JP2011236978A - One-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an one-way clutch which can reduce drag torque, accelerate synchronous action in idling, and operate stably.SOLUTION: The one-way clutch includes an outer ring, an inner ring segregated from the outer ring in an inside diameter direction and concentrically arranged so as to be relatively rotatable, a plurality of sprags arranged between the outer ring and the inner ring to transmit a torque, a ribbon spring providing sprags with couple moment, a block bearing arranged between the outer ring and the inner ring to have a bearing function, an inside retainer with both the first opening radially passed through to hold the sprags and the second opening radially passed through to store and hold the block bearing, and an outside retainer arranged on outer diameter side of the inside retainer to have both the first opening radially passed through to hold the sprags and the second opening radially passed through to store and hold the block bearing, wherein the block bearing is prevented from missing in radial direction.

Description

  The present invention relates to a one-way clutch used as a component for torque transmission, backstop, and the like in a drive device such as an automobile or an industrial machine.

  Generally, a one-way clutch is arranged between an outer ring, an inner ring arranged concentrically with the outer ring, a plurality of sprags arranged between the inner ring and the outer ring, transmitting torque, a retainer for holding the sprags, and a sprag with an outer ring. It consists of a spring biased in the direction of engagement with the inner ring.

  In the one-way clutch having such a configuration, the sprag is engaged with the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, so that the inner ring rotates in only one direction with respect to the outer ring. In other words, the inner ring idles in one direction with respect to the outer ring, and the sprag can mesh between the inner and outer rings only in the opposite direction to apply rotational torque to the outer ring. At this time, the sprag is biased in the meshing direction (engagement direction) by a biasing member such as a spring.

  Some of these one-way clutches are provided with an annular end bearing having a bearing function between the inner and outer rings in order to maintain the concentricity of the inner and outer rings. For example, Patent Document 1 describes such an example.

Prior art document information related to the invention of this application includes the following.
Japanese Utility Model Publication No. 59-101021

  However, the end bearing is effective in order to compensate for a decrease in sealing performance (decrease in lubricity) of the lubricating oil, but has the following problems. When the end bearing is used, a lubricating oil film interposed on the bearing surface with the inner and outer rings is continuously generated on the circumference. For this reason, it is difficult to reduce drag torque during idling.

  Accordingly, an object of the present invention is to provide a one-way clutch that can reduce drag torque, promotes a synchronizing action during idling, and has a stable operation.

In order to achieve the above object, the one-way clutch of the present invention is
A one-way clutch,
Outer ring,
An inner ring spaced from the outer ring in the inner diameter direction and concentrically disposed so as to be relatively rotatable;
A plurality of sprags arranged between the outer ring and the inner ring and transmitting torque;
A ribbon spring that gives the sprag a moment to rise,
A block bearing disposed between the outer ring and the inner ring and having a bearing function;
An inner retainer having a first opening penetrating in the radial direction and holding the sprag; and a second opening penetrating in the radial direction and receiving and holding the block bearing;
An outer holding having a first opening penetrating in the radial direction and holding the sprag and a second opening penetrating in the radial direction to receive and hold the block bearing and disposed on the outer diameter side of the inner cage And
The block bearing is characterized in that it is prevented from falling off in the radial direction.

  According to the present invention, the following effects can be obtained.

  When used for outer ring fixation (inner ring rotation), the block bearing tends to rotate in the idling direction due to the sliding resistance of the inner ring. This accompanying force moves the inner cage in the idling direction, and the sprag is lifted. Therefore, it is possible to promote the synchronization action during idling.

  When the lubricating oil film on the bearing surface is an end bearing, it continuously occurs on the circumference, whereas in the case of a block bearing, the oil film is intermittent and the shearing property of the oil film is improved. Can be reduced.

1 is a partially broken front view of a one-way clutch showing a first embodiment of the present invention. It is an axial sectional view along the AA line of FIG. It is a partial front view which shows the detail of the one-way clutch of 1st Example. FIG. 4 is an axial cross-sectional view along the line BB in FIG. 3. It is a partial front view which shows the state at the time of no load of the one-way clutch of 1st Example. It is a partial front view which shows the state at the time of the inner ring | wheel idling of the one-way clutch of 1st Example. It is a partial front view which shows the one-way clutch of 2nd Example. FIG. 8 is an axial sectional view of FIG. 7. It is a partial front view which shows the one-way clutch of 3rd Example. FIG. 10 is an axial sectional view of FIG. 9. It is a graph which shows the relationship between the drag torque at the time of using an end bearing and a block bearing at the time of using a block bearing, and rotation speed.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, it is needless to say that each Example described below illustrates the present invention by way of example, and does not limit the present invention. In the drawings, the same parts are denoted by the same reference numerals.

