JP2007182954A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To arrange a sprag in position and stabilize the attitude without increasing the number of parts. <P>SOLUTION: An one-way clutch is equipped with: an inner ring having an outer periphery cylindrical surface; an outer ring 1 having an inner periphery cylindrical surface coaxially arranged and opposed to the outer periphery cylindrical surface and side walls 1a, 1b extending from both sides thereof to an inner radial side; a sprag 2 having recesses in a plurality of cam surfaces corresponding to the outer periphery cylindrical surface and inner periphery cylindrical surface and in end surfaces thereof; and a garter spring 3 for restricting circumferential movement between respective sprags 2 in a partially formed large-diameter part 3b while coming into contact with the recess and side wall 1b and biasing each sprag 2 in a diameter expansion direction. The recess is biased from the garter spring 3 in a rotation direction of the sprag 2. Each cam surface is formed so as to abut on the outer periphery cylindrical surface and inner periphery cylindrical surface, respectively. The garter spring 3 itself has a positioning function of the sprag 2, whereby the sprag is arranged in a predetermined position, and the attitude thereof is stabilized without increasing the number of part items. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a one-way clutch that switches between transmission and interruption of power on a power transmission path.

A one-way clutch is a directional coupling that transmits power when the rotational speed on the drive side is faster than the driven side, and reverses the rotational direction on the drive side, or the rotational speed on the driven side is greater than the drive side. If it becomes faster, the transmission of power is cut off.
This one-way clutch includes a sprag type in which a sprag is interposed between the inner ring and the outer ring, and the sprag is engaged and disengaged with the inner and outer rings in accordance with the relative movement to transmit and block torque. .
In addition, as an aspect in which the sprags are interposed in the inner and outer rings, there are known a plurality of sprags provided appropriately spaced apart from each other and a plurality of sprags provided adjacent to each other.

As an example of the former, a large number of sprags are arranged in an annular shape between the inner and outer rings, and the sprags are held at a predetermined interval by a retainer and are urged in the engagement direction by springs. There are those provided with a pair of annular side plates on both side surfaces (see Fig. 3 of Patent Document 1).
As an example of the latter, a large number of sprags are annularly arranged between the inner and outer rings, each sprag is clamped by a garter spring and a retainer, each sprag is urged in the engaging direction, and the annular side plate is placed between the sprag side surface and the retainer. (See Fig. 6 of Patent Document 2).
JP 59-73632 A JP 58-163832 A

These conventional one-way clutches use a retainer or a retainer to hold the sprags, and therefore the number of parts increases, so that a simpler configuration is desired.
However, if a retainer or a cage is not used, adjacent sprags may come into contact with each other as the sprag changes in posture, and may interfere with each other's movement. If the sprags come into contact with each other and interfere with each other's movement, an appropriate change in posture cannot be obtained, resulting in poor meshing and the like.

  Accordingly, an object of the present invention is to arrange sprags at predetermined positions without increasing the number of parts and to stabilize the posture thereof.

In order to solve the above-mentioned problems, the present invention provides a large-diameter portion and a small-diameter portion by changing the coil diameter of the garter spring halfway, and the large-diameter portion is sandwiched between adjacent sprags.
As a specific configuration, a one-way clutch, an inner ring formed with an outer peripheral cylindrical surface, an outer ring formed coaxially with the inner ring and formed with an inner peripheral cylindrical surface facing the outer peripheral cylindrical surface, A plurality of sprags disposed between an outer peripheral cylindrical surface and the inner peripheral cylindrical surface and having a plurality of cam surfaces corresponding to the outer peripheral cylindrical surface and the inner peripheral cylindrical surface and a recess formed on any one of the surfaces; A garter spring that is disposed in the recess and urges the plurality of sprags by an elastic force in the diameter increasing direction or the diameter reducing direction, and restricts circumferential movement between the plurality of sprags at a large diameter portion formed in part. The recess is urged in a direction in which the sprag rotates when receiving an elastic force from the garter spring, so that the plurality of cam surfaces abut against the outer peripheral cylindrical surface and the inner peripheral cylindrical surface, respectively. Configuration formed into a unique shape It can be adopted.

