One-way clutch

Abstract

The present invention provides a one-way clutch that allows a lubricating fluid to be easily and efficiently spread across the friction surface. [Solution] The one-way clutch 1 comprises an inner clutch 2, an outer clutch 3, a clutch key 4 housed in a clutch key housing recess 11, and an elastic member 5 housed in the housing recess 11 together with the clutch key 4. When the clutch key 4 sinks into the housing recess 11 against the biasing force of the elastic member 5, an inner clutch side supply groove 15 for supplying lubricating fluid housed in the housing recess 11 between the clutch 2 and the clutch 3 is formed in at least one of the two circumferential sides of the clutch key housing recess 11 with a predetermined groove depth.

Description

Technical Field

[0001] The present invention relates to a one-way clutch.

Background Art

[0002] There is known a one-way clutch (also referred to as an "overrunning clutch") that supplies lubricating oil (lubricating fluid) through holes provided in side plates (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there is room for improvement in the conventional one-way clutch in terms of easily and efficiently spreading the lubricating fluid over the friction surface.

[0005] An object of the present invention is to provide a one-way clutch capable of easily and efficiently spreading the lubricating fluid over the friction surface.

Means for Solving the Problems

[0006] (1) The one-way clutch according to the present invention comprises an inner clutch, an outer clutch, a clutch key housed in a clutch key housing recess provided in the inner clutch, and an elastic member housed together with the clutch key in the clutch key housing recess, wherein an inner clutch side supply groove is formed in the clutch key housing recess with a predetermined groove depth on at least one of the two circumferential sides of the clutch key housing recess for supplying lubricating fluid housed in the clutch key housing recess between the inner clutch and the outer clutch when the clutch key sinks into the clutch key housing recess against the biasing force of the elastic member.

[0007] (2) In the one-way clutch described in (1) above, the inner clutch side supply groove may be formed by a radial supply groove and an axial supply groove intersecting the radial supply groove.

[0008] (3) In the one-way clutch described in (1) or (2) above, the radial supply groove and the axial supply groove may have equal groove depths.

[0009] (4) In the one-way clutch described in (1) or (2) above, the radial supply groove and the axial supply groove may have different groove depths.

[0010] (5) In the one-way clutch described in any of (1) to (4) above, it is preferable that the outer clutch has an outer clutch side supply groove for supplying the lubricating fluid between the inner clutch and the outer clutch.

[0011] (6) In the one-way clutch described in (5) above, it is preferable that the outer clutch side supply groove includes a helical supply groove that extends helically in the axial direction.

[0012] (7) In the one-way clutch described in (6) above, the axial end of the helical supply groove may be discontinuous with the axial end of the outer clutch.

[0013] (8) The one-way clutch described in any of (1) to (7) above preferably comprises at least one annular sealing member for suppressing leakage of the lubricating fluid supplied between the inner clutch and the outer clutch. For example, any one of the one-way clutches according to the present invention may comprises at least one annular sealing member for suppressing leakage of the lubricating fluid supplied between the inner clutch and the outer clutch. [Effects of the Invention]

[0014] According to the present invention, a one-way clutch can be provided that allows a lubricating fluid to be easily and efficiently spread across the friction surface. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic half-cross-sectional view of a yoke unit, in which a one-way clutch according to one embodiment of the present invention is integrally configured with a yoke of a universal joint, as seen from the side of the yoke unit. [Figure 2] Figure 1 is a schematic front view showing the yoke unit from the shaft connection side. [Figure 3] This is a cross-sectional view AA in Figure 1. [Figure 4] This is a schematic front view showing an example of an inner clutch applicable to the one-way clutch in Figure 1, viewed from the shaft connection side. [Figure 5] This is a view taken in the direction of arrow D in Figure 4. [Figure 6] Figure 4 is a cross-sectional view of BB. [Figure 7] Figure 5 is a cross-sectional view of CC. [Figure 8]It is a front view schematically showing an example of an outer clutch applicable to the one-way clutch of FIG. 1 from the shaft connection side. [Figure 9] It is a sectional view taken along line D-D of FIG. 8. [Figure 10] It is a view showing another example of an inner clutch applicable to the one-way clutch of FIG. 1, corresponding to the arrow view in the D direction of FIG. 4. [Figure 11] It is a sectional view taken along line C-C of FIG. 10.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, with reference to the drawings, a one-way clutch according to an embodiment of the present invention will be described.

