacting the outer ring in the idle state.

  In one embodiment of the one-way clutch, the retainer has a main body portion that is formed between the two column portions that are connected to each other by a plurality of column portions and the pockets are opposed to each other. The sprag restraint portion extends substantially in the axial direction of the retainer and connects between the portions of the two annular portions facing the pockets, and penetrates the sprag in the axial direction. It is a pin part which is supporting so that rocking | fluctuation is possible.

  According to the embodiment, since the sprag is supported so as to be swingable by the pin portion connecting the two annular portions, the pin portion in the sprag penetrates through. The through-hole portion that is present does not move in the radial direction, and the sprag can be prevented from coming into contact with the outer ring in the idle state.

  According to the one-way clutch of the present invention, since the cage rotates synchronously with the inner ring that is a rotating wheel, the sprags held by the cage are synchronized with the inner ring accompanying the rotation of the inner ring. Can be rotated. Therefore, the centrifugal force resulting from the circumferential rotation can be applied to the sprags, so that the sprags can be easily tilted, and the sprags can be improved in the locked position.

  Further, according to the one-way clutch of the present invention, the sprag has a sprag restraining portion that prevents the sprag from coming into contact with the outer ring in the idle state, so that the sprag is moved radially outward by centrifugal force. Even if it tries to move, the movement of the sprag in the radial direction can be limited by the sprag restraint portion, and the sprag can be prevented from contacting the outer ring in the idle state. Therefore, no friction torque is generated between the sprag and the outer ring in the idle state, and the fuel consumption of an automobile or the like having this one-way clutch can be significantly reduced.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a front view of an engaged state of a one-way clutch according to a first embodiment of the present invention.

  The one-way clutch includes an outer ring 1 that is a fixed wheel, an inner ring 2 that is a rotating wheel, a sprag 3, an annular outer cage 4 and an annular ring disposed radially inward of the outer cage 4. The inner cage 5 is provided.

  The outer ring 1 has a cylindrical engagement surface 14 as an example of an inner peripheral engagement surface, and the inner ring 2 has a cylindrical engagement surface 15 as an example of an outer peripheral engagement surface. The outer retainer 4 is disposed between the outer ring 1 and the inner ring 2 in a free state in which neither the outer ring 1 nor the inner ring 2 is restrained. The outer retainer 4 has two annular portions and a plurality of column portions 17 that are connected at an approximately equal interval in the circumferential direction and connects the two annular portions, and faces the circumferential direction. A pocket 7 is formed between the two pillar portions 17.

  On the other hand, the inner cage 5 and the inner ring 2 are connected by a pin (not shown) extending substantially in the radial direction of the inner ring 2, and the inner cage 5 rotates synchronously with the inner ring 2. The inner cage 5 has two annular portions and a plurality of column portions 18 arranged between the two annular portions at substantially equal intervals in the circumferential direction, and is opposed to the circumferential direction. A pocket 8 is formed between the two pillar portions 18. The number of column parts 17 is equal to the number of column parts 18, and the number of pockets 7 is equal to the number of pockets 8. Although not shown, a biasing member is disposed on the outer side of the inner cage 5 in the radial direction. The shape of the outer peripheral surface of this urging member is substantially the same as the shape of the inner peripheral surface of the inner cage 5. A claw portion extending from the vicinity of the center toward the inside of the pocket 8 is formed in the vicinity of the center in the axial direction in the portion corresponding to the edge extending in the axial direction of each pocket 8 of the biasing member.

  The sprag 3 is incorporated in a pocket 7 and a pocket 8 that are arranged to face each other in the radial direction. The sprags 3 are held at equal intervals in the circumferential direction while being held by the outer cage 4 and the inner cage 5 between the cylindrical engagement surface 14 of the outer ring 2 and the cylindrical engagement surface 15 of the inner ring 1. Is arranged in multiple. Each sprag 3 is urged in the engaging direction (lock position direction) by the claw portion of the urging member.

  On both end faces of the sprag 3 in the thickness direction (direction perpendicular to the paper surface of FIG. 1), protrusions 10 projecting from each end surface in a substantially normal direction of the end surface (direction perpendicular to the paper surface of FIG. 1). Is formed. The shape of the radially outer edge surface 11 of the projecting portion 10 is a substantially arc shape that is convex outward in the radial direction, and the radially outer edge surface 11 of this substantially arc shape. Both ends of the spline 3 extend to the edge of the sprag 3. The protruding portion 10 protrudes from an inner portion in the radial direction from the substantially arc-shaped edge surface 11 on both end faces of the sprag 3. The arc-shaped edge surface 11 is disposed on the radially inner end surface 13 of the annular portion of the inner cage 5 in the radial direction, and is the outermost portion of the arc-shaped edge surface 11 in the radial direction. The peripheral portion comes into contact with the radially inner end face 13 of the annular portion of the inner cage 5. The radially inner end face 13 of the annular portion of the inner cage 5 can support the arcuate edge face 11 in a swingable manner. An inner end surface 13 in the radial direction of the annular portion of the inner cage 5 is a sprag restraining portion that prevents the sprag 3 from contacting the outer ring 1 in the loosely fitted state.

