JPH01216128A - Both direction clutch - Google Patents

Abstract

PURPOSE:To obtain the compact structure and cut production cost by forming a sprag whose outer surface is constituted of two clutch cylindrical surfaces having difficult radius of curvature and in which the centers of radii of curvatures of the both partial cylindrical surfaces are offset. CONSTITUTION:The part of a sprag 4 which contacts an outer peripheral engagement surface 7 is formed from a partial cylindrical surface 17 having radius R of curvature, while the part which contacts an inner peripheral engagement surface 6 is formed from a partial cylindrical surface 18 having a radius (r) of curvature. The centers O and O' of the radii of curvatures of the partial cylindrical surfaces 17 and 18 are offset. Since the radial gap is exceedingly small between the partial cylindrical surfaces 17 of the sprag 4 and the outer peripheral engagement surface 7 of an inner ring 3, if the inner ring 3 turns in the leftward direction, the sprag 4 tilts rightward, and is wedge-engaged with the both engagement surfaces 6 and 7, and locked. Therefore, a turning moment is transmitted to an outer ring 2 from the inner ring 3 through the sprag 4, and the inner ring 3 and the outer ring 2 are integrally revolved in the leftward direction. Further, if a holding device 5 is shifted in the turning direction, a pocket 9 tilts the sprag 4 in the leftward direction in a moment, and the wedge engagement is released.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a bidirectional clutch in which the clutch locks and unlocks in both rotational directions.

[Prior art and its problems]

As this kind of bidirectional clutch, for example, JP-A-62-
The one shown in Japanese Patent No. 52227 is known. In this conventional two-way clutch, the sprag has a substantially rectangular cross section with an outer surface that is wedge-engaged in one direction of rotation. Since sprags engage in wedge engagement only in one direction, two rows of cylindrical engagement surfaces are formed on the outer and inner rings, and the sprags arranged on the cylindrical engagement surfaces of one row and the other The sprags disposed on the cylindrical engagement surfaces of the rows are in opposite directions. In the conventional bidirectional clutch, since the sprags and engagement surfaces are arranged in two rows, the clutch is large in the longitudinal direction, and the manufacturing cost is high.Furthermore, the sprags have a special shape, which causes problems in manufacturing the sprags. .

[Means to solve the problem]

In order to solve the above problems, the present invention provides an outer ring having a cylindrical inner circumferential engagement surface, an inner ring having a cylindrical outer circumferential engagement surface, and the front engagement surface facing each other, and disposed between them. In a two-way clutch consisting of a plurality of sprags and a retainer that accommodates the sprags, the outer surface of the sprags is composed of two partial cylindrical surfaces with different radii of curvature, and the curvature of the blue partial cylindrical surface is The center is offset so that the sprags can be engaged with each other, and the motive engagement of the sprags can be released by moving the retainer in the rotational direction. The outer surface of a sprag is composed of two partial cylindrical surfaces with different radii of curvature, and the centers of curvature of both cylindrical surfaces are offset, so the sprag in the negative row locks and locks the clutch in both rotational directions. Unlocked, the structure is simple and compact. In addition, since the outer surface of the sprag is composed of two simple-shaped partial cylindrical surfaces, the sprag can be manufactured easily, with high precision, and at low cost.