[0017] Here, in the present disclosure, the "axial direction" refers to a direction extending along the central axis O1 of the yoke unit 100 described later. Further, in the present disclosure, the "axial normal direction" refers to a direction orthogonal to the axial direction (so-called circular radial direction). In particular, in the present disclosure, among the axial normal directions, the direction approaching the central axis O1 is referred to as the inner side in the axial normal direction, and the direction moving away from the central axis O1 is referred to as the outer side in the axial normal direction. Furthermore, in the present disclosure, the "circumferential direction" refers to the circumferential direction around the central axis O1.

[0018] In FIG. 1, reference numeral 100 is a yoke unit including one yoke 101 of two yokes constituting a universal joint (the overall view is omitted). The yoke unit 100 extends along the central axis O1 of the yoke unit 100. In the present disclosure, one side in the extending direction of the central axis O1 of the yoke unit 100 is the shaft side, and the other side in the extending direction of the central axis O1 is the universal joint side. In the present disclosure, a drive shaft (not shown) can be connected to the shaft side of the yoke unit 100, and the other yoke (not shown) of the universal joint can be coupled to the universal joint side.

[0019] In this disclosure, the yoke unit 100 is equipped with a one-way clutch 1 according to one embodiment of the present invention, which is integrally configured together with the yoke 101.

[0020] The one-way clutch 1 comprises an inner clutch 2, an outer clutch 3, a clutch key 4 housed in a clutch key housing recess 11 provided in the inner clutch 2, and an elastic member 5 housed in the clutch key housing recess 11 together with the clutch key 4.

[0021] In this disclosure, the inner clutch 2 is a cylindrical inner clutch. In this disclosure, the central axis of the inner clutch 2 is the same as the central axis O1 of the yoke unit 100. In this disclosure, a plurality of spline grooves 2s for connecting the drive shaft are formed on the inner circumferential surface of the inner clutch 2. The spline grooves 2s extend along the central axis O1. As shown in Figure 2, the spline grooves 2s are spaced apart in the circumferential direction around the central axis O1. In this disclosure, for example, the drive shaft has spline projections (not shown) that fit into the spline grooves 2s and can be fitted into the spline grooves 2s of the inner clutch 2.

[0022] Furthermore, in this disclosure, the inner clutch 2 has a through hole 2h extending in the axial direction, as shown in Figure 1. A ball B is disposed in the through hole 2h. The axial inner opening of the through hole 2h opens into a spline groove 2s, exposing a portion of the ball B. On the other hand, the axial outer opening of the through hole 2h opens onto the outer circumferential surface of the inner clutch 2 and is closed by an annular set cover C. The set cover C is biased toward the axial shaft by a coil spring S between a backup ring R1 and an L-shaped ring R2. However, in this disclosure, the backup ring R1 is held toward the axial universal joint by a step in the inner clutch 2, and the L-shaped ring R2 is held toward the axial shaft by a stopper ring R3.

[0023] The clutch key housing recess 11 is a recess formed in the inner clutch 2 that is recessed inward in the direction perpendicular to the axis. The clutch key housing recess 11 extends in the axial direction. In this disclosure, the shaft-side end of the clutch key housing recess 11 is closed by a shaft-side partition member 6. The shaft-side partition member 6 is an annular shaft-side partition member that extends in the circumferential direction around the central axis O1. The shaft-side partition member 6 is fixed to the outer circumferential surface of the inner clutch 2. On the other hand, in this disclosure, the universal joint-side end of the clutch key housing recess 11 is partitioned by a universal joint-side partition member 7. The universal joint-side partition member 7 is coupled to the outer clutch 3 and the yoke 101, respectively, as described later.

[0024] A clutch key 4 is housed in the clutch key housing recess 11. In this disclosure, the clutch key 4 is a flat clutch key. Specifically, as shown in Figure 1, the clutch key 4 is an elongated member extending in the axial direction, and as shown in Figure 3, has a flat cross-sectional shape. In this disclosure, the clutch key 4 has a tip portion 4a that can be locked into a notch 3a described later, and a rear end portion 4b that serves as a pivot point when the clutch key 4 is swung in the axial direction. Furthermore, in this disclosure, the clutch key 4 has a stepped surface 4c directly below the tip portion 4a. The stepped surface 4c is provided on the side facing the bottom surface 12 of the clutch key housing recess 11 when the clutch key 4 is housed in the clutch key housing recess 11. In this disclosure, the stepped surface 4c is continuous with each of the two axial ends 4e (see Figure 1) of the clutch key 4 and is open to each of the two axial ends 4e.

