JP2012163125A - One-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-way clutch capable of lengthening life of an energizing member, and preventing deterioration of power transmission performance between an outer annular member and an inner member.SOLUTION: A cam surface 16 is formed on an inner side of an outer race 1; and grooves 50 positioned at mutual intervals and becoming gradually shallower toward one side in a circumferential direction of an inner circumferential surface of the outer race 1, are formed on an inner shaft 2. In the inner shaft 2, a step 51 is formed in a portion connecting each groove 50 and a groove 50 contiguously positioned at one side thereof in a circumferential direction of the groove 50.

Description

  The present invention relates to a one-way clutch, for example, a one-way clutch that is suitable for use in a copying machine, a fishing reel, or the like.

  Conventionally, as a one-way clutch, there is one described in JP 2010-116932 A (Patent Document 1). This one-way clutch urges an engaging roller disposed between the cam surface of the outer ring and the cylindrical outer peripheral surface of the inner shaft in one direction by a urging member.

  The one-way clutch rotates the outer ring relatively to one side in the circumferential direction with respect to the inner shaft, moves the engaging roller to the meshing position (lock position), and moves the engaging roller to the cam surface of the outer ring. Power is transmitted between the outer ring and the inner shaft, sandwiched between the cylindrical outer peripheral surfaces of the inner shaft. In addition, the one-way clutch rotates the outer ring relative to the other side in the circumferential direction with respect to the inner shaft, and moves the engaging roller to the loose-fitting position (unlock position) so that the outer ring moves to the inner shaft. The power between the outer ring and the inner shaft is interrupted by enabling relative movement.

  In the one-way clutch, the outer ring rotates relative to one side in the circumferential direction with respect to the inner shaft, and the engaging rollers are in the meshing position to transmit power between the outer ring and the inner shaft. When the outer ring rotates relative to the other side in the circumferential direction with respect to the inner shaft, a large compressive force due to the static frictional force between the engaging roller and the inner and outer rings is applied to the biasing member. It works for a certain time.

  Therefore, in the one-way clutch, due to the intermittent transition between power transmission and non-transmission, the biasing member repeatedly receives the large compressive force every time the power transmission is shifted from the non-transmission. There is a problem that the elastic force is easily lost and the life of the biasing member is short.

  Further, here, in order to extend the life of the biasing member, if the outer diameter of the cylindrical outer peripheral surface of the outer ring is reduced for the purpose of reducing the compression force, the engagement roller and the inner and outer portions at the lock position of the engagement roller are reduced. There is a problem in that the static frictional force with the wheel is reduced, and the power transmission performance between the outer ring and the inner shaft is lowered.

JP 2010-116932 A

  Therefore, an object of the present invention is to provide a one-way clutch that can extend the life of an urging member and that does not deteriorate the power transmission performance between the outer member and the inner member.

In order to solve the above problems, the one-way clutch of the present invention is
An inner member having an outer peripheral surface;
An outer annular member having an inner peripheral surface;
An engagement element disposed between the outer peripheral surface of the inner member and the inner peripheral surface of the outer annular member;
A biasing member that biases the engagement element in a direction to engage the inner member and the outer annular member;
One of the outer peripheral surface of the inner member and the inner peripheral surface of the outer annular member has a cam surface, while the other of the outer peripheral surface of the inner member and the inner peripheral surface of the outer annular member is The opposite surface,
The facing surface is
A plurality of grooves arranged in the circumferential direction of the facing surface and having a depth that decreases toward one side of the circumferential direction;
A step located between the grooves adjacent in the circumferential direction,
The engaging element engages with the inner member and the outer annular member when the facing surface rotates relative to the cam surface in one side in the circumferential direction.

  The depth of the groove is defined as a radial distance between the groove and a virtual circumscribed cylindrical surface circumscribing the opposing surface when the opposing surface is an inner peripheral surface. The depth of the groove is defined as a radial distance between the groove and a virtual inscribed cylindrical surface that is inscribed in the opposed surface when the opposed surface is an outer peripheral surface.

  In addition, the groove whose depth becomes shallower as it goes to one side in the circumferential direction is a diameter-enlarged outer peripheral surface portion whose outer diameter increases as it goes to one side in the circumferential direction when the facing surface is an inner peripheral surface. Means that. Further, the groove whose depth becomes shallower as it goes to one side in the circumferential direction means that, when the facing surface is an outer peripheral surface, the inner diameter surface portion of the reduced diameter becomes smaller in inner diameter as it goes to one side in the circumferential direction. Means that.

