JP2006207809A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-way clutch capable of preventing a sprag from hitting on a tip of a collar part provided on a side wall of an outer ring and suppressing worsening of attitude of the sprag. <P>SOLUTION: This one-way clutch is provided with an inner ring, the outer ring 1 having side walls 1a, 1b extending in the direction of inside diameter, a plurality of sprags 2 arranged between them, and an elastic member 3 for energizing each sprag 2 to transmit and shut off torque between the outer ring 1 and the inner ring through each sprag 2. A projecting part 2d is provided at an end opposing to the side wall 1a on the other side of the outer ring 1 of each sprag 2. A collar part 1<SB>F</SB>facing an inner side is provided at a tip fringe of the side wall 1a on the other side. The elastic member 3 energizes each sprag 2 toward the side wall 1a on the other side in addition to energizing the sprag 2 in the direction of engagement to let the projecting part 2d abut on the side wall 1a on the other side on an outer side in the radial direction more than the collar part 1<SB>F</SB>and provide a clearance w between a tip of the collar part 1<SB>F</SB>and each sprag 2 in this condition. Since the projecting part 2d of the sprag 2 is abutted on an inner face of the side wall 1a on the other side and cannot move any more, the sprag 2 does not hit the tip of the collar part 1<SB>F</SB>to suppress worsening of attitude of the sprag 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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 slid to 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 predetermined intervals by a retainer and are urged in the engaging 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

Since these conventional one-way clutches incorporate many sprags between the inner ring and the outer ring during assembly, there is a problem that the sprags are easily separated.
In addition, the number of parts is large, and therefore the configuration itself needs to be reconsidered in order to make the whole simple, the width dimension compact, and inexpensive. Further, since the inner ring and the outer ring are necessarily required as the constituent members, it is necessary to perform a curing process (heat treatment or the like) on each rolling surface where the sprag contacts the inner ring and the outer ring. In addition, various problems such as easy separation of parts at the time of assembling remain, and the width dimension, weight and cost are all insufficient.

  In this regard, for example, as shown in FIG. 1 which is an explanatory view of the embodiment of the present invention, the elastic member 3 provided in the outer ring 1 holds the sprag 2 in the outer ring 1 and the sprag 2 in the engaging direction. If biased, members such as retainers can be omitted and the structure can be simplified. Further, the sprag 2 and the elastic member 3 are not separated from the outer ring 1 at the time of assembly, and a separate member for holding the sprag 2 is not necessary, so that the number of parts is reduced. Further, the width dimension can be made compact by reducing the number of parts.

In this type of one-way clutch, the elastic member 3 is provided between the sprag 2 and one side wall 1 b of the outer ring 1, and each sprag 2 is at the end facing the other side wall 1 a of the outer ring 1. protrusion 2d is provided to the distal edge of the other side wall 1a of the outer ring 1, the flange portion 1 _F is provided facing inward.
Since the flange portion 1 _F provided on the other side wall 1a of the outer ring 1 protrudes axially inward, the convex portion 2d of the sprags 2 without abutting on the other side wall 1a, sprags 2 and the flange portion 1 _F may cause a strong hit (see, for example, FIG. 6A). When the sprag 2 and the flange portion 1 _F are in strong contact with each other, the sprag 2 is likely to be in a skew state (a state where the sprag rotation shaft is inclined with respect to the rotation shaft of the inner and outer rings), and the posture may deteriorate. Therefore, it is not preferable. Therefore, it is preferable that the convex portion 2d of the sprag 2 always abuts against the other side wall 1a of the outer ring 1 (see, for example, FIG. 6B).

  Accordingly, an object of the present invention is to suppress deterioration of the sprag posture.