[0025] Furthermore, as shown in Figure 1, an elastic member 5 is interposed between the clutch key 4 and the bottom surface 12 of the clutch key housing recess 11. In this disclosure, as shown in Figure 1, the elastic member 5 has a portion that locally contacts the bottom surface 12 of the clutch key housing recess 11 and a portion that locally contacts the stepped surface 4c of the clutch key 4. As a result, when the clutch key 4 is housed in the clutch key housing recess 11, it is biased (pressed) outward in the direction perpendicular to the axis. In this disclosure, the elastic member 5 is a leaf spring. However, the elastic member 5 is not limited to a leaf spring, and any member that biases the clutch key 4 radially outward is acceptable.

[0026] In addition, as shown in Figure 3, the elastic member 5 is housed in the stepped surface 4c of the clutch key 4. This allows the clutch key 4 to swing in the axial direction with its rear end 4b as the pivot point. As shown in Figure 3, in the initial state, the elastic member 5 biases the tip 4a of the clutch key 4 outward in the axial direction so that the tip 4a of the clutch key 4 is exposed from the outer circumferential surface of the inner clutch 2. This allows the tip 4a of the clutch key 4 to hook onto the notch 3a provided in the outer clutch 3 and lock into the notch 3a, and also allows the tip 4a of the clutch key 4 to be pushed into the clutch key housing recess 11 against the biasing force (pressing force) of the elastic member 5 by contact with the inner circumferential surface of the outer clutch 3.

[0027] The outer clutch 3 is also a cylindrical outer clutch. The outer clutch 3 houses the inner clutch 2 inside it. The central axis of the outer clutch 3 is also the same as the central axis O1 of the yoke unit 100. As shown in Figure 3, in this disclosure, the clutch key 4 is biased outward in the axial direction by the elastic member 5 and is exposed outward from the outer circumferential surface of the inner clutch 2. A notch 3a is formed on the inner circumferential surface of the outer clutch 3 for engaging the clutch key 4, which is biased outward in the axial direction by the elastic member 5.

[0028] Multiple clutch key housing recesses 11 are formed on the outer circumferential surface of the inner clutch 2 at intervals in the circumferential direction. As shown in Figure 4, in this disclosure, the inner clutch 2 comprises two clutch key housing recesses 11. The two clutch key housing recesses 11 are formed at positions at an angle of 180° in the circumferential direction around the central axis O. That is, the two clutch key housing recesses 11 are positioned opposite each other across the central axis O. In other words, in this disclosure, the one-way clutch 1 comprises two clutch keys 4, and the two clutch keys 4 are positioned opposite each other across the central axis O.

[0029] On the other hand, as shown in Figure 8, a plurality of notches 3a are formed on the inner circumferential surface of the outer clutch 3 at intervals in the circumferential direction. In this disclosure, the outer clutch 3 has four notches 3a. The four notches 3a are positioned at an angle of 90° in the circumferential direction. That is, the four notches 3a are arranged at equal intervals in the circumferential direction. As a result, the two clutch keys 4 are simultaneously engaged with two notches 3a positioned opposite each other across the central axis O, or pass through the two notches 3a simultaneously.

[0030] Referring to Figure 3, in the one-way clutch 1, when the inner clutch 2 attempts to rotate in one direction circumferentially relative to the outer clutch 3, the clutch key 4 engages with the notch 3a of the outer clutch 3. Conversely, when the inner clutch 2 attempts to rotate in the other direction circumferentially relative to the outer clutch 3, the clutch key 4 sinks into the clutch key housing recess 11 against the biasing force of the elastic member 5, causing the inner clutch 2 to rotate freely.

[0031] Specifically, as shown in Figure 3, when viewed from the axial shaft side, counterclockwise rotation is defined as positive rotation (rotation in one direction in the circumferential direction). When the positive rotational speed of the inner clutch 2 is greater than or equal to the positive rotational speed of the outer clutch 3, the inner clutch 2 rotates the outer clutch 3 integrally with the clutch key 4 through engagement with the notch 3a. That is, in this disclosure, the yoke unit 100 transmits the input rotation from the drive shaft to the universal joint (yoke 101) when the positive rotational speed of the drive shaft is greater than or equal to the positive rotational speed of the universal joint (yoke 101). On the other hand, when the positive rotational speed of the inner clutch 2 is less than the positive rotational speed of the outer clutch 3, the inner clutch 2 rotates freely relative to the outer clutch 3 as the engagement between the clutch key 4 and the notch 3a is released. In other words, in this disclosure, the yoke unit 100 prevents the input rotation from the universal joint (yoke 101) from being transmitted to the drive shaft when the forward rotational speed of the drive shaft is less than the forward rotational speed of the universal joint (yoke 101).