  According to the present invention, there is a step portion at a portion connecting each groove and the groove located on one side of the groove in the circumferential direction. Excessive compressive force due to excessive frictional force acts on the urging member only during the period until the joint moves over the stepped portion. This is because when the engagement element moves from the engagement position to a position beyond the stepped portion, the excessive frictional force acting on the engagement element disappears, and the engagement element is released from the compression force caused by the excessive frictional force. This is because that. Therefore, compared to the conventional configuration in which the inner member does not have a stepped portion, the time for applying the compressive force based on the excessive frictional force to the urging member at the time of transition from transmission of power to non-transmission is remarkably shortened. Therefore, the period until the biasing member loses the elastic force can be lengthened, and the life of the biasing member can be extended.

  Further, according to the present invention, when the groove is on the outer peripheral surface of the inner member, the outer diameter of the end portion on the side where the outer diameter in the circumferential direction of the groove is larger is set to the cylindrical outer peripheral surface of the conventional outer cam type one-way clutch. If the groove is on the inner peripheral surface of the outer annular member, the inner diameter of the end on the side where the inner diameter in the circumferential direction of the groove is smaller is set to one direction of the conventional inner cam system. By setting it equal to the inner diameter of the cylindrical inner peripheral surface of the clutch, the distance between the inner member and the outer annular member at the engagement position (at the lock position) is set to the distance between the conventional inner member and the outer annular member. Can be set equally. Therefore, compared with the conventional case, the static frictional force between the engagement element, the inner member and the outer annular member is approximately the same as the static frictional force between the engagement element, the inner member and the outer annular member in the conventional one-way clutch. Thus, the power transmission performance equivalent to that of the conventional one-way clutch can be secured.

In one embodiment,
Each groove is a curved surface.

  According to the above embodiment, the engaging element can be smoothly moved from the loose fitting position (free position) to the engaging position (lock position).

In one embodiment,
The step portion includes an end portion on one side in the circumferential direction of each groove and an end portion on the opposite side to the one side in the circumferential direction of the groove located on one side in the circumferential direction of the groove. It is connected.

  According to the embodiment, each groove and the groove on one side in the circumferential direction of the groove are connected by the stepped portion, and therefore, the end on the one side in the circumferential direction of each groove that is an engagement position. Can be smoothly reached, the distance that the engagement element moves from the engagement position until it exceeds the stepped portion, the time for receiving the excessive compressive force can be further reduced, and the biasing member The lifetime can be further increased.

In one embodiment,
Each said groove | channel consists of a part of plane.

  According to the said embodiment, since each groove | channel consists of a part of plane, each groove | channel can be processed easily.

  According to the present invention, it is possible to realize a one-way clutch that can extend the life of the biasing member and that does not deteriorate the power transmission performance between the inner member and the outer annular member.

It is sectional drawing of the radial direction of the one way clutch of one Embodiment of this invention. It is an expanded sectional view of the radial direction of the outer peripheral surface of a shaft member. It is sectional drawing of the radial direction of the one-way clutch of a modification.

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

  FIG. 1 is a radial sectional view of a one-way clutch according to an embodiment of the present invention.

  As shown in FIG. 1, the one-way clutch includes an outer ring 1 as an outer annular member, an inner shaft 2 as an example of an inner member, a cage 3, a biasing member 5, and a plurality of engaging rollers 6. With. The engagement roller constitutes an engagement element. The outer ring 1 has a plurality of cam surfaces 16 on the inner periphery, and the plurality of cam surfaces 16 are located at intervals in the circumferential direction of the outer ring 1. Each cam surface 16 has an inner diameter that gradually decreases toward one side in the circumferential direction. In this way, a wedge-shaped space 15 is formed between the cam surface 16 of the outer ring 1 and the outer peripheral surface 18 as the opposing surface of the inner shaft 2.

  The cage 3 includes a first annular part (not shown), a second annular part (not shown), and a plurality of pillars 22, and the first annular part is opposed to the axial direction of the second annular part. The plurality of column portions 22 are spaced from each other in the circumferential direction of the first annular portion, and each column portion 22 connects the first annular portion and the second annular portion. A pocket 33 for accommodating the engaging roller 6 is formed between the column portions 22 adjacent in the circumferential direction. The cage 3 is not movable relative to the outer ring 1. Each of the column portions 22 exists at a position spaced from the cam surface 16 in the circumferential direction.