(First embodiment)
FIG. 1 is a partially broken front view of a one-way clutch 10 showing a first embodiment of the present invention, and FIG. 2 is an axial sectional view taken along line AA of FIG. Although an example using a gourd-shaped sprag as the torque transmitting member is shown, the present invention can also be applied to other types of one-way clutches.

  In FIG. 1, the outer ring 1 includes a substantially circular inner peripheral surface 1 a, and the inner ring 2 includes a substantially circular outer peripheral surface 2 a. The outer ring 1 and the inner ring 2 are relatively rotatable with the inner peripheral surface 1a and the outer peripheral surface 2a facing each other.

  In an annular space defined by the outer ring 1 and the inner ring 2, a plurality of torque transmission members for transmitting torque between the two wheels, that is, gourd-shaped sprags 3 are equally arranged in the circumferential direction. The sprag 3 is held in a substantially rectangular first opening 8 that is provided in a pair of cages, that is, the outer cage 5 and the inner cage 6 and penetrates in the radial direction. A ribbon spring 4 is disposed between the outer and inner cages 5 and 6 to give the sprag 3 a rising moment in a direction to engage with the engagement surface.

  In order to fit the outer ring 1 to a mating member (not shown), a plurality of splines 9 projecting in the outer diameter direction are provided on the outer periphery of the outer ring 1 at equal intervals in the circumferential direction. Further, an annular side plate 11 and an annular retaining ring 12 for fixing the side plate 11 are provided at both axial ends of the one-way clutch 10.

  A plurality of block bearings 17 are arranged between the plurality of sprags 3 in an annular space defined between the outer ring 1 and the inner ring 2. Although the block bearings 17 are provided at five locations in the circumferential direction, it is needless to say that this number is arbitrary and other numbers can be provided. The number of sprags 3 between adjacent block bearings 17 is the same.

  FIG. 2 is an axial sectional view taken along line AA in FIG. As apparent from FIG. 2, the annular inner retainer 6 having a substantially perfect inner diameter has an annular flange portion 6a extending at a predetermined distance in one end portion in the axial direction substantially perpendicularly, that is, radially inward. The front end of the flange 6a faces the inner ring 2 with a predetermined clearance.

  The annular outer cage 5 having a substantially perfect inner diameter has an annular flange portion 5a extending at a predetermined distance outward in the axial direction, that is, radially outward at one end portion in the axial direction. The front end portion of the is opposed to the outer ring 1 with a predetermined clearance.

  The block bearing 17 is disposed between the outer ring 1 and the inner ring 2 as described above, and holds the outer ring 1 and the inner ring 2 concentrically. That is, it functions as a bearing for the inner and outer rings. The inner diameter surface 17 a of the block bearing 17 has a bearing function with respect to the inner ring 2, and the outer diameter surface 17 b has a bearing function with respect to the outer ring 1.

  As shown in FIG. 3, the block bearing 17 includes three protrusions extending in the circumferential direction between the inner diameter surface 17 a and the outer diameter surface 17 b in the radial cross section. A first protrusion 13 is provided on the inner diameter side, a second protrusion 14 is provided on the outer diameter side, and a third protrusion 15 is provided between the first protrusion and the second protrusion. The first protrusion 13, the second protrusion 14, and the third protrusion 15 are formed integrally with the main body of the block bearing 17.

  The block bearing 17 is provided in the outer cage 5 and is provided in the second opening 18 penetrating in the radial direction, the opening 7 of the ribbon spring 4, and further provided in the outer cage 5 and penetrating in the radial direction. It fits in each of the openings 18.

  As can be seen from FIG. 3, the circumferential length of the first protrusion 13 is larger than the circumferential width of the first opening 8 of the inner cage 6. Therefore, the block bearing 17 does not fall off to the outer diameter side.