[0032] On the other hand, as shown in Figure 3, when viewed from the axial shaft side, if clockwise rotation is considered as reverse rotation (rotation in the other circumferential direction), if the reverse rotational speed of the inner clutch 2 is greater than or equal to the reverse rotational speed of the outer clutch 3, the inner clutch 2 will rotate freely relative to the outer clutch 3 as the engagement between the clutch key 4 and the notch 3a is released. In other words, in this disclosure, the yoke unit 100 prevents the input rotation from the drive shaft from being transmitted to the universal joint (yoke 101) when the reverse rotational speed of the drive shaft is greater than or equal to the reverse rotational speed of the universal joint (yoke 101). On the other hand, when the reverse rotational speed of the inner clutch 2 is less than the reverse rotational speed of the outer clutch 3, the inner clutch 2 rotates integrally with the outer clutch 3 due to the engagement between the clutch key 4 and the notch 3a. In other words, in this disclosure, the yoke unit 100 transmits the input rotation from the universal joint (yoke 101) to the drive shaft when the reverse rotational speed of the drive shaft is less than the reverse rotational speed of the universal joint (yoke 101).

[0033] Here, the clutch key housing recess 11 has an inner clutch side supply groove 15 formed therein for supplying lubricating fluid contained in the clutch key housing recess 11 between the inner clutch 2 and the outer clutch 3 when the clutch key 4 sinks into the clutch key housing recess 11 against the biasing force of the elastic member 5.

[0034] Referring to Figure 3, the lubricating fluid is contained (filled) in the clutch key housing recess 11. This allows the clutch key 4 and the elastic member 5 to move smoothly. On the other hand, when the inner clutch 2 and the outer clutch 3 rotate relative to each other, the clutch key 4 may be pressed inward in the direction perpendicular to the axis by the outer clutch 3. In this case, the clutch key 4 sinks into the clutch key housing recess 11 against the biasing force of the elastic member 5. As a result, the lubricating fluid contained in the clutch key housing recess 11 is compressed between the clutch key 4 and the clutch key housing recess 11 due to the sinking of the clutch key 4. The lubricating fluid compressed between the clutch key 4 and the clutch key housing recess 11 is then pumped between the inner clutch 2 and the outer clutch 3 through the inner clutch side supply groove 15. This allows the lubricating fluid contained in the clutch key housing recess 11 to be easily and efficiently spread between the inner clutch 2 and the outer clutch 3. Therefore, the one-way clutch 1 allows the lubricating fluid to be easily and efficiently spread against the friction surface.

[0035] On the other hand, when the inner clutch 2 and the outer clutch 3 rotate relative to each other, the clutch key 4 may separate from the bottom surface 12 of the clutch key housing recess 11 due to the biasing force of the elastic member 5. Also, when the inner clutch 2 and the outer clutch 3 rotate integrally, the clutch key 4 is locked in the notch 3a. In this case as well, the clutch key 4 separates from the bottom surface 12 of the clutch key housing recess 11 due to the biasing force of the elastic member 5. In this case, the lubricating fluid that has been pumped between the inner clutch 2 and the outer clutch 3 can be returned to the space formed between the clutch key 4 and the clutch key housing recess 11 through the inner clutch side supply groove 15.

[0036] Referring to Figure 7, the clutch key housing recess 11 is formed by a bottom surface 12 and two circumferential side surfaces 13. The two circumferential side surfaces 13 are spaced apart in the circumferential direction and are connected to the bottom surface 12. In this disclosure, the clutch key housing recess 11 further includes two circumferential outer edge surfaces 14. The axially perpendicular inner end of a circumferential outer edge surface 14 is connected to a circumferential side surface 13 adjacent to the circumferential outer edge surface 14. In contrast, the axially perpendicular outer end of a circumferential outer edge surface 14 is connected to the outer circumferential surface of the inner clutch 2. In this disclosure, the circumferential outer edge surfaces 14 of the clutch key housing recess 11 are tapered surfaces that move away from each other in the circumferential direction as they move outward in the axial direction.