  In this case, since the sprag is positioned in the circumferential direction by the large diameter portion, the garter spring itself that urges the plurality of cam surfaces of the sprag to abut against the outer peripheral cylindrical surface and the inner peripheral cylindrical surface, respectively. The sprag has a positioning function. For this reason, without increasing the number of parts, the sprag can be arranged at a predetermined position and its posture can be stabilized.

  Moreover, the following structure is also employable. That is, a one-way clutch, an inner ring formed with an outer peripheral cylindrical surface, an outer ring formed coaxially with the inner ring and formed with an inner peripheral cylindrical surface facing the outer peripheral cylindrical surface, the outer peripheral cylindrical surface and the A plurality of sprags arranged between an inner peripheral cylindrical surface and having a plurality of cam surfaces corresponding to the outer peripheral cylindrical surface and the inner peripheral cylindrical surface; and a recess formed in any one of the cam surfaces; Arranged to restrict the circumferential movement between the plurality of sprags and bias the sprags in a rotating direction to bring the plurality of cam surfaces into contact with the outer cylindrical surface and the inner cylindrical surface. It is the structure provided with the garter spring in which the diameter part was formed.

  In the one-way clutch in which the garter spring is housed in the recess formed on the cam surface of the sprag and urges the sprag in the outer diameter direction or the inner diameter direction, the sprag Since the garter spring is positioned in the circumferential direction by the large diameter portion, the sprag can be arranged at a predetermined position and the posture can be stabilized without increasing the number of parts.

  In each of the above configurations, the outer ring is formed with side walls extending from both sides of the inner peripheral cylindrical surface toward the inner diameter side, and the concave portion is formed on each end surface of the plurality of sprags facing one of the side walls. The garter spring may employ a configuration in which the garter spring is disposed so as to be in contact with one of the concave portion and the side wall and to exert an elastic force in the diameter expanding direction.

  According to the one-way clutch of this configuration, the garter spring provided between the sprag and one side wall of the outer ring applies a contact force to the inner surface of the outer ring to each sprag, and the garter spring The sprag and the outer ring hold itself in the outer ring by stretching to the other side wall, and the sprag is held in the outer ring by abutment of the held garter spring and the inner surface of the outer ring by the applied force. . Therefore, the sprag and the garter spring are not separated from the outer ring at the time of assembly, and a separate member for holding the sprag is unnecessary, and the number of parts is reduced. Further, the width dimension can be made compact by reducing the number of parts.

  Further, the large diameter portion may be formed so as to be eccentric to the bottom side of the concave portion with respect to a portion (hereinafter referred to as a small diameter portion) that is not the large diameter portion of the garter spring. In this way, the large diameter portion penetrates deeper between adjacent sprags, so that the sprag positioning action by the large diameter portion becomes more effective.

In each of the above-described configurations, it is desirable that the width (circumferential length) of the small-diameter portion of the garter spring is set to be the same as or slightly larger than the sprag width (circumferential width).
In each of the above configurations, it is preferable that the small diameter portion and the large diameter portion are provided at equal intervals along the circumferential direction. This is because the sprags are positioned at equal intervals along the circumferential direction.

  Moreover, you may provide the adjustment part from which a coil diameter changes gradually between the said small diameter part and a large diameter part. In this way, it is easy to squeeze the large diameter portion between adjacent sprags. That is, there is an effect that the large diameter portion can be easily inserted between the two sprags.

  According to the present invention, since the garter spring itself has a sprag positioning function, the sprag is arranged at a predetermined position without increasing the number of parts, and the posture is stabilized.

  1 and 2 show a first embodiment, FIG. 1 (a) is a partial front view, FIG. 1 (b) is a sectional view taken along the line B-B in FIG. 1 (a), and FIG. 1 (a) is a partially enlarged view, and FIGS. 1 (b) and 1 (c) are partially enlarged views of the garter spring 3. FIG.