In order to solve the above problems, the present invention includes an inner ring having an outer peripheral cylindrical surface, an outer ring having an inner peripheral cylindrical surface disposed coaxially with the inner ring so as to face the outer peripheral cylindrical surface, and the outer periphery A plurality of sprags disposed between a cylindrical surface and the inner peripheral cylindrical surface; and an elastic member that urges each sprag in a direction in which the respective sprags engage with the outer peripheral cylindrical surface and the inner peripheral cylindrical surface; And a one-way clutch that transmits and shuts off torque between the outer ring and the inner ring via each sprag.
That is, a side wall extending in the inner diameter direction from both sides of the inner peripheral cylindrical surface of the outer ring is provided, and a convex portion is provided at an end of each sprag facing the other side wall of the outer ring, and the other side wall of the outer ring is provided. In addition to the biasing in the engaging direction, the elastic member is provided along the circumferential direction between each sprag and one side wall of the outer ring. The sprags are urged toward the other side wall of the outer ring, and the convex part is brought into contact with the other side wall of the outer ring on the outer side in the radial direction from the flange part. A gap is formed between each sprag.

  In this way, the convex portion of the sprag comes into contact with the other side wall of the outer ring and cannot move further to the other side wall side, so that the sprag does not hit the tip of the collar portion. Therefore, the convex portion of the sprag always comes into contact with the other side wall of the outer ring, and the deterioration of the sprag posture can be suppressed.

  Since the present invention is configured as described above, there is an effect that the sprag does not hit the tip of the flange provided on the side wall of the outer ring, and the deterioration of the sprag posture can be suppressed.

  1 and 2 show a first embodiment, FIG. 1 (a) is a front view, FIG. 1 (b) is a sectional view taken along the line BB in FIG. 1 (a), and FIG. 2 (a) is FIG. The partial enlarged view of (a) and the same (b) show the partial enlarged view of FIG.1 (b), respectively.

The one-way clutch C ₁ of this embodiment, an inner ring outer peripheral cylindrical surface is formed, the inner peripheral cylindrical surface which is disposed in inner ring coaxially formed so as to face the outer circumferential cylindrical surface and the inner circumferential cylindrical surface An outer ring 1 formed with side walls 1a, 1b extending in the inner diameter direction from both sides of the outer peripheral surface, a plurality of sprags 2 disposed between the outer peripheral cylindrical surface and the inner peripheral cylindrical surface, An elastic member that is provided between the side walls 1b of the outer ring 1 along the circumferential direction thereof and biases the sprags 2 in a direction in which the sprags 2 engage with the outer peripheral cylindrical surface and the inner peripheral cylindrical surface. 3.
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 elastic member 3 is made of an elastic material such as a ring spring, a garter spring, a disc spring, and other various springs and rubber along one surface of the axial end face of the sprags 2.

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. 2 (b), in the cross section in the axial direction (the axial direction of the clutch), the left side wall (side plate) 1a in the drawing of the outer ring 1 is slightly recessed inward, and the right side wall (side plates) 1b is formed as a curved convex outward, the outer peripheral portion 1c to bond the outer shaft a _XO is formed flat. In addition, the left side wall (side plate) 1a in the figure of the outer ring 1 may be flat as shown in FIG. 6 (b).

  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.) have been applied.

  The left and right end surfaces 2a and 2b of the sprag 2 housed in the hollow cross section of the outer ring 1 are formed such that the left end surface 2a has a convex shape with an arc surface and the right end surface 2b has a concave shape with an arc surface. The convex portion of the left end surface 2a is defined as a convex portion 2d, and the concave portion of the right end surface 2b is defined as a concave portion 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.

In the hollow cross section of the outer ring 1, the elastic member 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 surface of the outer ring 1 (the inner surface of the cylindrical portion extending in the axial direction) by the elastic member 3, and the elastic member 3 is located between the sprag 2 and the outer ring side wall 1b. The self is held in the outer ring 1 by the tension to the both 2 and 1b based on the force, and the sprag 2 is brought into the outer ring 1 by abutting the held elastic member 3 and the inner surface of the outer ring 1 by the applied force. Retained.

Further, the biasing force of the elastic member 3 always makes the sprag 2 engage with the outer ring 1 around the sprag center line parallel to the center of the clutch shaft. The couple of f ₁ and −f ₁ shown in FIG. 2 (a) is generated, and the sprag 2 is engaged with the outer ring 1 (in the upright direction) by the couple, and the sprag 2 is a one-way clutch. The movement and twisting of C _{1 in} the axial direction and the circumferential direction are prevented, and the sprag 2 is prevented from falling off during handling.