[0037] On the other hand, the inner clutch side supply groove 15 includes a radial supply groove 16. The radial supply groove 16 is formed on the circumferential side surface 13 of the clutch key housing recess 11. The radial supply groove 16 extends in the direction perpendicular to the axis. This allows the lubricating fluid housed in the clutch key housing recess 11 to be efficiently supplied between the inner clutch 2 and the outer clutch 3 through the radial supply groove 16.

[0038] Furthermore, in this disclosure, the radial supply groove 16 is formed in a range extending from the circumferential side surface 13 to the circumferential outer edge surface 14. In this disclosure, the axial inner end of the radial supply groove 16 is spaced apart from the bottom surface 12 of the clutch key housing recess 11 and is discontinuous with the bottom surface 12. However, the axial inner end of the radial supply groove 16 can be made to contact the bottom surface 12 of the clutch key housing recess 11 by making it continuous with the bottom surface 12. In contrast, the axial outer end of the radial supply groove 16 is made to be open to the circumferential outer edge surface 14 of the clutch key housing recess 11 by making it continuous with the circumferential outer edge surface 14 of the clutch key housing recess 11. The circumferential outer edge surface 14 of the clutch key housing recess 11 forms a gap between the inner clutch 2 and the outer clutch 3. This gap extends along the central axis O1 because the clutch key 4 extends along the central axis O1. Therefore, the circumferential outer edge surface 14 of the clutch key housing recess 11 is effective in spreading the lubricating fluid over a wider area. However, the circumferential outer edge surface 14 of the clutch key housing recess 11 can be omitted.

[0039] Furthermore, the inner clutch side supply groove 15 can be formed by a radial supply groove 16 and an axial supply groove 17 intersecting the radial supply groove 16. In this case, the lubricating fluid contained in the clutch key housing recess 11 can be efficiently distributed throughout the entire axial direction through the radial supply groove 16 and the axial supply groove 17.

[0040] As shown in Figure 5, the inner clutch side supply groove 15 includes an axial supply groove 17 in addition to a radial supply groove 16. The axial supply groove 17 is formed on the circumferential side surface 13. The axial supply groove 17 extends in the axial direction and merges with the radial supply groove 16. As a result, the lubricating fluid contained in the clutch key housing recess 11 can be efficiently distributed throughout the entire axial direction by passing through the axial supply groove 17 in addition to the radial supply groove 16. In this disclosure, the axial end of the axial supply groove 17 is continuous with the axial end of the clutch key housing recess 11, and is therefore open to the axial end of the clutch key housing recess 11. However, the axial end of the axial supply groove 17 can also be separated from the axial end of the clutch key housing recess 11, thereby making it discontinuous with the axial end of the clutch key housing recess 11.

[0041] As shown in Figure 5, the radial supply groove can consist of multiple radial supply grooves 16. The multiple radial supply grooves 16 are spaced apart in the axial direction. In this case, the lubricating fluid can be more efficiently spread throughout the entire axial direction. In this disclosure, the radial supply groove consists of two radial supply grooves 16, but a larger number of radial supply grooves 16 may be provided. Also in this disclosure, the axial supply groove is one axial supply groove 17. However, the axial supply groove can also consist of multiple axial supply grooves 17. In this case, the multiple axial supply grooves 17 are spaced apart in the direction perpendicular to the axis.

[0042] Furthermore, in this disclosure, the radial supply groove 16 and the axial supply groove 17 have equal groove depths. As shown in Figure 7, the groove depth of the radial supply groove 16 and the groove depth of the axial supply groove 17 are equal. In this case, an equal amount of the lubricating fluid can be distributed between the inner clutch 2 and the outer clutch 3 through the radial supply groove 16 and the axial supply groove 17.

[0043] Furthermore, as shown in Figure 6, in this disclosure, the inner clutch 2 is formed by a large-diameter portion 21, a medium-diameter portion 22, and a small-diameter portion 23 along the axial direction. The large-diameter portion 21 is the portion of the inner clutch 2 with the largest axial width (radial width). The small-diameter portion 23 is the portion of the inner clutch 2 with the smallest axial width (radial width). The medium-diameter portion 22 is the portion whose axial width (radial width) is intermediate between the axial width of the large-diameter portion 21 and the axial width of the small-diameter portion 23. In this disclosure, the medium-diameter portion 22 is formed by a first medium-diameter portion 22a and a second medium-diameter portion 22b. In this disclosure, the first medium-diameter portion 22a is the portion whose axial width (radial width) is larger than the axial width (radial width) of the second medium-diameter portion 22b.