The one-way clutch C ₁ of this embodiment, the inside diameter an inner ring outer peripheral cylindrical surface is formed, an inner peripheral cylindrical surface arranged in the inner ring coaxially opposed to the outer peripheral cylindrical surface, from either side of the inner peripheral cylindrical surface And an outer ring 1 having side walls 1a, 1b extending to the side. A plurality of sprags are disposed between the outer peripheral cylindrical surface and the inner peripheral cylindrical surface.

The outer ring 1 is a ring-shaped member having a U-shaped cross-section that has flanges 1 _F and 1 _F that can come into contact with the inner shaft on the side of the inner shaft A _Xi that forms the inner ring, and between the flanges. A plurality of sprags 2 are provided adjacent to each other within the open hollow section of the outer ring 1.

The outer ring 1 is formed by pressing a disk-shaped flat steel plate having a predetermined thickness into a cup shape by bending the outer edge side thereof by press molding, punching out the inner diameter portion, and further bending the outer portion of the bent outer edge portion. In the cross-sectional view, a U-shaped open cross-sectional shape is formed. Further, both end portions of a pipe-shaped steel material having the same diameter as the outer peripheral portion 1c of the outer ring 1 can be bent inward to form a U-shaped open cross section in a cross-sectional view.
At this time, as shown in FIG.1 (b), in the cross section of an axial direction (the axial direction of a clutch), the other side wall (left side wall) 1a in the figure of the outer ring | wheel 1 is dented inside a little concavely, one side wall (right side wall) 1b is formed as a curved convex outward, the outer peripheral portion 1c to bond the outer shaft a _XO is formed flat.

  It should be noted that at least the sprag contact portion (the inner peripheral surface of the outer peripheral portion 1c) that is the rolling surface of the outer ring 1 is previously hardened by induction hardening or carburizing quenching so as to have a required hardness as a clutch. (Heat treatment etc.) has been applied.

  The left and right end surfaces 2a and 2b of the sprag 2 arranged inside the outer ring 1 are formed such that the left end surface 2a in the drawing has a convex shape with an arc surface, and the right end surface 2b in the drawing has a concave shape with an arc surface. Let the convex part of the left end surface 2a be the convex part 2d, and let the concave part of the right end surface 2b be the recessed part 2e. The arc surface may be a column surface or a spherical surface, but in this embodiment, the former is a spherical surface and the latter is a column surface. The former is a point contact and the latter is a line contact. At this time, the former can also be a pillar surface.

On the inner side of the outer ring 1, the garter spring 3 is loaded between one side wall 1 b of the outer ring 1 and each sprag 2 along the recess 2 e of the right end surface 2 b of each sprag 2.
The sprag 2 is brought into contact with the inner peripheral surface of the outer ring 1 (the inner peripheral surface of the outer peripheral portion 1c) by the garter spring 3, and the garter spring 3 is provided between the sprag 2 and the outer ring side wall 1b. The sprag 2 holds itself in the outer ring 1 by the tension to the both 2, 1b based on the force, and the sprag 2 is brought into contact with the held garter spring 3 and the inner peripheral surface of the outer ring 1 by the applied force. Retained.

The sprag 2 is tilted and engaged with the outer ring 1 about the sprag center line parallel to the axial center of the clutch by the biasing force of the garter spring 3. That is, the urging force generates a couple of f ₁ and −f ₁ shown in FIG. 2 (a), and the sprag 2 is engaged with the outer ring 1 by the couple (applying in an upright direction). )