  As shown in FIG. 3, the third protrusion 15 that protrudes in the circumferential direction is disposed in the opening 7 of the ribbon spring 4, and the block bearing 17 falls to the inner diameter side by engaging with the side 19 of the opening 7. Is prevented. Therefore, the circumferential length of the third protrusion 15 is set larger than the circumferential width of the opening 7 of the ribbon spring 4.

  When the circumferential length of the third protrusion 15 is set to be sufficiently larger than the circumferential width of the opening 7 of the ribbon spring 4, a protruding piece that protrudes from the side 19 into the opening 7 is provided, and the protruding piece By engaging the third protrusion 15, the block bearing 17 can be prevented from falling off.

  In any case, when the outer cage 5, the inner cage 6, the ribbon spring 4, the sprag 3, and the block bearing 17 are assembled, they can be handled as a single clutch assembly, so that the assembly to the one-way clutch 10 becomes easy. .

  In the first embodiment described above, in order to prevent the clutch assembly of the one-way clutch 10 from dropping off in the axial direction, side plates 11 and retaining rings 12 are provided at both ends in the axial direction. This is not an essential configuration for the invention and is not necessarily provided. However, under use conditions where the lubrication environment is severe, it is preferable to provide side plates on both sides in the axial direction in order to prevent the sealing performance (lubricity) of the lubricating oil from being lowered by not providing the end bearing. The same applies to the second and third embodiments described below.

  FIG. 5 is a partial front view showing a state of the one-way clutch according to the first embodiment when there is no load. At the time of no load, the sprag 3 is in contact with both the outer ring 1 and the inner ring 2. FIG. 6 shows a state in which the outer ring 1 is fixed and the inner ring 2 is rotated (idled) from this no-load state. When the outer ring 1 is fixed and the inner ring 2 is rotated, the block bearing 17 tends to rotate in the idling direction of the inner ring 2 due to the sliding resistance generated by the rotation of the inner ring 2. This accompanying force moves the inner cage 6 in the idling direction. As a result, the block bearing 17 having a bearing function is in contact with the inner ring 2, while all the sprags 3 are lifted from the outer peripheral surface 2 a of the inner ring 2. That is, the synchronization action during idling is promoted. FIG. 6 shows this state. The sprag 3 is lifted from the outer peripheral surface 2 a of the inner ring 2, and a clearance is generated between the inner ring 2 and the sprag 3.

(Second embodiment)
FIG. 7 is a partial front view showing a one-way clutch according to a second embodiment of the present invention, and FIG. 8 is an axial sectional view of FIG. Since the basic configuration of the one-way clutch 10 is the same as that of the first embodiment, different parts will be described.

  The block bearing 27 is integrally provided with an outer diameter portion 28 and an inner diameter portion 29. As shown in FIG. 7, the outer diameter portion 28 has a larger axial width than the inner diameter portion 29, and a step portion 30 is formed between the two portions.

  The axial width of the inner diameter portion 29 is set slightly smaller than the axial width of the second opening 18 of the inner cage 6. Similarly, the axial width of the outer diameter portion 28 is set slightly smaller than the axial width of the second opening 18 of the outer cage 5. Further, the axial width of the second opening 18 of the inner cage 6 is set smaller than the axial width of the second opening 18 of the outer cage 5.

  Since the block bearing 27 is configured as described above, the outer diameter portion 28 of the block bearing 27 is a stepped portion 30, and is engaged with both edges in the axial direction of the second opening 18 of the inner cage 6 so as to be on the inner diameter side. Dropping out is prevented.

  As shown in FIG. 7, in the second embodiment, the protrusion in the radial direction of the block bearing 27 is shorter than the protrusion 15 of the first embodiment, and at the edge of the opening 7 of the ribbon spring 4. It is not a supported structure.

(Third embodiment)
FIG. 9 is a partial front view showing a one-way clutch according to a third embodiment of the present invention, and FIG. 10 is an axial sectional view of FIG. Since the basic configuration of the one-way clutch 10 is the same as that of the first embodiment, different parts will be described.

  Unlike the first embodiment and the second embodiment in which the block bearing has a one-piece structure, in this embodiment, the block bearing has a two-piece structure divided into two. The block bearing 37 includes an inner diameter block 31 that contacts the inner ring 2 and an outer diameter block 32 that is separated from the inner diameter block 31 and contacts the outer ring 1.