[0044] In this disclosure, the clutch key housing recess 11 is formed by a notch formed in the large-diameter portion 21 of the inner clutch 2. The notch is made continuous with each of the two axial ends of the large-diameter portion 21, thereby opening to each of the two axial ends of the large-diameter portion 21. That is, in this disclosure, the clutch key housing recess 11 is open to the axial end of the large-diameter portion 21 at both the shaft-side axial end and the universal joint-side axial end. However, in this disclosure, an annular fixing groove 24 for fixing the shaft-side partition member 6 is formed in the first medium-diameter portion 22a. Referring to Figure 1, the shaft-side axial end of the clutch key housing recess 11 is closed by the shaft-side partition member 6.

[0045] Referring to Figure 1, the axial end of the clutch key housing recess 11 on the universal joint side is closed by the universal joint side partition member 7. A yoke 101 is fixed to the inner circumference of the universal joint side partition member 7. Reference numeral M1 indicates an annular weld that fixes the universal joint side partition member 7 and the yoke 101. An outer clutch 3 is also fixed to the outer circumference of the universal joint side partition member 7. Reference numeral M2 indicates an annular weld that fixes the universal joint side partition member 7 and the outer clutch 3.

[0046] Furthermore, referring to Figure 9, the outer clutch 3 has an outer clutch side supply groove 30 formed therein for supplying the lubricating fluid between the inner clutch 2 and the outer clutch 3.

[0047] The outer clutch side supply groove 30 is formed on the inner circumferential surface of the outer clutch 3. The outer clutch side supply groove 30 works in cooperation with the inner clutch side supply groove 15 to spread the lubricating fluid. As a result, the lubricating fluid is efficiently supplied between the inner clutch 2 and the outer clutch 3 through the outer clutch side supply groove 30, in addition to the inner clutch side supply groove 15.

[0048] Specifically, in this disclosure, the outer clutch side supply groove 30 includes a helical supply groove 31 that extends helically in the axial direction. The helical supply groove 31 extends helically around the central axis O1. This allows the lubricating fluid to be more efficiently distributed throughout the entire axial direction through the helical supply groove 31. In this disclosure, the groove depth of the helical supply groove 31 is shallower than the groove depth of the notch 3a.

[0049] Furthermore, in this disclosure, the outer clutch 3 is provided with a lubrication fluid introduction section (lubrication fluid introduction nipple) 33. The lubrication fluid introduction section 33 penetrates the outer clutch 3 in the direction perpendicular to the axis, enabling the introduction of lubrication fluid from the outer circumference to the inner circumference of the outer clutch 3. As a result, the lubrication fluid can be supplied from outside the outer clutch 3 through the lubrication fluid introduction section 33 between the inner clutch 2 and the outer clutch 3.

[0050] In addition, in this disclosure, the outer clutch side supply groove 30 includes an annular supply groove 32 that extends circumferentially around the central axis O1. In this disclosure, the lubrication fluid introduction section 33 is connected to the annular supply groove 32. This allows the lubrication fluid introduced from outside the outer clutch 3 through the lubrication fluid introduction section 33 to be supplied circumferentially around the central axis O1. In this disclosure, the groove depth of the annular supply groove 32 is shallower than the groove depth of the notch 3a.

[0051] Furthermore, in this disclosure, the annular supply groove 32 is joined by the helical supply groove 31. This allows the lubricating fluid introduced from the lubricating fluid introduction section 33 to be supplied to the helical supply groove 31 through the annular supply groove 32. In this disclosure, the groove depth of the annular supply groove 32 is shallower than the groove depth of the helical supply groove 31. That is, in this disclosure, the groove depth of the annular supply groove 32 is the shallowest, followed by the helical supply groove 31, and then the notch 3a, in that order.

[0052] In this disclosure, the axial end 31a of the helical supply groove 31 is spaced apart in the axial direction from the axial end 3b of the outer clutch 3, and is discontinuous with the axial end 3b of the outer clutch 3. That is, in this disclosure, the axial end 31a of the helical supply groove 31 is not open to the axial end 3b of the outer clutch 3. This prevents the lubricating fluid that flows through the helical supply groove 31 from leaking out from the axial end 3b of the outer clutch 3.