Perpendicular direction of the cross section (the axial direction of the one-way clutch C ₁₎ sprags 2 axes, FIG. 2 (a), the upper and lower end faces curved cam surface of the projection 2 projecting outside _U, 2 It is formed in the asymmetrical barrel shape which each has _D. Cam surfaces 2 _U, 2 _D state to the upright with respect to the circumferential direction and the inner shaft A _Xi in (both cam surfaces 2 _U, 2 _D of the outer ring 1 inner surface and a state where the distance is relatively large between the contacts) the outer ring 1 (Fig. 2 (a) solid line state), and as the sprag 2 inclines in the circumferential direction, the inner shaft _AXi slides against the outer ring 1 and the torque transmission is interrupted (Fig. 2 ( a) Chain line state).
Although the movement of the sprag 2 at the time of transmission / non-transmission of torque is slight, the solid line state and the chain line state shown in the figure are described as having moved greatly so that they can be easily understood.
At the time of transmission, each sprag 2 has its lower side face in contact with the lower side face of another adjacent sprag 2, and an excessive torque in the engagement direction (direction of arrow f ₁ ) acts on the sprag 2. When the rotational force due to the above acts on the contact surface, the two sprags 2 and 2 that contact each other try to rotate in opposite directions (reaction force in the opposite direction acts), and become locked. That is, the sprags 2 do not fall over even if they contact each other and receive excessive torque. As a result, the engagement / disengagement action of the sprag 2 with the outer ring 1 is stabilized and the clutch operation is smoothly performed.

An oil groove 5 (see FIG. 1B) is formed on the inner surface of the flange 1 _F of the outer ring 1 (the surface that contacts the inner shaft A _Xi ), and between the flange 1 _F and the inner shaft A _Xi . An oil sump is provided to improve the lubrication conditions between them. Even if the oil groove 5 is not formed, the oil groove 5 can be omitted in the case of an oil sump with sufficient lubrication conditions. Then, even if there is no flange portion 1 _F, when the side walls 1a, between the end face and the inner shaft A _Xi and 1b can form a sufficient oil reservoir, the flange portion 1 _F may be omitted.

As shown in FIG. 1 (a), the right side wall 1b of the outer ring 1 is formed with notches (openings) 4 at a predetermined interval (equal interval). Therefore, after forming one side wall 1a, The sprag 2, the garter spring 3, etc. can be loaded inside the side wall 1a and the outer peripheral part 1c, and then the other side wall 1b can be formed by press molding. Reference numeral 4 a in FIG. 1B denotes an end face of the notch 4.
However, after the outer ring 1 is press-molded into a U-shaped cross section, the sprag 2 can be inserted into the outer ring 1 obliquely from between the flanges 1 _F and 1 _F and loaded. In this case, the notch 4 can be omitted. On the other hand, the sprag 2 and the like can be loaded into the outer ring 1 from the notch 4. Since the notch 4 also acts to prevent the generation of bending wrinkles during bending, its width (outer ring circumferential direction) and interval are appropriately set so that the effect is obtained.
The flange portions 1 _F and 1 _F facing the inner shaft A _Xi end of each of the outer ring side walls 1 a and 1 b are provided so as to have a very slight gap with respect to the curved surface of the inner shaft A _Xi .

The garter spring 3 is alternately provided with small diameter portions 3a and large diameter portions 3b having different coil diameters. FIG. 2C schematically shows the positional relationship between the garter spring 3 and the sprag 2 in a state where they are engaged with each other. In this figure, the garter spring 3 shows a straight state before being incorporated into the outer ring 1.
The small-diameter portion 3a and the large-diameter portion 3b are provided at equal intervals along the circumferential direction when the garter spring 3 is incorporated in the outer ring 1, and this arrangement allows the sprag 2 to be Positioned at equal intervals along the circumferential direction.

  As shown in FIG. 1B, the small diameter portion 3a of the garter spring 3 is disposed so as to be joined to the recess 2e provided in each sprag 2, and the large diameter portion 3b is disposed between the adjacent sprags 2 and 2. Enter and hold each sprag at an appropriate distance.

FIG. 3 shows a one-way clutch C2 of the _second embodiment, and this one-way clutch uses the garter spring 3 shown in FIG. 3C in the one-way clutch of the first embodiment. . Fig.3 (a) shows the partial expanded sectional view of a present Example in the part applicable to arrow BB of Fig.1 (a). The basic configuration is the same as that of the first embodiment (FIG. 1), and the same reference numerals are given to the same configurations and functional members in the drawing.