  2 is a cross-sectional view taken along the line AA of FIG. 1 and is a cross-sectional view in a plane including a contact line between the sprag 3 and the outer ring 1 and a contact line between the sprag 3 and the inner ring 2.

  As shown in FIG. 2, the two protruding portions 10 protruding from both end surfaces in the thickness direction of the sprag 3 are substantially symmetrical with respect to a plane passing through the center of gravity of the sprag 3 and perpendicular to the thickness direction of the sprag 3. positioned. Further, the height of the protruding portion 10 is such that the axial position of the outer end surface in the axial direction of the protruding portion 10 is substantially the same as the axial position of the outer end surface in the axial direction of the annular portion of the inner cage 5. It is set to be equal.

  In the above configuration, when the inner ring 2 rotates in the direction indicated by C in FIG. 1, in addition to the urging force from the urging member, the sprag 3 is formed on the inner wall surface of the pocket 8 of the inner cage 5 that rotates synchronously with the inner ring 2. As a result of the moment being applied and the sprag 3 rotating between the outer ring 1 and the inner ring 2 in a direction in which the radial length component of the inner ring 2 of the sprag 3 increases, as shown in FIG. A radially outer engagement cam surface of the sprag 3 and the cylindrical engagement surface 14 of the outer ring 1 are in contact with each other, and a radially inner engagement cam surface of the sprag 3 and a cylindrical engagement surface 15 of the inner ring 2 are contacted. And the outer ring 1, the inner ring 2 and the sprag 3 cannot move relative to each other and move together. At this time, the clutch is engaged, and the rotational power of the inner ring 2 is transmitted to the outer ring 1.

  On the other hand, when the inner ring 2 rotates in the direction indicated by D in FIG. 1, the radial component of the inner ring 2 of the sprag 3 between the outer ring 1 and the inner ring 2 is caused by the centrifugal force acting on the sprag 3. The sprag 3 rotates freely with respect to the outer ring 1. At this time, the clutch is disengaged and the rotational power of the inner ring 2 is not transmitted to the outer ring 1. When the inner ring 2 rotates in the direction indicated by D in FIG. 1, the sprag 3 moves radially outward in the pockets 8 and 9 due to the centrifugal force resulting from the rotation of the sprag 3. In the one-way clutch of this embodiment, the radially inner end face 13 of the inner cage 5 comes into contact with the radially outer edge face 11 of the protrusion 10, so that the sprag 3 is radially outward. To prevent you from moving to. The sprag 3 is prevented from coming into contact with the outer ring 1 when the clutch is disengaged.

  According to the one-way clutch of the above-described embodiment, the inner cage 5 rotates synchronously with the inner ring 2 that is a rotating wheel, so that the sprag 3 held by the inner cage 5 is connected to the inner ring 2. Along with the rotation, the inner ring 2 can be rotated synchronously. Therefore, since the moment resulting from the rotation of the sprag 3 in the circumferential direction can be applied to the sprag 3, the sprag 3 can be easily tilted, and the engagement of the sprag 3 during power transmission can be improved.

  Further, according to the one-way clutch of the above-described embodiment, the sprag 3 has the protruding portion 10 protruding from the end surface thereof, and the inner cage 5 comes into contact with the protruding portion 10 in the idle state. Since it has a radially inner end face 13 which is a sprag restraint portion for preventing 3 from coming into contact with the outer ring 1, the sprag 3 is rotated synchronously with the inner ring 2 in order to improve the engagement at the lock position. Thus, even if the sprag 3 tries to move outward in the radial direction due to the centrifugal force, the sprag 3 can be prevented from coming into contact with the outer ring 1 in the idle state. Therefore, since friction torque is not generated between the sprag 3 and the outer ring 1 in the idle state, the fuel consumption of an automobile or the like having this one-way clutch can be significantly reduced.

  Further, according to the one-way clutch of the above-described embodiment, the radially outer edge surface 11 of the protruding portion 10 has a generally arcuate shape convex outward in the radial direction. The radial inner end face 13 of the annular portion 5 can support the sprag 3 so as to be able to rotate (swing) and prevent the sprag 3 from contacting the outer ring 1 in the idle state.

  In the one-way clutch of the above embodiment, the inner peripheral engagement surface of the outer ring 1 and the outer peripheral engagement surface of the inner ring 2 are both cylindrical engagement surfaces. However, in the present invention, one of the inner peripheral engagement surface of the outer ring and the outer peripheral engagement surface of the inner ring may be an engagement cam surface that defines a space where the sprag is present in a wedge-shaped space.

  In the one-way clutch of the above-described embodiment, the sprag 3 is held by the outer cage 4 and the inner cage 5 having the sprag restraint portion, and two cages are used. However, in this invention, you may make it hold | maintain a sprag with one holder | retainer which has a sprag restraint part.