  The urging member 5 includes a leaf spring mounting bracket 30 and a leaf spring 31. Each of the leaf spring mounting brackets 30 has a bent integrated cage locking portion 35, and the cage locking portion 35 has a circumferentially extending portion 40 and a leaf spring mounting portion 42. . The circumferentially extending portion 40 is in contact with the radially outer surface of the column portion 22 of the cage 3. The leaf spring mounting portion 42 is continuous with the circumferentially extending portion 40 through a bent portion. The leaf spring mounting portion 42 is in contact with the radially inward side portion of the side surface 47 facing the larger inner diameter of the cam surface 16 in the column portion 22 of the cage 3.

  As shown in FIG. 1, the leaf spring mounting portion 42 has a circumferential distance from the side surface 47 of the pillar portion 22 of the cage 3 as it goes from the radially inner side to the outer side of the outer ring 1. It extends to be larger. In this way, the elasticity in the circumferential direction of the leaf spring mounting portion 42 is increased. The leaf spring 31 is in contact with the radially inner end of the leaf spring mounting portion 42. The leaf spring 31 plays a role of urging the engaging roller 6 in one direction as will be described below.

  Specifically, each of the engagement rollers 6 is accommodated in the pocket 33 and is disposed in a wedge-shaped space. A free position (free fitting position) where the inner diameter of the cam surface 16 is large and the engaging roller 6 can move relative to the outer ring 1 and the inner shaft 2 is located on the circumferential side of the wedge-shaped space 15 in the leaf spring 31 side. On the other hand, on the opposite side of the wedge-shaped space 15 from the circumferential leaf spring 31 side, the cam surface 16 has a small inner diameter, and the engaging roller 6 cannot be moved relative to the outer ring 1 and the inner shaft 2. A position (engagement position) exists. The end of the plate spring 31 on the side opposite to the plate spring mounting portion 42 side in the circumferential direction is in contact with the engagement roller 6. The leaf spring 31 urges the engaging roller 6 from the circumferential free position, which is one side in the circumferential direction, toward the lock position.

  FIG. 2 is an enlarged sectional view of the inner shaft 2 in the radial direction.

  As shown in FIG. 2, the inner shaft 2 has a plurality of grooves 50 and a plurality of step portions 51, the plurality of grooves 50 are located at a distance from each other, and each groove 50 is a curved surface. It consists of a convex surface. Each groove 50 goes to one side (corresponding to the direction from the free position in the circumferential direction to the lock position) of the inner circumferential surface of the inner shaft 2 indicated by arrow C (coincident with the direction of arrow A in FIG. 1). The depth gradually becomes smaller. Specifically, each groove 50 includes a virtual circumscribing cylindrical surface that circumscribes the outer peripheral surface of the inner shaft 2 that is the opposing surface as it goes to one side of the inner peripheral surface of the inner shaft 2 indicated by an arrow C, and a groove The distance in the radial direction of the outer ring 1 from 50 gradually decreases. In other words, the outer diameter of each groove 50 gradually increases as it goes to one side in the circumferential direction of the inner peripheral surface of the inner shaft 2 indicated by the arrow C.

  Further, the stepped portion 51 is an end portion on the side where the depth of each groove 50 is shallow (the end portion on the side where the outer diameter of each groove 50 is large, and the end portion on one side in the circumferential direction of each groove 50). And the end of the groove 50 located on one side in the circumferential direction of the groove 50 on the deep side (the end on the side where the outer diameter of the groove 50 is small and on the one side in the circumferential direction of the groove 50 To the opposite end).

  In the above configuration, when the inner shaft 2 rotates relative to the outer ring 1 relative to one side in the circumferential direction indicated by the arrow A in FIG. 1, the engagement roller 6 moves in the direction in which the leaf spring 31 extends. The outer ring 1 is sandwiched between the end of the cam surface 16 on the side where the inner diameter is small and the end 60 (see FIG. 2) on the side where the groove 50 of the inner shaft 2 is shallow. Then, the outer ring 1, the inner shaft 2 and the engaging roller 6 cannot move relative to each other, the clutch is engaged, and power is transmitted between the outer ring 1 and the inner shaft 2.