In this one-way clutch C _2, garter spring 3, between the small diameter portion 3a and a large diameter portion 3b, because the adjustment portion 3c of the coil diameter changes gradually is provided (FIG. 3 (c) refer) The large-diameter portion 3b is easily squeezed between the adjacent sprags 2 and 2.

The operation of the one-way clutches C ₁ and C _{2 in} the above embodiments is the same, and an elastic force acts on each sprag 2 in the direction in which the garter spring 3 expands. Therefore, for example, as shown in FIG. 2A, each sprag 2 is urged to roll about a rotation center line x parallel to the axial center of the clutch, and the upper and lower asymmetric cam surfaces 2 _U 2 and 2 _D engage with the inner surface of the outer peripheral portion of the outer ring 1 and the inner shaft A _Xi , respectively.

Therefore, when the outer ring 1 is the driving side, the inner shaft A _Xi of the driven side, when the rotational force arrow -f ₁ direction to the outer ring 1 becomes a direction in which the sprag 2 is upright, Therefore, clutch C _1, The inner shaft A _Xi that is stationary with C ₂ engaged is rotated in the same direction (direction of arrow f ₂ ).
On the other hand, if the rotational force to the outer ring 1 is in the opposite direction, the sprags 2 are rotated in the opposite direction against the elastic force of the garter spring 3, and as a result, as indicated by the chain line in FIG. In addition, each sprag 2 is tilted from the upright state, the rotational force is not transmitted to the inner shaft A _Xi , and the clutch is turned off (disengaged). Further, when the inner shaft A _Xi is on the driving side and the outer ring 1 is on the driven side, the clutch C ₁ , if the rotational force to the inner ring A _Xi is in the direction of the arrow f _{1 in} the completely opposite relationship. If the outer ring 1 that is stationary with C ₂ engaged is rotated in the same direction (the direction of the arrow −f ₂ ), and the rotational force to the inner ring is the opposite direction (the direction of the arrow f ₂ ), the outer ring 1 No torque is transmitted to the clutch, and the clutch is turned off (disengaged).

Further, in the one-way clutches C ₁ and C ₂ of each of the above embodiments, for example, the large diameter portion 3b of the garter spring 3 abuts the side surface of the sprag 2, and the large diameter portion 3b connects each sprag 2 to FIG. As indicated by the arrow c), the urging force is applied in the engaging direction. At this time, the outer edge of the large-diameter portion 3b is a contact point y, a portion relatively away from the position of the rotation center line x (see the same figure) of the sprag 2 in the radially inward or outward direction. It contacts the sprag 2 as z. For this reason, the biasing force can also give a large rotational moment to the sprag 2.

Furthermore, the one-way clutch C3 of the _third embodiment shown in FIG. 4 is provided with a circumferential groove 2f on the inner ring side of each sprag 2 and a garter spring 3 in the circumferential groove 2f. Note that reference numeral 3 'in the drawing is an elastic member provided as necessary.
In this embodiment, the coil center of the large-diameter portion 3b is provided eccentric to the sprag 2 side with respect to the coil center of the small-diameter portion 3a, and the larger-diameter portion 3b is adjacent to the sprag 2 as the eccentric amount increases. , 2 (see dimension d shown in FIG. 4A), the positioning action of the sprag 2 by the large diameter portion 3b becomes more effective.

Further, the one-way clutches C ₄ and C ₅ of the fourth and fifth embodiments shown in FIGS. 5 (a) and 5 (b) are each provided with a circumferential groove 2f on the inner ring side of each sprag 2 and its circumferential direction. A garter spring 3 is provided in the groove 2f. (A) uses a garter spring 3 of a type in which the coil center of the large diameter portion 3b and the coil center of the small diameter portion 3a shown in FIG. 4 (b) are eccentric, and FIG. A garter spring 3 of the type in which both the coil centers shown are coaxial is used.
Furthermore, the one-way clutch C ₆ of the sixth embodiment shown in FIG. 5 (c), condensation of elastic force by placing a garter spring 3 to form a groove 2f on the outer diameter side of the sprags 2 from the outer diameter side The sprags 2 are made to act in the radial direction, and the respective sprags 2 are tilted by the elastic force so as to contact the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring.