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. Between the inner shaft A _Xi and the outer ring 1 in a state where the cam surfaces 2 _U, 2 _D is upright with respect to the circumferential direction (distance is relatively large state of the contacts of both cam surfaces 2 _U, 2 _D outer ring 1 the inner surface of) Torque is transmitted (solid line state in FIG. 2), and as the sprag 2 is inclined in the circumferential direction, the inner shaft A _Xi slides against the outer ring 1 and the torque transmission is interrupted (chain line state in FIG. 2).
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, even if the sprags 2 are in contact with each other and receive excessive torque, they do not fall over. 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 the two. 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.

Further, the convex portion 2d of the sprags 2 by the elastic member 3 to urge the sprags 2 toward the other side wall 1a of the outer ring 1, the outer ring 1 in the radial direction outside than the flange portion 1 _F It always abuts against the inner surface of the other side wall 1a. At this time, since the gap w shown in the figure is provided between the front end of the flange portion 1 _F and the jaw portion of each sprag 2, the front end of the flange portion 1 _F is prevented from hitting the jaw portion of the sprag 2. is doing.

As shown in FIGS. 1A and 1B, notches 4 are formed at predetermined intervals (equal intervals) on the right side wall 1b of the outer ring 1, so that one side wall 1a is formed. Thereafter, the sprag 2 and the elastic member 3 are loaded inside the side wall 1a and the outer peripheral portion 1c, and then the other side wall 1b is easily press-formed. 2 a in FIG. 2B is 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 shafts A _Xi near the inner shafts A _Xi 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 .

3 to 5 show one-way clutches C ₂ , C ₃ , and C _{4 according} to other embodiments, in which (a) is a front view and (b) is a portion taken along the line B-B in (a). An enlarged sectional view is shown. In any of the embodiments, the basic configuration is the same as that of the first embodiment (FIG. 1), the same configurations and functional members are denoted by the same reference numerals, and different points will be described below.

The one-way clutch C _{2 in the} embodiment of FIG. 3 uses a plurality of coil springs 3 ′ having different ring shapes as the elastic member 3 in the first embodiment. At this time, the coil spring 3 ′ may be spirally formed into a truncated cone shape made of a single spring wire.
Figure one-way clutch C ₃ embodiment 4 uses a garter spring (coil spring) 3a that the entire winding spring member to the small diameter of the spiral and a ring-shaped as an elastic member 3 of the above embodiment.

The one-way clutch embodiment FIG 5 C ₄ uses a spiral garter spring and ring-shaped throughout the coils further a smaller diameter than the embodiment of FIG. 4 (a coil spring) 3a 'as the elastic member 3 . In this embodiment, the region of the notch 4 is widened in the circumferential direction and the side wall 1b is short, and is provided at three locations in the illustrated example. In addition, a donut-like spacer 6 (a part of the outer periphery is cut into a straight line) extending along the inner surface of the side wall 1b of the outer ring 1 is provided to hold the garter spring 3a '. The structure of the outer ring 1 is also slightly different.

  The elastic members 3 (3 ′, 3a, 3a ′) of the respective embodiments shown in FIGS. 3 to 5 are always the clutch members when viewed in FIG. In order to apply an elastic force to the sprag 2 so that the sprag 2 engages with the outer ring 1 about a sprag center line parallel to the axis center, the sprag 2 engages along the concave portion of the end surface 2b on one side. Is provided.

The operations of the one-way clutches C _{1 to} C ₄ of the respective embodiments are the same, and the ring diameter of each sprag 2 is increased by an elastic member 3 (coil spring 3 ′, garter springs 3a, 3a ′). The elastic force is always acting in the direction. Therefore, as shown in FIGS. 2 (a) and 2 (b), each sprag 2 is urged so as to roll around a rotation center line X parallel to the axial center of the clutch. Forces (couples) in the directions of −f ₁ and f ₁ act through the surfaces 2 _U and 2 _D to engage with the inner surface of the outer peripheral portion of the outer ring 1 and the inner shaft A _Xi , respectively.