  The inner diameter block 31 includes protrusions 33 and 34 extending in the circumferential direction on both sides of the outer diameter surface in the circumferential direction. The outer diameter block 32 includes a protrusion 35 extending in the circumferential direction on one circumferential side of the inner diameter surface. The inner diameter block 31 is fitted in the second opening 18 of the inner cage 6, and the outer diameter block 32 is fitted in the second opening 8 of the outer cage 5.

  As can be seen from FIG. 9, since the projections 33 and 34 extend beyond the second opening 18 of the inner retainer 6, the inner diameter block 31 has a diameter from the second opening 18 of the inner retainer 6. It is prevented from falling off in the direction. Further, since the projection 35 extends beyond the second opening 18 of the outer cage 5, the outer diameter block 32 falls off from the second opening 18 of the outer cage 5 in the radial direction. Is prevented. At this time, since the inner diameter block 31 and the outer diameter block 32 are in contact with each other, they apparently function as an integral member.

  In the second and third embodiments described above, it goes without saying that the synchronization action during idling described with reference to FIG. 6 is promoted.

  FIG. 11 is a graph showing the relationship between drag torque and rotational speed when using an end bearing and when using a block bearing. In the case of a one-way clutch using an end bearing (graph (b)), the drag torque increases as the rotational speed increases. In the case of a one-way clutch using a block bearing (graph (a)), the rotational speed As the value increases, the drag torque decreases. In particular, it can be seen that the drag torque is substantially constant regardless of the rotational speed in the range exceeding the predetermined rotational speed. That is, drag torque (drag torque) during idling can be significantly reduced.

  When an end bearing is used, a lubricating oil film is continuously generated on the circumference of the bearing surface with the inner and outer rings, whereas when a block bearing is used, this oil film is generated intermittently. Therefore, it can be seen from FIG. 11 that when the block bearing is used, the drag torque is significantly reduced during idling.

  In the description of each of the embodiments described above, the one-way clutch has been described as having two cages, the outer cage and the inner cage. However, the present invention is also applicable to a one-way clutch having only one cage. Needless to say, it can be applied.

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner ring 3 Sprag 4 Ribbon spring 5 Outer cage 6 Inner cage 8 First opening 18 Second opening 10 One-way clutch 11 Side plate 15, 33, 34, 35 Projection 17, 27, 37 Block bearing 30 Step

Claims (5)

A one-way clutch,
Outer ring,
An inner ring spaced from the outer ring in the inner diameter direction and concentrically disposed so as to be relatively rotatable;
A plurality of sprags arranged between the outer ring and the inner ring and transmitting torque;
A ribbon spring that gives the sprag a moment to rise;
A block bearing disposed between the outer ring and the inner ring and having a bearing function;
An inner retainer having a first opening penetrating in the radial direction and holding the sprag; and a second opening penetrating in the radial direction and containing and holding the block bearing;
A first opening that penetrates in the radial direction and holds the sprag and a second opening that penetrates in the radial direction and receives and holds the block bearing are disposed on the outer diameter side of the inner cage. An outer cage
And the block bearing is prevented from falling off in the radial direction.   2. The block bearing according to claim 1, wherein the block bearing has a protrusion protruding in a circumferential direction, and the protrusion is engaged with the ribbon spring to prevent the block bearing from dropping in a radial direction. The one-way clutch described.   The block bearing includes a portion having an axial width larger than the axial width of the second opening of the inner cage, thereby preventing the block bearing from falling off in the radial direction. The one-way clutch according to claim 1.   The block bearing is divided into an outer diameter portion and an inner diameter portion, the outer diameter portion is fitted into the opening of the outer cage, and the outer diameter portion has a protrusion protruding in the circumferential direction, A protrusion engages with the opening of the outer cage, the inner diameter portion fits into the opening of the inner cage, and the inner diameter portion has a protrusion protruding in the circumferential direction, and the protrusion is the inner holding The one-way clutch according to claim 1, wherein the one-way clutch is engaged with an opening of the container.   The one-way clutch according to any one of claims 1 to 4, wherein side plates are provided on both sides in the axial direction between the outer ring and the inner ring.

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