【Example】

The present invention will be explained in detail below. 1 to 5 show a first embodiment. In FIG. 1 and FIG. 2, which is a cross section taken along the line X--X in FIG. 1, the two-way clutch 1 has an outer ring 2. Inner circle 3. The main components are a sprag 4 and a retainer 5. The outer ring 2 has a cylindrical inner engagement surface 6, and the inner ring 3 has a cylindrical outer engagement surface 7.
has. The inner circumferential engagement surface 6 and the outer circumferential engagement surface 7 are arranged to face each other, and a plurality of sprags 4 are arranged between the front engagement surfaces 6.7. The sprag 4 has guide collars 1 provided on both sides of the engagement surface 6.
Guided by 5. Each sprag 4 is housed in a pocket 9 provided in a retainer 5, and the retainer 5 guides each sprag 4 in the pocket 9. The inner ring 3 extends further in the axial direction than the outer ring 2, and a control ring 11 is rotatably fitted to the outer circumferential surface γ of this extension 10. The control ring 11 has a pulley groove 12 on its outer periphery, on which a belt (not shown) is hung. A convex portion 13 is formed at one end of the control ring 11, and the convex portion 13 engages with a concave portion 14 provided at one end of the retainer 5, and by rotating the control ring 11, the retainer 'a5 is rotated. It is configured as follows. The control ring 11 is prevented from moving in the axial direction by a retaining ring 16. The outer ring 2 is assembled and fixed to a rotating member (not shown), and the inner ring 3 has an inner diameter hole 17 and is connected to a drive shaft (not shown). 1
8 is a keyway. As shown in FIG. 3, the sprag 4 has a portion in contact with the outer circumferential engagement surface 7 formed by a partial cylindrical surface 17 with a radius of curvature R,
On the other hand, the part in contact with the inner peripheral retaining surface 6 is formed by a partial cylindrical surface 18 with a radius of curvature r, and the center of curvature of the partial cylindrical surface 17.18 is 0.
．． 0' is offset as shown. Therefore, the sprag 4 has a center of curvature of 0. It is symmetrical when cut along the plane passing through o'. The dimensional relationship between R and r is R>r as shown in Figure 9, which shows the locked state of the clutch in detail, and the strut angle α is ta.
The radius of curvature R of the sprag 4, r, the radius of the inner engagement surface 6, Ro s, so that nα<μ (coefficient of friction between the μ varnish/lug 4 and the front engagement surface 6.7). Radius R11 of surface 7 Height Hl of sprag 4 and sprag 4 and front engagement surface 6.7
Determine the radial clearance between The radial clearance between the sprag 4 and the front engagement surfaces 6, 7 is set to an extremely small value of several microns in the neutral position of the sprag 4 shown in FIG. Prevent slipping between. Next, the effect will be explained. FIG. 4 shows the state when the inner ring 3 is rotated to the left. Since the radial clearance between the partial cylindrical surface 17 of the sprag 4 and the outer peripheral engagement surface 7 of the inner ring 3 is extremely small, when the inner ring 3 rotates to the left, the sprag 4 tilts to the right, and the re-engaging surfaces 6, 7 Wedge engages and locks. The details are shown in Figure 9. Therefore, rotational force is transmitted from the inner ring 3 to the outer ring 2 via the sprags 4, and the inner ring 3 and outer ring 2 rotate to the left as one. To release the lock next time when the inner ring 3 and outer ring 2 are rotating in the left direction as one unit, turn the control ring 1 shown in FIG.
Operate 1. When the inner ring 3 and outer ring 2 are rotating in a locked state, the control ring is also rotating together. Therefore, when the rotational speed of the control ring 11 is made faster than the rotational speed of the inner ring 3 by a belt (not shown) hooked on the pulley groove 12 of the control ring 11, the rotational speed of the retainer 5 engaged with the control ring 11 also becomes faster. At that moment, pocket 9 tilts sprag 4 to the left as shown in FIG. 5, releasing the wedge engagement. This will release the lock. Therefore, the leftward rotational force of the inner ring 3 is no longer transmitted to the outer ring 2. The locking and unlocking functions have been described above when the inner ring 3 rotates to the left, but the same effect can be achieved by operating the control ring 11 in the opposite direction when rotating the inner ring 3 to the right. Further, the control ring 11 may have other structures such as a chain, a gear, a link mechanism, etc., in addition to the structure in which the rotation is controlled by a belt. FIG. 6 shows a second embodiment of the invention, in which the sprag 24
The shape is slightly different from that of the first embodiment. sprag 2
4 has a partial cylindrical surface 37 having a radius of curvature R and a partial cylindrical surface 38 having a radius of curvature r, as in the first embodiment, and a guide is provided in the portion where the pocket 29 formed in the retainer 25 contacts. A recess 36 is provided to ensure this. The other configurations and operations are the same as those in the first embodiment, so their explanations will be omitted. FIG. 7 shows a third embodiment of the present invention, and the shape of the retainer 45 is different from that of the first embodiment. The pocket 49 of the retainer 45 contacts the sprag 44 . Since the pocket 49 guides the sprag 44 below the sprag 44, the tilting movement of the sprag 44 relative to the rotation of the retainer 45 is opposite to that of the first embodiment. Therefore, when the inner ring 43 is rotating to the left, the retainer 4
5 (same as control ring 11 in FIG. 1) is stopped by a belt, the sprag 44 can be tilted to the left and unlocked. FIG. 8 shows a fourth embodiment of the present invention, in which the shape of the sprag 64 is different from the first to third embodiments. That is, in this embodiment, a partial cylindrical surface 77 having a large radius of curvature R contacts the inner peripheral engagement surface 66, and a partial cylindrical surface 78 having a small radius r of curvature contacts the outer peripheral engaging surface 67.

【effect】

Since the present invention is configured as described above, it has the following effects. (a) Since the clutch is locked and unlocked in both rotational directions by the - row sprags, the structure can be made simple and compact. (b) Since the outer surface of the sprag is composed of two simple-shaped partial cylindrical surfaces, the sprag can be manufactured easily, with high precision, and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a two-way clutch according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line XX of FIG. 1, and FIG. 3 is a partially enlarged cross-sectional view showing the shape of the sprag. 4 and 5 are partially enlarged cross-sectional views for explaining the operation, FIG. 6 is a partially enlarged cross-sectional view of the two-way clutch according to the second embodiment, and FIG. 7 is a partially enlarged cross-sectional view of the bidirectional clutch according to the second embodiment. Partially enlarged cross-sectional view of the bidirectional clutch according to #! FIG. 8 is a partially enlarged cross-sectional view of the bidirectional clutch according to the fourth embodiment, and FIG. 9 is a partially enlarged cross-sectional view showing the locked state in detail.

Claims (1)

[Claims] An outer ring having a cylindrical inner circumferential engagement surface, an inner ring having a cylindrical outer circumferential engagement surface, a plurality of sprags disposed between the two engaging surfaces facing each other, and a holder for accommodating the sprags. In the two-way clutch, the sprag has an outer surface composed of two partial cylindrical surfaces with different radii of curvature, and the center of curvature of both partial cylindrical surfaces is offset so that the sprag engages in a wedge manner. A two-way clutch, characterized in that the wedge engagement of the sprags is released by moving the retainer in the rotational direction.