The embodiments described above, was constructed in an inner shaft A _Xi inner ring, as an inner ring of the annular, can be employed structure linked by such fitting the shaft into the inner ring. Moreover, the outer ring | wheel 1 can also be comprised with a cylindrical axis | shaft.

The one-way clutch of 1st embodiment is shown, (a) is a half front view, (b) is a side view including the partial cross section of arrow BB of the same (a). (A) is a partially enlarged sectional view of FIG. 1 (a), (b) and (c) are detailed views of a garter spring. The one way clutch of 2nd embodiment is shown, (a) is a partial expanded sectional view, (b) (c) is a detailed drawing of a garter spring The one way clutch of 3rd embodiment is shown, (a) is a partial expanded sectional view, (b) (c) is a detailed view of a garter spring (A) is a partially enlarged sectional view of a one-way clutch of the fourth embodiment, (b) is a partially enlarged sectional view of a one-way clutch of the fifth embodiment, and (c) is one-way of the sixth embodiment. Partial enlarged sectional view of the clutch

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 1a, 1b Outer ring side wall 1c Outer ring outer peripheral part 1 _F collar part 2 Sprag 2a Left end face 2b Right end face 2d Sprag convex part 2e Sprag concave part 2 _U sprag outer ring side cam face 2 _D sprag inner ring side cam face 3 Garter Spring 4 Notch (opening)
5 oil groove _{A Xi} in axis _{A XO} outer shaft _C 1 -C ₆ way clutch

Claims (4)

An one-way clutch, an inner ring formed with an outer peripheral cylindrical surface, an outer ring (1) formed coaxially with the inner ring and opposed to the outer peripheral cylindrical surface, and an outer peripheral cylindrical surface; A plurality of sprags (2) disposed between the inner peripheral cylindrical surfaces and having a plurality of cam surfaces corresponding to the outer peripheral cylindrical surface and the inner peripheral cylindrical surface, and concave portions formed on any surface, and the concave portions The plurality of sprags (2) are urged by an elastic force in the diameter-expanding direction or the diameter-decreasing direction, and the plurality of sprags (2) are surrounded by a large-diameter portion (3b) formed in part. A garter spring (3) for restricting directional movement,
The recess is biased in a direction in which the sprag (2) rotates when receiving an elastic force from the garter spring (3), and the plurality of cam surfaces are respectively formed on the outer peripheral cylindrical surface and the inner peripheral cylindrical surface. A one-way clutch formed into a shape that abuts.   An one-way clutch, an inner ring formed with an outer peripheral cylindrical surface, an outer ring (1) formed coaxially with the inner ring and opposed to the outer peripheral cylindrical surface, and an outer peripheral cylindrical surface; A plurality of sprags (2) having a plurality of cam surfaces disposed between the inner peripheral cylindrical surfaces and corresponding to the outer peripheral cylindrical surfaces and the inner peripheral cylindrical surfaces, and concave portions formed in any of the cam surfaces. And restricting the circumferential movement between the plurality of sprags (2) disposed in the recesses and biasing the sprags (2) in a rotating direction so that the plurality of cam surfaces and the outer cylindrical surface A one-way clutch provided with a garter spring (3) formed with a large diameter portion (3b) to be brought into contact with the inner peripheral cylindrical surface.   The outer ring (1) is formed with side walls extending from both sides of the inner peripheral cylindrical surface toward the inner diameter side, and the recess is formed on each end surface of the plurality of sprags (2) facing one of the side walls, The one-way clutch according to claim 1 or 2, wherein the garter spring (3) is arranged so as to be in contact with one of the recess and the side wall and to exert an elastic force in the diameter increasing direction.   The said large diameter part (3b) is formed so that it may decenter to the bottom side of the said recessed part with respect to the part which is not a large diameter part of the said garter spring (3). Direction clutch.

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