  On the other hand, when the inner shaft 2 rotates relative to the outer ring 1 in a direction opposite to one side in the circumferential direction indicated by an arrow B in FIG. 1, the engaging roller 6 moves in a direction in which the leaf spring 31 is compressed. As a result, the clutch is disengaged between the cam surface 16 of the outer ring 1 and the outer peripheral surface 18 of the inner shaft 2. At this time, transmission of power is interrupted between the outer ring 1 and the inner shaft 2.

  According to the one-way clutch of the above-described embodiment, the step portion 51 is present at the portion connecting the grooves 50 and the grooves 50 located on one side in the circumferential direction of the grooves 50. At the time of transition to transmission, an excessive compressive force due to an excessive frictional force is applied to the leaf spring 31 only during a period until the engaging roller 6 gets over the stepped portion. This is because when the engagement roller 6 moves from the engagement position to a position beyond the stepped portion, the excessive frictional force acting on the engagement roller 6 disappears, and the engagement roller 6 is caused by the excessive frictional force. It is because it is released from the compressive force. Therefore, as compared with the conventional configuration in which the inner member does not have a stepped portion, the time required for the compression force based on an excessive frictional force to be applied to the leaf spring 31 is significantly shortened when the power is transferred from non-transmission. Therefore, the period until the leaf spring 31 loses the elastic force can be lengthened, and the life of the leaf spring 31 can be lengthened.

  Further, according to the one-way clutch of the above-described embodiment, the outer diameter of the end portion of the groove 50 on the side where the outer diameter in the circumferential direction is large is set to the outside of the cylindrical outer peripheral surface of the inner member of the conventional outer cam type one-way clutch. By setting it equal to the diameter, the distance between the outer ring 1 and the inner shaft 2 at the engagement position (at the lock position) is the distance between the inner member and the outer annular member of the conventional outer cam type one-way clutch. Can be set equal to Therefore, compared to the conventional case, the static frictional force between the engaging roller 6 and the outer ring 1 and the inner shaft 2 is determined by the engagement element, the inner member and the outer annular member in the conventional outer cam type one-way clutch. The frictional force can be set to the same level as the static frictional force, and the power transmission performance equivalent to that of the conventional one-way clutch can be ensured.

  Moreover, according to the one-way clutch of the said embodiment, since the groove | channel 50 consists of a curved surface, the engagement roller 6 can be smoothly moved from an engagement position (free position) to an engagement position (lock position).

  Moreover, according to the one-way clutch of the said embodiment, since each groove | channel 50 and the groove | channel 50 of the circumferential direction one side of the groove | channel 50 are connected by the step part 51, the engagement roller 6 is made into an engagement position. Each groove 50 can smoothly reach one end 60 in the circumferential direction (the end 60 on the side where each groove 50 is shallow) and the engaging roller 6 is stepped from the engaging position. It is possible to reduce the distance traveled before exceeding 51, further reduce the time during which the leaf spring 31 receives an excessive compressive force, and further increase the life of the leaf spring 31.

  In the one-way clutch of the above embodiment, the inner member is the inner shaft 2, but in the present invention, the inner member may be an inner ring. In particular, the inner ring may have a groove on the outer peripheral side, while the inner peripheral surface of the inner ring may be press-fitted into the outer peripheral surface of the shaft member. In the present invention, the inner ring has a groove on the outer peripheral side, while the inner peripheral side of the inner ring is connected to the outer peripheral side of the shaft member by spline fitting, serration fitting, key fitting, etc. It may be configured to be fitted to the side so that relative rotation is impossible.

  In the one-way clutch of the above embodiment, the urging member 5 has the leaf spring 31. In this invention, the urging member is a leaf spring such as a compression coil spring, a tension coil spring, or a torsion coil spring. Other spring members may be included, or an elastic member capable of applying an urging force other than the spring may be included.

  In the one-way clutch of the above embodiment, the urging member 5 is a separate member from the cage 3. However, in this invention, the cage is formed of a rigid resin, and the urging member is attached to the cage. It may be provided integrally and formed of the same synthetic resin as the cage.

  In the one-way clutch of the above embodiment, the engagement element is the engagement roller 6. However, in the present invention, the engagement element may be an engagement element other than the engagement roller such as a sprag.