Thus, the outer ring 1 is the driving side, when the inner shaft A _Xi is driven, if the rotational force arrow -f ₁ direction to the outer ring 1 becomes a direction in which the sprag 2 is upright, this end, clutches C ₁ ~ The inner shaft A _Xi that is stationary with the C ₄ engaged is rotated in the same direction (the direction of the arrow f ₂ ).
On the other hand, if the rotational force to the outer ring 1 is in the opposite direction, each sprag 2 is rotated in the opposite direction against the elastic force by the elastic member 3, and as shown 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 clutches C ₁ to C ₁ are in the opposite relationship, that is, when the rotational force to the inner ring A _Xi is in the direction of the arrow f _1. If the outer ring 1 that is stationary with the C ₄ engaged is rotated in the same direction (the direction of the arrow −f ₂ ) and the rotational force to the inner ring is in 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).

Any embodiment also, the gap between the state where the protrusion 2d of the sprag 2 is in contact with the other side wall 1a inner surface of the outer ring 1, the flange portion 1 _F tip and sprags 2 provided at the other side wall 1a of the The point that w is provided is the same.

  In each of the above embodiments, the notch 4 for the outer ring 1 is provided only on the right side wall 1b shown in FIG. 1B. However, the notch 4 has both the right and left side walls 1a, 1b. Alternatively, it may be provided only on the left side wall 1a. Further, the relationship between the side walls 1a, 1b and the uneven surfaces 2a, 2b of the sprags 2 may be opposite to the illustrated example. Furthermore, the elastic member 3 is not limited to the above-described embodiments, but may have other shapes as long as they have the same function.

Further, the above embodiment has been constituted by the 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. Furthermore, a retainer that holds each sprag 2 at a required interval in the circumferential direction of the outer ring 1 may be provided. Further, the elastic member 3 (coil spring 3 ′, garter springs 3a, 3a ′) can always be subjected to an elastic force in the direction in which the ring diameter is reduced.

The one-way clutch of a 1st Example is shown, (a) is a front view, (b) is a side view including the partial cross section of arrow BB of the same (a). (A), (b) is a partial expanded sectional view of FIG. 1 (a), (b), respectively. The one-way clutch of 2nd Example is shown, (a) is a half front view, (b) is the elements on larger scale of the arrow (BB) of the same (a). The one-way clutch of 3rd Example is shown, (a) is a semi-front view, (b) is the elements on larger scale of arrow BB of the same (a). The one-way clutch of 4th Example is shown, (a) is a front view, (b) is the fragmentary expanded sectional view of arrow BB of the same (a). The positional relationship between the sprag and the outer ring is shown, (a) shows a state where the buttocks and the sprag hit each other, and (b) shows a good state.

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 Elasticity member 3 'coil springs 3a, 3a' garter spring 4 notches shaft 5 oil groove _{A Xi A XO} outer shaft _C 1 -C ₄ one-way clutch

Claims (1)

An inner ring formed with an outer peripheral cylindrical surface, an outer ring (1) arranged coaxially with the inner ring and formed with an inner peripheral cylindrical surface so as to face the outer peripheral cylindrical surface, the outer peripheral cylindrical surface and the inner peripheral cylindrical surface And a plurality of sprags (2) disposed between the elastic spurs (2) and the elastic members that urge the sprags (2) in a direction in which the sprags (2) engage the outer peripheral cylindrical surface and the inner peripheral cylindrical surface. (3), and a one-way clutch that transmits and blocks torque between the outer ring (1) and the inner ring via each sprag (2),
Side walls (1a, 1b) extending in the inner diameter direction from both sides of the inner peripheral cylindrical surface of the outer ring (1) are provided and opposed to the other side wall (1a) of the outer ring (1) of each sprag (2). A convex portion (2d) is provided at the end of the outer ring (1), a flange portion (1 _F ) facing inward is provided at the tip edge of the other side wall (1a) of the outer ring (1), and the elastic member (3) is connected to each sprag. (2) and one side wall (1b) of the outer ring (1) are provided along the circumferential direction thereof, and in addition to urging in the engaging direction, each sprag (2) is connected to the outer ring (1). ) To the other side wall (1a) of the outer ring (1) on the outer side in the radial direction from the flange (1 _F ). is contact, a gap (w) is formed between said flange portion in this state (1 _F) tip and said the sprags (2) The one-way clutch which is characterized.

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