[0053] Furthermore, in this disclosure, it is preferable that the one-way clutch 1 includes at least one annular sealing member 8 for suppressing leakage of the lubricating fluid supplied between the inner clutch 2 and the outer clutch 3. In this case, leakage of the lubricating fluid from the axial end 3b of the outer clutch 3 can be further suppressed.

[0054] Referring to Figure 1, in this disclosure, an annular sealing member 8 is provided between the outer clutch 3 and the shaft-side partition member 6, extending circumferentially around the central axis O1. Examples of the annular sealing member 8 include elastic members made of rubber or resin, such as packing or O-rings. In this disclosure, the annular sealing member 8 seals the space between the inner circumferential surface of the outer clutch 3 and the outer circumferential surface of the shaft-side partition member 6. This further suppresses the phenomenon of the lubricating fluid leaking from the axial end 3b on the shaft side of the outer clutch 3. In this disclosure, the axial end 3b on the universal joint side of the outer clutch 3 is welded to the universal joint-side partition member 7 and the yoke 101, thereby suppressing the leakage of the lubricating fluid. For this reason, the arrangement of the annular sealing member 8 on the universal joint side of the outer clutch 3 can be omitted.

[0055] As described above, when the inner clutch 2 and outer clutch 3 rotate relative to each other, the clutch key 4 sinks into the clutch key housing recess 11, thereby distributing the lubricating fluid contained in the clutch key housing recess 11 through the inner clutch side supply groove 15 between the inner clutch 2 and the outer clutch 3. This reduces the frictional resistance between the inner clutch 2 and the outer clutch 3 during operation. In this case, heat generation can be suppressed (heat generation is reduced) and the operating life of the one-way clutch 1 can be extended.

[0056] In particular, in this disclosure, the inner clutch side supply groove 15 is formed by a radial supply groove 16 and an axial supply groove 17 intersecting the radial supply groove 16. In this case, the lubricating fluid can be distributed more efficiently between the inner clutch 2 and the outer clutch 3.

[0057] Furthermore, in this disclosure, the radial supply groove 16 and the axial supply groove 17 have equal groove depths. In this case, an equal amount of lubricating fluid can be supplied between the inner clutch 2 and the outer clutch 3 through the radial supply groove 16 and the axial supply groove 17.

[0058] Furthermore, in this disclosure, the lubricating fluid pumped by the clutch key 4 is also supplied between the inner clutch 2 and the outer clutch 3 through the outer clutch side supply groove 30 formed in the outer clutch 3. This further reduces the frictional resistance between the inner clutch 2 and the outer clutch 3 during operation. In this case, further suppression of heat generation (reduction in the amount of heat generated) and extension of the operating life of the one-way clutch 1 can be achieved.

[0059] In particular, in this disclosure, the outer clutch side supply groove 30 includes a helical supply groove 31 that extends helically in the axial direction. This allows the lubricating fluid to be more efficiently distributed along the entire axial direction through the helical supply groove 31.

[0060] Furthermore, in this disclosure, the axial end 31a of the helical supply groove 31 is discontinuous with the axial end 3b of the outer clutch 3. This makes it possible to suppress the phenomenon of the lubricating fluid, which is distributed through the helical supply groove 31, leaking out from the axial end 3b of the outer clutch 3.

[0061] In particular, in this disclosure, the one-way clutch 1 includes at least one annular sealing member 8 to suppress leakage of the lubricating fluid supplied between the inner clutch 2 and the outer clutch 3. In this case, the phenomenon of the lubricating fluid leaking from the axial end 3b of the outer clutch 3 can be further suppressed. However, this does not negate the fact that the annular sealing member 8 can be omitted. Furthermore, the annular sealing member 8 can also be used alone instead of discontinuing the axial end 31a of the helical supply groove 31 with the axial end 3b of the outer clutch 3.

[0062] Incidentally, in the inner clutch 2, the radial supply groove 16 and the axial supply groove 17 may have different groove depths. In this case, by changing the groove depth of the radial supply groove 16 and the groove depth of the axial supply groove 17, more lubricating fluid can be supplied to the desired portion.

[0063] Figures 10 and 11 show the main parts of modified versions of the inner clutch 2 shown in Figures 4 to 7. However, parts that are substantially the same as the above configuration will not be described. As shown in Figures 10 and 11, in the modified version of the inner clutch 2, the groove depth of the axial supply groove 17 is deeper than the groove depth of the radial supply groove 16. In this case, more lubricating fluid can be supplied to the axial end of the inner clutch 2, which is prone to wear due to contact (here, the axial end of the clutch key housing recess 11, specifically the shaft-side partition member 6 and the universal joint-side partition member 7), than to the radial supply groove 16.