  In the one-way clutch of the above-described embodiment, the urging member separate from the inner cage 5 is arranged on the outer side in the radial direction of the inner cage 5, but in this invention, the cage and the urging member are An integral member may be used to hold the sprag with this member and bias the sprag in one direction. Furthermore, the arrangement location of the biasing member may be changed.

  Further, in the one-way clutch of the above embodiment, the protruding portion 10 that protrudes from the most inner portion in the radial direction from the inner cage 5 on the end face of the sprag 3 is employed. As shown in the drawing, a projecting portion 30 having a radially outward edge surface projecting radially outward and having an arc shape, and an axially outward end surface having an arc shape is employed. You can also. In this way, the volume of the protruding portion 30 can be reduced compared to the protruding portion 10 shown in FIG. 1, and the material cost of the sprag 33 can be reduced (in FIG. 3, the parts with the same reference numbers as in FIG. 1 are The configuration is the same as in FIG.

  FIG. 4 is a front view of the second embodiment of the present invention in the engaged state of the one-way clutch.

  The one-way clutch of the second embodiment is different from the one-way clutch of the first embodiment in that the sprag 43 is restrained to be swingable (rotatable) using the pin portion 47 of the inner cage 45.

  In the one-way clutch of the second embodiment, the same components as those of the one-way clutch of the first embodiment are denoted by the same reference numerals and description thereof is omitted. In the one-way clutch of the second embodiment, the description of the operation and effect common to the one-way clutch of the first embodiment will be omitted, and the configuration and action different from those of the one-way clutch of the first embodiment. Only the effect will be described.

  The inner cage 45 is fixed to the inner ring 2 that is a rotating wheel, and rotates in synchronization with the inner ring 2. The inner holder 45 has a main body portion composed of two annular portions and a plurality of pillar portions connecting the two annular portions, and extends substantially in the axial direction to face the pockets of the two annular portions. It consists of the pin part 47 which has couple | bonded the part. The sprag 43 has a pin through hole penetrating in the thickness direction, and the pin portion 47 is inserted through the pin insertion hole. The pin portion 47 supports the sprag 43 so as to be swingable. The pin portion 47 is a sprag restraining portion that supports the sprag 43 so as to be swingable and prevents the sprag 43 from contacting the outer ring 1 in the idle state.

  According to the one-way clutch of the second embodiment, the sprag 43 is swingably supported by the pin portion 47 that connects the two annular portions. The through hole portion through which 47 penetrates does not move in the radial direction, and it is possible to reliably prevent the sprag 43 from contacting the outer ring 1 in the idle state.

  Although the embodiments other than those described above will not be described, as in the first and second embodiments, the retainer supports the sprags so as to be swingable, and the sprags contact the outer ring in the idle state. And a sprag restraining portion that prevents the sprag from contacting the outer ring by contacting the sprag restraining portion in the idle state (in the first embodiment, Needless to say, a first-order clutch that corresponds to the protrusions 10 and 30 and corresponds to the pin insertion hole in the second embodiment falls within the scope of the present invention.

It is a front view in the engagement state of the one way clutch of 1st Embodiment of this invention. It is AA sectional view taken on the line of FIG. It is a front view in the engagement state of the one way clutch of the modification of the one way clutch of 1st Embodiment. It is a front view in the engagement state of the one way clutch of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner ring 3,33,43 Sprag 5,45 Inner cage 8 Pocket 10,30 Protruding part 11 Radial outer edge surface of projecting part 13 Radial inner end surface of annular part of inner cage 47 Pin part

Claims (3)

An outer ring that is a fixed ring and has an inner peripheral engagement surface;
An inner ring that is a rotating wheel and has an outer peripheral engagement surface;
A sprag disposed between the inner peripheral engagement surface and the outer peripheral engagement surface;
A pocket for accommodating the sprag; and a sprag restraining portion for supporting the sprag so as to be swingable and preventing the sprag from contacting the outer ring in an idle state, and the inner ring And a cage that rotates in synchronization with the one-way clutch. The one-way clutch according to claim 1,
The cage has a structure in which two annular portions are connected by a plurality of pillars and the pockets are formed between the opposing pillars,
Both end surfaces in the thickness direction of the sprags protrude from the respective end surfaces in the normal direction of the end surfaces, and the shape of the radially outer portion of the edge surface is a substantially circular shape protruding outward in the radial direction. An arcuate protrusion is formed,
The sprag restraint portion is in contact with a radially outward portion of the edge surface to prevent the sprags from moving outward in the radial direction. The one-way clutch characterized by being. The one-way clutch according to claim 1,
The retainer has a main body portion formed between the pillar portions where the two annular portions are connected by a plurality of pillar portions and the pockets are opposed to each other.
The sprag restraint portion extends substantially in the axial direction of the cage and connects between the portions of the two annular portions facing the pockets, and penetrates the sprag in the axial direction to swing the sprag. A one-way clutch characterized by being a pin portion that is movably supported.

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