  In the one-way clutch of the above embodiment, the step portion 51 connects each groove 50 and the groove 50 adjacent to each groove 50 in the circumferential direction. However, in the present invention, the stepped portion may be a part of a portion connecting each groove and a groove adjacent to each groove in the circumferential direction. For example, as shown below, the connecting portion However, you may have a cylindrical surface part other than a step part.

  FIG. 3 is a radial cross-sectional view of a modified one-way clutch.

  In this modified one-way clutch, only the inner shaft 102 is changed in comparison with the one-way clutch of the above-described embodiment. In this modified one-way clutch, the same reference numerals are assigned to the same components as those in the one-way clutch in the above embodiment, and the description thereof is omitted.

  In this one-way clutch, the groove 150 is connected to the radially inner end of the step portion 151, and the depth of the groove 150 goes to one side in the circumferential direction of the outer peripheral surface of the inner shaft 102. It becomes shallower. The end of the groove 150 having a shallow depth is connected to the outer peripheral cylindrical surface portion 155. The end of the outer peripheral cylindrical surface 155 opposite to the circumferential groove 150 is connected to the radially outer end of the step 151. The groove 150 is a part of a plane. If each groove 150 is configured by a part of a plane as in this modification, each groove 150 can be easily processed.

  Further, in the one-way clutch of the above embodiment, the stepped portion 51 and the end portion on the side where the depth of the groove 150 is deep (the end portion on the side where the outer diameter in the circumferential direction is small and the one side in the circumferential direction is In the present invention, the step portion and the end portion on the side where the depth of the groove is deep (the end portion on the opposite side to the one side in the circumferential direction) are connected. In addition, there may be a surface unrelated to the groove whose depth gradually decreases toward one side in the circumferential direction, such as a cylindrical surface portion or a wavy peripheral surface portion.

  In the one-way clutch of the above embodiment, the outer ring 1 as the outer annular member has the cam surface 16, and the inner shaft 2 as the inner member has the groove 50. However, in the present invention, the inner member may be an inner shaft or an inner ring and may have a cam surface, while the outer annular member may have a groove. Specifically, the outer ring has a groove that is located at a distance from each other and that gradually decreases in depth toward the one side in the circumferential direction of the inner peripheral surface of the outer ring. The structure which has a step part in the connection part with the groove | channel located in the one side of the circumferential direction may be sufficient.

  Needless to say, the one-way clutch of the present invention can be used for applications other than reels and copiers. For example, the one-way clutch of the present invention can be used for facsimiles, packaging equipment, vending machines, money changer blinds, paper -Needless to say, it can be used for tape feeding mechanisms, vehicles (automobiles, motorcycles, etc.). It goes without saying that the one-way clutch of the present invention can be used in any machine that needs to both transmit and shut off power.

DESCRIPTION OF SYMBOLS 1 Outer ring 2,102 Inner shaft 3 Cage 5 Energizing member 6 Engaging roller 16 Cam surface 18 Outer surface of inner shaft 50,150 Groove 51,151 Step part

Claims (4)

An inner member having an outer peripheral surface;
An outer annular member having an inner peripheral surface;
An engagement element disposed between the outer peripheral surface of the inner member and the inner peripheral surface of the outer annular member;
A biasing member that biases the engagement element in a direction to engage the inner member and the outer annular member;
One of the outer peripheral surface of the inner member and the inner peripheral surface of the outer annular member has a cam surface, while the other of the outer peripheral surface of the inner member and the inner peripheral surface of the outer annular member is The opposite surface,
The facing surface is
A plurality of grooves arranged in the circumferential direction of the facing surface and having a depth that decreases toward one side of the circumferential direction;
A step located between the grooves adjacent in the circumferential direction,
The one-way clutch, wherein the engagement element engages with the inner member and the outer annular member when the opposing surface rotates relative to the cam surface in one side in the circumferential direction. The one-way clutch according to claim 1,
Each said groove | channel consists of curved surfaces, The one-way clutch characterized by the above-mentioned. The one-way clutch according to claim 1 or 2,
The step portion includes an end portion on one side in the circumferential direction of each groove and an end portion on the opposite side to the one side in the circumferential direction of the groove located on one side in the circumferential direction of the groove. A one-way clutch characterized by being connected. The one-way clutch according to claim 1,
Each said groove | channel consists of a part of plane, The one-way clutch characterized by the above-mentioned.

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