[0064] However, the groove depth of the supply groove can be made deeper for the radial supply groove 16 than for the axial supply groove 17. In this case, more lubricating fluid can be supplied in the circumferential direction around the central axis O1. Also, if there are multiple radial supply grooves 16, the groove depth can be varied among the multiple radial supply grooves 16. Similarly, if there are multiple axial supply grooves 17, the groove depth can be varied among the multiple axial supply grooves 17.

[0065] Although a one-way clutch according to one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways within the scope described in the claims.

[0066] For example, in this disclosure, the inner clutch side supply groove 15 is formed on each of the two circumferential side surfaces 13 of the clutch key housing recess 11. However, the inner clutch side supply groove 15 may be formed on only one of the two circumferential side surfaces 13. For example, the inner clutch side supply groove 15 may be formed only on the circumferential side surface 13 located opposite the tip portion 4a of the clutch key 4.

[0067] Furthermore, in this disclosure, the radial supply groove 16 is parallel to the axial direction, for example as shown in Figure 5, but it may be inclined with respect to the axial direction. Similarly, the axial supply groove 17 is parallel to the axial direction, for example as shown in Figure 5, but it may be inclined with respect to the axial direction. Also, in this disclosure, multiple radial supply grooves 16 are parallel to each other, but they can be inclined to each other. The same applies when there are multiple axial supply grooves 17.

[0068] Furthermore, lubricating fluids include, for example, semi-solid or semi-fluid lubricants such as grease, and lubricating liquids such as lubricating oil. [Explanation of Symbols]

[0069] 1: One-way clutch, 2: Inner clutch, 2s: Spline groove, 2h: Through hole, 21: Large diameter section, 22: Medium diameter section, 22a: First medium diameter section, 22b: Second medium diameter section, 23: Small diameter section, 3: Outer clutch, 3a: Notch, 3b: Axial end of outer clutch, 4: Clutch key, 4a: Tip of clutch key, 4b: Rear end of clutch key, 4c: Stepped surface of clutch key, 4e: Axial end of clutch key, 5: Elastic member, 6: Shaft side partition member, 7: Universal joint side partition member, 8: Annular seal member, 11: Clutch key housing recess, 12: Bottom surface of clutch key housing recess, 13: Circumferential side surface of clutch key housing recess, 14: Circumferential outer edge surface of clutch key housing recess, 15: Inner clutch side supply groove, 16: Radial supply groove, 17: Axial supply groove, 30: Outer clutch side supply groove, 31: Helical supply groove, 32: Annular supply groove, 33: Lubrication fluid introduction section, 100: Yoke unit, 101: Yoke, B: Ball, C: Set cover, M1, M2: Welded parts, R1: Backup ring, R2: L-shaped ring, R3: Stopper ring

Claims

1. A one-way clutch comprising an inner clutch, an outer clutch, a clutch key housed in a clutch key housing recess provided in the inner clutch, and an elastic member housed together with the clutch key in the clutch key housing recess, A one-way clutch, wherein an inner clutch side supply groove is formed in the clutch key housing recess with a predetermined groove depth on at least one of the two circumferential sides of the clutch key housing recess for supplying lubricating fluid contained in the clutch key housing recess between the inner clutch and the outer clutch when the clutch key sinks into the clutch key housing recess against the biasing force of the elastic member.

2. The one-way clutch according to claim 1, wherein the inner clutch side supply groove is formed by a radial supply groove and an axial supply groove intersecting the radial supply groove.

3. The one-way clutch according to claim 2, wherein the radial supply groove and the axial supply groove have equal groove depths.

4. The one-way clutch according to claim 2, wherein the radial supply groove and the axial supply groove have different groove depths.

5. A one-way clutch according to any one of claims 1 to 4, wherein the outer clutch has an outer clutch side supply groove formed therein for supplying the lubricating fluid between the inner clutch and the outer clutch.

6. The one-way clutch according to claim 5, wherein the outer clutch side supply groove includes a helical supply groove extending helically in the axial direction.

7. The one-way clutch according to claim 6, wherein the axial end of the helical supply groove is discontinuous with the axial end of the outer clutch.

8. The one-way clutch according to claim 7, further comprising at least one annular sealing member for suppressing leakage of the lubricating fluid supplied between the inner clutch and the outer clutch.

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